sqlite3.h revision 355326
1251883Speter/* 2322444Speter** 2001-09-15 3251883Speter** 4251883Speter** The author disclaims copyright to this source code. In place of 5251883Speter** a legal notice, here is a blessing: 6251883Speter** 7251883Speter** May you do good and not evil. 8251883Speter** May you find forgiveness for yourself and forgive others. 9251883Speter** May you share freely, never taking more than you give. 10251883Speter** 11251883Speter************************************************************************* 12251883Speter** This header file defines the interface that the SQLite library 13251883Speter** presents to client programs. If a C-function, structure, datatype, 14251883Speter** or constant definition does not appear in this file, then it is 15251883Speter** not a published API of SQLite, is subject to change without 16251883Speter** notice, and should not be referenced by programs that use SQLite. 17251883Speter** 18251883Speter** Some of the definitions that are in this file are marked as 19251883Speter** "experimental". Experimental interfaces are normally new 20251883Speter** features recently added to SQLite. We do not anticipate changes 21251883Speter** to experimental interfaces but reserve the right to make minor changes 22251883Speter** if experience from use "in the wild" suggest such changes are prudent. 23251883Speter** 24251883Speter** The official C-language API documentation for SQLite is derived 25251883Speter** from comments in this file. This file is the authoritative source 26286510Speter** on how SQLite interfaces are supposed to operate. 27251883Speter** 28251883Speter** The name of this file under configuration management is "sqlite.h.in". 29251883Speter** The makefile makes some minor changes to this file (such as inserting 30251883Speter** the version number) and changes its name to "sqlite3.h" as 31251883Speter** part of the build process. 32251883Speter*/ 33305002Scy#ifndef SQLITE3_H 34305002Scy#define SQLITE3_H 35251883Speter#include <stdarg.h> /* Needed for the definition of va_list */ 36251883Speter 37251883Speter/* 38251883Speter** Make sure we can call this stuff from C++. 39251883Speter*/ 40251883Speter#ifdef __cplusplus 41251883Speterextern "C" { 42251883Speter#endif 43251883Speter 44251883Speter 45251883Speter/* 46282328Sbapt** Provide the ability to override linkage features of the interface. 47251883Speter*/ 48251883Speter#ifndef SQLITE_EXTERN 49251883Speter# define SQLITE_EXTERN extern 50251883Speter#endif 51251883Speter#ifndef SQLITE_API 52251883Speter# define SQLITE_API 53251883Speter#endif 54282328Sbapt#ifndef SQLITE_CDECL 55282328Sbapt# define SQLITE_CDECL 56282328Sbapt#endif 57305002Scy#ifndef SQLITE_APICALL 58305002Scy# define SQLITE_APICALL 59305002Scy#endif 60282328Sbapt#ifndef SQLITE_STDCALL 61305002Scy# define SQLITE_STDCALL SQLITE_APICALL 62282328Sbapt#endif 63305002Scy#ifndef SQLITE_CALLBACK 64305002Scy# define SQLITE_CALLBACK 65305002Scy#endif 66305002Scy#ifndef SQLITE_SYSAPI 67305002Scy# define SQLITE_SYSAPI 68305002Scy#endif 69251883Speter 70251883Speter/* 71251883Speter** These no-op macros are used in front of interfaces to mark those 72251883Speter** interfaces as either deprecated or experimental. New applications 73282328Sbapt** should not use deprecated interfaces - they are supported for backwards 74251883Speter** compatibility only. Application writers should be aware that 75251883Speter** experimental interfaces are subject to change in point releases. 76251883Speter** 77251883Speter** These macros used to resolve to various kinds of compiler magic that 78251883Speter** would generate warning messages when they were used. But that 79251883Speter** compiler magic ended up generating such a flurry of bug reports 80251883Speter** that we have taken it all out and gone back to using simple 81251883Speter** noop macros. 82251883Speter*/ 83251883Speter#define SQLITE_DEPRECATED 84251883Speter#define SQLITE_EXPERIMENTAL 85251883Speter 86251883Speter/* 87251883Speter** Ensure these symbols were not defined by some previous header file. 88251883Speter*/ 89251883Speter#ifdef SQLITE_VERSION 90251883Speter# undef SQLITE_VERSION 91251883Speter#endif 92251883Speter#ifdef SQLITE_VERSION_NUMBER 93251883Speter# undef SQLITE_VERSION_NUMBER 94251883Speter#endif 95251883Speter 96251883Speter/* 97251883Speter** CAPI3REF: Compile-Time Library Version Numbers 98251883Speter** 99251883Speter** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100251883Speter** evaluates to a string literal that is the SQLite version in the 101251883Speter** format "X.Y.Z" where X is the major version number (always 3 for 102251883Speter** SQLite3) and Y is the minor version number and Z is the release number.)^ 103251883Speter** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104251883Speter** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105251883Speter** numbers used in [SQLITE_VERSION].)^ 106251883Speter** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107251883Speter** be larger than the release from which it is derived. Either Y will 108251883Speter** be held constant and Z will be incremented or else Y will be incremented 109251883Speter** and Z will be reset to zero. 110251883Speter** 111322444Speter** Since [version 3.6.18] ([dateof:3.6.18]), 112322444Speter** SQLite source code has been stored in the 113251883Speter** <a href="http://www.fossil-scm.org/">Fossil configuration management 114251883Speter** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115251883Speter** a string which identifies a particular check-in of SQLite 116251883Speter** within its configuration management system. ^The SQLITE_SOURCE_ID 117322444Speter** string contains the date and time of the check-in (UTC) and a SHA1 118342292Scy** or SHA3-256 hash of the entire source tree. If the source code has 119342292Scy** been edited in any way since it was last checked in, then the last 120342292Scy** four hexadecimal digits of the hash may be modified. 121251883Speter** 122251883Speter** See also: [sqlite3_libversion()], 123251883Speter** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124251883Speter** [sqlite_version()] and [sqlite_source_id()]. 125251883Speter*/ 126355326Scy#define SQLITE_VERSION "3.30.1" 127355326Scy#define SQLITE_VERSION_NUMBER 3030001 128355326Scy#define SQLITE_SOURCE_ID "2019-10-10 20:19:45 18db032d058f1436ce3dea84081f4ee5a0f2259ad97301d43c426bc7f3df1b0b" 129251883Speter 130251883Speter/* 131251883Speter** CAPI3REF: Run-Time Library Version Numbers 132322444Speter** KEYWORDS: sqlite3_version sqlite3_sourceid 133251883Speter** 134251883Speter** These interfaces provide the same information as the [SQLITE_VERSION], 135251883Speter** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136251883Speter** but are associated with the library instead of the header file. ^(Cautious 137251883Speter** programmers might include assert() statements in their application to 138251883Speter** verify that values returned by these interfaces match the macros in 139298161Sbapt** the header, and thus ensure that the application is 140251883Speter** compiled with matching library and header files. 141251883Speter** 142251883Speter** <blockquote><pre> 143251883Speter** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144342292Scy** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145251883Speter** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146251883Speter** </pre></blockquote>)^ 147251883Speter** 148251883Speter** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149251883Speter** macro. ^The sqlite3_libversion() function returns a pointer to the 150251883Speter** to the sqlite3_version[] string constant. The sqlite3_libversion() 151251883Speter** function is provided for use in DLLs since DLL users usually do not have 152251883Speter** direct access to string constants within the DLL. ^The 153251883Speter** sqlite3_libversion_number() function returns an integer equal to 154342292Scy** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155251883Speter** a pointer to a string constant whose value is the same as the 156342292Scy** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157342292Scy** using an edited copy of [the amalgamation], then the last four characters 158342292Scy** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159251883Speter** 160251883Speter** See also: [sqlite_version()] and [sqlite_source_id()]. 161251883Speter*/ 162251883SpeterSQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163322444SpeterSQLITE_API const char *sqlite3_libversion(void); 164322444SpeterSQLITE_API const char *sqlite3_sourceid(void); 165322444SpeterSQLITE_API int sqlite3_libversion_number(void); 166251883Speter 167251883Speter/* 168251883Speter** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169251883Speter** 170251883Speter** ^The sqlite3_compileoption_used() function returns 0 or 1 171251883Speter** indicating whether the specified option was defined at 172251883Speter** compile time. ^The SQLITE_ prefix may be omitted from the 173251883Speter** option name passed to sqlite3_compileoption_used(). 174251883Speter** 175251883Speter** ^The sqlite3_compileoption_get() function allows iterating 176251883Speter** over the list of options that were defined at compile time by 177251883Speter** returning the N-th compile time option string. ^If N is out of range, 178251883Speter** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179251883Speter** prefix is omitted from any strings returned by 180251883Speter** sqlite3_compileoption_get(). 181251883Speter** 182251883Speter** ^Support for the diagnostic functions sqlite3_compileoption_used() 183251883Speter** and sqlite3_compileoption_get() may be omitted by specifying the 184251883Speter** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185251883Speter** 186251883Speter** See also: SQL functions [sqlite_compileoption_used()] and 187251883Speter** [sqlite_compileoption_get()] and the [compile_options pragma]. 188251883Speter*/ 189251883Speter#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190322444SpeterSQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191322444SpeterSQLITE_API const char *sqlite3_compileoption_get(int N); 192347347Scy#else 193347347Scy# define sqlite3_compileoption_used(X) 0 194347347Scy# define sqlite3_compileoption_get(X) ((void*)0) 195251883Speter#endif 196251883Speter 197251883Speter/* 198251883Speter** CAPI3REF: Test To See If The Library Is Threadsafe 199251883Speter** 200251883Speter** ^The sqlite3_threadsafe() function returns zero if and only if 201251883Speter** SQLite was compiled with mutexing code omitted due to the 202251883Speter** [SQLITE_THREADSAFE] compile-time option being set to 0. 203251883Speter** 204251883Speter** SQLite can be compiled with or without mutexes. When 205251883Speter** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206251883Speter** are enabled and SQLite is threadsafe. When the 207251883Speter** [SQLITE_THREADSAFE] macro is 0, 208251883Speter** the mutexes are omitted. Without the mutexes, it is not safe 209251883Speter** to use SQLite concurrently from more than one thread. 210251883Speter** 211251883Speter** Enabling mutexes incurs a measurable performance penalty. 212251883Speter** So if speed is of utmost importance, it makes sense to disable 213251883Speter** the mutexes. But for maximum safety, mutexes should be enabled. 214251883Speter** ^The default behavior is for mutexes to be enabled. 215251883Speter** 216251883Speter** This interface can be used by an application to make sure that the 217251883Speter** version of SQLite that it is linking against was compiled with 218251883Speter** the desired setting of the [SQLITE_THREADSAFE] macro. 219251883Speter** 220251883Speter** This interface only reports on the compile-time mutex setting 221251883Speter** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222251883Speter** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223251883Speter** can be fully or partially disabled using a call to [sqlite3_config()] 224251883Speter** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225282328Sbapt** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226251883Speter** sqlite3_threadsafe() function shows only the compile-time setting of 227251883Speter** thread safety, not any run-time changes to that setting made by 228251883Speter** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229251883Speter** is unchanged by calls to sqlite3_config().)^ 230251883Speter** 231251883Speter** See the [threading mode] documentation for additional information. 232251883Speter*/ 233322444SpeterSQLITE_API int sqlite3_threadsafe(void); 234251883Speter 235251883Speter/* 236251883Speter** CAPI3REF: Database Connection Handle 237251883Speter** KEYWORDS: {database connection} {database connections} 238251883Speter** 239251883Speter** Each open SQLite database is represented by a pointer to an instance of 240251883Speter** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241251883Speter** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242251883Speter** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243251883Speter** and [sqlite3_close_v2()] are its destructors. There are many other 244251883Speter** interfaces (such as 245251883Speter** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246251883Speter** [sqlite3_busy_timeout()] to name but three) that are methods on an 247251883Speter** sqlite3 object. 248251883Speter*/ 249251883Spetertypedef struct sqlite3 sqlite3; 250251883Speter 251251883Speter/* 252251883Speter** CAPI3REF: 64-Bit Integer Types 253251883Speter** KEYWORDS: sqlite_int64 sqlite_uint64 254251883Speter** 255251883Speter** Because there is no cross-platform way to specify 64-bit integer types 256251883Speter** SQLite includes typedefs for 64-bit signed and unsigned integers. 257251883Speter** 258251883Speter** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259251883Speter** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260251883Speter** compatibility only. 261251883Speter** 262251883Speter** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263251883Speter** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264251883Speter** sqlite3_uint64 and sqlite_uint64 types can store integer values 265251883Speter** between 0 and +18446744073709551615 inclusive. 266251883Speter*/ 267251883Speter#ifdef SQLITE_INT64_TYPE 268251883Speter typedef SQLITE_INT64_TYPE sqlite_int64; 269322444Speter# ifdef SQLITE_UINT64_TYPE 270322444Speter typedef SQLITE_UINT64_TYPE sqlite_uint64; 271322444Speter# else 272322444Speter typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273322444Speter# endif 274251883Speter#elif defined(_MSC_VER) || defined(__BORLANDC__) 275251883Speter typedef __int64 sqlite_int64; 276251883Speter typedef unsigned __int64 sqlite_uint64; 277251883Speter#else 278251883Speter typedef long long int sqlite_int64; 279251883Speter typedef unsigned long long int sqlite_uint64; 280251883Speter#endif 281251883Spetertypedef sqlite_int64 sqlite3_int64; 282251883Spetertypedef sqlite_uint64 sqlite3_uint64; 283251883Speter 284251883Speter/* 285251883Speter** If compiling for a processor that lacks floating point support, 286251883Speter** substitute integer for floating-point. 287251883Speter*/ 288251883Speter#ifdef SQLITE_OMIT_FLOATING_POINT 289251883Speter# define double sqlite3_int64 290251883Speter#endif 291251883Speter 292251883Speter/* 293251883Speter** CAPI3REF: Closing A Database Connection 294286510Speter** DESTRUCTOR: sqlite3 295251883Speter** 296251883Speter** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297251883Speter** for the [sqlite3] object. 298274884Sbapt** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299251883Speter** the [sqlite3] object is successfully destroyed and all associated 300251883Speter** resources are deallocated. 301251883Speter** 302251883Speter** ^If the database connection is associated with unfinalized prepared 303251883Speter** statements or unfinished sqlite3_backup objects then sqlite3_close() 304251883Speter** will leave the database connection open and return [SQLITE_BUSY]. 305251883Speter** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306274884Sbapt** and/or unfinished sqlite3_backups, then the database connection becomes 307251883Speter** an unusable "zombie" which will automatically be deallocated when the 308251883Speter** last prepared statement is finalized or the last sqlite3_backup is 309251883Speter** finished. The sqlite3_close_v2() interface is intended for use with 310251883Speter** host languages that are garbage collected, and where the order in which 311251883Speter** destructors are called is arbitrary. 312251883Speter** 313251883Speter** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314251883Speter** [sqlite3_blob_close | close] all [BLOB handles], and 315251883Speter** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316251883Speter** with the [sqlite3] object prior to attempting to close the object. ^If 317251883Speter** sqlite3_close_v2() is called on a [database connection] that still has 318251883Speter** outstanding [prepared statements], [BLOB handles], and/or 319274884Sbapt** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320251883Speter** of resources is deferred until all [prepared statements], [BLOB handles], 321251883Speter** and [sqlite3_backup] objects are also destroyed. 322251883Speter** 323251883Speter** ^If an [sqlite3] object is destroyed while a transaction is open, 324251883Speter** the transaction is automatically rolled back. 325251883Speter** 326251883Speter** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327251883Speter** must be either a NULL 328251883Speter** pointer or an [sqlite3] object pointer obtained 329251883Speter** from [sqlite3_open()], [sqlite3_open16()], or 330251883Speter** [sqlite3_open_v2()], and not previously closed. 331251883Speter** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332251883Speter** argument is a harmless no-op. 333251883Speter*/ 334322444SpeterSQLITE_API int sqlite3_close(sqlite3*); 335322444SpeterSQLITE_API int sqlite3_close_v2(sqlite3*); 336251883Speter 337251883Speter/* 338251883Speter** The type for a callback function. 339251883Speter** This is legacy and deprecated. It is included for historical 340251883Speter** compatibility and is not documented. 341251883Speter*/ 342251883Spetertypedef int (*sqlite3_callback)(void*,int,char**, char**); 343251883Speter 344251883Speter/* 345251883Speter** CAPI3REF: One-Step Query Execution Interface 346286510Speter** METHOD: sqlite3 347251883Speter** 348251883Speter** The sqlite3_exec() interface is a convenience wrapper around 349251883Speter** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350251883Speter** that allows an application to run multiple statements of SQL 351251883Speter** without having to use a lot of C code. 352251883Speter** 353251883Speter** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354251883Speter** semicolon-separate SQL statements passed into its 2nd argument, 355251883Speter** in the context of the [database connection] passed in as its 1st 356251883Speter** argument. ^If the callback function of the 3rd argument to 357251883Speter** sqlite3_exec() is not NULL, then it is invoked for each result row 358251883Speter** coming out of the evaluated SQL statements. ^The 4th argument to 359251883Speter** sqlite3_exec() is relayed through to the 1st argument of each 360251883Speter** callback invocation. ^If the callback pointer to sqlite3_exec() 361251883Speter** is NULL, then no callback is ever invoked and result rows are 362251883Speter** ignored. 363251883Speter** 364251883Speter** ^If an error occurs while evaluating the SQL statements passed into 365251883Speter** sqlite3_exec(), then execution of the current statement stops and 366251883Speter** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367251883Speter** is not NULL then any error message is written into memory obtained 368251883Speter** from [sqlite3_malloc()] and passed back through the 5th parameter. 369251883Speter** To avoid memory leaks, the application should invoke [sqlite3_free()] 370251883Speter** on error message strings returned through the 5th parameter of 371298161Sbapt** sqlite3_exec() after the error message string is no longer needed. 372251883Speter** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373251883Speter** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374251883Speter** NULL before returning. 375251883Speter** 376251883Speter** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377251883Speter** routine returns SQLITE_ABORT without invoking the callback again and 378251883Speter** without running any subsequent SQL statements. 379251883Speter** 380251883Speter** ^The 2nd argument to the sqlite3_exec() callback function is the 381251883Speter** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382251883Speter** callback is an array of pointers to strings obtained as if from 383251883Speter** [sqlite3_column_text()], one for each column. ^If an element of a 384251883Speter** result row is NULL then the corresponding string pointer for the 385251883Speter** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386251883Speter** sqlite3_exec() callback is an array of pointers to strings where each 387251883Speter** entry represents the name of corresponding result column as obtained 388251883Speter** from [sqlite3_column_name()]. 389251883Speter** 390251883Speter** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391251883Speter** to an empty string, or a pointer that contains only whitespace and/or 392251883Speter** SQL comments, then no SQL statements are evaluated and the database 393251883Speter** is not changed. 394251883Speter** 395251883Speter** Restrictions: 396251883Speter** 397251883Speter** <ul> 398298161Sbapt** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399251883Speter** is a valid and open [database connection]. 400269851Speter** <li> The application must not close the [database connection] specified by 401251883Speter** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402251883Speter** <li> The application must not modify the SQL statement text passed into 403251883Speter** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404251883Speter** </ul> 405251883Speter*/ 406322444SpeterSQLITE_API int sqlite3_exec( 407251883Speter sqlite3*, /* An open database */ 408251883Speter const char *sql, /* SQL to be evaluated */ 409251883Speter int (*callback)(void*,int,char**,char**), /* Callback function */ 410251883Speter void *, /* 1st argument to callback */ 411251883Speter char **errmsg /* Error msg written here */ 412251883Speter); 413251883Speter 414251883Speter/* 415251883Speter** CAPI3REF: Result Codes 416274884Sbapt** KEYWORDS: {result code definitions} 417251883Speter** 418251883Speter** Many SQLite functions return an integer result code from the set shown 419251883Speter** here in order to indicate success or failure. 420251883Speter** 421251883Speter** New error codes may be added in future versions of SQLite. 422251883Speter** 423274884Sbapt** See also: [extended result code definitions] 424251883Speter*/ 425251883Speter#define SQLITE_OK 0 /* Successful result */ 426251883Speter/* beginning-of-error-codes */ 427322444Speter#define SQLITE_ERROR 1 /* Generic error */ 428251883Speter#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429251883Speter#define SQLITE_PERM 3 /* Access permission denied */ 430251883Speter#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431251883Speter#define SQLITE_BUSY 5 /* The database file is locked */ 432251883Speter#define SQLITE_LOCKED 6 /* A table in the database is locked */ 433251883Speter#define SQLITE_NOMEM 7 /* A malloc() failed */ 434251883Speter#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435251883Speter#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436251883Speter#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437251883Speter#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438251883Speter#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439251883Speter#define SQLITE_FULL 13 /* Insertion failed because database is full */ 440251883Speter#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441251883Speter#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442342292Scy#define SQLITE_EMPTY 16 /* Internal use only */ 443251883Speter#define SQLITE_SCHEMA 17 /* The database schema changed */ 444251883Speter#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445251883Speter#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446251883Speter#define SQLITE_MISMATCH 20 /* Data type mismatch */ 447251883Speter#define SQLITE_MISUSE 21 /* Library used incorrectly */ 448251883Speter#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449251883Speter#define SQLITE_AUTH 23 /* Authorization denied */ 450322444Speter#define SQLITE_FORMAT 24 /* Not used */ 451251883Speter#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452251883Speter#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453251883Speter#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454251883Speter#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455251883Speter#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456251883Speter#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457251883Speter/* end-of-error-codes */ 458251883Speter 459251883Speter/* 460251883Speter** CAPI3REF: Extended Result Codes 461274884Sbapt** KEYWORDS: {extended result code definitions} 462251883Speter** 463274884Sbapt** In its default configuration, SQLite API routines return one of 30 integer 464274884Sbapt** [result codes]. However, experience has shown that many of 465251883Speter** these result codes are too coarse-grained. They do not provide as 466251883Speter** much information about problems as programmers might like. In an effort to 467322444Speter** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468322444Speter** and later) include 469251883Speter** support for additional result codes that provide more detailed information 470274884Sbapt** about errors. These [extended result codes] are enabled or disabled 471251883Speter** on a per database connection basis using the 472274884Sbapt** [sqlite3_extended_result_codes()] API. Or, the extended code for 473274884Sbapt** the most recent error can be obtained using 474274884Sbapt** [sqlite3_extended_errcode()]. 475251883Speter*/ 476342292Scy#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477342292Scy#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478342292Scy#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479251883Speter#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480251883Speter#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481251883Speter#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482251883Speter#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483251883Speter#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484251883Speter#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485251883Speter#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486251883Speter#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487251883Speter#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488251883Speter#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489251883Speter#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490251883Speter#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491251883Speter#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492251883Speter#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493251883Speter#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494251883Speter#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495251883Speter#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496251883Speter#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497251883Speter#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498251883Speter#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499251883Speter#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500251883Speter#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501251883Speter#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502251883Speter#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503269851Speter#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504269851Speter#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505298161Sbapt#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506298161Sbapt#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507342292Scy#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508342292Scy#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509342292Scy#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510251883Speter#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511342292Scy#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512251883Speter#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513269851Speter#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514251883Speter#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515251883Speter#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516251883Speter#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517269851Speter#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518342292Scy#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519251883Speter#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520342292Scy#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 521251883Speter#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 522251883Speter#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 523251883Speter#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 524269851Speter#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 525342292Scy#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 526342292Scy#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 527251883Speter#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 528251883Speter#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 529251883Speter#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 530251883Speter#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 531251883Speter#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 532251883Speter#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 533251883Speter#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 534251883Speter#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 535251883Speter#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 536251883Speter#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 537269851Speter#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 538251883Speter#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 539251883Speter#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 540269851Speter#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 541274884Sbapt#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 542305002Scy#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 543251883Speter 544251883Speter/* 545251883Speter** CAPI3REF: Flags For File Open Operations 546251883Speter** 547251883Speter** These bit values are intended for use in the 548251883Speter** 3rd parameter to the [sqlite3_open_v2()] interface and 549251883Speter** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 550251883Speter*/ 551251883Speter#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 552251883Speter#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 553251883Speter#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 554251883Speter#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 555251883Speter#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 556251883Speter#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 557251883Speter#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 558251883Speter#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 559251883Speter#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 560251883Speter#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 561251883Speter#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 562251883Speter#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 563251883Speter#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 564251883Speter#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 565251883Speter#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 566251883Speter#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 567251883Speter#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 568251883Speter#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 569251883Speter#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 570251883Speter#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 571251883Speter 572251883Speter/* Reserved: 0x00F00000 */ 573251883Speter 574251883Speter/* 575251883Speter** CAPI3REF: Device Characteristics 576251883Speter** 577251883Speter** The xDeviceCharacteristics method of the [sqlite3_io_methods] 578251883Speter** object returns an integer which is a vector of these 579251883Speter** bit values expressing I/O characteristics of the mass storage 580251883Speter** device that holds the file that the [sqlite3_io_methods] 581251883Speter** refers to. 582251883Speter** 583251883Speter** The SQLITE_IOCAP_ATOMIC property means that all writes of 584251883Speter** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 585251883Speter** mean that writes of blocks that are nnn bytes in size and 586251883Speter** are aligned to an address which is an integer multiple of 587251883Speter** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 588251883Speter** that when data is appended to a file, the data is appended 589251883Speter** first then the size of the file is extended, never the other 590251883Speter** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 591251883Speter** information is written to disk in the same order as calls 592251883Speter** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 593251883Speter** after reboot following a crash or power loss, the only bytes in a 594251883Speter** file that were written at the application level might have changed 595251883Speter** and that adjacent bytes, even bytes within the same sector are 596269851Speter** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 597322444Speter** flag indicates that a file cannot be deleted when open. The 598269851Speter** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 599269851Speter** read-only media and cannot be changed even by processes with 600269851Speter** elevated privileges. 601342292Scy** 602342292Scy** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 603342292Scy** filesystem supports doing multiple write operations atomically when those 604342292Scy** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 605342292Scy** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 606251883Speter*/ 607251883Speter#define SQLITE_IOCAP_ATOMIC 0x00000001 608251883Speter#define SQLITE_IOCAP_ATOMIC512 0x00000002 609251883Speter#define SQLITE_IOCAP_ATOMIC1K 0x00000004 610251883Speter#define SQLITE_IOCAP_ATOMIC2K 0x00000008 611251883Speter#define SQLITE_IOCAP_ATOMIC4K 0x00000010 612251883Speter#define SQLITE_IOCAP_ATOMIC8K 0x00000020 613251883Speter#define SQLITE_IOCAP_ATOMIC16K 0x00000040 614251883Speter#define SQLITE_IOCAP_ATOMIC32K 0x00000080 615251883Speter#define SQLITE_IOCAP_ATOMIC64K 0x00000100 616251883Speter#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 617251883Speter#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 618251883Speter#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 619251883Speter#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 620269851Speter#define SQLITE_IOCAP_IMMUTABLE 0x00002000 621342292Scy#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 622251883Speter 623251883Speter/* 624251883Speter** CAPI3REF: File Locking Levels 625251883Speter** 626251883Speter** SQLite uses one of these integer values as the second 627251883Speter** argument to calls it makes to the xLock() and xUnlock() methods 628251883Speter** of an [sqlite3_io_methods] object. 629251883Speter*/ 630251883Speter#define SQLITE_LOCK_NONE 0 631251883Speter#define SQLITE_LOCK_SHARED 1 632251883Speter#define SQLITE_LOCK_RESERVED 2 633251883Speter#define SQLITE_LOCK_PENDING 3 634251883Speter#define SQLITE_LOCK_EXCLUSIVE 4 635251883Speter 636251883Speter/* 637251883Speter** CAPI3REF: Synchronization Type Flags 638251883Speter** 639251883Speter** When SQLite invokes the xSync() method of an 640251883Speter** [sqlite3_io_methods] object it uses a combination of 641251883Speter** these integer values as the second argument. 642251883Speter** 643251883Speter** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 644251883Speter** sync operation only needs to flush data to mass storage. Inode 645251883Speter** information need not be flushed. If the lower four bits of the flag 646251883Speter** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 647251883Speter** If the lower four bits equal SQLITE_SYNC_FULL, that means 648251883Speter** to use Mac OS X style fullsync instead of fsync(). 649251883Speter** 650251883Speter** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 651251883Speter** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 652251883Speter** settings. The [synchronous pragma] determines when calls to the 653251883Speter** xSync VFS method occur and applies uniformly across all platforms. 654251883Speter** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 655251883Speter** energetic or rigorous or forceful the sync operations are and 656251883Speter** only make a difference on Mac OSX for the default SQLite code. 657251883Speter** (Third-party VFS implementations might also make the distinction 658251883Speter** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 659251883Speter** operating systems natively supported by SQLite, only Mac OSX 660251883Speter** cares about the difference.) 661251883Speter*/ 662251883Speter#define SQLITE_SYNC_NORMAL 0x00002 663251883Speter#define SQLITE_SYNC_FULL 0x00003 664251883Speter#define SQLITE_SYNC_DATAONLY 0x00010 665251883Speter 666251883Speter/* 667251883Speter** CAPI3REF: OS Interface Open File Handle 668251883Speter** 669251883Speter** An [sqlite3_file] object represents an open file in the 670251883Speter** [sqlite3_vfs | OS interface layer]. Individual OS interface 671251883Speter** implementations will 672251883Speter** want to subclass this object by appending additional fields 673251883Speter** for their own use. The pMethods entry is a pointer to an 674251883Speter** [sqlite3_io_methods] object that defines methods for performing 675251883Speter** I/O operations on the open file. 676251883Speter*/ 677251883Spetertypedef struct sqlite3_file sqlite3_file; 678251883Speterstruct sqlite3_file { 679251883Speter const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 680251883Speter}; 681251883Speter 682251883Speter/* 683251883Speter** CAPI3REF: OS Interface File Virtual Methods Object 684251883Speter** 685251883Speter** Every file opened by the [sqlite3_vfs.xOpen] method populates an 686251883Speter** [sqlite3_file] object (or, more commonly, a subclass of the 687251883Speter** [sqlite3_file] object) with a pointer to an instance of this object. 688251883Speter** This object defines the methods used to perform various operations 689251883Speter** against the open file represented by the [sqlite3_file] object. 690251883Speter** 691251883Speter** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 692251883Speter** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 693251883Speter** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 694251883Speter** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 695251883Speter** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 696251883Speter** to NULL. 697251883Speter** 698251883Speter** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 699251883Speter** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 700251883Speter** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 701251883Speter** flag may be ORed in to indicate that only the data of the file 702251883Speter** and not its inode needs to be synced. 703251883Speter** 704251883Speter** The integer values to xLock() and xUnlock() are one of 705251883Speter** <ul> 706251883Speter** <li> [SQLITE_LOCK_NONE], 707251883Speter** <li> [SQLITE_LOCK_SHARED], 708251883Speter** <li> [SQLITE_LOCK_RESERVED], 709251883Speter** <li> [SQLITE_LOCK_PENDING], or 710251883Speter** <li> [SQLITE_LOCK_EXCLUSIVE]. 711251883Speter** </ul> 712251883Speter** xLock() increases the lock. xUnlock() decreases the lock. 713251883Speter** The xCheckReservedLock() method checks whether any database connection, 714251883Speter** either in this process or in some other process, is holding a RESERVED, 715251883Speter** PENDING, or EXCLUSIVE lock on the file. It returns true 716251883Speter** if such a lock exists and false otherwise. 717251883Speter** 718251883Speter** The xFileControl() method is a generic interface that allows custom 719251883Speter** VFS implementations to directly control an open file using the 720251883Speter** [sqlite3_file_control()] interface. The second "op" argument is an 721251883Speter** integer opcode. The third argument is a generic pointer intended to 722251883Speter** point to a structure that may contain arguments or space in which to 723251883Speter** write return values. Potential uses for xFileControl() might be 724251883Speter** functions to enable blocking locks with timeouts, to change the 725251883Speter** locking strategy (for example to use dot-file locks), to inquire 726251883Speter** about the status of a lock, or to break stale locks. The SQLite 727251883Speter** core reserves all opcodes less than 100 for its own use. 728274884Sbapt** A [file control opcodes | list of opcodes] less than 100 is available. 729251883Speter** Applications that define a custom xFileControl method should use opcodes 730251883Speter** greater than 100 to avoid conflicts. VFS implementations should 731251883Speter** return [SQLITE_NOTFOUND] for file control opcodes that they do not 732251883Speter** recognize. 733251883Speter** 734251883Speter** The xSectorSize() method returns the sector size of the 735251883Speter** device that underlies the file. The sector size is the 736251883Speter** minimum write that can be performed without disturbing 737251883Speter** other bytes in the file. The xDeviceCharacteristics() 738251883Speter** method returns a bit vector describing behaviors of the 739251883Speter** underlying device: 740251883Speter** 741251883Speter** <ul> 742251883Speter** <li> [SQLITE_IOCAP_ATOMIC] 743251883Speter** <li> [SQLITE_IOCAP_ATOMIC512] 744251883Speter** <li> [SQLITE_IOCAP_ATOMIC1K] 745251883Speter** <li> [SQLITE_IOCAP_ATOMIC2K] 746251883Speter** <li> [SQLITE_IOCAP_ATOMIC4K] 747251883Speter** <li> [SQLITE_IOCAP_ATOMIC8K] 748251883Speter** <li> [SQLITE_IOCAP_ATOMIC16K] 749251883Speter** <li> [SQLITE_IOCAP_ATOMIC32K] 750251883Speter** <li> [SQLITE_IOCAP_ATOMIC64K] 751251883Speter** <li> [SQLITE_IOCAP_SAFE_APPEND] 752251883Speter** <li> [SQLITE_IOCAP_SEQUENTIAL] 753322444Speter** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 754322444Speter** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 755322444Speter** <li> [SQLITE_IOCAP_IMMUTABLE] 756342292Scy** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 757251883Speter** </ul> 758251883Speter** 759251883Speter** The SQLITE_IOCAP_ATOMIC property means that all writes of 760251883Speter** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 761251883Speter** mean that writes of blocks that are nnn bytes in size and 762251883Speter** are aligned to an address which is an integer multiple of 763251883Speter** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 764251883Speter** that when data is appended to a file, the data is appended 765251883Speter** first then the size of the file is extended, never the other 766251883Speter** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 767251883Speter** information is written to disk in the same order as calls 768251883Speter** to xWrite(). 769251883Speter** 770251883Speter** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 771251883Speter** in the unread portions of the buffer with zeros. A VFS that 772251883Speter** fails to zero-fill short reads might seem to work. However, 773251883Speter** failure to zero-fill short reads will eventually lead to 774251883Speter** database corruption. 775251883Speter*/ 776251883Spetertypedef struct sqlite3_io_methods sqlite3_io_methods; 777251883Speterstruct sqlite3_io_methods { 778251883Speter int iVersion; 779251883Speter int (*xClose)(sqlite3_file*); 780251883Speter int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 781251883Speter int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 782251883Speter int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 783251883Speter int (*xSync)(sqlite3_file*, int flags); 784251883Speter int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 785251883Speter int (*xLock)(sqlite3_file*, int); 786251883Speter int (*xUnlock)(sqlite3_file*, int); 787251883Speter int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 788251883Speter int (*xFileControl)(sqlite3_file*, int op, void *pArg); 789251883Speter int (*xSectorSize)(sqlite3_file*); 790251883Speter int (*xDeviceCharacteristics)(sqlite3_file*); 791251883Speter /* Methods above are valid for version 1 */ 792251883Speter int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 793251883Speter int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 794251883Speter void (*xShmBarrier)(sqlite3_file*); 795251883Speter int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 796251883Speter /* Methods above are valid for version 2 */ 797251883Speter int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 798251883Speter int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 799251883Speter /* Methods above are valid for version 3 */ 800251883Speter /* Additional methods may be added in future releases */ 801251883Speter}; 802251883Speter 803251883Speter/* 804251883Speter** CAPI3REF: Standard File Control Opcodes 805274884Sbapt** KEYWORDS: {file control opcodes} {file control opcode} 806251883Speter** 807251883Speter** These integer constants are opcodes for the xFileControl method 808251883Speter** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 809251883Speter** interface. 810251883Speter** 811282328Sbapt** <ul> 812282328Sbapt** <li>[[SQLITE_FCNTL_LOCKSTATE]] 813251883Speter** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 814251883Speter** opcode causes the xFileControl method to write the current state of 815251883Speter** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 816251883Speter** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 817251883Speter** into an integer that the pArg argument points to. This capability 818282328Sbapt** is used during testing and is only available when the SQLITE_TEST 819282328Sbapt** compile-time option is used. 820282328Sbapt** 821251883Speter** <li>[[SQLITE_FCNTL_SIZE_HINT]] 822251883Speter** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 823251883Speter** layer a hint of how large the database file will grow to be during the 824251883Speter** current transaction. This hint is not guaranteed to be accurate but it 825251883Speter** is often close. The underlying VFS might choose to preallocate database 826251883Speter** file space based on this hint in order to help writes to the database 827251883Speter** file run faster. 828251883Speter** 829346442Scy** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 830346442Scy** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 831346442Scy** implements [sqlite3_deserialize()] to set an upper bound on the size 832346442Scy** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 833346442Scy** If the integer pointed to is negative, then it is filled in with the 834346442Scy** current limit. Otherwise the limit is set to the larger of the value 835346442Scy** of the integer pointed to and the current database size. The integer 836346442Scy** pointed to is set to the new limit. 837346442Scy** 838251883Speter** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 839251883Speter** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 840251883Speter** extends and truncates the database file in chunks of a size specified 841251883Speter** by the user. The fourth argument to [sqlite3_file_control()] should 842251883Speter** point to an integer (type int) containing the new chunk-size to use 843251883Speter** for the nominated database. Allocating database file space in large 844251883Speter** chunks (say 1MB at a time), may reduce file-system fragmentation and 845251883Speter** improve performance on some systems. 846251883Speter** 847251883Speter** <li>[[SQLITE_FCNTL_FILE_POINTER]] 848251883Speter** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 849251883Speter** to the [sqlite3_file] object associated with a particular database 850298161Sbapt** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 851251883Speter** 852298161Sbapt** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 853298161Sbapt** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 854298161Sbapt** to the [sqlite3_file] object associated with the journal file (either 855298161Sbapt** the [rollback journal] or the [write-ahead log]) for a particular database 856298161Sbapt** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 857298161Sbapt** 858251883Speter** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 859269851Speter** No longer in use. 860251883Speter** 861269851Speter** <li>[[SQLITE_FCNTL_SYNC]] 862269851Speter** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 863269851Speter** sent to the VFS immediately before the xSync method is invoked on a 864269851Speter** database file descriptor. Or, if the xSync method is not invoked 865269851Speter** because the user has configured SQLite with 866269851Speter** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 867269851Speter** of the xSync method. In most cases, the pointer argument passed with 868269851Speter** this file-control is NULL. However, if the database file is being synced 869269851Speter** as part of a multi-database commit, the argument points to a nul-terminated 870269851Speter** string containing the transactions master-journal file name. VFSes that 871269851Speter** do not need this signal should silently ignore this opcode. Applications 872269851Speter** should not call [sqlite3_file_control()] with this opcode as doing so may 873269851Speter** disrupt the operation of the specialized VFSes that do require it. 874269851Speter** 875269851Speter** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 876269851Speter** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 877269851Speter** and sent to the VFS after a transaction has been committed immediately 878269851Speter** but before the database is unlocked. VFSes that do not need this signal 879269851Speter** should silently ignore this opcode. Applications should not call 880269851Speter** [sqlite3_file_control()] with this opcode as doing so may disrupt the 881269851Speter** operation of the specialized VFSes that do require it. 882269851Speter** 883251883Speter** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 884251883Speter** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 885251883Speter** retry counts and intervals for certain disk I/O operations for the 886251883Speter** windows [VFS] in order to provide robustness in the presence of 887251883Speter** anti-virus programs. By default, the windows VFS will retry file read, 888251883Speter** file write, and file delete operations up to 10 times, with a delay 889251883Speter** of 25 milliseconds before the first retry and with the delay increasing 890251883Speter** by an additional 25 milliseconds with each subsequent retry. This 891251883Speter** opcode allows these two values (10 retries and 25 milliseconds of delay) 892251883Speter** to be adjusted. The values are changed for all database connections 893251883Speter** within the same process. The argument is a pointer to an array of two 894322444Speter** integers where the first integer is the new retry count and the second 895251883Speter** integer is the delay. If either integer is negative, then the setting 896251883Speter** is not changed but instead the prior value of that setting is written 897251883Speter** into the array entry, allowing the current retry settings to be 898251883Speter** interrogated. The zDbName parameter is ignored. 899251883Speter** 900251883Speter** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 901251883Speter** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 902251883Speter** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 903342292Scy** write ahead log ([WAL file]) and shared memory 904342292Scy** files used for transaction control 905251883Speter** are automatically deleted when the latest connection to the database 906251883Speter** closes. Setting persistent WAL mode causes those files to persist after 907251883Speter** close. Persisting the files is useful when other processes that do not 908251883Speter** have write permission on the directory containing the database file want 909251883Speter** to read the database file, as the WAL and shared memory files must exist 910251883Speter** in order for the database to be readable. The fourth parameter to 911251883Speter** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 912251883Speter** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 913251883Speter** WAL mode. If the integer is -1, then it is overwritten with the current 914251883Speter** WAL persistence setting. 915251883Speter** 916251883Speter** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 917251883Speter** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 918251883Speter** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 919251883Speter** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 920251883Speter** xDeviceCharacteristics methods. The fourth parameter to 921251883Speter** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 922251883Speter** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 923251883Speter** mode. If the integer is -1, then it is overwritten with the current 924251883Speter** zero-damage mode setting. 925251883Speter** 926251883Speter** <li>[[SQLITE_FCNTL_OVERWRITE]] 927251883Speter** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 928251883Speter** a write transaction to indicate that, unless it is rolled back for some 929251883Speter** reason, the entire database file will be overwritten by the current 930251883Speter** transaction. This is used by VACUUM operations. 931251883Speter** 932251883Speter** <li>[[SQLITE_FCNTL_VFSNAME]] 933251883Speter** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 934251883Speter** all [VFSes] in the VFS stack. The names are of all VFS shims and the 935251883Speter** final bottom-level VFS are written into memory obtained from 936251883Speter** [sqlite3_malloc()] and the result is stored in the char* variable 937251883Speter** that the fourth parameter of [sqlite3_file_control()] points to. 938251883Speter** The caller is responsible for freeing the memory when done. As with 939251883Speter** all file-control actions, there is no guarantee that this will actually 940251883Speter** do anything. Callers should initialize the char* variable to a NULL 941251883Speter** pointer in case this file-control is not implemented. This file-control 942251883Speter** is intended for diagnostic use only. 943251883Speter** 944298161Sbapt** <li>[[SQLITE_FCNTL_VFS_POINTER]] 945298161Sbapt** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 946298161Sbapt** [VFSes] currently in use. ^(The argument X in 947298161Sbapt** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 948298161Sbapt** of type "[sqlite3_vfs] **". This opcodes will set *X 949298161Sbapt** to a pointer to the top-level VFS.)^ 950298161Sbapt** ^When there are multiple VFS shims in the stack, this opcode finds the 951298161Sbapt** upper-most shim only. 952298161Sbapt** 953251883Speter** <li>[[SQLITE_FCNTL_PRAGMA]] 954251883Speter** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 955251883Speter** file control is sent to the open [sqlite3_file] object corresponding 956251883Speter** to the database file to which the pragma statement refers. ^The argument 957251883Speter** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 958251883Speter** pointers to strings (char**) in which the second element of the array 959251883Speter** is the name of the pragma and the third element is the argument to the 960251883Speter** pragma or NULL if the pragma has no argument. ^The handler for an 961251883Speter** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 962251883Speter** of the char** argument point to a string obtained from [sqlite3_mprintf()] 963251883Speter** or the equivalent and that string will become the result of the pragma or 964251883Speter** the error message if the pragma fails. ^If the 965251883Speter** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 966251883Speter** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 967251883Speter** file control returns [SQLITE_OK], then the parser assumes that the 968251883Speter** VFS has handled the PRAGMA itself and the parser generates a no-op 969282328Sbapt** prepared statement if result string is NULL, or that returns a copy 970282328Sbapt** of the result string if the string is non-NULL. 971282328Sbapt** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 972251883Speter** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 973251883Speter** that the VFS encountered an error while handling the [PRAGMA] and the 974251883Speter** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 975251883Speter** file control occurs at the beginning of pragma statement analysis and so 976251883Speter** it is able to override built-in [PRAGMA] statements. 977251883Speter** 978251883Speter** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 979251883Speter** ^The [SQLITE_FCNTL_BUSYHANDLER] 980251883Speter** file-control may be invoked by SQLite on the database file handle 981251883Speter** shortly after it is opened in order to provide a custom VFS with access 982251883Speter** to the connections busy-handler callback. The argument is of type (void **) 983251883Speter** - an array of two (void *) values. The first (void *) actually points 984251883Speter** to a function of type (int (*)(void *)). In order to invoke the connections 985251883Speter** busy-handler, this function should be invoked with the second (void *) in 986251883Speter** the array as the only argument. If it returns non-zero, then the operation 987251883Speter** should be retried. If it returns zero, the custom VFS should abandon the 988251883Speter** current operation. 989251883Speter** 990251883Speter** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 991251883Speter** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 992251883Speter** to have SQLite generate a 993251883Speter** temporary filename using the same algorithm that is followed to generate 994251883Speter** temporary filenames for TEMP tables and other internal uses. The 995251883Speter** argument should be a char** which will be filled with the filename 996251883Speter** written into memory obtained from [sqlite3_malloc()]. The caller should 997251883Speter** invoke [sqlite3_free()] on the result to avoid a memory leak. 998251883Speter** 999251883Speter** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1000251883Speter** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1001251883Speter** maximum number of bytes that will be used for memory-mapped I/O. 1002251883Speter** The argument is a pointer to a value of type sqlite3_int64 that 1003251883Speter** is an advisory maximum number of bytes in the file to memory map. The 1004251883Speter** pointer is overwritten with the old value. The limit is not changed if 1005251883Speter** the value originally pointed to is negative, and so the current limit 1006251883Speter** can be queried by passing in a pointer to a negative number. This 1007251883Speter** file-control is used internally to implement [PRAGMA mmap_size]. 1008251883Speter** 1009269851Speter** <li>[[SQLITE_FCNTL_TRACE]] 1010269851Speter** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1011269851Speter** to the VFS about what the higher layers of the SQLite stack are doing. 1012269851Speter** This file control is used by some VFS activity tracing [shims]. 1013269851Speter** The argument is a zero-terminated string. Higher layers in the 1014269851Speter** SQLite stack may generate instances of this file control if 1015269851Speter** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1016269851Speter** 1017269851Speter** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1018269851Speter** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1019269851Speter** pointer to an integer and it writes a boolean into that integer depending 1020269851Speter** on whether or not the file has been renamed, moved, or deleted since it 1021269851Speter** was first opened. 1022269851Speter** 1023322444Speter** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1024322444Speter** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1025322444Speter** underlying native file handle associated with a file handle. This file 1026322444Speter** control interprets its argument as a pointer to a native file handle and 1027322444Speter** writes the resulting value there. 1028322444Speter** 1029269851Speter** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1030269851Speter** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1031269851Speter** opcode causes the xFileControl method to swap the file handle with the one 1032269851Speter** pointed to by the pArg argument. This capability is used during testing 1033269851Speter** and only needs to be supported when SQLITE_TEST is defined. 1034269851Speter** 1035282328Sbapt** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1036282328Sbapt** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1037282328Sbapt** be advantageous to block on the next WAL lock if the lock is not immediately 1038282328Sbapt** available. The WAL subsystem issues this signal during rare 1039282328Sbapt** circumstances in order to fix a problem with priority inversion. 1040282328Sbapt** Applications should <em>not</em> use this file-control. 1041282328Sbapt** 1042286510Speter** <li>[[SQLITE_FCNTL_ZIPVFS]] 1043286510Speter** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1044286510Speter** VFS should return SQLITE_NOTFOUND for this opcode. 1045286510Speter** 1046286510Speter** <li>[[SQLITE_FCNTL_RBU]] 1047286510Speter** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1048286510Speter** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1049286510Speter** this opcode. 1050342292Scy** 1051342292Scy** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1052342292Scy** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1053342292Scy** the file descriptor is placed in "batch write mode", which 1054342292Scy** means all subsequent write operations will be deferred and done 1055342292Scy** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1056342292Scy** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1057342292Scy** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1058342292Scy** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1059342292Scy** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1060342292Scy** no VFS interface calls on the same [sqlite3_file] file descriptor 1061342292Scy** except for calls to the xWrite method and the xFileControl method 1062342292Scy** with [SQLITE_FCNTL_SIZE_HINT]. 1063342292Scy** 1064342292Scy** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1065342292Scy** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1066342292Scy** operations since the previous successful call to 1067342292Scy** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1068342292Scy** This file control returns [SQLITE_OK] if and only if the writes were 1069342292Scy** all performed successfully and have been committed to persistent storage. 1070342292Scy** ^Regardless of whether or not it is successful, this file control takes 1071342292Scy** the file descriptor out of batch write mode so that all subsequent 1072342292Scy** write operations are independent. 1073342292Scy** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1074342292Scy** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1075342292Scy** 1076342292Scy** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1077342292Scy** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1078342292Scy** operations since the previous successful call to 1079342292Scy** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1080342292Scy** ^This file control takes the file descriptor out of batch write mode 1081342292Scy** so that all subsequent write operations are independent. 1082342292Scy** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1083342292Scy** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1084342292Scy** 1085342292Scy** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1086342292Scy** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1087342292Scy** a file lock using the xLock or xShmLock methods of the VFS to wait 1088342292Scy** for up to M milliseconds before failing, where M is the single 1089342292Scy** unsigned integer parameter. 1090342292Scy** 1091342292Scy** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1092342292Scy** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1093342292Scy** a database file. The argument is a pointer to a 32-bit unsigned integer. 1094342292Scy** The "data version" for the pager is written into the pointer. The 1095342292Scy** "data version" changes whenever any change occurs to the corresponding 1096342292Scy** database file, either through SQL statements on the same database 1097342292Scy** connection or through transactions committed by separate database 1098342292Scy** connections possibly in other processes. The [sqlite3_total_changes()] 1099342292Scy** interface can be used to find if any database on the connection has changed, 1100342292Scy** but that interface responds to changes on TEMP as well as MAIN and does 1101342292Scy** not provide a mechanism to detect changes to MAIN only. Also, the 1102342292Scy** [sqlite3_total_changes()] interface responds to internal changes only and 1103342292Scy** omits changes made by other database connections. The 1104342292Scy** [PRAGMA data_version] command provide a mechanism to detect changes to 1105342292Scy** a single attached database that occur due to other database connections, 1106342292Scy** but omits changes implemented by the database connection on which it is 1107342292Scy** called. This file control is the only mechanism to detect changes that 1108342292Scy** happen either internally or externally and that are associated with 1109342292Scy** a particular attached database. 1110251883Speter** </ul> 1111251883Speter*/ 1112251883Speter#define SQLITE_FCNTL_LOCKSTATE 1 1113282328Sbapt#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1114282328Sbapt#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1115282328Sbapt#define SQLITE_FCNTL_LAST_ERRNO 4 1116251883Speter#define SQLITE_FCNTL_SIZE_HINT 5 1117251883Speter#define SQLITE_FCNTL_CHUNK_SIZE 6 1118251883Speter#define SQLITE_FCNTL_FILE_POINTER 7 1119251883Speter#define SQLITE_FCNTL_SYNC_OMITTED 8 1120251883Speter#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1121251883Speter#define SQLITE_FCNTL_PERSIST_WAL 10 1122251883Speter#define SQLITE_FCNTL_OVERWRITE 11 1123251883Speter#define SQLITE_FCNTL_VFSNAME 12 1124251883Speter#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1125251883Speter#define SQLITE_FCNTL_PRAGMA 14 1126251883Speter#define SQLITE_FCNTL_BUSYHANDLER 15 1127251883Speter#define SQLITE_FCNTL_TEMPFILENAME 16 1128251883Speter#define SQLITE_FCNTL_MMAP_SIZE 18 1129269851Speter#define SQLITE_FCNTL_TRACE 19 1130269851Speter#define SQLITE_FCNTL_HAS_MOVED 20 1131269851Speter#define SQLITE_FCNTL_SYNC 21 1132269851Speter#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1133269851Speter#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1134282328Sbapt#define SQLITE_FCNTL_WAL_BLOCK 24 1135286510Speter#define SQLITE_FCNTL_ZIPVFS 25 1136286510Speter#define SQLITE_FCNTL_RBU 26 1137298161Sbapt#define SQLITE_FCNTL_VFS_POINTER 27 1138298161Sbapt#define SQLITE_FCNTL_JOURNAL_POINTER 28 1139322444Speter#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1140322444Speter#define SQLITE_FCNTL_PDB 30 1141342292Scy#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1142342292Scy#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1143342292Scy#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1144342292Scy#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1145342292Scy#define SQLITE_FCNTL_DATA_VERSION 35 1146346442Scy#define SQLITE_FCNTL_SIZE_LIMIT 36 1147251883Speter 1148282328Sbapt/* deprecated names */ 1149282328Sbapt#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1150282328Sbapt#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1151282328Sbapt#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1152282328Sbapt 1153282328Sbapt 1154251883Speter/* 1155251883Speter** CAPI3REF: Mutex Handle 1156251883Speter** 1157251883Speter** The mutex module within SQLite defines [sqlite3_mutex] to be an 1158251883Speter** abstract type for a mutex object. The SQLite core never looks 1159251883Speter** at the internal representation of an [sqlite3_mutex]. It only 1160251883Speter** deals with pointers to the [sqlite3_mutex] object. 1161251883Speter** 1162251883Speter** Mutexes are created using [sqlite3_mutex_alloc()]. 1163251883Speter*/ 1164251883Spetertypedef struct sqlite3_mutex sqlite3_mutex; 1165251883Speter 1166251883Speter/* 1167305002Scy** CAPI3REF: Loadable Extension Thunk 1168305002Scy** 1169305002Scy** A pointer to the opaque sqlite3_api_routines structure is passed as 1170305002Scy** the third parameter to entry points of [loadable extensions]. This 1171305002Scy** structure must be typedefed in order to work around compiler warnings 1172305002Scy** on some platforms. 1173305002Scy*/ 1174305002Scytypedef struct sqlite3_api_routines sqlite3_api_routines; 1175305002Scy 1176305002Scy/* 1177251883Speter** CAPI3REF: OS Interface Object 1178251883Speter** 1179251883Speter** An instance of the sqlite3_vfs object defines the interface between 1180251883Speter** the SQLite core and the underlying operating system. The "vfs" 1181251883Speter** in the name of the object stands for "virtual file system". See 1182251883Speter** the [VFS | VFS documentation] for further information. 1183251883Speter** 1184342292Scy** The VFS interface is sometimes extended by adding new methods onto 1185342292Scy** the end. Each time such an extension occurs, the iVersion field 1186342292Scy** is incremented. The iVersion value started out as 1 in 1187342292Scy** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1188342292Scy** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1189342292Scy** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1190342292Scy** may be appended to the sqlite3_vfs object and the iVersion value 1191342292Scy** may increase again in future versions of SQLite. 1192342292Scy** Note that the structure 1193342292Scy** of the sqlite3_vfs object changes in the transition from 1194342292Scy** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1195342292Scy** and yet the iVersion field was not modified. 1196251883Speter** 1197251883Speter** The szOsFile field is the size of the subclassed [sqlite3_file] 1198251883Speter** structure used by this VFS. mxPathname is the maximum length of 1199251883Speter** a pathname in this VFS. 1200251883Speter** 1201251883Speter** Registered sqlite3_vfs objects are kept on a linked list formed by 1202251883Speter** the pNext pointer. The [sqlite3_vfs_register()] 1203251883Speter** and [sqlite3_vfs_unregister()] interfaces manage this list 1204251883Speter** in a thread-safe way. The [sqlite3_vfs_find()] interface 1205251883Speter** searches the list. Neither the application code nor the VFS 1206251883Speter** implementation should use the pNext pointer. 1207251883Speter** 1208251883Speter** The pNext field is the only field in the sqlite3_vfs 1209251883Speter** structure that SQLite will ever modify. SQLite will only access 1210251883Speter** or modify this field while holding a particular static mutex. 1211251883Speter** The application should never modify anything within the sqlite3_vfs 1212251883Speter** object once the object has been registered. 1213251883Speter** 1214251883Speter** The zName field holds the name of the VFS module. The name must 1215251883Speter** be unique across all VFS modules. 1216251883Speter** 1217251883Speter** [[sqlite3_vfs.xOpen]] 1218251883Speter** ^SQLite guarantees that the zFilename parameter to xOpen 1219251883Speter** is either a NULL pointer or string obtained 1220251883Speter** from xFullPathname() with an optional suffix added. 1221251883Speter** ^If a suffix is added to the zFilename parameter, it will 1222251883Speter** consist of a single "-" character followed by no more than 1223251883Speter** 11 alphanumeric and/or "-" characters. 1224251883Speter** ^SQLite further guarantees that 1225251883Speter** the string will be valid and unchanged until xClose() is 1226251883Speter** called. Because of the previous sentence, 1227251883Speter** the [sqlite3_file] can safely store a pointer to the 1228251883Speter** filename if it needs to remember the filename for some reason. 1229251883Speter** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1230251883Speter** must invent its own temporary name for the file. ^Whenever the 1231251883Speter** xFilename parameter is NULL it will also be the case that the 1232251883Speter** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1233251883Speter** 1234251883Speter** The flags argument to xOpen() includes all bits set in 1235251883Speter** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1236251883Speter** or [sqlite3_open16()] is used, then flags includes at least 1237251883Speter** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1238251883Speter** If xOpen() opens a file read-only then it sets *pOutFlags to 1239251883Speter** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1240251883Speter** 1241251883Speter** ^(SQLite will also add one of the following flags to the xOpen() 1242251883Speter** call, depending on the object being opened: 1243251883Speter** 1244251883Speter** <ul> 1245251883Speter** <li> [SQLITE_OPEN_MAIN_DB] 1246251883Speter** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1247251883Speter** <li> [SQLITE_OPEN_TEMP_DB] 1248251883Speter** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1249251883Speter** <li> [SQLITE_OPEN_TRANSIENT_DB] 1250251883Speter** <li> [SQLITE_OPEN_SUBJOURNAL] 1251251883Speter** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1252251883Speter** <li> [SQLITE_OPEN_WAL] 1253251883Speter** </ul>)^ 1254251883Speter** 1255251883Speter** The file I/O implementation can use the object type flags to 1256251883Speter** change the way it deals with files. For example, an application 1257251883Speter** that does not care about crash recovery or rollback might make 1258251883Speter** the open of a journal file a no-op. Writes to this journal would 1259251883Speter** also be no-ops, and any attempt to read the journal would return 1260251883Speter** SQLITE_IOERR. Or the implementation might recognize that a database 1261251883Speter** file will be doing page-aligned sector reads and writes in a random 1262251883Speter** order and set up its I/O subsystem accordingly. 1263251883Speter** 1264251883Speter** SQLite might also add one of the following flags to the xOpen method: 1265251883Speter** 1266251883Speter** <ul> 1267251883Speter** <li> [SQLITE_OPEN_DELETEONCLOSE] 1268251883Speter** <li> [SQLITE_OPEN_EXCLUSIVE] 1269251883Speter** </ul> 1270251883Speter** 1271251883Speter** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1272251883Speter** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1273251883Speter** will be set for TEMP databases and their journals, transient 1274251883Speter** databases, and subjournals. 1275251883Speter** 1276251883Speter** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1277251883Speter** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1278251883Speter** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1279251883Speter** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1280251883Speter** SQLITE_OPEN_CREATE, is used to indicate that file should always 1281251883Speter** be created, and that it is an error if it already exists. 1282251883Speter** It is <i>not</i> used to indicate the file should be opened 1283251883Speter** for exclusive access. 1284251883Speter** 1285251883Speter** ^At least szOsFile bytes of memory are allocated by SQLite 1286251883Speter** to hold the [sqlite3_file] structure passed as the third 1287251883Speter** argument to xOpen. The xOpen method does not have to 1288251883Speter** allocate the structure; it should just fill it in. Note that 1289251883Speter** the xOpen method must set the sqlite3_file.pMethods to either 1290251883Speter** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1291251883Speter** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1292251883Speter** element will be valid after xOpen returns regardless of the success 1293251883Speter** or failure of the xOpen call. 1294251883Speter** 1295251883Speter** [[sqlite3_vfs.xAccess]] 1296251883Speter** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1297251883Speter** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1298251883Speter** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1299351633Scy** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1300351633Scy** flag is never actually used and is not implemented in the built-in 1301351633Scy** VFSes of SQLite. The file is named by the second argument and can be a 1302351633Scy** directory. The xAccess method returns [SQLITE_OK] on success or some 1303351633Scy** non-zero error code if there is an I/O error or if the name of 1304351633Scy** the file given in the second argument is illegal. If SQLITE_OK 1305351633Scy** is returned, then non-zero or zero is written into *pResOut to indicate 1306351633Scy** whether or not the file is accessible. 1307251883Speter** 1308251883Speter** ^SQLite will always allocate at least mxPathname+1 bytes for the 1309251883Speter** output buffer xFullPathname. The exact size of the output buffer 1310251883Speter** is also passed as a parameter to both methods. If the output buffer 1311251883Speter** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1312251883Speter** handled as a fatal error by SQLite, vfs implementations should endeavor 1313251883Speter** to prevent this by setting mxPathname to a sufficiently large value. 1314251883Speter** 1315251883Speter** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1316251883Speter** interfaces are not strictly a part of the filesystem, but they are 1317251883Speter** included in the VFS structure for completeness. 1318251883Speter** The xRandomness() function attempts to return nBytes bytes 1319251883Speter** of good-quality randomness into zOut. The return value is 1320251883Speter** the actual number of bytes of randomness obtained. 1321251883Speter** The xSleep() method causes the calling thread to sleep for at 1322251883Speter** least the number of microseconds given. ^The xCurrentTime() 1323251883Speter** method returns a Julian Day Number for the current date and time as 1324251883Speter** a floating point value. 1325251883Speter** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1326251883Speter** Day Number multiplied by 86400000 (the number of milliseconds in 1327251883Speter** a 24-hour day). 1328251883Speter** ^SQLite will use the xCurrentTimeInt64() method to get the current 1329251883Speter** date and time if that method is available (if iVersion is 2 or 1330251883Speter** greater and the function pointer is not NULL) and will fall back 1331251883Speter** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1332251883Speter** 1333251883Speter** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1334251883Speter** are not used by the SQLite core. These optional interfaces are provided 1335251883Speter** by some VFSes to facilitate testing of the VFS code. By overriding 1336251883Speter** system calls with functions under its control, a test program can 1337251883Speter** simulate faults and error conditions that would otherwise be difficult 1338251883Speter** or impossible to induce. The set of system calls that can be overridden 1339251883Speter** varies from one VFS to another, and from one version of the same VFS to the 1340251883Speter** next. Applications that use these interfaces must be prepared for any 1341251883Speter** or all of these interfaces to be NULL or for their behavior to change 1342251883Speter** from one release to the next. Applications must not attempt to access 1343251883Speter** any of these methods if the iVersion of the VFS is less than 3. 1344251883Speter*/ 1345251883Spetertypedef struct sqlite3_vfs sqlite3_vfs; 1346251883Spetertypedef void (*sqlite3_syscall_ptr)(void); 1347251883Speterstruct sqlite3_vfs { 1348251883Speter int iVersion; /* Structure version number (currently 3) */ 1349251883Speter int szOsFile; /* Size of subclassed sqlite3_file */ 1350251883Speter int mxPathname; /* Maximum file pathname length */ 1351251883Speter sqlite3_vfs *pNext; /* Next registered VFS */ 1352251883Speter const char *zName; /* Name of this virtual file system */ 1353251883Speter void *pAppData; /* Pointer to application-specific data */ 1354251883Speter int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1355251883Speter int flags, int *pOutFlags); 1356251883Speter int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1357251883Speter int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1358251883Speter int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1359251883Speter void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1360251883Speter void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1361251883Speter void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1362251883Speter void (*xDlClose)(sqlite3_vfs*, void*); 1363251883Speter int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1364251883Speter int (*xSleep)(sqlite3_vfs*, int microseconds); 1365251883Speter int (*xCurrentTime)(sqlite3_vfs*, double*); 1366251883Speter int (*xGetLastError)(sqlite3_vfs*, int, char *); 1367251883Speter /* 1368251883Speter ** The methods above are in version 1 of the sqlite_vfs object 1369251883Speter ** definition. Those that follow are added in version 2 or later 1370251883Speter */ 1371251883Speter int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1372251883Speter /* 1373251883Speter ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1374251883Speter ** Those below are for version 3 and greater. 1375251883Speter */ 1376251883Speter int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1377251883Speter sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1378251883Speter const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1379251883Speter /* 1380251883Speter ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1381298161Sbapt ** New fields may be appended in future versions. The iVersion 1382251883Speter ** value will increment whenever this happens. 1383251883Speter */ 1384251883Speter}; 1385251883Speter 1386251883Speter/* 1387251883Speter** CAPI3REF: Flags for the xAccess VFS method 1388251883Speter** 1389251883Speter** These integer constants can be used as the third parameter to 1390251883Speter** the xAccess method of an [sqlite3_vfs] object. They determine 1391251883Speter** what kind of permissions the xAccess method is looking for. 1392251883Speter** With SQLITE_ACCESS_EXISTS, the xAccess method 1393251883Speter** simply checks whether the file exists. 1394251883Speter** With SQLITE_ACCESS_READWRITE, the xAccess method 1395251883Speter** checks whether the named directory is both readable and writable 1396251883Speter** (in other words, if files can be added, removed, and renamed within 1397251883Speter** the directory). 1398251883Speter** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1399251883Speter** [temp_store_directory pragma], though this could change in a future 1400251883Speter** release of SQLite. 1401251883Speter** With SQLITE_ACCESS_READ, the xAccess method 1402251883Speter** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1403251883Speter** currently unused, though it might be used in a future release of 1404251883Speter** SQLite. 1405251883Speter*/ 1406251883Speter#define SQLITE_ACCESS_EXISTS 0 1407251883Speter#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1408251883Speter#define SQLITE_ACCESS_READ 2 /* Unused */ 1409251883Speter 1410251883Speter/* 1411251883Speter** CAPI3REF: Flags for the xShmLock VFS method 1412251883Speter** 1413251883Speter** These integer constants define the various locking operations 1414251883Speter** allowed by the xShmLock method of [sqlite3_io_methods]. The 1415251883Speter** following are the only legal combinations of flags to the 1416251883Speter** xShmLock method: 1417251883Speter** 1418251883Speter** <ul> 1419251883Speter** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1420251883Speter** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1421251883Speter** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1422251883Speter** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1423251883Speter** </ul> 1424251883Speter** 1425251883Speter** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1426282328Sbapt** was given on the corresponding lock. 1427251883Speter** 1428251883Speter** The xShmLock method can transition between unlocked and SHARED or 1429251883Speter** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1430251883Speter** and EXCLUSIVE. 1431251883Speter*/ 1432251883Speter#define SQLITE_SHM_UNLOCK 1 1433251883Speter#define SQLITE_SHM_LOCK 2 1434251883Speter#define SQLITE_SHM_SHARED 4 1435251883Speter#define SQLITE_SHM_EXCLUSIVE 8 1436251883Speter 1437251883Speter/* 1438251883Speter** CAPI3REF: Maximum xShmLock index 1439251883Speter** 1440251883Speter** The xShmLock method on [sqlite3_io_methods] may use values 1441251883Speter** between 0 and this upper bound as its "offset" argument. 1442251883Speter** The SQLite core will never attempt to acquire or release a 1443251883Speter** lock outside of this range 1444251883Speter*/ 1445251883Speter#define SQLITE_SHM_NLOCK 8 1446251883Speter 1447251883Speter 1448251883Speter/* 1449251883Speter** CAPI3REF: Initialize The SQLite Library 1450251883Speter** 1451251883Speter** ^The sqlite3_initialize() routine initializes the 1452251883Speter** SQLite library. ^The sqlite3_shutdown() routine 1453251883Speter** deallocates any resources that were allocated by sqlite3_initialize(). 1454251883Speter** These routines are designed to aid in process initialization and 1455251883Speter** shutdown on embedded systems. Workstation applications using 1456251883Speter** SQLite normally do not need to invoke either of these routines. 1457251883Speter** 1458251883Speter** A call to sqlite3_initialize() is an "effective" call if it is 1459251883Speter** the first time sqlite3_initialize() is invoked during the lifetime of 1460251883Speter** the process, or if it is the first time sqlite3_initialize() is invoked 1461251883Speter** following a call to sqlite3_shutdown(). ^(Only an effective call 1462251883Speter** of sqlite3_initialize() does any initialization. All other calls 1463251883Speter** are harmless no-ops.)^ 1464251883Speter** 1465251883Speter** A call to sqlite3_shutdown() is an "effective" call if it is the first 1466251883Speter** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1467251883Speter** an effective call to sqlite3_shutdown() does any deinitialization. 1468251883Speter** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1469251883Speter** 1470251883Speter** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1471251883Speter** is not. The sqlite3_shutdown() interface must only be called from a 1472251883Speter** single thread. All open [database connections] must be closed and all 1473251883Speter** other SQLite resources must be deallocated prior to invoking 1474251883Speter** sqlite3_shutdown(). 1475251883Speter** 1476251883Speter** Among other things, ^sqlite3_initialize() will invoke 1477251883Speter** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1478251883Speter** will invoke sqlite3_os_end(). 1479251883Speter** 1480251883Speter** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1481251883Speter** ^If for some reason, sqlite3_initialize() is unable to initialize 1482251883Speter** the library (perhaps it is unable to allocate a needed resource such 1483251883Speter** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1484251883Speter** 1485251883Speter** ^The sqlite3_initialize() routine is called internally by many other 1486251883Speter** SQLite interfaces so that an application usually does not need to 1487251883Speter** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1488251883Speter** calls sqlite3_initialize() so the SQLite library will be automatically 1489251883Speter** initialized when [sqlite3_open()] is called if it has not be initialized 1490251883Speter** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1491251883Speter** compile-time option, then the automatic calls to sqlite3_initialize() 1492251883Speter** are omitted and the application must call sqlite3_initialize() directly 1493251883Speter** prior to using any other SQLite interface. For maximum portability, 1494251883Speter** it is recommended that applications always invoke sqlite3_initialize() 1495251883Speter** directly prior to using any other SQLite interface. Future releases 1496251883Speter** of SQLite may require this. In other words, the behavior exhibited 1497251883Speter** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1498251883Speter** default behavior in some future release of SQLite. 1499251883Speter** 1500251883Speter** The sqlite3_os_init() routine does operating-system specific 1501251883Speter** initialization of the SQLite library. The sqlite3_os_end() 1502251883Speter** routine undoes the effect of sqlite3_os_init(). Typical tasks 1503251883Speter** performed by these routines include allocation or deallocation 1504251883Speter** of static resources, initialization of global variables, 1505251883Speter** setting up a default [sqlite3_vfs] module, or setting up 1506251883Speter** a default configuration using [sqlite3_config()]. 1507251883Speter** 1508251883Speter** The application should never invoke either sqlite3_os_init() 1509251883Speter** or sqlite3_os_end() directly. The application should only invoke 1510251883Speter** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1511251883Speter** interface is called automatically by sqlite3_initialize() and 1512251883Speter** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1513251883Speter** implementations for sqlite3_os_init() and sqlite3_os_end() 1514251883Speter** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1515251883Speter** When [custom builds | built for other platforms] 1516251883Speter** (using the [SQLITE_OS_OTHER=1] compile-time 1517251883Speter** option) the application must supply a suitable implementation for 1518251883Speter** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1519251883Speter** implementation of sqlite3_os_init() or sqlite3_os_end() 1520251883Speter** must return [SQLITE_OK] on success and some other [error code] upon 1521251883Speter** failure. 1522251883Speter*/ 1523322444SpeterSQLITE_API int sqlite3_initialize(void); 1524322444SpeterSQLITE_API int sqlite3_shutdown(void); 1525322444SpeterSQLITE_API int sqlite3_os_init(void); 1526322444SpeterSQLITE_API int sqlite3_os_end(void); 1527251883Speter 1528251883Speter/* 1529251883Speter** CAPI3REF: Configuring The SQLite Library 1530251883Speter** 1531251883Speter** The sqlite3_config() interface is used to make global configuration 1532251883Speter** changes to SQLite in order to tune SQLite to the specific needs of 1533251883Speter** the application. The default configuration is recommended for most 1534251883Speter** applications and so this routine is usually not necessary. It is 1535251883Speter** provided to support rare applications with unusual needs. 1536251883Speter** 1537298161Sbapt** <b>The sqlite3_config() interface is not threadsafe. The application 1538298161Sbapt** must ensure that no other SQLite interfaces are invoked by other 1539298161Sbapt** threads while sqlite3_config() is running.</b> 1540298161Sbapt** 1541298161Sbapt** The sqlite3_config() interface 1542251883Speter** may only be invoked prior to library initialization using 1543251883Speter** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1544251883Speter** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1545251883Speter** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1546251883Speter** Note, however, that ^sqlite3_config() can be called as part of the 1547251883Speter** implementation of an application-defined [sqlite3_os_init()]. 1548251883Speter** 1549251883Speter** The first argument to sqlite3_config() is an integer 1550251883Speter** [configuration option] that determines 1551251883Speter** what property of SQLite is to be configured. Subsequent arguments 1552251883Speter** vary depending on the [configuration option] 1553251883Speter** in the first argument. 1554251883Speter** 1555251883Speter** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1556251883Speter** ^If the option is unknown or SQLite is unable to set the option 1557251883Speter** then this routine returns a non-zero [error code]. 1558251883Speter*/ 1559322444SpeterSQLITE_API int sqlite3_config(int, ...); 1560251883Speter 1561251883Speter/* 1562251883Speter** CAPI3REF: Configure database connections 1563286510Speter** METHOD: sqlite3 1564251883Speter** 1565251883Speter** The sqlite3_db_config() interface is used to make configuration 1566251883Speter** changes to a [database connection]. The interface is similar to 1567251883Speter** [sqlite3_config()] except that the changes apply to a single 1568251883Speter** [database connection] (specified in the first argument). 1569251883Speter** 1570251883Speter** The second argument to sqlite3_db_config(D,V,...) is the 1571251883Speter** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1572251883Speter** that indicates what aspect of the [database connection] is being configured. 1573251883Speter** Subsequent arguments vary depending on the configuration verb. 1574251883Speter** 1575251883Speter** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1576251883Speter** the call is considered successful. 1577251883Speter*/ 1578322444SpeterSQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1579251883Speter 1580251883Speter/* 1581251883Speter** CAPI3REF: Memory Allocation Routines 1582251883Speter** 1583251883Speter** An instance of this object defines the interface between SQLite 1584251883Speter** and low-level memory allocation routines. 1585251883Speter** 1586251883Speter** This object is used in only one place in the SQLite interface. 1587251883Speter** A pointer to an instance of this object is the argument to 1588251883Speter** [sqlite3_config()] when the configuration option is 1589251883Speter** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1590251883Speter** By creating an instance of this object 1591251883Speter** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1592251883Speter** during configuration, an application can specify an alternative 1593251883Speter** memory allocation subsystem for SQLite to use for all of its 1594251883Speter** dynamic memory needs. 1595251883Speter** 1596251883Speter** Note that SQLite comes with several [built-in memory allocators] 1597251883Speter** that are perfectly adequate for the overwhelming majority of applications 1598251883Speter** and that this object is only useful to a tiny minority of applications 1599251883Speter** with specialized memory allocation requirements. This object is 1600251883Speter** also used during testing of SQLite in order to specify an alternative 1601251883Speter** memory allocator that simulates memory out-of-memory conditions in 1602251883Speter** order to verify that SQLite recovers gracefully from such 1603251883Speter** conditions. 1604251883Speter** 1605251883Speter** The xMalloc, xRealloc, and xFree methods must work like the 1606251883Speter** malloc(), realloc() and free() functions from the standard C library. 1607251883Speter** ^SQLite guarantees that the second argument to 1608251883Speter** xRealloc is always a value returned by a prior call to xRoundup. 1609251883Speter** 1610251883Speter** xSize should return the allocated size of a memory allocation 1611251883Speter** previously obtained from xMalloc or xRealloc. The allocated size 1612251883Speter** is always at least as big as the requested size but may be larger. 1613251883Speter** 1614251883Speter** The xRoundup method returns what would be the allocated size of 1615251883Speter** a memory allocation given a particular requested size. Most memory 1616251883Speter** allocators round up memory allocations at least to the next multiple 1617251883Speter** of 8. Some allocators round up to a larger multiple or to a power of 2. 1618251883Speter** Every memory allocation request coming in through [sqlite3_malloc()] 1619251883Speter** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1620251883Speter** that causes the corresponding memory allocation to fail. 1621251883Speter** 1622269851Speter** The xInit method initializes the memory allocator. For example, 1623251883Speter** it might allocate any require mutexes or initialize internal data 1624251883Speter** structures. The xShutdown method is invoked (indirectly) by 1625251883Speter** [sqlite3_shutdown()] and should deallocate any resources acquired 1626251883Speter** by xInit. The pAppData pointer is used as the only parameter to 1627251883Speter** xInit and xShutdown. 1628251883Speter** 1629251883Speter** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1630251883Speter** the xInit method, so the xInit method need not be threadsafe. The 1631251883Speter** xShutdown method is only called from [sqlite3_shutdown()] so it does 1632251883Speter** not need to be threadsafe either. For all other methods, SQLite 1633251883Speter** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1634251883Speter** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1635251883Speter** it is by default) and so the methods are automatically serialized. 1636251883Speter** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1637251883Speter** methods must be threadsafe or else make their own arrangements for 1638251883Speter** serialization. 1639251883Speter** 1640251883Speter** SQLite will never invoke xInit() more than once without an intervening 1641251883Speter** call to xShutdown(). 1642251883Speter*/ 1643251883Spetertypedef struct sqlite3_mem_methods sqlite3_mem_methods; 1644251883Speterstruct sqlite3_mem_methods { 1645251883Speter void *(*xMalloc)(int); /* Memory allocation function */ 1646251883Speter void (*xFree)(void*); /* Free a prior allocation */ 1647251883Speter void *(*xRealloc)(void*,int); /* Resize an allocation */ 1648251883Speter int (*xSize)(void*); /* Return the size of an allocation */ 1649251883Speter int (*xRoundup)(int); /* Round up request size to allocation size */ 1650251883Speter int (*xInit)(void*); /* Initialize the memory allocator */ 1651251883Speter void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1652251883Speter void *pAppData; /* Argument to xInit() and xShutdown() */ 1653251883Speter}; 1654251883Speter 1655251883Speter/* 1656251883Speter** CAPI3REF: Configuration Options 1657251883Speter** KEYWORDS: {configuration option} 1658251883Speter** 1659251883Speter** These constants are the available integer configuration options that 1660251883Speter** can be passed as the first argument to the [sqlite3_config()] interface. 1661251883Speter** 1662251883Speter** New configuration options may be added in future releases of SQLite. 1663251883Speter** Existing configuration options might be discontinued. Applications 1664251883Speter** should check the return code from [sqlite3_config()] to make sure that 1665251883Speter** the call worked. The [sqlite3_config()] interface will return a 1666251883Speter** non-zero [error code] if a discontinued or unsupported configuration option 1667251883Speter** is invoked. 1668251883Speter** 1669251883Speter** <dl> 1670251883Speter** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1671251883Speter** <dd>There are no arguments to this option. ^This option sets the 1672251883Speter** [threading mode] to Single-thread. In other words, it disables 1673251883Speter** all mutexing and puts SQLite into a mode where it can only be used 1674251883Speter** by a single thread. ^If SQLite is compiled with 1675251883Speter** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1676251883Speter** it is not possible to change the [threading mode] from its default 1677251883Speter** value of Single-thread and so [sqlite3_config()] will return 1678251883Speter** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1679251883Speter** configuration option.</dd> 1680251883Speter** 1681251883Speter** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1682251883Speter** <dd>There are no arguments to this option. ^This option sets the 1683251883Speter** [threading mode] to Multi-thread. In other words, it disables 1684251883Speter** mutexing on [database connection] and [prepared statement] objects. 1685251883Speter** The application is responsible for serializing access to 1686251883Speter** [database connections] and [prepared statements]. But other mutexes 1687251883Speter** are enabled so that SQLite will be safe to use in a multi-threaded 1688251883Speter** environment as long as no two threads attempt to use the same 1689251883Speter** [database connection] at the same time. ^If SQLite is compiled with 1690251883Speter** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1691251883Speter** it is not possible to set the Multi-thread [threading mode] and 1692251883Speter** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1693251883Speter** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1694251883Speter** 1695251883Speter** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1696251883Speter** <dd>There are no arguments to this option. ^This option sets the 1697251883Speter** [threading mode] to Serialized. In other words, this option enables 1698251883Speter** all mutexes including the recursive 1699251883Speter** mutexes on [database connection] and [prepared statement] objects. 1700251883Speter** In this mode (which is the default when SQLite is compiled with 1701251883Speter** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1702251883Speter** to [database connections] and [prepared statements] so that the 1703251883Speter** application is free to use the same [database connection] or the 1704251883Speter** same [prepared statement] in different threads at the same time. 1705251883Speter** ^If SQLite is compiled with 1706251883Speter** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1707251883Speter** it is not possible to set the Serialized [threading mode] and 1708251883Speter** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1709251883Speter** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1710251883Speter** 1711251883Speter** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1712282328Sbapt** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1713282328Sbapt** a pointer to an instance of the [sqlite3_mem_methods] structure. 1714282328Sbapt** The argument specifies 1715251883Speter** alternative low-level memory allocation routines to be used in place of 1716251883Speter** the memory allocation routines built into SQLite.)^ ^SQLite makes 1717251883Speter** its own private copy of the content of the [sqlite3_mem_methods] structure 1718251883Speter** before the [sqlite3_config()] call returns.</dd> 1719251883Speter** 1720251883Speter** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1721282328Sbapt** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1722282328Sbapt** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1723282328Sbapt** The [sqlite3_mem_methods] 1724251883Speter** structure is filled with the currently defined memory allocation routines.)^ 1725251883Speter** This option can be used to overload the default memory allocation 1726251883Speter** routines with a wrapper that simulations memory allocation failure or 1727251883Speter** tracks memory usage, for example. </dd> 1728251883Speter** 1729342292Scy** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1730342292Scy** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1731342292Scy** type int, interpreted as a boolean, which if true provides a hint to 1732342292Scy** SQLite that it should avoid large memory allocations if possible. 1733342292Scy** SQLite will run faster if it is free to make large memory allocations, 1734342292Scy** but some application might prefer to run slower in exchange for 1735342292Scy** guarantees about memory fragmentation that are possible if large 1736342292Scy** allocations are avoided. This hint is normally off. 1737342292Scy** </dd> 1738342292Scy** 1739251883Speter** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1740282328Sbapt** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1741282328Sbapt** interpreted as a boolean, which enables or disables the collection of 1742282328Sbapt** memory allocation statistics. ^(When memory allocation statistics are 1743282328Sbapt** disabled, the following SQLite interfaces become non-operational: 1744251883Speter** <ul> 1745251883Speter** <li> [sqlite3_memory_used()] 1746251883Speter** <li> [sqlite3_memory_highwater()] 1747251883Speter** <li> [sqlite3_soft_heap_limit64()] 1748282328Sbapt** <li> [sqlite3_status64()] 1749251883Speter** </ul>)^ 1750251883Speter** ^Memory allocation statistics are enabled by default unless SQLite is 1751251883Speter** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1752251883Speter** allocation statistics are disabled by default. 1753251883Speter** </dd> 1754251883Speter** 1755251883Speter** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1756342292Scy** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1757282328Sbapt** </dd> 1758251883Speter** 1759251883Speter** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1760298161Sbapt** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1761282328Sbapt** that SQLite can use for the database page cache with the default page 1762282328Sbapt** cache implementation. 1763298161Sbapt** This configuration option is a no-op if an application-define page 1764298161Sbapt** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1765282328Sbapt** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1766298161Sbapt** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1767298161Sbapt** and the number of cache lines (N). 1768251883Speter** The sz argument should be the size of the largest database page 1769282328Sbapt** (a power of two between 512 and 65536) plus some extra bytes for each 1770282328Sbapt** page header. ^The number of extra bytes needed by the page header 1771298161Sbapt** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1772282328Sbapt** ^It is harmless, apart from the wasted memory, 1773298161Sbapt** for the sz parameter to be larger than necessary. The pMem 1774298161Sbapt** argument must be either a NULL pointer or a pointer to an 8-byte 1775298161Sbapt** aligned block of memory of at least sz*N bytes, otherwise 1776298161Sbapt** subsequent behavior is undefined. 1777298161Sbapt** ^When pMem is not NULL, SQLite will strive to use the memory provided 1778298161Sbapt** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1779298161Sbapt** a page cache line is larger than sz bytes or if all of the pMem buffer 1780298161Sbapt** is exhausted. 1781298161Sbapt** ^If pMem is NULL and N is non-zero, then each database connection 1782298161Sbapt** does an initial bulk allocation for page cache memory 1783298161Sbapt** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1784298161Sbapt** of -1024*N bytes if N is negative, . ^If additional 1785298161Sbapt** page cache memory is needed beyond what is provided by the initial 1786298161Sbapt** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1787298161Sbapt** additional cache line. </dd> 1788251883Speter** 1789251883Speter** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1790282328Sbapt** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1791282328Sbapt** that SQLite will use for all of its dynamic memory allocation needs 1792342292Scy** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1793282328Sbapt** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1794282328Sbapt** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1795282328Sbapt** [SQLITE_ERROR] if invoked otherwise. 1796282328Sbapt** ^There are three arguments to SQLITE_CONFIG_HEAP: 1797282328Sbapt** An 8-byte aligned pointer to the memory, 1798251883Speter** the number of bytes in the memory buffer, and the minimum allocation size. 1799251883Speter** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1800251883Speter** to using its default memory allocator (the system malloc() implementation), 1801251883Speter** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1802282328Sbapt** memory pointer is not NULL then the alternative memory 1803251883Speter** allocator is engaged to handle all of SQLites memory allocation needs. 1804251883Speter** The first pointer (the memory pointer) must be aligned to an 8-byte 1805251883Speter** boundary or subsequent behavior of SQLite will be undefined. 1806251883Speter** The minimum allocation size is capped at 2**12. Reasonable values 1807251883Speter** for the minimum allocation size are 2**5 through 2**8.</dd> 1808251883Speter** 1809251883Speter** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1810282328Sbapt** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1811282328Sbapt** pointer to an instance of the [sqlite3_mutex_methods] structure. 1812282328Sbapt** The argument specifies alternative low-level mutex routines to be used 1813282328Sbapt** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1814282328Sbapt** the content of the [sqlite3_mutex_methods] structure before the call to 1815251883Speter** [sqlite3_config()] returns. ^If SQLite is compiled with 1816251883Speter** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1817251883Speter** the entire mutexing subsystem is omitted from the build and hence calls to 1818251883Speter** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1819251883Speter** return [SQLITE_ERROR].</dd> 1820251883Speter** 1821251883Speter** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1822282328Sbapt** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1823282328Sbapt** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1824251883Speter** [sqlite3_mutex_methods] 1825251883Speter** structure is filled with the currently defined mutex routines.)^ 1826251883Speter** This option can be used to overload the default mutex allocation 1827251883Speter** routines with a wrapper used to track mutex usage for performance 1828251883Speter** profiling or testing, for example. ^If SQLite is compiled with 1829251883Speter** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1830251883Speter** the entire mutexing subsystem is omitted from the build and hence calls to 1831251883Speter** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1832251883Speter** return [SQLITE_ERROR].</dd> 1833251883Speter** 1834251883Speter** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1835282328Sbapt** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1836282328Sbapt** the default size of lookaside memory on each [database connection]. 1837282328Sbapt** The first argument is the 1838251883Speter** size of each lookaside buffer slot and the second is the number of 1839282328Sbapt** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1840282328Sbapt** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1841282328Sbapt** option to [sqlite3_db_config()] can be used to change the lookaside 1842251883Speter** configuration on individual connections.)^ </dd> 1843251883Speter** 1844251883Speter** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1845282328Sbapt** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1846282328Sbapt** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1847282328Sbapt** the interface to a custom page cache implementation.)^ 1848282328Sbapt** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1849251883Speter** 1850251883Speter** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1851282328Sbapt** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1852282328Sbapt** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1853282328Sbapt** the current page cache implementation into that object.)^ </dd> 1854251883Speter** 1855251883Speter** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1856251883Speter** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1857251883Speter** global [error log]. 1858251883Speter** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1859251883Speter** function with a call signature of void(*)(void*,int,const char*), 1860251883Speter** and a pointer to void. ^If the function pointer is not NULL, it is 1861251883Speter** invoked by [sqlite3_log()] to process each logging event. ^If the 1862251883Speter** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1863251883Speter** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1864251883Speter** passed through as the first parameter to the application-defined logger 1865251883Speter** function whenever that function is invoked. ^The second parameter to 1866251883Speter** the logger function is a copy of the first parameter to the corresponding 1867251883Speter** [sqlite3_log()] call and is intended to be a [result code] or an 1868251883Speter** [extended result code]. ^The third parameter passed to the logger is 1869251883Speter** log message after formatting via [sqlite3_snprintf()]. 1870251883Speter** The SQLite logging interface is not reentrant; the logger function 1871251883Speter** supplied by the application must not invoke any SQLite interface. 1872251883Speter** In a multi-threaded application, the application-defined logger 1873251883Speter** function must be threadsafe. </dd> 1874251883Speter** 1875251883Speter** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1876282328Sbapt** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1877282328Sbapt** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1878282328Sbapt** then URI handling is globally disabled.)^ ^If URI handling is globally 1879282328Sbapt** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1880282328Sbapt** [sqlite3_open16()] or 1881251883Speter** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1882251883Speter** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1883269851Speter** connection is opened. ^If it is globally disabled, filenames are 1884251883Speter** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1885269851Speter** database connection is opened. ^(By default, URI handling is globally 1886251883Speter** disabled. The default value may be changed by compiling with the 1887269851Speter** [SQLITE_USE_URI] symbol defined.)^ 1888251883Speter** 1889251883Speter** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1890282328Sbapt** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1891282328Sbapt** argument which is interpreted as a boolean in order to enable or disable 1892282328Sbapt** the use of covering indices for full table scans in the query optimizer. 1893282328Sbapt** ^The default setting is determined 1894251883Speter** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1895251883Speter** if that compile-time option is omitted. 1896251883Speter** The ability to disable the use of covering indices for full table scans 1897251883Speter** is because some incorrectly coded legacy applications might malfunction 1898269851Speter** when the optimization is enabled. Providing the ability to 1899251883Speter** disable the optimization allows the older, buggy application code to work 1900251883Speter** without change even with newer versions of SQLite. 1901251883Speter** 1902251883Speter** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1903251883Speter** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1904251883Speter** <dd> These options are obsolete and should not be used by new code. 1905251883Speter** They are retained for backwards compatibility but are now no-ops. 1906251883Speter** </dd> 1907251883Speter** 1908251883Speter** [[SQLITE_CONFIG_SQLLOG]] 1909251883Speter** <dt>SQLITE_CONFIG_SQLLOG 1910251883Speter** <dd>This option is only available if sqlite is compiled with the 1911251883Speter** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1912251883Speter** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1913251883Speter** The second should be of type (void*). The callback is invoked by the library 1914251883Speter** in three separate circumstances, identified by the value passed as the 1915251883Speter** fourth parameter. If the fourth parameter is 0, then the database connection 1916251883Speter** passed as the second argument has just been opened. The third argument 1917251883Speter** points to a buffer containing the name of the main database file. If the 1918251883Speter** fourth parameter is 1, then the SQL statement that the third parameter 1919251883Speter** points to has just been executed. Or, if the fourth parameter is 2, then 1920251883Speter** the connection being passed as the second parameter is being closed. The 1921251883Speter** third parameter is passed NULL In this case. An example of using this 1922251883Speter** configuration option can be seen in the "test_sqllog.c" source file in 1923251883Speter** the canonical SQLite source tree.</dd> 1924251883Speter** 1925251883Speter** [[SQLITE_CONFIG_MMAP_SIZE]] 1926251883Speter** <dt>SQLITE_CONFIG_MMAP_SIZE 1927269851Speter** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1928251883Speter** that are the default mmap size limit (the default setting for 1929251883Speter** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1930269851Speter** ^The default setting can be overridden by each database connection using 1931251883Speter** either the [PRAGMA mmap_size] command, or by using the 1932269851Speter** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1933282328Sbapt** will be silently truncated if necessary so that it does not exceed the 1934282328Sbapt** compile-time maximum mmap size set by the 1935269851Speter** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1936269851Speter** ^If either argument to this option is negative, then that argument is 1937251883Speter** changed to its compile-time default. 1938269851Speter** 1939269851Speter** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1940269851Speter** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1941282328Sbapt** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1942282328Sbapt** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1943282328Sbapt** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1944269851Speter** that specifies the maximum size of the created heap. 1945282328Sbapt** 1946282328Sbapt** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1947282328Sbapt** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1948282328Sbapt** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1949282328Sbapt** is a pointer to an integer and writes into that integer the number of extra 1950282328Sbapt** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1951282328Sbapt** The amount of extra space required can change depending on the compiler, 1952282328Sbapt** target platform, and SQLite version. 1953282328Sbapt** 1954282328Sbapt** [[SQLITE_CONFIG_PMASZ]] 1955282328Sbapt** <dt>SQLITE_CONFIG_PMASZ 1956282328Sbapt** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1957282328Sbapt** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1958282328Sbapt** sorter to that integer. The default minimum PMA Size is set by the 1959282328Sbapt** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1960282328Sbapt** to help with sort operations when multithreaded sorting 1961282328Sbapt** is enabled (using the [PRAGMA threads] command) and the amount of content 1962282328Sbapt** to be sorted exceeds the page size times the minimum of the 1963282328Sbapt** [PRAGMA cache_size] setting and this value. 1964298161Sbapt** 1965298161Sbapt** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1966298161Sbapt** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1967298161Sbapt** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1968298161Sbapt** becomes the [statement journal] spill-to-disk threshold. 1969298161Sbapt** [Statement journals] are held in memory until their size (in bytes) 1970298161Sbapt** exceeds this threshold, at which point they are written to disk. 1971298161Sbapt** Or if the threshold is -1, statement journals are always held 1972298161Sbapt** exclusively in memory. 1973298161Sbapt** Since many statement journals never become large, setting the spill 1974298161Sbapt** threshold to a value such as 64KiB can greatly reduce the amount of 1975298161Sbapt** I/O required to support statement rollback. 1976298161Sbapt** The default value for this setting is controlled by the 1977298161Sbapt** [SQLITE_STMTJRNL_SPILL] compile-time option. 1978342292Scy** 1979342292Scy** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1980342292Scy** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1981342292Scy** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1982342292Scy** of type (int) - the new value of the sorter-reference size threshold. 1983342292Scy** Usually, when SQLite uses an external sort to order records according 1984342292Scy** to an ORDER BY clause, all fields required by the caller are present in the 1985342292Scy** sorted records. However, if SQLite determines based on the declared type 1986342292Scy** of a table column that its values are likely to be very large - larger 1987342292Scy** than the configured sorter-reference size threshold - then a reference 1988342292Scy** is stored in each sorted record and the required column values loaded 1989342292Scy** from the database as records are returned in sorted order. The default 1990342292Scy** value for this option is to never use this optimization. Specifying a 1991342292Scy** negative value for this option restores the default behaviour. 1992342292Scy** This option is only available if SQLite is compiled with the 1993342292Scy** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1994346442Scy** 1995346442Scy** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 1996346442Scy** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 1997346442Scy** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 1998346442Scy** [sqlite3_int64] parameter which is the default maximum size for an in-memory 1999346442Scy** database created using [sqlite3_deserialize()]. This default maximum 2000346442Scy** size can be adjusted up or down for individual databases using the 2001346442Scy** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2002346442Scy** configuration setting is never used, then the default maximum is determined 2003346442Scy** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2004346442Scy** compile-time option is not set, then the default maximum is 1073741824. 2005251883Speter** </dl> 2006251883Speter*/ 2007251883Speter#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2008251883Speter#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2009251883Speter#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2010251883Speter#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2011251883Speter#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2012342292Scy#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2013251883Speter#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2014251883Speter#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2015251883Speter#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2016251883Speter#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2017251883Speter#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2018251883Speter/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2019251883Speter#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2020251883Speter#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2021251883Speter#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2022251883Speter#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2023251883Speter#define SQLITE_CONFIG_URI 17 /* int */ 2024251883Speter#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2025251883Speter#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2026251883Speter#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2027251883Speter#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2028251883Speter#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2029269851Speter#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2030282328Sbapt#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2031282328Sbapt#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2032298161Sbapt#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2033342292Scy#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2034342292Scy#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2035346442Scy#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2036251883Speter 2037251883Speter/* 2038251883Speter** CAPI3REF: Database Connection Configuration Options 2039251883Speter** 2040251883Speter** These constants are the available integer configuration options that 2041251883Speter** can be passed as the second argument to the [sqlite3_db_config()] interface. 2042251883Speter** 2043251883Speter** New configuration options may be added in future releases of SQLite. 2044251883Speter** Existing configuration options might be discontinued. Applications 2045251883Speter** should check the return code from [sqlite3_db_config()] to make sure that 2046251883Speter** the call worked. ^The [sqlite3_db_config()] interface will return a 2047251883Speter** non-zero [error code] if a discontinued or unsupported configuration option 2048251883Speter** is invoked. 2049251883Speter** 2050251883Speter** <dl> 2051342292Scy** [[SQLITE_DBCONFIG_LOOKASIDE]] 2052251883Speter** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2053251883Speter** <dd> ^This option takes three additional arguments that determine the 2054251883Speter** [lookaside memory allocator] configuration for the [database connection]. 2055251883Speter** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2056251883Speter** pointer to a memory buffer to use for lookaside memory. 2057251883Speter** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2058251883Speter** may be NULL in which case SQLite will allocate the 2059251883Speter** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2060251883Speter** size of each lookaside buffer slot. ^The third argument is the number of 2061251883Speter** slots. The size of the buffer in the first argument must be greater than 2062251883Speter** or equal to the product of the second and third arguments. The buffer 2063251883Speter** must be aligned to an 8-byte boundary. ^If the second argument to 2064251883Speter** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2065251883Speter** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2066251883Speter** configuration for a database connection can only be changed when that 2067251883Speter** connection is not currently using lookaside memory, or in other words 2068251883Speter** when the "current value" returned by 2069251883Speter** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2070251883Speter** Any attempt to change the lookaside memory configuration when lookaside 2071251883Speter** memory is in use leaves the configuration unchanged and returns 2072251883Speter** [SQLITE_BUSY].)^</dd> 2073251883Speter** 2074342292Scy** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2075251883Speter** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2076251883Speter** <dd> ^This option is used to enable or disable the enforcement of 2077251883Speter** [foreign key constraints]. There should be two additional arguments. 2078251883Speter** The first argument is an integer which is 0 to disable FK enforcement, 2079251883Speter** positive to enable FK enforcement or negative to leave FK enforcement 2080251883Speter** unchanged. The second parameter is a pointer to an integer into which 2081251883Speter** is written 0 or 1 to indicate whether FK enforcement is off or on 2082251883Speter** following this call. The second parameter may be a NULL pointer, in 2083251883Speter** which case the FK enforcement setting is not reported back. </dd> 2084251883Speter** 2085342292Scy** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2086251883Speter** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2087251883Speter** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2088251883Speter** There should be two additional arguments. 2089251883Speter** The first argument is an integer which is 0 to disable triggers, 2090251883Speter** positive to enable triggers or negative to leave the setting unchanged. 2091251883Speter** The second parameter is a pointer to an integer into which 2092251883Speter** is written 0 or 1 to indicate whether triggers are disabled or enabled 2093251883Speter** following this call. The second parameter may be a NULL pointer, in 2094251883Speter** which case the trigger setting is not reported back. </dd> 2095251883Speter** 2096355326Scy** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2097355326Scy** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2098355326Scy** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2099355326Scy** There should be two additional arguments. 2100355326Scy** The first argument is an integer which is 0 to disable views, 2101355326Scy** positive to enable views or negative to leave the setting unchanged. 2102355326Scy** The second parameter is a pointer to an integer into which 2103355326Scy** is written 0 or 1 to indicate whether views are disabled or enabled 2104355326Scy** following this call. The second parameter may be a NULL pointer, in 2105355326Scy** which case the view setting is not reported back. </dd> 2106355326Scy** 2107342292Scy** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2108298161Sbapt** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2109347347Scy** <dd> ^This option is used to enable or disable the 2110347347Scy** [fts3_tokenizer()] function which is part of the 2111298161Sbapt** [FTS3] full-text search engine extension. 2112298161Sbapt** There should be two additional arguments. 2113298161Sbapt** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2114298161Sbapt** positive to enable fts3_tokenizer() or negative to leave the setting 2115298161Sbapt** unchanged. 2116298161Sbapt** The second parameter is a pointer to an integer into which 2117298161Sbapt** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2118298161Sbapt** following this call. The second parameter may be a NULL pointer, in 2119298161Sbapt** which case the new setting is not reported back. </dd> 2120298161Sbapt** 2121342292Scy** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2122305002Scy** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2123305002Scy** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2124305002Scy** interface independently of the [load_extension()] SQL function. 2125305002Scy** The [sqlite3_enable_load_extension()] API enables or disables both the 2126305002Scy** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2127305002Scy** There should be two additional arguments. 2128305002Scy** When the first argument to this interface is 1, then only the C-API is 2129305002Scy** enabled and the SQL function remains disabled. If the first argument to 2130305002Scy** this interface is 0, then both the C-API and the SQL function are disabled. 2131305002Scy** If the first argument is -1, then no changes are made to state of either the 2132305002Scy** C-API or the SQL function. 2133305002Scy** The second parameter is a pointer to an integer into which 2134305002Scy** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2135305002Scy** is disabled or enabled following this call. The second parameter may 2136305002Scy** be a NULL pointer, in which case the new setting is not reported back. 2137305002Scy** </dd> 2138305002Scy** 2139342292Scy** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2140322444Speter** <dd> ^This option is used to change the name of the "main" database 2141322444Speter** schema. ^The sole argument is a pointer to a constant UTF8 string 2142322444Speter** which will become the new schema name in place of "main". ^SQLite 2143322444Speter** does not make a copy of the new main schema name string, so the application 2144322444Speter** must ensure that the argument passed into this DBCONFIG option is unchanged 2145322444Speter** until after the database connection closes. 2146322444Speter** </dd> 2147322444Speter** 2148342292Scy** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2149322444Speter** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2150322444Speter** <dd> Usually, when a database in wal mode is closed or detached from a 2151322444Speter** database handle, SQLite checks if this will mean that there are now no 2152322444Speter** connections at all to the database. If so, it performs a checkpoint 2153322444Speter** operation before closing the connection. This option may be used to 2154322444Speter** override this behaviour. The first parameter passed to this operation 2155342292Scy** is an integer - positive to disable checkpoints-on-close, or zero (the 2156342292Scy** default) to enable them, and negative to leave the setting unchanged. 2157342292Scy** The second parameter is a pointer to an integer 2158322444Speter** into which is written 0 or 1 to indicate whether checkpoints-on-close 2159322444Speter** have been disabled - 0 if they are not disabled, 1 if they are. 2160322444Speter** </dd> 2161322444Speter** 2162342292Scy** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2163322444Speter** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2164322444Speter** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2165322444Speter** a single SQL query statement will always use the same algorithm regardless 2166322444Speter** of values of [bound parameters].)^ The QPSG disables some query optimizations 2167322444Speter** that look at the values of bound parameters, which can make some queries 2168322444Speter** slower. But the QPSG has the advantage of more predictable behavior. With 2169322444Speter** the QPSG active, SQLite will always use the same query plan in the field as 2170322444Speter** was used during testing in the lab. 2171342292Scy** The first argument to this setting is an integer which is 0 to disable 2172342292Scy** the QPSG, positive to enable QPSG, or negative to leave the setting 2173342292Scy** unchanged. The second parameter is a pointer to an integer into which 2174342292Scy** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2175342292Scy** following this call. 2176322444Speter** </dd> 2177322444Speter** 2178342292Scy** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2179342292Scy** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2180342292Scy** include output for any operations performed by trigger programs. This 2181342292Scy** option is used to set or clear (the default) a flag that governs this 2182342292Scy** behavior. The first parameter passed to this operation is an integer - 2183342292Scy** positive to enable output for trigger programs, or zero to disable it, 2184342292Scy** or negative to leave the setting unchanged. 2185342292Scy** The second parameter is a pointer to an integer into which is written 2186342292Scy** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2187342292Scy** it is not disabled, 1 if it is. 2188342292Scy** </dd> 2189342292Scy** 2190342292Scy** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2191342292Scy** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2192342292Scy** [VACUUM] in order to reset a database back to an empty database 2193342292Scy** with no schema and no content. The following process works even for 2194342292Scy** a badly corrupted database file: 2195342292Scy** <ol> 2196342292Scy** <li> If the database connection is newly opened, make sure it has read the 2197342292Scy** database schema by preparing then discarding some query against the 2198342292Scy** database, or calling sqlite3_table_column_metadata(), ignoring any 2199342292Scy** errors. This step is only necessary if the application desires to keep 2200342292Scy** the database in WAL mode after the reset if it was in WAL mode before 2201342292Scy** the reset. 2202342292Scy** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2203342292Scy** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2204342292Scy** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2205342292Scy** </ol> 2206342292Scy** Because resetting a database is destructive and irreversible, the 2207342292Scy** process requires the use of this obscure API and multiple steps to help 2208342292Scy** ensure that it does not happen by accident. 2209342292Scy** 2210342292Scy** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2211342292Scy** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2212342292Scy** "defensive" flag for a database connection. When the defensive 2213342292Scy** flag is enabled, language features that allow ordinary SQL to 2214342292Scy** deliberately corrupt the database file are disabled. The disabled 2215342292Scy** features include but are not limited to the following: 2216342292Scy** <ul> 2217342292Scy** <li> The [PRAGMA writable_schema=ON] statement. 2218351633Scy** <li> The [PRAGMA journal_mode=OFF] statement. 2219342292Scy** <li> Writes to the [sqlite_dbpage] virtual table. 2220342292Scy** <li> Direct writes to [shadow tables]. 2221342292Scy** </ul> 2222342292Scy** </dd> 2223347347Scy** 2224347347Scy** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2225347347Scy** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2226347347Scy** "writable_schema" flag. This has the same effect and is logically equivalent 2227347347Scy** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2228347347Scy** The first argument to this setting is an integer which is 0 to disable 2229347347Scy** the writable_schema, positive to enable writable_schema, or negative to 2230347347Scy** leave the setting unchanged. The second parameter is a pointer to an 2231347347Scy** integer into which is written 0 or 1 to indicate whether the writable_schema 2232347347Scy** is enabled or disabled following this call. 2233347347Scy** </dd> 2234351633Scy** 2235351633Scy** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2236351633Scy** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2237351633Scy** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2238351633Scy** the legacy behavior of the [ALTER TABLE RENAME] command such it 2239351633Scy** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2240351633Scy** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2241351633Scy** additional information. This feature can also be turned on and off 2242351633Scy** using the [PRAGMA legacy_alter_table] statement. 2243351633Scy** </dd> 2244351633Scy** 2245351633Scy** [[SQLITE_DBCONFIG_DQS_DML]] 2246351633Scy** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2247351633Scy** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2248351633Scy** the legacy [double-quoted string literal] misfeature for DML statement 2249351633Scy** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2250351633Scy** default value of this setting is determined by the [-DSQLITE_DQS] 2251351633Scy** compile-time option. 2252351633Scy** </dd> 2253351633Scy** 2254351633Scy** [[SQLITE_DBCONFIG_DQS_DDL]] 2255351633Scy** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2256351633Scy** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2257351633Scy** the legacy [double-quoted string literal] misfeature for DDL statements, 2258351633Scy** such as CREATE TABLE and CREATE INDEX. The 2259351633Scy** default value of this setting is determined by the [-DSQLITE_DQS] 2260351633Scy** compile-time option. 2261351633Scy** </dd> 2262251883Speter** </dl> 2263251883Speter*/ 2264322444Speter#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2265298161Sbapt#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2266298161Sbapt#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2267298161Sbapt#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2268298161Sbapt#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2269305002Scy#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2270322444Speter#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2271322444Speter#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2272342292Scy#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2273342292Scy#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2274342292Scy#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2275347347Scy#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2276351633Scy#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2277351633Scy#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2278351633Scy#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2279355326Scy#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2280355326Scy#define SQLITE_DBCONFIG_MAX 1015 /* Largest DBCONFIG */ 2281251883Speter 2282251883Speter/* 2283251883Speter** CAPI3REF: Enable Or Disable Extended Result Codes 2284286510Speter** METHOD: sqlite3 2285251883Speter** 2286251883Speter** ^The sqlite3_extended_result_codes() routine enables or disables the 2287251883Speter** [extended result codes] feature of SQLite. ^The extended result 2288251883Speter** codes are disabled by default for historical compatibility. 2289251883Speter*/ 2290322444SpeterSQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2291251883Speter 2292251883Speter/* 2293251883Speter** CAPI3REF: Last Insert Rowid 2294286510Speter** METHOD: sqlite3 2295251883Speter** 2296269851Speter** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2297269851Speter** has a unique 64-bit signed 2298251883Speter** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2299251883Speter** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2300251883Speter** names are not also used by explicitly declared columns. ^If 2301251883Speter** the table has a column of type [INTEGER PRIMARY KEY] then that column 2302251883Speter** is another alias for the rowid. 2303251883Speter** 2304322444Speter** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2305322444Speter** the most recent successful [INSERT] into a rowid table or [virtual table] 2306322444Speter** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2307322444Speter** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2308322444Speter** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2309322444Speter** zero. 2310251883Speter** 2311322444Speter** As well as being set automatically as rows are inserted into database 2312322444Speter** tables, the value returned by this function may be set explicitly by 2313322444Speter** [sqlite3_set_last_insert_rowid()] 2314251883Speter** 2315322444Speter** Some virtual table implementations may INSERT rows into rowid tables as 2316322444Speter** part of committing a transaction (e.g. to flush data accumulated in memory 2317322444Speter** to disk). In this case subsequent calls to this function return the rowid 2318322444Speter** associated with these internal INSERT operations, which leads to 2319322444Speter** unintuitive results. Virtual table implementations that do write to rowid 2320322444Speter** tables in this way can avoid this problem by restoring the original 2321322444Speter** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2322322444Speter** control to the user. 2323322444Speter** 2324322444Speter** ^(If an [INSERT] occurs within a trigger then this routine will 2325322444Speter** return the [rowid] of the inserted row as long as the trigger is 2326322444Speter** running. Once the trigger program ends, the value returned 2327322444Speter** by this routine reverts to what it was before the trigger was fired.)^ 2328322444Speter** 2329251883Speter** ^An [INSERT] that fails due to a constraint violation is not a 2330251883Speter** successful [INSERT] and does not change the value returned by this 2331251883Speter** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2332251883Speter** and INSERT OR ABORT make no changes to the return value of this 2333251883Speter** routine when their insertion fails. ^(When INSERT OR REPLACE 2334251883Speter** encounters a constraint violation, it does not fail. The 2335251883Speter** INSERT continues to completion after deleting rows that caused 2336251883Speter** the constraint problem so INSERT OR REPLACE will always change 2337251883Speter** the return value of this interface.)^ 2338251883Speter** 2339251883Speter** ^For the purposes of this routine, an [INSERT] is considered to 2340251883Speter** be successful even if it is subsequently rolled back. 2341251883Speter** 2342251883Speter** This function is accessible to SQL statements via the 2343251883Speter** [last_insert_rowid() SQL function]. 2344251883Speter** 2345251883Speter** If a separate thread performs a new [INSERT] on the same 2346251883Speter** database connection while the [sqlite3_last_insert_rowid()] 2347251883Speter** function is running and thus changes the last insert [rowid], 2348251883Speter** then the value returned by [sqlite3_last_insert_rowid()] is 2349251883Speter** unpredictable and might not equal either the old or the new 2350251883Speter** last insert [rowid]. 2351251883Speter*/ 2352322444SpeterSQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2353251883Speter 2354251883Speter/* 2355322444Speter** CAPI3REF: Set the Last Insert Rowid value. 2356322444Speter** METHOD: sqlite3 2357322444Speter** 2358322444Speter** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2359322444Speter** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2360322444Speter** without inserting a row into the database. 2361322444Speter*/ 2362322444SpeterSQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2363322444Speter 2364322444Speter/* 2365251883Speter** CAPI3REF: Count The Number Of Rows Modified 2366286510Speter** METHOD: sqlite3 2367251883Speter** 2368282328Sbapt** ^This function returns the number of rows modified, inserted or 2369282328Sbapt** deleted by the most recently completed INSERT, UPDATE or DELETE 2370282328Sbapt** statement on the database connection specified by the only parameter. 2371282328Sbapt** ^Executing any other type of SQL statement does not modify the value 2372282328Sbapt** returned by this function. 2373251883Speter** 2374282328Sbapt** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2375282328Sbapt** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2376282328Sbapt** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2377282328Sbapt** 2378282328Sbapt** Changes to a view that are intercepted by 2379282328Sbapt** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2380282328Sbapt** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2381282328Sbapt** DELETE statement run on a view is always zero. Only changes made to real 2382282328Sbapt** tables are counted. 2383251883Speter** 2384282328Sbapt** Things are more complicated if the sqlite3_changes() function is 2385282328Sbapt** executed while a trigger program is running. This may happen if the 2386282328Sbapt** program uses the [changes() SQL function], or if some other callback 2387282328Sbapt** function invokes sqlite3_changes() directly. Essentially: 2388282328Sbapt** 2389282328Sbapt** <ul> 2390282328Sbapt** <li> ^(Before entering a trigger program the value returned by 2391282328Sbapt** sqlite3_changes() function is saved. After the trigger program 2392282328Sbapt** has finished, the original value is restored.)^ 2393282328Sbapt** 2394282328Sbapt** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2395282328Sbapt** statement sets the value returned by sqlite3_changes() 2396282328Sbapt** upon completion as normal. Of course, this value will not include 2397282328Sbapt** any changes performed by sub-triggers, as the sqlite3_changes() 2398282328Sbapt** value will be saved and restored after each sub-trigger has run.)^ 2399282328Sbapt** </ul> 2400282328Sbapt** 2401282328Sbapt** ^This means that if the changes() SQL function (or similar) is used 2402282328Sbapt** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2403282328Sbapt** returns the value as set when the calling statement began executing. 2404282328Sbapt** ^If it is used by the second or subsequent such statement within a trigger 2405282328Sbapt** program, the value returned reflects the number of rows modified by the 2406282328Sbapt** previous INSERT, UPDATE or DELETE statement within the same trigger. 2407251883Speter** 2408251883Speter** If a separate thread makes changes on the same database connection 2409251883Speter** while [sqlite3_changes()] is running then the value returned 2410251883Speter** is unpredictable and not meaningful. 2411342292Scy** 2412342292Scy** See also: 2413342292Scy** <ul> 2414342292Scy** <li> the [sqlite3_total_changes()] interface 2415342292Scy** <li> the [count_changes pragma] 2416342292Scy** <li> the [changes() SQL function] 2417342292Scy** <li> the [data_version pragma] 2418342292Scy** </ul> 2419251883Speter*/ 2420322444SpeterSQLITE_API int sqlite3_changes(sqlite3*); 2421251883Speter 2422251883Speter/* 2423251883Speter** CAPI3REF: Total Number Of Rows Modified 2424286510Speter** METHOD: sqlite3 2425251883Speter** 2426282328Sbapt** ^This function returns the total number of rows inserted, modified or 2427282328Sbapt** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2428282328Sbapt** since the database connection was opened, including those executed as 2429282328Sbapt** part of trigger programs. ^Executing any other type of SQL statement 2430282328Sbapt** does not affect the value returned by sqlite3_total_changes(). 2431282328Sbapt** 2432282328Sbapt** ^Changes made as part of [foreign key actions] are included in the 2433282328Sbapt** count, but those made as part of REPLACE constraint resolution are 2434282328Sbapt** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2435282328Sbapt** are not counted. 2436342292Scy** 2437346983Scy** The [sqlite3_total_changes(D)] interface only reports the number 2438342292Scy** of rows that changed due to SQL statement run against database 2439342292Scy** connection D. Any changes by other database connections are ignored. 2440342292Scy** To detect changes against a database file from other database 2441342292Scy** connections use the [PRAGMA data_version] command or the 2442342292Scy** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2443282328Sbapt** 2444251883Speter** If a separate thread makes changes on the same database connection 2445251883Speter** while [sqlite3_total_changes()] is running then the value 2446251883Speter** returned is unpredictable and not meaningful. 2447342292Scy** 2448342292Scy** See also: 2449342292Scy** <ul> 2450342292Scy** <li> the [sqlite3_changes()] interface 2451342292Scy** <li> the [count_changes pragma] 2452342292Scy** <li> the [changes() SQL function] 2453342292Scy** <li> the [data_version pragma] 2454342292Scy** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2455342292Scy** </ul> 2456251883Speter*/ 2457322444SpeterSQLITE_API int sqlite3_total_changes(sqlite3*); 2458251883Speter 2459251883Speter/* 2460251883Speter** CAPI3REF: Interrupt A Long-Running Query 2461286510Speter** METHOD: sqlite3 2462251883Speter** 2463251883Speter** ^This function causes any pending database operation to abort and 2464251883Speter** return at its earliest opportunity. This routine is typically 2465251883Speter** called in response to a user action such as pressing "Cancel" 2466251883Speter** or Ctrl-C where the user wants a long query operation to halt 2467251883Speter** immediately. 2468251883Speter** 2469251883Speter** ^It is safe to call this routine from a thread different from the 2470251883Speter** thread that is currently running the database operation. But it 2471251883Speter** is not safe to call this routine with a [database connection] that 2472251883Speter** is closed or might close before sqlite3_interrupt() returns. 2473251883Speter** 2474251883Speter** ^If an SQL operation is very nearly finished at the time when 2475251883Speter** sqlite3_interrupt() is called, then it might not have an opportunity 2476251883Speter** to be interrupted and might continue to completion. 2477251883Speter** 2478251883Speter** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2479251883Speter** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2480251883Speter** that is inside an explicit transaction, then the entire transaction 2481251883Speter** will be rolled back automatically. 2482251883Speter** 2483251883Speter** ^The sqlite3_interrupt(D) call is in effect until all currently running 2484251883Speter** SQL statements on [database connection] D complete. ^Any new SQL statements 2485251883Speter** that are started after the sqlite3_interrupt() call and before the 2486251883Speter** running statements reaches zero are interrupted as if they had been 2487251883Speter** running prior to the sqlite3_interrupt() call. ^New SQL statements 2488251883Speter** that are started after the running statement count reaches zero are 2489251883Speter** not effected by the sqlite3_interrupt(). 2490251883Speter** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2491251883Speter** SQL statements is a no-op and has no effect on SQL statements 2492251883Speter** that are started after the sqlite3_interrupt() call returns. 2493251883Speter*/ 2494322444SpeterSQLITE_API void sqlite3_interrupt(sqlite3*); 2495251883Speter 2496251883Speter/* 2497251883Speter** CAPI3REF: Determine If An SQL Statement Is Complete 2498251883Speter** 2499251883Speter** These routines are useful during command-line input to determine if the 2500251883Speter** currently entered text seems to form a complete SQL statement or 2501251883Speter** if additional input is needed before sending the text into 2502251883Speter** SQLite for parsing. ^These routines return 1 if the input string 2503251883Speter** appears to be a complete SQL statement. ^A statement is judged to be 2504251883Speter** complete if it ends with a semicolon token and is not a prefix of a 2505251883Speter** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2506251883Speter** string literals or quoted identifier names or comments are not 2507251883Speter** independent tokens (they are part of the token in which they are 2508251883Speter** embedded) and thus do not count as a statement terminator. ^Whitespace 2509251883Speter** and comments that follow the final semicolon are ignored. 2510251883Speter** 2511251883Speter** ^These routines return 0 if the statement is incomplete. ^If a 2512251883Speter** memory allocation fails, then SQLITE_NOMEM is returned. 2513251883Speter** 2514251883Speter** ^These routines do not parse the SQL statements thus 2515251883Speter** will not detect syntactically incorrect SQL. 2516251883Speter** 2517251883Speter** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2518251883Speter** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2519251883Speter** automatically by sqlite3_complete16(). If that initialization fails, 2520251883Speter** then the return value from sqlite3_complete16() will be non-zero 2521251883Speter** regardless of whether or not the input SQL is complete.)^ 2522251883Speter** 2523251883Speter** The input to [sqlite3_complete()] must be a zero-terminated 2524251883Speter** UTF-8 string. 2525251883Speter** 2526251883Speter** The input to [sqlite3_complete16()] must be a zero-terminated 2527251883Speter** UTF-16 string in native byte order. 2528251883Speter*/ 2529322444SpeterSQLITE_API int sqlite3_complete(const char *sql); 2530322444SpeterSQLITE_API int sqlite3_complete16(const void *sql); 2531251883Speter 2532251883Speter/* 2533251883Speter** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2534282328Sbapt** KEYWORDS: {busy-handler callback} {busy handler} 2535286510Speter** METHOD: sqlite3 2536251883Speter** 2537274884Sbapt** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2538274884Sbapt** that might be invoked with argument P whenever 2539274884Sbapt** an attempt is made to access a database table associated with 2540274884Sbapt** [database connection] D when another thread 2541274884Sbapt** or process has the table locked. 2542274884Sbapt** The sqlite3_busy_handler() interface is used to implement 2543274884Sbapt** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2544251883Speter** 2545274884Sbapt** ^If the busy callback is NULL, then [SQLITE_BUSY] 2546251883Speter** is returned immediately upon encountering the lock. ^If the busy callback 2547251883Speter** is not NULL, then the callback might be invoked with two arguments. 2548251883Speter** 2549251883Speter** ^The first argument to the busy handler is a copy of the void* pointer which 2550251883Speter** is the third argument to sqlite3_busy_handler(). ^The second argument to 2551251883Speter** the busy handler callback is the number of times that the busy handler has 2552282328Sbapt** been invoked previously for the same locking event. ^If the 2553251883Speter** busy callback returns 0, then no additional attempts are made to 2554274884Sbapt** access the database and [SQLITE_BUSY] is returned 2555274884Sbapt** to the application. 2556251883Speter** ^If the callback returns non-zero, then another attempt 2557274884Sbapt** is made to access the database and the cycle repeats. 2558251883Speter** 2559251883Speter** The presence of a busy handler does not guarantee that it will be invoked 2560251883Speter** when there is lock contention. ^If SQLite determines that invoking the busy 2561251883Speter** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2562274884Sbapt** to the application instead of invoking the 2563274884Sbapt** busy handler. 2564251883Speter** Consider a scenario where one process is holding a read lock that 2565251883Speter** it is trying to promote to a reserved lock and 2566251883Speter** a second process is holding a reserved lock that it is trying 2567251883Speter** to promote to an exclusive lock. The first process cannot proceed 2568251883Speter** because it is blocked by the second and the second process cannot 2569251883Speter** proceed because it is blocked by the first. If both processes 2570251883Speter** invoke the busy handlers, neither will make any progress. Therefore, 2571251883Speter** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2572251883Speter** will induce the first process to release its read lock and allow 2573251883Speter** the second process to proceed. 2574251883Speter** 2575251883Speter** ^The default busy callback is NULL. 2576251883Speter** 2577251883Speter** ^(There can only be a single busy handler defined for each 2578251883Speter** [database connection]. Setting a new busy handler clears any 2579251883Speter** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2580274884Sbapt** or evaluating [PRAGMA busy_timeout=N] will change the 2581274884Sbapt** busy handler and thus clear any previously set busy handler. 2582251883Speter** 2583251883Speter** The busy callback should not take any actions which modify the 2584274884Sbapt** database connection that invoked the busy handler. In other words, 2585274884Sbapt** the busy handler is not reentrant. Any such actions 2586251883Speter** result in undefined behavior. 2587251883Speter** 2588251883Speter** A busy handler must not close the database connection 2589251883Speter** or [prepared statement] that invoked the busy handler. 2590251883Speter*/ 2591322444SpeterSQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2592251883Speter 2593251883Speter/* 2594251883Speter** CAPI3REF: Set A Busy Timeout 2595286510Speter** METHOD: sqlite3 2596251883Speter** 2597251883Speter** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2598251883Speter** for a specified amount of time when a table is locked. ^The handler 2599251883Speter** will sleep multiple times until at least "ms" milliseconds of sleeping 2600251883Speter** have accumulated. ^After at least "ms" milliseconds of sleeping, 2601251883Speter** the handler returns 0 which causes [sqlite3_step()] to return 2602274884Sbapt** [SQLITE_BUSY]. 2603251883Speter** 2604251883Speter** ^Calling this routine with an argument less than or equal to zero 2605251883Speter** turns off all busy handlers. 2606251883Speter** 2607251883Speter** ^(There can only be a single busy handler for a particular 2608274884Sbapt** [database connection] at any given moment. If another busy handler 2609251883Speter** was defined (using [sqlite3_busy_handler()]) prior to calling 2610251883Speter** this routine, that other busy handler is cleared.)^ 2611274884Sbapt** 2612274884Sbapt** See also: [PRAGMA busy_timeout] 2613251883Speter*/ 2614322444SpeterSQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2615251883Speter 2616251883Speter/* 2617251883Speter** CAPI3REF: Convenience Routines For Running Queries 2618286510Speter** METHOD: sqlite3 2619251883Speter** 2620251883Speter** This is a legacy interface that is preserved for backwards compatibility. 2621251883Speter** Use of this interface is not recommended. 2622251883Speter** 2623251883Speter** Definition: A <b>result table</b> is memory data structure created by the 2624251883Speter** [sqlite3_get_table()] interface. A result table records the 2625251883Speter** complete query results from one or more queries. 2626251883Speter** 2627251883Speter** The table conceptually has a number of rows and columns. But 2628251883Speter** these numbers are not part of the result table itself. These 2629251883Speter** numbers are obtained separately. Let N be the number of rows 2630251883Speter** and M be the number of columns. 2631251883Speter** 2632251883Speter** A result table is an array of pointers to zero-terminated UTF-8 strings. 2633251883Speter** There are (N+1)*M elements in the array. The first M pointers point 2634251883Speter** to zero-terminated strings that contain the names of the columns. 2635251883Speter** The remaining entries all point to query results. NULL values result 2636251883Speter** in NULL pointers. All other values are in their UTF-8 zero-terminated 2637251883Speter** string representation as returned by [sqlite3_column_text()]. 2638251883Speter** 2639251883Speter** A result table might consist of one or more memory allocations. 2640251883Speter** It is not safe to pass a result table directly to [sqlite3_free()]. 2641251883Speter** A result table should be deallocated using [sqlite3_free_table()]. 2642251883Speter** 2643251883Speter** ^(As an example of the result table format, suppose a query result 2644251883Speter** is as follows: 2645251883Speter** 2646251883Speter** <blockquote><pre> 2647251883Speter** Name | Age 2648251883Speter** ----------------------- 2649251883Speter** Alice | 43 2650251883Speter** Bob | 28 2651251883Speter** Cindy | 21 2652251883Speter** </pre></blockquote> 2653251883Speter** 2654251883Speter** There are two column (M==2) and three rows (N==3). Thus the 2655251883Speter** result table has 8 entries. Suppose the result table is stored 2656251883Speter** in an array names azResult. Then azResult holds this content: 2657251883Speter** 2658251883Speter** <blockquote><pre> 2659251883Speter** azResult[0] = "Name"; 2660251883Speter** azResult[1] = "Age"; 2661251883Speter** azResult[2] = "Alice"; 2662251883Speter** azResult[3] = "43"; 2663251883Speter** azResult[4] = "Bob"; 2664251883Speter** azResult[5] = "28"; 2665251883Speter** azResult[6] = "Cindy"; 2666251883Speter** azResult[7] = "21"; 2667251883Speter** </pre></blockquote>)^ 2668251883Speter** 2669251883Speter** ^The sqlite3_get_table() function evaluates one or more 2670251883Speter** semicolon-separated SQL statements in the zero-terminated UTF-8 2671251883Speter** string of its 2nd parameter and returns a result table to the 2672251883Speter** pointer given in its 3rd parameter. 2673251883Speter** 2674251883Speter** After the application has finished with the result from sqlite3_get_table(), 2675251883Speter** it must pass the result table pointer to sqlite3_free_table() in order to 2676251883Speter** release the memory that was malloced. Because of the way the 2677251883Speter** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2678251883Speter** function must not try to call [sqlite3_free()] directly. Only 2679251883Speter** [sqlite3_free_table()] is able to release the memory properly and safely. 2680251883Speter** 2681251883Speter** The sqlite3_get_table() interface is implemented as a wrapper around 2682251883Speter** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2683251883Speter** to any internal data structures of SQLite. It uses only the public 2684251883Speter** interface defined here. As a consequence, errors that occur in the 2685251883Speter** wrapper layer outside of the internal [sqlite3_exec()] call are not 2686251883Speter** reflected in subsequent calls to [sqlite3_errcode()] or 2687251883Speter** [sqlite3_errmsg()]. 2688251883Speter*/ 2689322444SpeterSQLITE_API int sqlite3_get_table( 2690251883Speter sqlite3 *db, /* An open database */ 2691251883Speter const char *zSql, /* SQL to be evaluated */ 2692251883Speter char ***pazResult, /* Results of the query */ 2693251883Speter int *pnRow, /* Number of result rows written here */ 2694251883Speter int *pnColumn, /* Number of result columns written here */ 2695251883Speter char **pzErrmsg /* Error msg written here */ 2696251883Speter); 2697322444SpeterSQLITE_API void sqlite3_free_table(char **result); 2698251883Speter 2699251883Speter/* 2700251883Speter** CAPI3REF: Formatted String Printing Functions 2701251883Speter** 2702251883Speter** These routines are work-alikes of the "printf()" family of functions 2703251883Speter** from the standard C library. 2704342292Scy** These routines understand most of the common formatting options from 2705342292Scy** the standard library printf() 2706342292Scy** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2707342292Scy** See the [built-in printf()] documentation for details. 2708251883Speter** 2709251883Speter** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2710342292Scy** results into memory obtained from [sqlite3_malloc64()]. 2711251883Speter** The strings returned by these two routines should be 2712251883Speter** released by [sqlite3_free()]. ^Both routines return a 2713342292Scy** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2714251883Speter** memory to hold the resulting string. 2715251883Speter** 2716251883Speter** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2717251883Speter** the standard C library. The result is written into the 2718251883Speter** buffer supplied as the second parameter whose size is given by 2719251883Speter** the first parameter. Note that the order of the 2720251883Speter** first two parameters is reversed from snprintf().)^ This is an 2721251883Speter** historical accident that cannot be fixed without breaking 2722251883Speter** backwards compatibility. ^(Note also that sqlite3_snprintf() 2723251883Speter** returns a pointer to its buffer instead of the number of 2724251883Speter** characters actually written into the buffer.)^ We admit that 2725251883Speter** the number of characters written would be a more useful return 2726251883Speter** value but we cannot change the implementation of sqlite3_snprintf() 2727251883Speter** now without breaking compatibility. 2728251883Speter** 2729251883Speter** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2730251883Speter** guarantees that the buffer is always zero-terminated. ^The first 2731251883Speter** parameter "n" is the total size of the buffer, including space for 2732251883Speter** the zero terminator. So the longest string that can be completely 2733251883Speter** written will be n-1 characters. 2734251883Speter** 2735251883Speter** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2736251883Speter** 2737342292Scy** See also: [built-in printf()], [printf() SQL function] 2738251883Speter*/ 2739322444SpeterSQLITE_API char *sqlite3_mprintf(const char*,...); 2740322444SpeterSQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2741322444SpeterSQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2742322444SpeterSQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2743251883Speter 2744251883Speter/* 2745251883Speter** CAPI3REF: Memory Allocation Subsystem 2746251883Speter** 2747251883Speter** The SQLite core uses these three routines for all of its own 2748251883Speter** internal memory allocation needs. "Core" in the previous sentence 2749251883Speter** does not include operating-system specific VFS implementation. The 2750251883Speter** Windows VFS uses native malloc() and free() for some operations. 2751251883Speter** 2752251883Speter** ^The sqlite3_malloc() routine returns a pointer to a block 2753251883Speter** of memory at least N bytes in length, where N is the parameter. 2754251883Speter** ^If sqlite3_malloc() is unable to obtain sufficient free 2755251883Speter** memory, it returns a NULL pointer. ^If the parameter N to 2756251883Speter** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2757251883Speter** a NULL pointer. 2758251883Speter** 2759274884Sbapt** ^The sqlite3_malloc64(N) routine works just like 2760274884Sbapt** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2761274884Sbapt** of a signed 32-bit integer. 2762274884Sbapt** 2763251883Speter** ^Calling sqlite3_free() with a pointer previously returned 2764251883Speter** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2765251883Speter** that it might be reused. ^The sqlite3_free() routine is 2766251883Speter** a no-op if is called with a NULL pointer. Passing a NULL pointer 2767251883Speter** to sqlite3_free() is harmless. After being freed, memory 2768251883Speter** should neither be read nor written. Even reading previously freed 2769251883Speter** memory might result in a segmentation fault or other severe error. 2770251883Speter** Memory corruption, a segmentation fault, or other severe error 2771251883Speter** might result if sqlite3_free() is called with a non-NULL pointer that 2772251883Speter** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2773251883Speter** 2774274884Sbapt** ^The sqlite3_realloc(X,N) interface attempts to resize a 2775274884Sbapt** prior memory allocation X to be at least N bytes. 2776274884Sbapt** ^If the X parameter to sqlite3_realloc(X,N) 2777251883Speter** is a NULL pointer then its behavior is identical to calling 2778274884Sbapt** sqlite3_malloc(N). 2779274884Sbapt** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2780251883Speter** negative then the behavior is exactly the same as calling 2781274884Sbapt** sqlite3_free(X). 2782274884Sbapt** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2783274884Sbapt** of at least N bytes in size or NULL if insufficient memory is available. 2784251883Speter** ^If M is the size of the prior allocation, then min(N,M) bytes 2785251883Speter** of the prior allocation are copied into the beginning of buffer returned 2786274884Sbapt** by sqlite3_realloc(X,N) and the prior allocation is freed. 2787274884Sbapt** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2788274884Sbapt** prior allocation is not freed. 2789251883Speter** 2790274884Sbapt** ^The sqlite3_realloc64(X,N) interfaces works the same as 2791274884Sbapt** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2792274884Sbapt** of a 32-bit signed integer. 2793274884Sbapt** 2794274884Sbapt** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2795274884Sbapt** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2796274884Sbapt** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2797274884Sbapt** ^The value returned by sqlite3_msize(X) might be larger than the number 2798274884Sbapt** of bytes requested when X was allocated. ^If X is a NULL pointer then 2799274884Sbapt** sqlite3_msize(X) returns zero. If X points to something that is not 2800274884Sbapt** the beginning of memory allocation, or if it points to a formerly 2801274884Sbapt** valid memory allocation that has now been freed, then the behavior 2802274884Sbapt** of sqlite3_msize(X) is undefined and possibly harmful. 2803274884Sbapt** 2804274884Sbapt** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2805274884Sbapt** sqlite3_malloc64(), and sqlite3_realloc64() 2806251883Speter** is always aligned to at least an 8 byte boundary, or to a 2807251883Speter** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2808251883Speter** option is used. 2809251883Speter** 2810251883Speter** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2811251883Speter** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2812251883Speter** implementation of these routines to be omitted. That capability 2813251883Speter** is no longer provided. Only built-in memory allocators can be used. 2814251883Speter** 2815251883Speter** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2816251883Speter** the system malloc() and free() directly when converting 2817251883Speter** filenames between the UTF-8 encoding used by SQLite 2818251883Speter** and whatever filename encoding is used by the particular Windows 2819251883Speter** installation. Memory allocation errors were detected, but 2820251883Speter** they were reported back as [SQLITE_CANTOPEN] or 2821251883Speter** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2822251883Speter** 2823251883Speter** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2824251883Speter** must be either NULL or else pointers obtained from a prior 2825251883Speter** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2826251883Speter** not yet been released. 2827251883Speter** 2828251883Speter** The application must not read or write any part of 2829251883Speter** a block of memory after it has been released using 2830251883Speter** [sqlite3_free()] or [sqlite3_realloc()]. 2831251883Speter*/ 2832322444SpeterSQLITE_API void *sqlite3_malloc(int); 2833322444SpeterSQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2834322444SpeterSQLITE_API void *sqlite3_realloc(void*, int); 2835322444SpeterSQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2836322444SpeterSQLITE_API void sqlite3_free(void*); 2837322444SpeterSQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2838251883Speter 2839251883Speter/* 2840251883Speter** CAPI3REF: Memory Allocator Statistics 2841251883Speter** 2842251883Speter** SQLite provides these two interfaces for reporting on the status 2843251883Speter** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2844251883Speter** routines, which form the built-in memory allocation subsystem. 2845251883Speter** 2846251883Speter** ^The [sqlite3_memory_used()] routine returns the number of bytes 2847251883Speter** of memory currently outstanding (malloced but not freed). 2848251883Speter** ^The [sqlite3_memory_highwater()] routine returns the maximum 2849251883Speter** value of [sqlite3_memory_used()] since the high-water mark 2850251883Speter** was last reset. ^The values returned by [sqlite3_memory_used()] and 2851251883Speter** [sqlite3_memory_highwater()] include any overhead 2852251883Speter** added by SQLite in its implementation of [sqlite3_malloc()], 2853251883Speter** but not overhead added by the any underlying system library 2854251883Speter** routines that [sqlite3_malloc()] may call. 2855251883Speter** 2856251883Speter** ^The memory high-water mark is reset to the current value of 2857251883Speter** [sqlite3_memory_used()] if and only if the parameter to 2858251883Speter** [sqlite3_memory_highwater()] is true. ^The value returned 2859251883Speter** by [sqlite3_memory_highwater(1)] is the high-water mark 2860251883Speter** prior to the reset. 2861251883Speter*/ 2862322444SpeterSQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2863322444SpeterSQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2864251883Speter 2865251883Speter/* 2866251883Speter** CAPI3REF: Pseudo-Random Number Generator 2867251883Speter** 2868251883Speter** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2869251883Speter** select random [ROWID | ROWIDs] when inserting new records into a table that 2870251883Speter** already uses the largest possible [ROWID]. The PRNG is also used for 2871251883Speter** the build-in random() and randomblob() SQL functions. This interface allows 2872251883Speter** applications to access the same PRNG for other purposes. 2873251883Speter** 2874251883Speter** ^A call to this routine stores N bytes of randomness into buffer P. 2875282328Sbapt** ^The P parameter can be a NULL pointer. 2876251883Speter** 2877269851Speter** ^If this routine has not been previously called or if the previous 2878282328Sbapt** call had N less than one or a NULL pointer for P, then the PRNG is 2879282328Sbapt** seeded using randomness obtained from the xRandomness method of 2880282328Sbapt** the default [sqlite3_vfs] object. 2881282328Sbapt** ^If the previous call to this routine had an N of 1 or more and a 2882282328Sbapt** non-NULL P then the pseudo-randomness is generated 2883251883Speter** internally and without recourse to the [sqlite3_vfs] xRandomness 2884251883Speter** method. 2885251883Speter*/ 2886322444SpeterSQLITE_API void sqlite3_randomness(int N, void *P); 2887251883Speter 2888251883Speter/* 2889251883Speter** CAPI3REF: Compile-Time Authorization Callbacks 2890286510Speter** METHOD: sqlite3 2891322444Speter** KEYWORDS: {authorizer callback} 2892251883Speter** 2893251883Speter** ^This routine registers an authorizer callback with a particular 2894251883Speter** [database connection], supplied in the first argument. 2895251883Speter** ^The authorizer callback is invoked as SQL statements are being compiled 2896251883Speter** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2897322444Speter** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2898322444Speter** and [sqlite3_prepare16_v3()]. ^At various 2899251883Speter** points during the compilation process, as logic is being created 2900251883Speter** to perform various actions, the authorizer callback is invoked to 2901251883Speter** see if those actions are allowed. ^The authorizer callback should 2902251883Speter** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2903251883Speter** specific action but allow the SQL statement to continue to be 2904251883Speter** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2905251883Speter** rejected with an error. ^If the authorizer callback returns 2906251883Speter** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2907251883Speter** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2908251883Speter** the authorizer will fail with an error message. 2909251883Speter** 2910251883Speter** When the callback returns [SQLITE_OK], that means the operation 2911251883Speter** requested is ok. ^When the callback returns [SQLITE_DENY], the 2912251883Speter** [sqlite3_prepare_v2()] or equivalent call that triggered the 2913251883Speter** authorizer will fail with an error message explaining that 2914251883Speter** access is denied. 2915251883Speter** 2916251883Speter** ^The first parameter to the authorizer callback is a copy of the third 2917251883Speter** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2918251883Speter** to the callback is an integer [SQLITE_COPY | action code] that specifies 2919251883Speter** the particular action to be authorized. ^The third through sixth parameters 2920322444Speter** to the callback are either NULL pointers or zero-terminated strings 2921322444Speter** that contain additional details about the action to be authorized. 2922322444Speter** Applications must always be prepared to encounter a NULL pointer in any 2923322444Speter** of the third through the sixth parameters of the authorization callback. 2924251883Speter** 2925251883Speter** ^If the action code is [SQLITE_READ] 2926251883Speter** and the callback returns [SQLITE_IGNORE] then the 2927251883Speter** [prepared statement] statement is constructed to substitute 2928251883Speter** a NULL value in place of the table column that would have 2929251883Speter** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2930251883Speter** return can be used to deny an untrusted user access to individual 2931251883Speter** columns of a table. 2932322444Speter** ^When a table is referenced by a [SELECT] but no column values are 2933322444Speter** extracted from that table (for example in a query like 2934322444Speter** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2935322444Speter** is invoked once for that table with a column name that is an empty string. 2936251883Speter** ^If the action code is [SQLITE_DELETE] and the callback returns 2937251883Speter** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2938251883Speter** [truncate optimization] is disabled and all rows are deleted individually. 2939251883Speter** 2940251883Speter** An authorizer is used when [sqlite3_prepare | preparing] 2941251883Speter** SQL statements from an untrusted source, to ensure that the SQL statements 2942251883Speter** do not try to access data they are not allowed to see, or that they do not 2943251883Speter** try to execute malicious statements that damage the database. For 2944251883Speter** example, an application may allow a user to enter arbitrary 2945251883Speter** SQL queries for evaluation by a database. But the application does 2946251883Speter** not want the user to be able to make arbitrary changes to the 2947251883Speter** database. An authorizer could then be put in place while the 2948251883Speter** user-entered SQL is being [sqlite3_prepare | prepared] that 2949251883Speter** disallows everything except [SELECT] statements. 2950251883Speter** 2951251883Speter** Applications that need to process SQL from untrusted sources 2952251883Speter** might also consider lowering resource limits using [sqlite3_limit()] 2953251883Speter** and limiting database size using the [max_page_count] [PRAGMA] 2954251883Speter** in addition to using an authorizer. 2955251883Speter** 2956251883Speter** ^(Only a single authorizer can be in place on a database connection 2957251883Speter** at a time. Each call to sqlite3_set_authorizer overrides the 2958251883Speter** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2959251883Speter** The authorizer is disabled by default. 2960251883Speter** 2961251883Speter** The authorizer callback must not do anything that will modify 2962251883Speter** the database connection that invoked the authorizer callback. 2963251883Speter** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2964251883Speter** database connections for the meaning of "modify" in this paragraph. 2965251883Speter** 2966251883Speter** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2967251883Speter** statement might be re-prepared during [sqlite3_step()] due to a 2968251883Speter** schema change. Hence, the application should ensure that the 2969251883Speter** correct authorizer callback remains in place during the [sqlite3_step()]. 2970251883Speter** 2971251883Speter** ^Note that the authorizer callback is invoked only during 2972251883Speter** [sqlite3_prepare()] or its variants. Authorization is not 2973251883Speter** performed during statement evaluation in [sqlite3_step()], unless 2974251883Speter** as stated in the previous paragraph, sqlite3_step() invokes 2975251883Speter** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2976251883Speter*/ 2977322444SpeterSQLITE_API int sqlite3_set_authorizer( 2978251883Speter sqlite3*, 2979251883Speter int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2980251883Speter void *pUserData 2981251883Speter); 2982251883Speter 2983251883Speter/* 2984251883Speter** CAPI3REF: Authorizer Return Codes 2985251883Speter** 2986251883Speter** The [sqlite3_set_authorizer | authorizer callback function] must 2987251883Speter** return either [SQLITE_OK] or one of these two constants in order 2988251883Speter** to signal SQLite whether or not the action is permitted. See the 2989251883Speter** [sqlite3_set_authorizer | authorizer documentation] for additional 2990251883Speter** information. 2991251883Speter** 2992274884Sbapt** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2993274884Sbapt** returned from the [sqlite3_vtab_on_conflict()] interface. 2994251883Speter*/ 2995251883Speter#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2996251883Speter#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2997251883Speter 2998251883Speter/* 2999251883Speter** CAPI3REF: Authorizer Action Codes 3000251883Speter** 3001251883Speter** The [sqlite3_set_authorizer()] interface registers a callback function 3002251883Speter** that is invoked to authorize certain SQL statement actions. The 3003251883Speter** second parameter to the callback is an integer code that specifies 3004251883Speter** what action is being authorized. These are the integer action codes that 3005251883Speter** the authorizer callback may be passed. 3006251883Speter** 3007251883Speter** These action code values signify what kind of operation is to be 3008251883Speter** authorized. The 3rd and 4th parameters to the authorization 3009251883Speter** callback function will be parameters or NULL depending on which of these 3010251883Speter** codes is used as the second parameter. ^(The 5th parameter to the 3011251883Speter** authorizer callback is the name of the database ("main", "temp", 3012251883Speter** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3013251883Speter** is the name of the inner-most trigger or view that is responsible for 3014251883Speter** the access attempt or NULL if this access attempt is directly from 3015251883Speter** top-level SQL code. 3016251883Speter*/ 3017251883Speter/******************************************* 3rd ************ 4th ***********/ 3018251883Speter#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3019251883Speter#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3020251883Speter#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3021251883Speter#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3022251883Speter#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3023251883Speter#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3024251883Speter#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3025251883Speter#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3026251883Speter#define SQLITE_DELETE 9 /* Table Name NULL */ 3027251883Speter#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3028251883Speter#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3029251883Speter#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3030251883Speter#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3031251883Speter#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3032251883Speter#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3033251883Speter#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3034251883Speter#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3035251883Speter#define SQLITE_INSERT 18 /* Table Name NULL */ 3036251883Speter#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3037251883Speter#define SQLITE_READ 20 /* Table Name Column Name */ 3038251883Speter#define SQLITE_SELECT 21 /* NULL NULL */ 3039251883Speter#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3040251883Speter#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3041251883Speter#define SQLITE_ATTACH 24 /* Filename NULL */ 3042251883Speter#define SQLITE_DETACH 25 /* Database Name NULL */ 3043251883Speter#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3044251883Speter#define SQLITE_REINDEX 27 /* Index Name NULL */ 3045251883Speter#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3046251883Speter#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3047251883Speter#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3048251883Speter#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3049251883Speter#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3050251883Speter#define SQLITE_COPY 0 /* No longer used */ 3051269851Speter#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3052251883Speter 3053251883Speter/* 3054251883Speter** CAPI3REF: Tracing And Profiling Functions 3055286510Speter** METHOD: sqlite3 3056251883Speter** 3057305002Scy** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3058305002Scy** instead of the routines described here. 3059305002Scy** 3060251883Speter** These routines register callback functions that can be used for 3061251883Speter** tracing and profiling the execution of SQL statements. 3062251883Speter** 3063251883Speter** ^The callback function registered by sqlite3_trace() is invoked at 3064251883Speter** various times when an SQL statement is being run by [sqlite3_step()]. 3065251883Speter** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3066251883Speter** SQL statement text as the statement first begins executing. 3067251883Speter** ^(Additional sqlite3_trace() callbacks might occur 3068251883Speter** as each triggered subprogram is entered. The callbacks for triggers 3069251883Speter** contain a UTF-8 SQL comment that identifies the trigger.)^ 3070251883Speter** 3071251883Speter** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3072251883Speter** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3073251883Speter** 3074251883Speter** ^The callback function registered by sqlite3_profile() is invoked 3075251883Speter** as each SQL statement finishes. ^The profile callback contains 3076251883Speter** the original statement text and an estimate of wall-clock time 3077251883Speter** of how long that statement took to run. ^The profile callback 3078251883Speter** time is in units of nanoseconds, however the current implementation 3079251883Speter** is only capable of millisecond resolution so the six least significant 3080251883Speter** digits in the time are meaningless. Future versions of SQLite 3081346442Scy** might provide greater resolution on the profiler callback. Invoking 3082346442Scy** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3083346442Scy** profile callback. 3084251883Speter*/ 3085322444SpeterSQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3086305002Scy void(*xTrace)(void*,const char*), void*); 3087322444SpeterSQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3088251883Speter void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3089251883Speter 3090251883Speter/* 3091305002Scy** CAPI3REF: SQL Trace Event Codes 3092305002Scy** KEYWORDS: SQLITE_TRACE 3093305002Scy** 3094305002Scy** These constants identify classes of events that can be monitored 3095342292Scy** using the [sqlite3_trace_v2()] tracing logic. The M argument 3096342292Scy** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3097305002Scy** the following constants. ^The first argument to the trace callback 3098305002Scy** is one of the following constants. 3099305002Scy** 3100305002Scy** New tracing constants may be added in future releases. 3101305002Scy** 3102305002Scy** ^A trace callback has four arguments: xCallback(T,C,P,X). 3103305002Scy** ^The T argument is one of the integer type codes above. 3104305002Scy** ^The C argument is a copy of the context pointer passed in as the 3105305002Scy** fourth argument to [sqlite3_trace_v2()]. 3106305002Scy** The P and X arguments are pointers whose meanings depend on T. 3107305002Scy** 3108305002Scy** <dl> 3109305002Scy** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3110305002Scy** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3111305002Scy** first begins running and possibly at other times during the 3112305002Scy** execution of the prepared statement, such as at the start of each 3113305002Scy** trigger subprogram. ^The P argument is a pointer to the 3114305002Scy** [prepared statement]. ^The X argument is a pointer to a string which 3115305002Scy** is the unexpanded SQL text of the prepared statement or an SQL comment 3116305002Scy** that indicates the invocation of a trigger. ^The callback can compute 3117305002Scy** the same text that would have been returned by the legacy [sqlite3_trace()] 3118305002Scy** interface by using the X argument when X begins with "--" and invoking 3119305002Scy** [sqlite3_expanded_sql(P)] otherwise. 3120305002Scy** 3121305002Scy** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3122305002Scy** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3123305002Scy** information as is provided by the [sqlite3_profile()] callback. 3124305002Scy** ^The P argument is a pointer to the [prepared statement] and the 3125305002Scy** X argument points to a 64-bit integer which is the estimated of 3126305002Scy** the number of nanosecond that the prepared statement took to run. 3127305002Scy** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3128305002Scy** 3129305002Scy** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3130305002Scy** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3131305002Scy** statement generates a single row of result. 3132305002Scy** ^The P argument is a pointer to the [prepared statement] and the 3133305002Scy** X argument is unused. 3134305002Scy** 3135305002Scy** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3136305002Scy** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3137305002Scy** connection closes. 3138305002Scy** ^The P argument is a pointer to the [database connection] object 3139305002Scy** and the X argument is unused. 3140305002Scy** </dl> 3141305002Scy*/ 3142305002Scy#define SQLITE_TRACE_STMT 0x01 3143305002Scy#define SQLITE_TRACE_PROFILE 0x02 3144305002Scy#define SQLITE_TRACE_ROW 0x04 3145305002Scy#define SQLITE_TRACE_CLOSE 0x08 3146305002Scy 3147305002Scy/* 3148305002Scy** CAPI3REF: SQL Trace Hook 3149305002Scy** METHOD: sqlite3 3150305002Scy** 3151305002Scy** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3152305002Scy** function X against [database connection] D, using property mask M 3153305002Scy** and context pointer P. ^If the X callback is 3154305002Scy** NULL or if the M mask is zero, then tracing is disabled. The 3155305002Scy** M argument should be the bitwise OR-ed combination of 3156305002Scy** zero or more [SQLITE_TRACE] constants. 3157305002Scy** 3158305002Scy** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3159305002Scy** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3160305002Scy** 3161305002Scy** ^The X callback is invoked whenever any of the events identified by 3162305002Scy** mask M occur. ^The integer return value from the callback is currently 3163305002Scy** ignored, though this may change in future releases. Callback 3164305002Scy** implementations should return zero to ensure future compatibility. 3165305002Scy** 3166305002Scy** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3167305002Scy** ^The T argument is one of the [SQLITE_TRACE] 3168305002Scy** constants to indicate why the callback was invoked. 3169305002Scy** ^The C argument is a copy of the context pointer. 3170305002Scy** The P and X arguments are pointers whose meanings depend on T. 3171305002Scy** 3172305002Scy** The sqlite3_trace_v2() interface is intended to replace the legacy 3173305002Scy** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3174305002Scy** are deprecated. 3175305002Scy*/ 3176322444SpeterSQLITE_API int sqlite3_trace_v2( 3177305002Scy sqlite3*, 3178305002Scy unsigned uMask, 3179305002Scy int(*xCallback)(unsigned,void*,void*,void*), 3180305002Scy void *pCtx 3181305002Scy); 3182305002Scy 3183305002Scy/* 3184251883Speter** CAPI3REF: Query Progress Callbacks 3185286510Speter** METHOD: sqlite3 3186251883Speter** 3187251883Speter** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3188251883Speter** function X to be invoked periodically during long running calls to 3189251883Speter** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3190251883Speter** database connection D. An example use for this 3191251883Speter** interface is to keep a GUI updated during a large query. 3192251883Speter** 3193251883Speter** ^The parameter P is passed through as the only parameter to the 3194269851Speter** callback function X. ^The parameter N is the approximate number of 3195251883Speter** [virtual machine instructions] that are evaluated between successive 3196269851Speter** invocations of the callback X. ^If N is less than one then the progress 3197269851Speter** handler is disabled. 3198251883Speter** 3199251883Speter** ^Only a single progress handler may be defined at one time per 3200251883Speter** [database connection]; setting a new progress handler cancels the 3201251883Speter** old one. ^Setting parameter X to NULL disables the progress handler. 3202251883Speter** ^The progress handler is also disabled by setting N to a value less 3203251883Speter** than 1. 3204251883Speter** 3205251883Speter** ^If the progress callback returns non-zero, the operation is 3206251883Speter** interrupted. This feature can be used to implement a 3207251883Speter** "Cancel" button on a GUI progress dialog box. 3208251883Speter** 3209251883Speter** The progress handler callback must not do anything that will modify 3210251883Speter** the database connection that invoked the progress handler. 3211251883Speter** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3212251883Speter** database connections for the meaning of "modify" in this paragraph. 3213251883Speter** 3214251883Speter*/ 3215322444SpeterSQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3216251883Speter 3217251883Speter/* 3218251883Speter** CAPI3REF: Opening A New Database Connection 3219286510Speter** CONSTRUCTOR: sqlite3 3220251883Speter** 3221251883Speter** ^These routines open an SQLite database file as specified by the 3222251883Speter** filename argument. ^The filename argument is interpreted as UTF-8 for 3223251883Speter** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3224251883Speter** order for sqlite3_open16(). ^(A [database connection] handle is usually 3225251883Speter** returned in *ppDb, even if an error occurs. The only exception is that 3226251883Speter** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3227251883Speter** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3228251883Speter** object.)^ ^(If the database is opened (and/or created) successfully, then 3229251883Speter** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3230251883Speter** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3231251883Speter** an English language description of the error following a failure of any 3232251883Speter** of the sqlite3_open() routines. 3233251883Speter** 3234274884Sbapt** ^The default encoding will be UTF-8 for databases created using 3235274884Sbapt** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3236274884Sbapt** created using sqlite3_open16() will be UTF-16 in the native byte order. 3237251883Speter** 3238251883Speter** Whether or not an error occurs when it is opened, resources 3239251883Speter** associated with the [database connection] handle should be released by 3240251883Speter** passing it to [sqlite3_close()] when it is no longer required. 3241251883Speter** 3242251883Speter** The sqlite3_open_v2() interface works like sqlite3_open() 3243251883Speter** except that it accepts two additional parameters for additional control 3244251883Speter** over the new database connection. ^(The flags parameter to 3245251883Speter** sqlite3_open_v2() can take one of 3246251883Speter** the following three values, optionally combined with the 3247251883Speter** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3248251883Speter** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3249251883Speter** 3250251883Speter** <dl> 3251251883Speter** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3252251883Speter** <dd>The database is opened in read-only mode. If the database does not 3253251883Speter** already exist, an error is returned.</dd>)^ 3254251883Speter** 3255251883Speter** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3256251883Speter** <dd>The database is opened for reading and writing if possible, or reading 3257251883Speter** only if the file is write protected by the operating system. In either 3258251883Speter** case the database must already exist, otherwise an error is returned.</dd>)^ 3259251883Speter** 3260251883Speter** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3261251883Speter** <dd>The database is opened for reading and writing, and is created if 3262251883Speter** it does not already exist. This is the behavior that is always used for 3263251883Speter** sqlite3_open() and sqlite3_open16().</dd>)^ 3264251883Speter** </dl> 3265251883Speter** 3266251883Speter** If the 3rd parameter to sqlite3_open_v2() is not one of the 3267251883Speter** combinations shown above optionally combined with other 3268251883Speter** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3269251883Speter** then the behavior is undefined. 3270251883Speter** 3271251883Speter** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3272251883Speter** opens in the multi-thread [threading mode] as long as the single-thread 3273251883Speter** mode has not been set at compile-time or start-time. ^If the 3274251883Speter** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3275251883Speter** in the serialized [threading mode] unless single-thread was 3276251883Speter** previously selected at compile-time or start-time. 3277251883Speter** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3278251883Speter** eligible to use [shared cache mode], regardless of whether or not shared 3279251883Speter** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3280251883Speter** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3281251883Speter** participate in [shared cache mode] even if it is enabled. 3282251883Speter** 3283251883Speter** ^The fourth parameter to sqlite3_open_v2() is the name of the 3284251883Speter** [sqlite3_vfs] object that defines the operating system interface that 3285251883Speter** the new database connection should use. ^If the fourth parameter is 3286251883Speter** a NULL pointer then the default [sqlite3_vfs] object is used. 3287251883Speter** 3288251883Speter** ^If the filename is ":memory:", then a private, temporary in-memory database 3289251883Speter** is created for the connection. ^This in-memory database will vanish when 3290251883Speter** the database connection is closed. Future versions of SQLite might 3291251883Speter** make use of additional special filenames that begin with the ":" character. 3292251883Speter** It is recommended that when a database filename actually does begin with 3293251883Speter** a ":" character you should prefix the filename with a pathname such as 3294251883Speter** "./" to avoid ambiguity. 3295251883Speter** 3296251883Speter** ^If the filename is an empty string, then a private, temporary 3297251883Speter** on-disk database will be created. ^This private database will be 3298251883Speter** automatically deleted as soon as the database connection is closed. 3299251883Speter** 3300251883Speter** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3301251883Speter** 3302251883Speter** ^If [URI filename] interpretation is enabled, and the filename argument 3303251883Speter** begins with "file:", then the filename is interpreted as a URI. ^URI 3304251883Speter** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3305342292Scy** set in the third argument to sqlite3_open_v2(), or if it has 3306251883Speter** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3307251883Speter** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3308342292Scy** URI filename interpretation is turned off 3309251883Speter** by default, but future releases of SQLite might enable URI filename 3310251883Speter** interpretation by default. See "[URI filenames]" for additional 3311251883Speter** information. 3312251883Speter** 3313251883Speter** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3314251883Speter** authority, then it must be either an empty string or the string 3315251883Speter** "localhost". ^If the authority is not an empty string or "localhost", an 3316251883Speter** error is returned to the caller. ^The fragment component of a URI, if 3317251883Speter** present, is ignored. 3318251883Speter** 3319251883Speter** ^SQLite uses the path component of the URI as the name of the disk file 3320251883Speter** which contains the database. ^If the path begins with a '/' character, 3321251883Speter** then it is interpreted as an absolute path. ^If the path does not begin 3322251883Speter** with a '/' (meaning that the authority section is omitted from the URI) 3323251883Speter** then the path is interpreted as a relative path. 3324274884Sbapt** ^(On windows, the first component of an absolute path 3325274884Sbapt** is a drive specification (e.g. "C:").)^ 3326251883Speter** 3327251883Speter** [[core URI query parameters]] 3328251883Speter** The query component of a URI may contain parameters that are interpreted 3329251883Speter** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3330274884Sbapt** SQLite and its built-in [VFSes] interpret the 3331274884Sbapt** following query parameters: 3332251883Speter** 3333251883Speter** <ul> 3334251883Speter** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3335251883Speter** a VFS object that provides the operating system interface that should 3336251883Speter** be used to access the database file on disk. ^If this option is set to 3337251883Speter** an empty string the default VFS object is used. ^Specifying an unknown 3338251883Speter** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3339251883Speter** present, then the VFS specified by the option takes precedence over 3340251883Speter** the value passed as the fourth parameter to sqlite3_open_v2(). 3341251883Speter** 3342251883Speter** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3343251883Speter** "rwc", or "memory". Attempting to set it to any other value is 3344251883Speter** an error)^. 3345251883Speter** ^If "ro" is specified, then the database is opened for read-only 3346251883Speter** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3347251883Speter** third argument to sqlite3_open_v2(). ^If the mode option is set to 3348251883Speter** "rw", then the database is opened for read-write (but not create) 3349251883Speter** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3350251883Speter** been set. ^Value "rwc" is equivalent to setting both 3351251883Speter** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3352251883Speter** set to "memory" then a pure [in-memory database] that never reads 3353251883Speter** or writes from disk is used. ^It is an error to specify a value for 3354251883Speter** the mode parameter that is less restrictive than that specified by 3355251883Speter** the flags passed in the third parameter to sqlite3_open_v2(). 3356251883Speter** 3357251883Speter** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3358251883Speter** "private". ^Setting it to "shared" is equivalent to setting the 3359251883Speter** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3360251883Speter** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3361251883Speter** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3362251883Speter** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3363251883Speter** a URI filename, its value overrides any behavior requested by setting 3364251883Speter** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3365269851Speter** 3366274884Sbapt** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3367269851Speter** [powersafe overwrite] property does or does not apply to the 3368274884Sbapt** storage media on which the database file resides. 3369269851Speter** 3370269851Speter** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3371269851Speter** which if set disables file locking in rollback journal modes. This 3372269851Speter** is useful for accessing a database on a filesystem that does not 3373269851Speter** support locking. Caution: Database corruption might result if two 3374269851Speter** or more processes write to the same database and any one of those 3375269851Speter** processes uses nolock=1. 3376269851Speter** 3377269851Speter** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3378269851Speter** parameter that indicates that the database file is stored on 3379269851Speter** read-only media. ^When immutable is set, SQLite assumes that the 3380269851Speter** database file cannot be changed, even by a process with higher 3381269851Speter** privilege, and so the database is opened read-only and all locking 3382269851Speter** and change detection is disabled. Caution: Setting the immutable 3383269851Speter** property on a database file that does in fact change can result 3384269851Speter** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3385269851Speter** See also: [SQLITE_IOCAP_IMMUTABLE]. 3386269851Speter** 3387251883Speter** </ul> 3388251883Speter** 3389251883Speter** ^Specifying an unknown parameter in the query component of a URI is not an 3390251883Speter** error. Future versions of SQLite might understand additional query 3391251883Speter** parameters. See "[query parameters with special meaning to SQLite]" for 3392251883Speter** additional information. 3393251883Speter** 3394251883Speter** [[URI filename examples]] <h3>URI filename examples</h3> 3395251883Speter** 3396251883Speter** <table border="1" align=center cellpadding=5> 3397251883Speter** <tr><th> URI filenames <th> Results 3398251883Speter** <tr><td> file:data.db <td> 3399251883Speter** Open the file "data.db" in the current directory. 3400251883Speter** <tr><td> file:/home/fred/data.db<br> 3401251883Speter** file:///home/fred/data.db <br> 3402251883Speter** file://localhost/home/fred/data.db <br> <td> 3403251883Speter** Open the database file "/home/fred/data.db". 3404251883Speter** <tr><td> file://darkstar/home/fred/data.db <td> 3405251883Speter** An error. "darkstar" is not a recognized authority. 3406251883Speter** <tr><td style="white-space:nowrap"> 3407251883Speter** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3408251883Speter** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3409251883Speter** C:. Note that the %20 escaping in this example is not strictly 3410251883Speter** necessary - space characters can be used literally 3411251883Speter** in URI filenames. 3412251883Speter** <tr><td> file:data.db?mode=ro&cache=private <td> 3413251883Speter** Open file "data.db" in the current directory for read-only access. 3414251883Speter** Regardless of whether or not shared-cache mode is enabled by 3415251883Speter** default, use a private cache. 3416269851Speter** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3417269851Speter** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3418269851Speter** that uses dot-files in place of posix advisory locking. 3419251883Speter** <tr><td> file:data.db?mode=readonly <td> 3420251883Speter** An error. "readonly" is not a valid option for the "mode" parameter. 3421251883Speter** </table> 3422251883Speter** 3423251883Speter** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3424251883Speter** query components of a URI. A hexadecimal escape sequence consists of a 3425251883Speter** percent sign - "%" - followed by exactly two hexadecimal digits 3426251883Speter** specifying an octet value. ^Before the path or query components of a 3427251883Speter** URI filename are interpreted, they are encoded using UTF-8 and all 3428251883Speter** hexadecimal escape sequences replaced by a single byte containing the 3429251883Speter** corresponding octet. If this process generates an invalid UTF-8 encoding, 3430251883Speter** the results are undefined. 3431251883Speter** 3432251883Speter** <b>Note to Windows users:</b> The encoding used for the filename argument 3433251883Speter** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3434251883Speter** codepage is currently defined. Filenames containing international 3435251883Speter** characters must be converted to UTF-8 prior to passing them into 3436251883Speter** sqlite3_open() or sqlite3_open_v2(). 3437251883Speter** 3438251883Speter** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3439251883Speter** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3440251883Speter** features that require the use of temporary files may fail. 3441251883Speter** 3442251883Speter** See also: [sqlite3_temp_directory] 3443251883Speter*/ 3444322444SpeterSQLITE_API int sqlite3_open( 3445251883Speter const char *filename, /* Database filename (UTF-8) */ 3446251883Speter sqlite3 **ppDb /* OUT: SQLite db handle */ 3447251883Speter); 3448322444SpeterSQLITE_API int sqlite3_open16( 3449251883Speter const void *filename, /* Database filename (UTF-16) */ 3450251883Speter sqlite3 **ppDb /* OUT: SQLite db handle */ 3451251883Speter); 3452322444SpeterSQLITE_API int sqlite3_open_v2( 3453251883Speter const char *filename, /* Database filename (UTF-8) */ 3454251883Speter sqlite3 **ppDb, /* OUT: SQLite db handle */ 3455251883Speter int flags, /* Flags */ 3456251883Speter const char *zVfs /* Name of VFS module to use */ 3457251883Speter); 3458251883Speter 3459251883Speter/* 3460251883Speter** CAPI3REF: Obtain Values For URI Parameters 3461251883Speter** 3462251883Speter** These are utility routines, useful to VFS implementations, that check 3463251883Speter** to see if a database file was a URI that contained a specific query 3464251883Speter** parameter, and if so obtains the value of that query parameter. 3465251883Speter** 3466251883Speter** If F is the database filename pointer passed into the xOpen() method of 3467251883Speter** a VFS implementation when the flags parameter to xOpen() has one or 3468251883Speter** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3469251883Speter** P is the name of the query parameter, then 3470251883Speter** sqlite3_uri_parameter(F,P) returns the value of the P 3471251883Speter** parameter if it exists or a NULL pointer if P does not appear as a 3472251883Speter** query parameter on F. If P is a query parameter of F 3473251883Speter** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3474251883Speter** a pointer to an empty string. 3475251883Speter** 3476251883Speter** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3477251883Speter** parameter and returns true (1) or false (0) according to the value 3478251883Speter** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3479251883Speter** value of query parameter P is one of "yes", "true", or "on" in any 3480251883Speter** case or if the value begins with a non-zero number. The 3481251883Speter** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3482251883Speter** query parameter P is one of "no", "false", or "off" in any case or 3483251883Speter** if the value begins with a numeric zero. If P is not a query 3484251883Speter** parameter on F or if the value of P is does not match any of the 3485251883Speter** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3486251883Speter** 3487251883Speter** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3488251883Speter** 64-bit signed integer and returns that integer, or D if P does not 3489251883Speter** exist. If the value of P is something other than an integer, then 3490251883Speter** zero is returned. 3491251883Speter** 3492251883Speter** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3493251883Speter** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3494251883Speter** is not a database file pathname pointer that SQLite passed into the xOpen 3495251883Speter** VFS method, then the behavior of this routine is undefined and probably 3496251883Speter** undesirable. 3497346442Scy** 3498346442Scy** See the [URI filename] documentation for additional information. 3499251883Speter*/ 3500322444SpeterSQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3501322444SpeterSQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3502322444SpeterSQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3503251883Speter 3504251883Speter 3505251883Speter/* 3506251883Speter** CAPI3REF: Error Codes And Messages 3507286510Speter** METHOD: sqlite3 3508251883Speter** 3509282328Sbapt** ^If the most recent sqlite3_* API call associated with 3510282328Sbapt** [database connection] D failed, then the sqlite3_errcode(D) interface 3511282328Sbapt** returns the numeric [result code] or [extended result code] for that 3512282328Sbapt** API call. 3513282328Sbapt** ^The sqlite3_extended_errcode() 3514251883Speter** interface is the same except that it always returns the 3515251883Speter** [extended result code] even when extended result codes are 3516251883Speter** disabled. 3517251883Speter** 3518342292Scy** The values returned by sqlite3_errcode() and/or 3519342292Scy** sqlite3_extended_errcode() might change with each API call. 3520342292Scy** Except, there are some interfaces that are guaranteed to never 3521342292Scy** change the value of the error code. The error-code preserving 3522342292Scy** interfaces are: 3523342292Scy** 3524342292Scy** <ul> 3525342292Scy** <li> sqlite3_errcode() 3526342292Scy** <li> sqlite3_extended_errcode() 3527342292Scy** <li> sqlite3_errmsg() 3528342292Scy** <li> sqlite3_errmsg16() 3529342292Scy** </ul> 3530342292Scy** 3531251883Speter** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3532251883Speter** text that describes the error, as either UTF-8 or UTF-16 respectively. 3533251883Speter** ^(Memory to hold the error message string is managed internally. 3534251883Speter** The application does not need to worry about freeing the result. 3535251883Speter** However, the error string might be overwritten or deallocated by 3536251883Speter** subsequent calls to other SQLite interface functions.)^ 3537251883Speter** 3538251883Speter** ^The sqlite3_errstr() interface returns the English-language text 3539251883Speter** that describes the [result code], as UTF-8. 3540251883Speter** ^(Memory to hold the error message string is managed internally 3541251883Speter** and must not be freed by the application)^. 3542251883Speter** 3543251883Speter** When the serialized [threading mode] is in use, it might be the 3544251883Speter** case that a second error occurs on a separate thread in between 3545251883Speter** the time of the first error and the call to these interfaces. 3546251883Speter** When that happens, the second error will be reported since these 3547251883Speter** interfaces always report the most recent result. To avoid 3548251883Speter** this, each thread can obtain exclusive use of the [database connection] D 3549251883Speter** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3550251883Speter** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3551251883Speter** all calls to the interfaces listed here are completed. 3552251883Speter** 3553251883Speter** If an interface fails with SQLITE_MISUSE, that means the interface 3554251883Speter** was invoked incorrectly by the application. In that case, the 3555251883Speter** error code and message may or may not be set. 3556251883Speter*/ 3557322444SpeterSQLITE_API int sqlite3_errcode(sqlite3 *db); 3558322444SpeterSQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3559322444SpeterSQLITE_API const char *sqlite3_errmsg(sqlite3*); 3560322444SpeterSQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3561322444SpeterSQLITE_API const char *sqlite3_errstr(int); 3562251883Speter 3563251883Speter/* 3564286510Speter** CAPI3REF: Prepared Statement Object 3565251883Speter** KEYWORDS: {prepared statement} {prepared statements} 3566251883Speter** 3567286510Speter** An instance of this object represents a single SQL statement that 3568286510Speter** has been compiled into binary form and is ready to be evaluated. 3569251883Speter** 3570286510Speter** Think of each SQL statement as a separate computer program. The 3571286510Speter** original SQL text is source code. A prepared statement object 3572286510Speter** is the compiled object code. All SQL must be converted into a 3573286510Speter** prepared statement before it can be run. 3574251883Speter** 3575286510Speter** The life-cycle of a prepared statement object usually goes like this: 3576286510Speter** 3577251883Speter** <ol> 3578286510Speter** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3579286510Speter** <li> Bind values to [parameters] using the sqlite3_bind_*() 3580251883Speter** interfaces. 3581251883Speter** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3582286510Speter** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3583251883Speter** to step 2. Do this zero or more times. 3584251883Speter** <li> Destroy the object using [sqlite3_finalize()]. 3585251883Speter** </ol> 3586251883Speter*/ 3587251883Spetertypedef struct sqlite3_stmt sqlite3_stmt; 3588251883Speter 3589251883Speter/* 3590251883Speter** CAPI3REF: Run-time Limits 3591286510Speter** METHOD: sqlite3 3592251883Speter** 3593251883Speter** ^(This interface allows the size of various constructs to be limited 3594251883Speter** on a connection by connection basis. The first parameter is the 3595251883Speter** [database connection] whose limit is to be set or queried. The 3596251883Speter** second parameter is one of the [limit categories] that define a 3597251883Speter** class of constructs to be size limited. The third parameter is the 3598251883Speter** new limit for that construct.)^ 3599251883Speter** 3600251883Speter** ^If the new limit is a negative number, the limit is unchanged. 3601251883Speter** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3602251883Speter** [limits | hard upper bound] 3603251883Speter** set at compile-time by a C preprocessor macro called 3604251883Speter** [limits | SQLITE_MAX_<i>NAME</i>]. 3605251883Speter** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3606251883Speter** ^Attempts to increase a limit above its hard upper bound are 3607251883Speter** silently truncated to the hard upper bound. 3608251883Speter** 3609251883Speter** ^Regardless of whether or not the limit was changed, the 3610251883Speter** [sqlite3_limit()] interface returns the prior value of the limit. 3611251883Speter** ^Hence, to find the current value of a limit without changing it, 3612251883Speter** simply invoke this interface with the third parameter set to -1. 3613251883Speter** 3614251883Speter** Run-time limits are intended for use in applications that manage 3615251883Speter** both their own internal database and also databases that are controlled 3616251883Speter** by untrusted external sources. An example application might be a 3617251883Speter** web browser that has its own databases for storing history and 3618251883Speter** separate databases controlled by JavaScript applications downloaded 3619251883Speter** off the Internet. The internal databases can be given the 3620251883Speter** large, default limits. Databases managed by external sources can 3621251883Speter** be given much smaller limits designed to prevent a denial of service 3622251883Speter** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3623251883Speter** interface to further control untrusted SQL. The size of the database 3624251883Speter** created by an untrusted script can be contained using the 3625251883Speter** [max_page_count] [PRAGMA]. 3626251883Speter** 3627251883Speter** New run-time limit categories may be added in future releases. 3628251883Speter*/ 3629322444SpeterSQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3630251883Speter 3631251883Speter/* 3632251883Speter** CAPI3REF: Run-Time Limit Categories 3633251883Speter** KEYWORDS: {limit category} {*limit categories} 3634251883Speter** 3635251883Speter** These constants define various performance limits 3636251883Speter** that can be lowered at run-time using [sqlite3_limit()]. 3637251883Speter** The synopsis of the meanings of the various limits is shown below. 3638251883Speter** Additional information is available at [limits | Limits in SQLite]. 3639251883Speter** 3640251883Speter** <dl> 3641251883Speter** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3642251883Speter** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3643251883Speter** 3644251883Speter** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3645251883Speter** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3646251883Speter** 3647251883Speter** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3648251883Speter** <dd>The maximum number of columns in a table definition or in the 3649251883Speter** result set of a [SELECT] or the maximum number of columns in an index 3650251883Speter** or in an ORDER BY or GROUP BY clause.</dd>)^ 3651251883Speter** 3652251883Speter** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3653251883Speter** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3654251883Speter** 3655251883Speter** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3656251883Speter** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3657251883Speter** 3658251883Speter** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3659251883Speter** <dd>The maximum number of instructions in a virtual machine program 3660322444Speter** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3661322444Speter** the equivalent tries to allocate space for more than this many opcodes 3662322444Speter** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3663251883Speter** 3664251883Speter** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3665251883Speter** <dd>The maximum number of arguments on a function.</dd>)^ 3666251883Speter** 3667251883Speter** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3668251883Speter** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3669251883Speter** 3670251883Speter** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3671251883Speter** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3672251883Speter** <dd>The maximum length of the pattern argument to the [LIKE] or 3673251883Speter** [GLOB] operators.</dd>)^ 3674251883Speter** 3675251883Speter** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3676251883Speter** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3677251883Speter** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3678251883Speter** 3679251883Speter** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3680251883Speter** <dd>The maximum depth of recursion for triggers.</dd>)^ 3681274884Sbapt** 3682274884Sbapt** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3683274884Sbapt** <dd>The maximum number of auxiliary worker threads that a single 3684274884Sbapt** [prepared statement] may start.</dd>)^ 3685251883Speter** </dl> 3686251883Speter*/ 3687251883Speter#define SQLITE_LIMIT_LENGTH 0 3688251883Speter#define SQLITE_LIMIT_SQL_LENGTH 1 3689251883Speter#define SQLITE_LIMIT_COLUMN 2 3690251883Speter#define SQLITE_LIMIT_EXPR_DEPTH 3 3691251883Speter#define SQLITE_LIMIT_COMPOUND_SELECT 4 3692251883Speter#define SQLITE_LIMIT_VDBE_OP 5 3693251883Speter#define SQLITE_LIMIT_FUNCTION_ARG 6 3694251883Speter#define SQLITE_LIMIT_ATTACHED 7 3695251883Speter#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3696251883Speter#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3697251883Speter#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3698274884Sbapt#define SQLITE_LIMIT_WORKER_THREADS 11 3699251883Speter 3700251883Speter/* 3701322444Speter** CAPI3REF: Prepare Flags 3702322444Speter** 3703322444Speter** These constants define various flags that can be passed into 3704322444Speter** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3705322444Speter** [sqlite3_prepare16_v3()] interfaces. 3706322444Speter** 3707322444Speter** New flags may be added in future releases of SQLite. 3708322444Speter** 3709322444Speter** <dl> 3710322444Speter** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3711322444Speter** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3712322444Speter** that the prepared statement will be retained for a long time and 3713322444Speter** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3714322444Speter** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3715322444Speter** be used just once or at most a few times and then destroyed using 3716322444Speter** [sqlite3_finalize()] relatively soon. The current implementation acts 3717322444Speter** on this hint by avoiding the use of [lookaside memory] so as not to 3718322444Speter** deplete the limited store of lookaside memory. Future versions of 3719322444Speter** SQLite may act on this hint differently. 3720342292Scy** 3721346442Scy** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3722346442Scy** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3723346442Scy** to be required for any prepared statement that wanted to use the 3724346442Scy** [sqlite3_normalized_sql()] interface. However, the 3725346442Scy** [sqlite3_normalized_sql()] interface is now available to all 3726346442Scy** prepared statements, regardless of whether or not they use this 3727346442Scy** flag. 3728346442Scy** 3729346442Scy** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3730346442Scy** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3731346442Scy** to return an error (error code SQLITE_ERROR) if the statement uses 3732346442Scy** any virtual tables. 3733322444Speter** </dl> 3734322444Speter*/ 3735322444Speter#define SQLITE_PREPARE_PERSISTENT 0x01 3736342292Scy#define SQLITE_PREPARE_NORMALIZE 0x02 3737346442Scy#define SQLITE_PREPARE_NO_VTAB 0x04 3738322444Speter 3739322444Speter/* 3740251883Speter** CAPI3REF: Compiling An SQL Statement 3741251883Speter** KEYWORDS: {SQL statement compiler} 3742286510Speter** METHOD: sqlite3 3743286510Speter** CONSTRUCTOR: sqlite3_stmt 3744251883Speter** 3745322444Speter** To execute an SQL statement, it must first be compiled into a byte-code 3746322444Speter** program using one of these routines. Or, in other words, these routines 3747322444Speter** are constructors for the [prepared statement] object. 3748251883Speter** 3749322444Speter** The preferred routine to use is [sqlite3_prepare_v2()]. The 3750322444Speter** [sqlite3_prepare()] interface is legacy and should be avoided. 3751322444Speter** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3752322444Speter** for special purposes. 3753322444Speter** 3754322444Speter** The use of the UTF-8 interfaces is preferred, as SQLite currently 3755322444Speter** does all parsing using UTF-8. The UTF-16 interfaces are provided 3756322444Speter** as a convenience. The UTF-16 interfaces work by converting the 3757322444Speter** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3758322444Speter** 3759251883Speter** The first argument, "db", is a [database connection] obtained from a 3760251883Speter** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3761251883Speter** [sqlite3_open16()]. The database connection must not have been closed. 3762251883Speter** 3763251883Speter** The second argument, "zSql", is the statement to be compiled, encoded 3764322444Speter** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3765322444Speter** and sqlite3_prepare_v3() 3766322444Speter** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3767322444Speter** and sqlite3_prepare16_v3() use UTF-16. 3768251883Speter** 3769282328Sbapt** ^If the nByte argument is negative, then zSql is read up to the 3770282328Sbapt** first zero terminator. ^If nByte is positive, then it is the 3771282328Sbapt** number of bytes read from zSql. ^If nByte is zero, then no prepared 3772282328Sbapt** statement is generated. 3773282328Sbapt** If the caller knows that the supplied string is nul-terminated, then 3774282328Sbapt** there is a small performance advantage to passing an nByte parameter that 3775282328Sbapt** is the number of bytes in the input string <i>including</i> 3776282328Sbapt** the nul-terminator. 3777251883Speter** 3778251883Speter** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3779251883Speter** past the end of the first SQL statement in zSql. These routines only 3780251883Speter** compile the first statement in zSql, so *pzTail is left pointing to 3781251883Speter** what remains uncompiled. 3782251883Speter** 3783251883Speter** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3784251883Speter** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3785251883Speter** to NULL. ^If the input text contains no SQL (if the input is an empty 3786251883Speter** string or a comment) then *ppStmt is set to NULL. 3787251883Speter** The calling procedure is responsible for deleting the compiled 3788251883Speter** SQL statement using [sqlite3_finalize()] after it has finished with it. 3789251883Speter** ppStmt may not be NULL. 3790251883Speter** 3791251883Speter** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3792251883Speter** otherwise an [error code] is returned. 3793251883Speter** 3794322444Speter** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3795322444Speter** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3796322444Speter** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3797322444Speter** are retained for backwards compatibility, but their use is discouraged. 3798322444Speter** ^In the "vX" interfaces, the prepared statement 3799251883Speter** that is returned (the [sqlite3_stmt] object) contains a copy of the 3800251883Speter** original SQL text. This causes the [sqlite3_step()] interface to 3801251883Speter** behave differently in three ways: 3802251883Speter** 3803251883Speter** <ol> 3804251883Speter** <li> 3805251883Speter** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3806251883Speter** always used to do, [sqlite3_step()] will automatically recompile the SQL 3807251883Speter** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3808251883Speter** retries will occur before sqlite3_step() gives up and returns an error. 3809251883Speter** </li> 3810251883Speter** 3811251883Speter** <li> 3812251883Speter** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3813251883Speter** [error codes] or [extended error codes]. ^The legacy behavior was that 3814251883Speter** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3815251883Speter** and the application would have to make a second call to [sqlite3_reset()] 3816251883Speter** in order to find the underlying cause of the problem. With the "v2" prepare 3817251883Speter** interfaces, the underlying reason for the error is returned immediately. 3818251883Speter** </li> 3819251883Speter** 3820251883Speter** <li> 3821251883Speter** ^If the specific value bound to [parameter | host parameter] in the 3822251883Speter** WHERE clause might influence the choice of query plan for a statement, 3823251883Speter** then the statement will be automatically recompiled, as if there had been 3824251883Speter** a schema change, on the first [sqlite3_step()] call following any change 3825251883Speter** to the [sqlite3_bind_text | bindings] of that [parameter]. 3826251883Speter** ^The specific value of WHERE-clause [parameter] might influence the 3827251883Speter** choice of query plan if the parameter is the left-hand side of a [LIKE] 3828251883Speter** or [GLOB] operator or if the parameter is compared to an indexed column 3829355326Scy** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3830251883Speter** </li> 3831342292Scy** </ol> 3832322444Speter** 3833322444Speter** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3834322444Speter** the extra prepFlags parameter, which is a bit array consisting of zero or 3835322444Speter** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3836322444Speter** sqlite3_prepare_v2() interface works exactly the same as 3837322444Speter** sqlite3_prepare_v3() with a zero prepFlags parameter. 3838251883Speter*/ 3839322444SpeterSQLITE_API int sqlite3_prepare( 3840251883Speter sqlite3 *db, /* Database handle */ 3841251883Speter const char *zSql, /* SQL statement, UTF-8 encoded */ 3842251883Speter int nByte, /* Maximum length of zSql in bytes. */ 3843251883Speter sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3844251883Speter const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3845251883Speter); 3846322444SpeterSQLITE_API int sqlite3_prepare_v2( 3847251883Speter sqlite3 *db, /* Database handle */ 3848251883Speter const char *zSql, /* SQL statement, UTF-8 encoded */ 3849251883Speter int nByte, /* Maximum length of zSql in bytes. */ 3850251883Speter sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3851251883Speter const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3852251883Speter); 3853322444SpeterSQLITE_API int sqlite3_prepare_v3( 3854251883Speter sqlite3 *db, /* Database handle */ 3855322444Speter const char *zSql, /* SQL statement, UTF-8 encoded */ 3856322444Speter int nByte, /* Maximum length of zSql in bytes. */ 3857322444Speter unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3858322444Speter sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3859322444Speter const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3860322444Speter); 3861322444SpeterSQLITE_API int sqlite3_prepare16( 3862322444Speter sqlite3 *db, /* Database handle */ 3863251883Speter const void *zSql, /* SQL statement, UTF-16 encoded */ 3864251883Speter int nByte, /* Maximum length of zSql in bytes. */ 3865251883Speter sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3866251883Speter const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3867251883Speter); 3868322444SpeterSQLITE_API int sqlite3_prepare16_v2( 3869251883Speter sqlite3 *db, /* Database handle */ 3870251883Speter const void *zSql, /* SQL statement, UTF-16 encoded */ 3871251883Speter int nByte, /* Maximum length of zSql in bytes. */ 3872251883Speter sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3873251883Speter const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3874251883Speter); 3875322444SpeterSQLITE_API int sqlite3_prepare16_v3( 3876322444Speter sqlite3 *db, /* Database handle */ 3877322444Speter const void *zSql, /* SQL statement, UTF-16 encoded */ 3878322444Speter int nByte, /* Maximum length of zSql in bytes. */ 3879322444Speter unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3880322444Speter sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3881322444Speter const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3882322444Speter); 3883251883Speter 3884251883Speter/* 3885251883Speter** CAPI3REF: Retrieving Statement SQL 3886286510Speter** METHOD: sqlite3_stmt 3887251883Speter** 3888305002Scy** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3889305002Scy** SQL text used to create [prepared statement] P if P was 3890322444Speter** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3891322444Speter** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3892305002Scy** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3893305002Scy** string containing the SQL text of prepared statement P with 3894305002Scy** [bound parameters] expanded. 3895342292Scy** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3896342292Scy** string containing the normalized SQL text of prepared statement P. The 3897342292Scy** semantics used to normalize a SQL statement are unspecified and subject 3898342292Scy** to change. At a minimum, literal values will be replaced with suitable 3899342292Scy** placeholders. 3900305002Scy** 3901305002Scy** ^(For example, if a prepared statement is created using the SQL 3902305002Scy** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3903305002Scy** and parameter :xyz is unbound, then sqlite3_sql() will return 3904305002Scy** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3905305002Scy** will return "SELECT 2345,NULL".)^ 3906305002Scy** 3907305002Scy** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3908305002Scy** is available to hold the result, or if the result would exceed the 3909305002Scy** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3910305002Scy** 3911305002Scy** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3912305002Scy** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3913305002Scy** option causes sqlite3_expanded_sql() to always return NULL. 3914305002Scy** 3915342292Scy** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3916342292Scy** are managed by SQLite and are automatically freed when the prepared 3917342292Scy** statement is finalized. 3918305002Scy** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3919305002Scy** is obtained from [sqlite3_malloc()] and must be free by the application 3920305002Scy** by passing it to [sqlite3_free()]. 3921251883Speter*/ 3922322444SpeterSQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3923322444SpeterSQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3924342292ScySQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3925251883Speter 3926251883Speter/* 3927251883Speter** CAPI3REF: Determine If An SQL Statement Writes The Database 3928286510Speter** METHOD: sqlite3_stmt 3929251883Speter** 3930251883Speter** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3931251883Speter** and only if the [prepared statement] X makes no direct changes to 3932251883Speter** the content of the database file. 3933251883Speter** 3934251883Speter** Note that [application-defined SQL functions] or 3935251883Speter** [virtual tables] might change the database indirectly as a side effect. 3936251883Speter** ^(For example, if an application defines a function "eval()" that 3937251883Speter** calls [sqlite3_exec()], then the following SQL statement would 3938251883Speter** change the database file through side-effects: 3939251883Speter** 3940251883Speter** <blockquote><pre> 3941251883Speter** SELECT eval('DELETE FROM t1') FROM t2; 3942251883Speter** </pre></blockquote> 3943251883Speter** 3944251883Speter** But because the [SELECT] statement does not change the database file 3945251883Speter** directly, sqlite3_stmt_readonly() would still return true.)^ 3946251883Speter** 3947251883Speter** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3948251883Speter** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3949251883Speter** since the statements themselves do not actually modify the database but 3950251883Speter** rather they control the timing of when other statements modify the 3951251883Speter** database. ^The [ATTACH] and [DETACH] statements also cause 3952251883Speter** sqlite3_stmt_readonly() to return true since, while those statements 3953251883Speter** change the configuration of a database connection, they do not make 3954251883Speter** changes to the content of the database files on disk. 3955322444Speter** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3956322444Speter** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3957322444Speter** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3958322444Speter** sqlite3_stmt_readonly() returns false for those commands. 3959251883Speter*/ 3960322444SpeterSQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3961251883Speter 3962251883Speter/* 3963347347Scy** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 3964347347Scy** METHOD: sqlite3_stmt 3965347347Scy** 3966347347Scy** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 3967347347Scy** prepared statement S is an EXPLAIN statement, or 2 if the 3968347347Scy** statement S is an EXPLAIN QUERY PLAN. 3969347347Scy** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 3970347347Scy** an ordinary statement or a NULL pointer. 3971347347Scy*/ 3972347347ScySQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 3973347347Scy 3974347347Scy/* 3975251883Speter** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3976286510Speter** METHOD: sqlite3_stmt 3977251883Speter** 3978251883Speter** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3979251883Speter** [prepared statement] S has been stepped at least once using 3980298161Sbapt** [sqlite3_step(S)] but has neither run to completion (returned 3981298161Sbapt** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3982251883Speter** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3983251883Speter** interface returns false if S is a NULL pointer. If S is not a 3984251883Speter** NULL pointer and is not a pointer to a valid [prepared statement] 3985251883Speter** object, then the behavior is undefined and probably undesirable. 3986251883Speter** 3987251883Speter** This interface can be used in combination [sqlite3_next_stmt()] 3988251883Speter** to locate all prepared statements associated with a database 3989251883Speter** connection that are in need of being reset. This can be used, 3990251883Speter** for example, in diagnostic routines to search for prepared 3991251883Speter** statements that are holding a transaction open. 3992251883Speter*/ 3993322444SpeterSQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3994251883Speter 3995251883Speter/* 3996251883Speter** CAPI3REF: Dynamically Typed Value Object 3997251883Speter** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3998251883Speter** 3999251883Speter** SQLite uses the sqlite3_value object to represent all values 4000251883Speter** that can be stored in a database table. SQLite uses dynamic typing 4001251883Speter** for the values it stores. ^Values stored in sqlite3_value objects 4002251883Speter** can be integers, floating point values, strings, BLOBs, or NULL. 4003251883Speter** 4004251883Speter** An sqlite3_value object may be either "protected" or "unprotected". 4005251883Speter** Some interfaces require a protected sqlite3_value. Other interfaces 4006251883Speter** will accept either a protected or an unprotected sqlite3_value. 4007251883Speter** Every interface that accepts sqlite3_value arguments specifies 4008286510Speter** whether or not it requires a protected sqlite3_value. The 4009286510Speter** [sqlite3_value_dup()] interface can be used to construct a new 4010286510Speter** protected sqlite3_value from an unprotected sqlite3_value. 4011251883Speter** 4012251883Speter** The terms "protected" and "unprotected" refer to whether or not 4013251883Speter** a mutex is held. An internal mutex is held for a protected 4014251883Speter** sqlite3_value object but no mutex is held for an unprotected 4015251883Speter** sqlite3_value object. If SQLite is compiled to be single-threaded 4016251883Speter** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4017251883Speter** or if SQLite is run in one of reduced mutex modes 4018251883Speter** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4019251883Speter** then there is no distinction between protected and unprotected 4020251883Speter** sqlite3_value objects and they can be used interchangeably. However, 4021251883Speter** for maximum code portability it is recommended that applications 4022251883Speter** still make the distinction between protected and unprotected 4023251883Speter** sqlite3_value objects even when not strictly required. 4024251883Speter** 4025251883Speter** ^The sqlite3_value objects that are passed as parameters into the 4026251883Speter** implementation of [application-defined SQL functions] are protected. 4027251883Speter** ^The sqlite3_value object returned by 4028251883Speter** [sqlite3_column_value()] is unprotected. 4029342292Scy** Unprotected sqlite3_value objects may only be used as arguments 4030342292Scy** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4031342292Scy** [sqlite3_value_dup()]. 4032251883Speter** The [sqlite3_value_blob | sqlite3_value_type()] family of 4033251883Speter** interfaces require protected sqlite3_value objects. 4034251883Speter*/ 4035322444Spetertypedef struct sqlite3_value sqlite3_value; 4036251883Speter 4037251883Speter/* 4038251883Speter** CAPI3REF: SQL Function Context Object 4039251883Speter** 4040251883Speter** The context in which an SQL function executes is stored in an 4041251883Speter** sqlite3_context object. ^A pointer to an sqlite3_context object 4042251883Speter** is always first parameter to [application-defined SQL functions]. 4043251883Speter** The application-defined SQL function implementation will pass this 4044251883Speter** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4045251883Speter** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4046251883Speter** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4047251883Speter** and/or [sqlite3_set_auxdata()]. 4048251883Speter*/ 4049251883Spetertypedef struct sqlite3_context sqlite3_context; 4050251883Speter 4051251883Speter/* 4052251883Speter** CAPI3REF: Binding Values To Prepared Statements 4053251883Speter** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4054251883Speter** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4055286510Speter** METHOD: sqlite3_stmt 4056251883Speter** 4057251883Speter** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4058251883Speter** literals may be replaced by a [parameter] that matches one of following 4059251883Speter** templates: 4060251883Speter** 4061251883Speter** <ul> 4062251883Speter** <li> ? 4063251883Speter** <li> ?NNN 4064251883Speter** <li> :VVV 4065251883Speter** <li> @VVV 4066251883Speter** <li> $VVV 4067251883Speter** </ul> 4068251883Speter** 4069251883Speter** In the templates above, NNN represents an integer literal, 4070251883Speter** and VVV represents an alphanumeric identifier.)^ ^The values of these 4071251883Speter** parameters (also called "host parameter names" or "SQL parameters") 4072251883Speter** can be set using the sqlite3_bind_*() routines defined here. 4073251883Speter** 4074251883Speter** ^The first argument to the sqlite3_bind_*() routines is always 4075251883Speter** a pointer to the [sqlite3_stmt] object returned from 4076251883Speter** [sqlite3_prepare_v2()] or its variants. 4077251883Speter** 4078251883Speter** ^The second argument is the index of the SQL parameter to be set. 4079251883Speter** ^The leftmost SQL parameter has an index of 1. ^When the same named 4080251883Speter** SQL parameter is used more than once, second and subsequent 4081251883Speter** occurrences have the same index as the first occurrence. 4082251883Speter** ^The index for named parameters can be looked up using the 4083251883Speter** [sqlite3_bind_parameter_index()] API if desired. ^The index 4084251883Speter** for "?NNN" parameters is the value of NNN. 4085251883Speter** ^The NNN value must be between 1 and the [sqlite3_limit()] 4086251883Speter** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4087251883Speter** 4088251883Speter** ^The third argument is the value to bind to the parameter. 4089251883Speter** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4090251883Speter** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4091251883Speter** is ignored and the end result is the same as sqlite3_bind_null(). 4092251883Speter** 4093251883Speter** ^(In those routines that have a fourth argument, its value is the 4094251883Speter** number of bytes in the parameter. To be clear: the value is the 4095251883Speter** number of <u>bytes</u> in the value, not the number of characters.)^ 4096251883Speter** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4097251883Speter** is negative, then the length of the string is 4098251883Speter** the number of bytes up to the first zero terminator. 4099251883Speter** If the fourth parameter to sqlite3_bind_blob() is negative, then 4100251883Speter** the behavior is undefined. 4101251883Speter** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4102274884Sbapt** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4103274884Sbapt** that parameter must be the byte offset 4104251883Speter** where the NUL terminator would occur assuming the string were NUL 4105251883Speter** terminated. If any NUL characters occur at byte offsets less than 4106251883Speter** the value of the fourth parameter then the resulting string value will 4107251883Speter** contain embedded NULs. The result of expressions involving strings 4108251883Speter** with embedded NULs is undefined. 4109251883Speter** 4110274884Sbapt** ^The fifth argument to the BLOB and string binding interfaces 4111274884Sbapt** is a destructor used to dispose of the BLOB or 4112251883Speter** string after SQLite has finished with it. ^The destructor is called 4113347347Scy** to dispose of the BLOB or string even if the call to the bind API fails, 4114347347Scy** except the destructor is not called if the third parameter is a NULL 4115347347Scy** pointer or the fourth parameter is negative. 4116251883Speter** ^If the fifth argument is 4117251883Speter** the special value [SQLITE_STATIC], then SQLite assumes that the 4118251883Speter** information is in static, unmanaged space and does not need to be freed. 4119251883Speter** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4120251883Speter** SQLite makes its own private copy of the data immediately, before 4121251883Speter** the sqlite3_bind_*() routine returns. 4122251883Speter** 4123274884Sbapt** ^The sixth argument to sqlite3_bind_text64() must be one of 4124274884Sbapt** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4125274884Sbapt** to specify the encoding of the text in the third parameter. If 4126274884Sbapt** the sixth argument to sqlite3_bind_text64() is not one of the 4127274884Sbapt** allowed values shown above, or if the text encoding is different 4128274884Sbapt** from the encoding specified by the sixth parameter, then the behavior 4129274884Sbapt** is undefined. 4130274884Sbapt** 4131251883Speter** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4132251883Speter** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4133251883Speter** (just an integer to hold its size) while it is being processed. 4134251883Speter** Zeroblobs are intended to serve as placeholders for BLOBs whose 4135251883Speter** content is later written using 4136251883Speter** [sqlite3_blob_open | incremental BLOB I/O] routines. 4137251883Speter** ^A negative value for the zeroblob results in a zero-length BLOB. 4138251883Speter** 4139322444Speter** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4140322444Speter** [prepared statement] S to have an SQL value of NULL, but to also be 4141322444Speter** associated with the pointer P of type T. ^D is either a NULL pointer or 4142322444Speter** a pointer to a destructor function for P. ^SQLite will invoke the 4143322444Speter** destructor D with a single argument of P when it is finished using 4144322444Speter** P. The T parameter should be a static string, preferably a string 4145322444Speter** literal. The sqlite3_bind_pointer() routine is part of the 4146322444Speter** [pointer passing interface] added for SQLite 3.20.0. 4147322444Speter** 4148251883Speter** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4149251883Speter** for the [prepared statement] or with a prepared statement for which 4150251883Speter** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4151251883Speter** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4152251883Speter** routine is passed a [prepared statement] that has been finalized, the 4153251883Speter** result is undefined and probably harmful. 4154251883Speter** 4155251883Speter** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4156251883Speter** ^Unbound parameters are interpreted as NULL. 4157251883Speter** 4158251883Speter** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4159251883Speter** [error code] if anything goes wrong. 4160274884Sbapt** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4161274884Sbapt** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4162274884Sbapt** [SQLITE_MAX_LENGTH]. 4163251883Speter** ^[SQLITE_RANGE] is returned if the parameter 4164251883Speter** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4165251883Speter** 4166251883Speter** See also: [sqlite3_bind_parameter_count()], 4167251883Speter** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4168251883Speter*/ 4169322444SpeterSQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4170322444SpeterSQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4171274884Sbapt void(*)(void*)); 4172322444SpeterSQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4173322444SpeterSQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4174322444SpeterSQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4175322444SpeterSQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4176322444SpeterSQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4177322444SpeterSQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4178322444SpeterSQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4179274884Sbapt void(*)(void*), unsigned char encoding); 4180322444SpeterSQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4181322444SpeterSQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4182322444SpeterSQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4183322444SpeterSQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4184251883Speter 4185251883Speter/* 4186251883Speter** CAPI3REF: Number Of SQL Parameters 4187286510Speter** METHOD: sqlite3_stmt 4188251883Speter** 4189251883Speter** ^This routine can be used to find the number of [SQL parameters] 4190251883Speter** in a [prepared statement]. SQL parameters are tokens of the 4191251883Speter** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4192251883Speter** placeholders for values that are [sqlite3_bind_blob | bound] 4193251883Speter** to the parameters at a later time. 4194251883Speter** 4195251883Speter** ^(This routine actually returns the index of the largest (rightmost) 4196251883Speter** parameter. For all forms except ?NNN, this will correspond to the 4197251883Speter** number of unique parameters. If parameters of the ?NNN form are used, 4198251883Speter** there may be gaps in the list.)^ 4199251883Speter** 4200251883Speter** See also: [sqlite3_bind_blob|sqlite3_bind()], 4201251883Speter** [sqlite3_bind_parameter_name()], and 4202251883Speter** [sqlite3_bind_parameter_index()]. 4203251883Speter*/ 4204322444SpeterSQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4205251883Speter 4206251883Speter/* 4207251883Speter** CAPI3REF: Name Of A Host Parameter 4208286510Speter** METHOD: sqlite3_stmt 4209251883Speter** 4210251883Speter** ^The sqlite3_bind_parameter_name(P,N) interface returns 4211251883Speter** the name of the N-th [SQL parameter] in the [prepared statement] P. 4212251883Speter** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4213251883Speter** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4214251883Speter** respectively. 4215251883Speter** In other words, the initial ":" or "$" or "@" or "?" 4216251883Speter** is included as part of the name.)^ 4217251883Speter** ^Parameters of the form "?" without a following integer have no name 4218251883Speter** and are referred to as "nameless" or "anonymous parameters". 4219251883Speter** 4220251883Speter** ^The first host parameter has an index of 1, not 0. 4221251883Speter** 4222251883Speter** ^If the value N is out of range or if the N-th parameter is 4223251883Speter** nameless, then NULL is returned. ^The returned string is 4224251883Speter** always in UTF-8 encoding even if the named parameter was 4225322444Speter** originally specified as UTF-16 in [sqlite3_prepare16()], 4226322444Speter** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4227251883Speter** 4228251883Speter** See also: [sqlite3_bind_blob|sqlite3_bind()], 4229251883Speter** [sqlite3_bind_parameter_count()], and 4230251883Speter** [sqlite3_bind_parameter_index()]. 4231251883Speter*/ 4232322444SpeterSQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4233251883Speter 4234251883Speter/* 4235251883Speter** CAPI3REF: Index Of A Parameter With A Given Name 4236286510Speter** METHOD: sqlite3_stmt 4237251883Speter** 4238251883Speter** ^Return the index of an SQL parameter given its name. ^The 4239251883Speter** index value returned is suitable for use as the second 4240251883Speter** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4241251883Speter** is returned if no matching parameter is found. ^The parameter 4242251883Speter** name must be given in UTF-8 even if the original statement 4243322444Speter** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4244322444Speter** [sqlite3_prepare16_v3()]. 4245251883Speter** 4246251883Speter** See also: [sqlite3_bind_blob|sqlite3_bind()], 4247251883Speter** [sqlite3_bind_parameter_count()], and 4248298161Sbapt** [sqlite3_bind_parameter_name()]. 4249251883Speter*/ 4250322444SpeterSQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4251251883Speter 4252251883Speter/* 4253251883Speter** CAPI3REF: Reset All Bindings On A Prepared Statement 4254286510Speter** METHOD: sqlite3_stmt 4255251883Speter** 4256251883Speter** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4257251883Speter** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4258251883Speter** ^Use this routine to reset all host parameters to NULL. 4259251883Speter*/ 4260322444SpeterSQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4261251883Speter 4262251883Speter/* 4263251883Speter** CAPI3REF: Number Of Columns In A Result Set 4264286510Speter** METHOD: sqlite3_stmt 4265251883Speter** 4266251883Speter** ^Return the number of columns in the result set returned by the 4267322444Speter** [prepared statement]. ^If this routine returns 0, that means the 4268322444Speter** [prepared statement] returns no data (for example an [UPDATE]). 4269322444Speter** ^However, just because this routine returns a positive number does not 4270322444Speter** mean that one or more rows of data will be returned. ^A SELECT statement 4271322444Speter** will always have a positive sqlite3_column_count() but depending on the 4272322444Speter** WHERE clause constraints and the table content, it might return no rows. 4273251883Speter** 4274251883Speter** See also: [sqlite3_data_count()] 4275251883Speter*/ 4276322444SpeterSQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4277251883Speter 4278251883Speter/* 4279251883Speter** CAPI3REF: Column Names In A Result Set 4280286510Speter** METHOD: sqlite3_stmt 4281251883Speter** 4282251883Speter** ^These routines return the name assigned to a particular column 4283251883Speter** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4284251883Speter** interface returns a pointer to a zero-terminated UTF-8 string 4285251883Speter** and sqlite3_column_name16() returns a pointer to a zero-terminated 4286251883Speter** UTF-16 string. ^The first parameter is the [prepared statement] 4287251883Speter** that implements the [SELECT] statement. ^The second parameter is the 4288251883Speter** column number. ^The leftmost column is number 0. 4289251883Speter** 4290251883Speter** ^The returned string pointer is valid until either the [prepared statement] 4291251883Speter** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4292251883Speter** reprepared by the first call to [sqlite3_step()] for a particular run 4293251883Speter** or until the next call to 4294251883Speter** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4295251883Speter** 4296251883Speter** ^If sqlite3_malloc() fails during the processing of either routine 4297251883Speter** (for example during a conversion from UTF-8 to UTF-16) then a 4298251883Speter** NULL pointer is returned. 4299251883Speter** 4300251883Speter** ^The name of a result column is the value of the "AS" clause for 4301251883Speter** that column, if there is an AS clause. If there is no AS clause 4302251883Speter** then the name of the column is unspecified and may change from 4303251883Speter** one release of SQLite to the next. 4304251883Speter*/ 4305322444SpeterSQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4306322444SpeterSQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4307251883Speter 4308251883Speter/* 4309251883Speter** CAPI3REF: Source Of Data In A Query Result 4310286510Speter** METHOD: sqlite3_stmt 4311251883Speter** 4312251883Speter** ^These routines provide a means to determine the database, table, and 4313251883Speter** table column that is the origin of a particular result column in 4314251883Speter** [SELECT] statement. 4315251883Speter** ^The name of the database or table or column can be returned as 4316251883Speter** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4317251883Speter** the database name, the _table_ routines return the table name, and 4318251883Speter** the origin_ routines return the column name. 4319251883Speter** ^The returned string is valid until the [prepared statement] is destroyed 4320251883Speter** using [sqlite3_finalize()] or until the statement is automatically 4321251883Speter** reprepared by the first call to [sqlite3_step()] for a particular run 4322251883Speter** or until the same information is requested 4323251883Speter** again in a different encoding. 4324251883Speter** 4325251883Speter** ^The names returned are the original un-aliased names of the 4326251883Speter** database, table, and column. 4327251883Speter** 4328251883Speter** ^The first argument to these interfaces is a [prepared statement]. 4329251883Speter** ^These functions return information about the Nth result column returned by 4330251883Speter** the statement, where N is the second function argument. 4331251883Speter** ^The left-most column is column 0 for these routines. 4332251883Speter** 4333251883Speter** ^If the Nth column returned by the statement is an expression or 4334251883Speter** subquery and is not a column value, then all of these functions return 4335251883Speter** NULL. ^These routine might also return NULL if a memory allocation error 4336251883Speter** occurs. ^Otherwise, they return the name of the attached database, table, 4337251883Speter** or column that query result column was extracted from. 4338251883Speter** 4339251883Speter** ^As with all other SQLite APIs, those whose names end with "16" return 4340251883Speter** UTF-16 encoded strings and the other functions return UTF-8. 4341251883Speter** 4342251883Speter** ^These APIs are only available if the library was compiled with the 4343251883Speter** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4344251883Speter** 4345251883Speter** If two or more threads call one or more of these routines against the same 4346251883Speter** prepared statement and column at the same time then the results are 4347251883Speter** undefined. 4348251883Speter** 4349251883Speter** If two or more threads call one or more 4350251883Speter** [sqlite3_column_database_name | column metadata interfaces] 4351251883Speter** for the same [prepared statement] and result column 4352251883Speter** at the same time then the results are undefined. 4353251883Speter*/ 4354322444SpeterSQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4355322444SpeterSQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4356322444SpeterSQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4357322444SpeterSQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4358322444SpeterSQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4359322444SpeterSQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4360251883Speter 4361251883Speter/* 4362251883Speter** CAPI3REF: Declared Datatype Of A Query Result 4363286510Speter** METHOD: sqlite3_stmt 4364251883Speter** 4365251883Speter** ^(The first parameter is a [prepared statement]. 4366251883Speter** If this statement is a [SELECT] statement and the Nth column of the 4367251883Speter** returned result set of that [SELECT] is a table column (not an 4368251883Speter** expression or subquery) then the declared type of the table 4369251883Speter** column is returned.)^ ^If the Nth column of the result set is an 4370251883Speter** expression or subquery, then a NULL pointer is returned. 4371251883Speter** ^The returned string is always UTF-8 encoded. 4372251883Speter** 4373251883Speter** ^(For example, given the database schema: 4374251883Speter** 4375251883Speter** CREATE TABLE t1(c1 VARIANT); 4376251883Speter** 4377251883Speter** and the following statement to be compiled: 4378251883Speter** 4379251883Speter** SELECT c1 + 1, c1 FROM t1; 4380251883Speter** 4381251883Speter** this routine would return the string "VARIANT" for the second result 4382251883Speter** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4383251883Speter** 4384251883Speter** ^SQLite uses dynamic run-time typing. ^So just because a column 4385251883Speter** is declared to contain a particular type does not mean that the 4386251883Speter** data stored in that column is of the declared type. SQLite is 4387251883Speter** strongly typed, but the typing is dynamic not static. ^Type 4388251883Speter** is associated with individual values, not with the containers 4389251883Speter** used to hold those values. 4390251883Speter*/ 4391322444SpeterSQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4392322444SpeterSQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4393251883Speter 4394251883Speter/* 4395251883Speter** CAPI3REF: Evaluate An SQL Statement 4396286510Speter** METHOD: sqlite3_stmt 4397251883Speter** 4398322444Speter** After a [prepared statement] has been prepared using any of 4399322444Speter** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4400322444Speter** or [sqlite3_prepare16_v3()] or one of the legacy 4401251883Speter** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4402251883Speter** must be called one or more times to evaluate the statement. 4403251883Speter** 4404251883Speter** The details of the behavior of the sqlite3_step() interface depend 4405322444Speter** on whether the statement was prepared using the newer "vX" interfaces 4406322444Speter** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4407322444Speter** [sqlite3_prepare16_v2()] or the older legacy 4408322444Speter** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4409322444Speter** new "vX" interface is recommended for new applications but the legacy 4410251883Speter** interface will continue to be supported. 4411251883Speter** 4412251883Speter** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4413251883Speter** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4414251883Speter** ^With the "v2" interface, any of the other [result codes] or 4415251883Speter** [extended result codes] might be returned as well. 4416251883Speter** 4417251883Speter** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4418251883Speter** database locks it needs to do its job. ^If the statement is a [COMMIT] 4419251883Speter** or occurs outside of an explicit transaction, then you can retry the 4420251883Speter** statement. If the statement is not a [COMMIT] and occurs within an 4421251883Speter** explicit transaction then you should rollback the transaction before 4422251883Speter** continuing. 4423251883Speter** 4424251883Speter** ^[SQLITE_DONE] means that the statement has finished executing 4425251883Speter** successfully. sqlite3_step() should not be called again on this virtual 4426251883Speter** machine without first calling [sqlite3_reset()] to reset the virtual 4427251883Speter** machine back to its initial state. 4428251883Speter** 4429251883Speter** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4430251883Speter** is returned each time a new row of data is ready for processing by the 4431251883Speter** caller. The values may be accessed using the [column access functions]. 4432251883Speter** sqlite3_step() is called again to retrieve the next row of data. 4433251883Speter** 4434251883Speter** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4435251883Speter** violation) has occurred. sqlite3_step() should not be called again on 4436251883Speter** the VM. More information may be found by calling [sqlite3_errmsg()]. 4437251883Speter** ^With the legacy interface, a more specific error code (for example, 4438251883Speter** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4439251883Speter** can be obtained by calling [sqlite3_reset()] on the 4440251883Speter** [prepared statement]. ^In the "v2" interface, 4441251883Speter** the more specific error code is returned directly by sqlite3_step(). 4442251883Speter** 4443251883Speter** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4444251883Speter** Perhaps it was called on a [prepared statement] that has 4445251883Speter** already been [sqlite3_finalize | finalized] or on one that had 4446251883Speter** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4447251883Speter** be the case that the same database connection is being used by two or 4448251883Speter** more threads at the same moment in time. 4449251883Speter** 4450251883Speter** For all versions of SQLite up to and including 3.6.23.1, a call to 4451251883Speter** [sqlite3_reset()] was required after sqlite3_step() returned anything 4452251883Speter** other than [SQLITE_ROW] before any subsequent invocation of 4453251883Speter** sqlite3_step(). Failure to reset the prepared statement using 4454251883Speter** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4455342292Scy** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4456322444Speter** sqlite3_step() began 4457251883Speter** calling [sqlite3_reset()] automatically in this circumstance rather 4458251883Speter** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4459251883Speter** break because any application that ever receives an SQLITE_MISUSE error 4460251883Speter** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4461251883Speter** can be used to restore the legacy behavior. 4462251883Speter** 4463251883Speter** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4464251883Speter** API always returns a generic error code, [SQLITE_ERROR], following any 4465251883Speter** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4466251883Speter** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4467251883Speter** specific [error codes] that better describes the error. 4468251883Speter** We admit that this is a goofy design. The problem has been fixed 4469251883Speter** with the "v2" interface. If you prepare all of your SQL statements 4470322444Speter** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4471322444Speter** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4472251883Speter** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4473251883Speter** then the more specific [error codes] are returned directly 4474322444Speter** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4475251883Speter*/ 4476322444SpeterSQLITE_API int sqlite3_step(sqlite3_stmt*); 4477251883Speter 4478251883Speter/* 4479251883Speter** CAPI3REF: Number of columns in a result set 4480286510Speter** METHOD: sqlite3_stmt 4481251883Speter** 4482251883Speter** ^The sqlite3_data_count(P) interface returns the number of columns in the 4483251883Speter** current row of the result set of [prepared statement] P. 4484251883Speter** ^If prepared statement P does not have results ready to return 4485251883Speter** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4486251883Speter** interfaces) then sqlite3_data_count(P) returns 0. 4487251883Speter** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4488251883Speter** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4489251883Speter** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4490251883Speter** will return non-zero if previous call to [sqlite3_step](P) returned 4491251883Speter** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4492251883Speter** where it always returns zero since each step of that multi-step 4493251883Speter** pragma returns 0 columns of data. 4494251883Speter** 4495251883Speter** See also: [sqlite3_column_count()] 4496251883Speter*/ 4497322444SpeterSQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4498251883Speter 4499251883Speter/* 4500251883Speter** CAPI3REF: Fundamental Datatypes 4501251883Speter** KEYWORDS: SQLITE_TEXT 4502251883Speter** 4503251883Speter** ^(Every value in SQLite has one of five fundamental datatypes: 4504251883Speter** 4505251883Speter** <ul> 4506251883Speter** <li> 64-bit signed integer 4507251883Speter** <li> 64-bit IEEE floating point number 4508251883Speter** <li> string 4509251883Speter** <li> BLOB 4510251883Speter** <li> NULL 4511251883Speter** </ul>)^ 4512251883Speter** 4513251883Speter** These constants are codes for each of those types. 4514251883Speter** 4515251883Speter** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4516251883Speter** for a completely different meaning. Software that links against both 4517251883Speter** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4518251883Speter** SQLITE_TEXT. 4519251883Speter*/ 4520251883Speter#define SQLITE_INTEGER 1 4521251883Speter#define SQLITE_FLOAT 2 4522251883Speter#define SQLITE_BLOB 4 4523251883Speter#define SQLITE_NULL 5 4524251883Speter#ifdef SQLITE_TEXT 4525251883Speter# undef SQLITE_TEXT 4526251883Speter#else 4527251883Speter# define SQLITE_TEXT 3 4528251883Speter#endif 4529251883Speter#define SQLITE3_TEXT 3 4530251883Speter 4531251883Speter/* 4532251883Speter** CAPI3REF: Result Values From A Query 4533251883Speter** KEYWORDS: {column access functions} 4534286510Speter** METHOD: sqlite3_stmt 4535251883Speter** 4536322444Speter** <b>Summary:</b> 4537322444Speter** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4538322444Speter** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4539322444Speter** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4540322444Speter** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4541322444Speter** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4542322444Speter** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4543322444Speter** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4544322444Speter** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4545322444Speter** [sqlite3_value|unprotected sqlite3_value] object. 4546322444Speter** <tr><td> <td> <td> 4547322444Speter** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4548322444Speter** or a UTF-8 TEXT result in bytes 4549322444Speter** <tr><td><b>sqlite3_column_bytes16 </b> 4550322444Speter** <td>→ <td>Size of UTF-16 4551322444Speter** TEXT in bytes 4552322444Speter** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4553322444Speter** datatype of the result 4554322444Speter** </table></blockquote> 4555322444Speter** 4556322444Speter** <b>Details:</b> 4557322444Speter** 4558251883Speter** ^These routines return information about a single column of the current 4559251883Speter** result row of a query. ^In every case the first argument is a pointer 4560251883Speter** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4561251883Speter** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4562251883Speter** and the second argument is the index of the column for which information 4563251883Speter** should be returned. ^The leftmost column of the result set has the index 0. 4564251883Speter** ^The number of columns in the result can be determined using 4565251883Speter** [sqlite3_column_count()]. 4566251883Speter** 4567251883Speter** If the SQL statement does not currently point to a valid row, or if the 4568251883Speter** column index is out of range, the result is undefined. 4569251883Speter** These routines may only be called when the most recent call to 4570251883Speter** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4571251883Speter** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4572251883Speter** If any of these routines are called after [sqlite3_reset()] or 4573251883Speter** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4574251883Speter** something other than [SQLITE_ROW], the results are undefined. 4575251883Speter** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4576251883Speter** are called from a different thread while any of these routines 4577251883Speter** are pending, then the results are undefined. 4578251883Speter** 4579322444Speter** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4580322444Speter** each return the value of a result column in a specific data format. If 4581322444Speter** the result column is not initially in the requested format (for example, 4582322444Speter** if the query returns an integer but the sqlite3_column_text() interface 4583322444Speter** is used to extract the value) then an automatic type conversion is performed. 4584322444Speter** 4585251883Speter** ^The sqlite3_column_type() routine returns the 4586251883Speter** [SQLITE_INTEGER | datatype code] for the initial data type 4587251883Speter** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4588322444Speter** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4589322444Speter** The return value of sqlite3_column_type() can be used to decide which 4590322444Speter** of the first six interface should be used to extract the column value. 4591322444Speter** The value returned by sqlite3_column_type() is only meaningful if no 4592322444Speter** automatic type conversions have occurred for the value in question. 4593322444Speter** After a type conversion, the result of calling sqlite3_column_type() 4594322444Speter** is undefined, though harmless. Future 4595251883Speter** versions of SQLite may change the behavior of sqlite3_column_type() 4596251883Speter** following a type conversion. 4597251883Speter** 4598322444Speter** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4599322444Speter** or sqlite3_column_bytes16() interfaces can be used to determine the size 4600322444Speter** of that BLOB or string. 4601322444Speter** 4602251883Speter** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4603251883Speter** routine returns the number of bytes in that BLOB or string. 4604251883Speter** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4605251883Speter** the string to UTF-8 and then returns the number of bytes. 4606251883Speter** ^If the result is a numeric value then sqlite3_column_bytes() uses 4607251883Speter** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4608251883Speter** the number of bytes in that string. 4609251883Speter** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4610251883Speter** 4611251883Speter** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4612251883Speter** routine returns the number of bytes in that BLOB or string. 4613251883Speter** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4614251883Speter** the string to UTF-16 and then returns the number of bytes. 4615251883Speter** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4616251883Speter** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4617251883Speter** the number of bytes in that string. 4618251883Speter** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4619251883Speter** 4620251883Speter** ^The values returned by [sqlite3_column_bytes()] and 4621251883Speter** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4622251883Speter** of the string. ^For clarity: the values returned by 4623251883Speter** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4624251883Speter** bytes in the string, not the number of characters. 4625251883Speter** 4626251883Speter** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4627251883Speter** even empty strings, are always zero-terminated. ^The return 4628251883Speter** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4629251883Speter** 4630286510Speter** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4631286510Speter** [unprotected sqlite3_value] object. In a multithreaded environment, 4632286510Speter** an unprotected sqlite3_value object may only be used safely with 4633286510Speter** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4634251883Speter** If the [unprotected sqlite3_value] object returned by 4635251883Speter** [sqlite3_column_value()] is used in any other way, including calls 4636251883Speter** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4637286510Speter** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4638322444Speter** Hence, the sqlite3_column_value() interface 4639322444Speter** is normally only useful within the implementation of 4640322444Speter** [application-defined SQL functions] or [virtual tables], not within 4641322444Speter** top-level application code. 4642251883Speter** 4643322444Speter** The these routines may attempt to convert the datatype of the result. 4644322444Speter** ^For example, if the internal representation is FLOAT and a text result 4645251883Speter** is requested, [sqlite3_snprintf()] is used internally to perform the 4646251883Speter** conversion automatically. ^(The following table details the conversions 4647251883Speter** that are applied: 4648251883Speter** 4649251883Speter** <blockquote> 4650251883Speter** <table border="1"> 4651251883Speter** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4652251883Speter** 4653251883Speter** <tr><td> NULL <td> INTEGER <td> Result is 0 4654251883Speter** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4655269851Speter** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4656269851Speter** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4657251883Speter** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4658251883Speter** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4659251883Speter** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4660269851Speter** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4661251883Speter** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4662269851Speter** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4663269851Speter** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4664269851Speter** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4665251883Speter** <tr><td> TEXT <td> BLOB <td> No change 4666269851Speter** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4667269851Speter** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4668251883Speter** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4669251883Speter** </table> 4670251883Speter** </blockquote>)^ 4671251883Speter** 4672251883Speter** Note that when type conversions occur, pointers returned by prior 4673251883Speter** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4674251883Speter** sqlite3_column_text16() may be invalidated. 4675251883Speter** Type conversions and pointer invalidations might occur 4676251883Speter** in the following cases: 4677251883Speter** 4678251883Speter** <ul> 4679251883Speter** <li> The initial content is a BLOB and sqlite3_column_text() or 4680251883Speter** sqlite3_column_text16() is called. A zero-terminator might 4681251883Speter** need to be added to the string.</li> 4682251883Speter** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4683251883Speter** sqlite3_column_text16() is called. The content must be converted 4684251883Speter** to UTF-16.</li> 4685251883Speter** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4686251883Speter** sqlite3_column_text() is called. The content must be converted 4687251883Speter** to UTF-8.</li> 4688251883Speter** </ul> 4689251883Speter** 4690251883Speter** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4691251883Speter** not invalidate a prior pointer, though of course the content of the buffer 4692251883Speter** that the prior pointer references will have been modified. Other kinds 4693251883Speter** of conversion are done in place when it is possible, but sometimes they 4694251883Speter** are not possible and in those cases prior pointers are invalidated. 4695251883Speter** 4696286510Speter** The safest policy is to invoke these routines 4697251883Speter** in one of the following ways: 4698251883Speter** 4699251883Speter** <ul> 4700251883Speter** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4701251883Speter** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4702251883Speter** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4703251883Speter** </ul> 4704251883Speter** 4705251883Speter** In other words, you should call sqlite3_column_text(), 4706251883Speter** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4707251883Speter** into the desired format, then invoke sqlite3_column_bytes() or 4708251883Speter** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4709251883Speter** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4710251883Speter** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4711251883Speter** with calls to sqlite3_column_bytes(). 4712251883Speter** 4713251883Speter** ^The pointers returned are valid until a type conversion occurs as 4714251883Speter** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4715251883Speter** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4716322444Speter** and BLOBs is freed automatically. Do not pass the pointers returned 4717269851Speter** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4718251883Speter** [sqlite3_free()]. 4719251883Speter** 4720342292Scy** As long as the input parameters are correct, these routines will only 4721342292Scy** fail if an out-of-memory error occurs during a format conversion. 4722342292Scy** Only the following subset of interfaces are subject to out-of-memory 4723342292Scy** errors: 4724342292Scy** 4725342292Scy** <ul> 4726342292Scy** <li> sqlite3_column_blob() 4727342292Scy** <li> sqlite3_column_text() 4728342292Scy** <li> sqlite3_column_text16() 4729342292Scy** <li> sqlite3_column_bytes() 4730342292Scy** <li> sqlite3_column_bytes16() 4731342292Scy** </ul> 4732342292Scy** 4733342292Scy** If an out-of-memory error occurs, then the return value from these 4734342292Scy** routines is the same as if the column had contained an SQL NULL value. 4735342292Scy** Valid SQL NULL returns can be distinguished from out-of-memory errors 4736342292Scy** by invoking the [sqlite3_errcode()] immediately after the suspect 4737342292Scy** return value is obtained and before any 4738342292Scy** other SQLite interface is called on the same [database connection]. 4739251883Speter*/ 4740322444SpeterSQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4741322444SpeterSQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4742322444SpeterSQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4743322444SpeterSQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4744322444SpeterSQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4745322444SpeterSQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4746322444SpeterSQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4747322444SpeterSQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4748322444SpeterSQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4749322444SpeterSQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4750251883Speter 4751251883Speter/* 4752251883Speter** CAPI3REF: Destroy A Prepared Statement Object 4753286510Speter** DESTRUCTOR: sqlite3_stmt 4754251883Speter** 4755251883Speter** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4756251883Speter** ^If the most recent evaluation of the statement encountered no errors 4757251883Speter** or if the statement is never been evaluated, then sqlite3_finalize() returns 4758251883Speter** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4759251883Speter** sqlite3_finalize(S) returns the appropriate [error code] or 4760251883Speter** [extended error code]. 4761251883Speter** 4762251883Speter** ^The sqlite3_finalize(S) routine can be called at any point during 4763251883Speter** the life cycle of [prepared statement] S: 4764251883Speter** before statement S is ever evaluated, after 4765251883Speter** one or more calls to [sqlite3_reset()], or after any call 4766251883Speter** to [sqlite3_step()] regardless of whether or not the statement has 4767251883Speter** completed execution. 4768251883Speter** 4769251883Speter** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4770251883Speter** 4771251883Speter** The application must finalize every [prepared statement] in order to avoid 4772251883Speter** resource leaks. It is a grievous error for the application to try to use 4773251883Speter** a prepared statement after it has been finalized. Any use of a prepared 4774251883Speter** statement after it has been finalized can result in undefined and 4775251883Speter** undesirable behavior such as segfaults and heap corruption. 4776251883Speter*/ 4777322444SpeterSQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4778251883Speter 4779251883Speter/* 4780251883Speter** CAPI3REF: Reset A Prepared Statement Object 4781286510Speter** METHOD: sqlite3_stmt 4782251883Speter** 4783251883Speter** The sqlite3_reset() function is called to reset a [prepared statement] 4784251883Speter** object back to its initial state, ready to be re-executed. 4785251883Speter** ^Any SQL statement variables that had values bound to them using 4786251883Speter** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4787251883Speter** Use [sqlite3_clear_bindings()] to reset the bindings. 4788251883Speter** 4789251883Speter** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4790251883Speter** back to the beginning of its program. 4791251883Speter** 4792251883Speter** ^If the most recent call to [sqlite3_step(S)] for the 4793251883Speter** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4794251883Speter** or if [sqlite3_step(S)] has never before been called on S, 4795251883Speter** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4796251883Speter** 4797251883Speter** ^If the most recent call to [sqlite3_step(S)] for the 4798251883Speter** [prepared statement] S indicated an error, then 4799251883Speter** [sqlite3_reset(S)] returns an appropriate [error code]. 4800251883Speter** 4801251883Speter** ^The [sqlite3_reset(S)] interface does not change the values 4802251883Speter** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4803251883Speter*/ 4804322444SpeterSQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4805251883Speter 4806251883Speter/* 4807251883Speter** CAPI3REF: Create Or Redefine SQL Functions 4808251883Speter** KEYWORDS: {function creation routines} 4809251883Speter** KEYWORDS: {application-defined SQL function} 4810251883Speter** KEYWORDS: {application-defined SQL functions} 4811286510Speter** METHOD: sqlite3 4812251883Speter** 4813251883Speter** ^These functions (collectively known as "function creation routines") 4814251883Speter** are used to add SQL functions or aggregates or to redefine the behavior 4815342292Scy** of existing SQL functions or aggregates. The only differences between 4816342292Scy** the three "sqlite3_create_function*" routines are the text encoding 4817342292Scy** expected for the second parameter (the name of the function being 4818342292Scy** created) and the presence or absence of a destructor callback for 4819342292Scy** the application data pointer. Function sqlite3_create_window_function() 4820342292Scy** is similar, but allows the user to supply the extra callback functions 4821342292Scy** needed by [aggregate window functions]. 4822251883Speter** 4823251883Speter** ^The first parameter is the [database connection] to which the SQL 4824251883Speter** function is to be added. ^If an application uses more than one database 4825251883Speter** connection then application-defined SQL functions must be added 4826251883Speter** to each database connection separately. 4827251883Speter** 4828251883Speter** ^The second parameter is the name of the SQL function to be created or 4829251883Speter** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4830251883Speter** representation, exclusive of the zero-terminator. ^Note that the name 4831251883Speter** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4832251883Speter** ^Any attempt to create a function with a longer name 4833251883Speter** will result in [SQLITE_MISUSE] being returned. 4834251883Speter** 4835251883Speter** ^The third parameter (nArg) 4836251883Speter** is the number of arguments that the SQL function or 4837251883Speter** aggregate takes. ^If this parameter is -1, then the SQL function or 4838251883Speter** aggregate may take any number of arguments between 0 and the limit 4839251883Speter** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4840251883Speter** parameter is less than -1 or greater than 127 then the behavior is 4841251883Speter** undefined. 4842251883Speter** 4843251883Speter** ^The fourth parameter, eTextRep, specifies what 4844251883Speter** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4845269851Speter** its parameters. The application should set this parameter to 4846269851Speter** [SQLITE_UTF16LE] if the function implementation invokes 4847269851Speter** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4848269851Speter** implementation invokes [sqlite3_value_text16be()] on an input, or 4849269851Speter** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4850269851Speter** otherwise. ^The same SQL function may be registered multiple times using 4851269851Speter** different preferred text encodings, with different implementations for 4852269851Speter** each encoding. 4853251883Speter** ^When multiple implementations of the same function are available, SQLite 4854251883Speter** will pick the one that involves the least amount of data conversion. 4855251883Speter** 4856269851Speter** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4857269851Speter** to signal that the function will always return the same result given 4858269851Speter** the same inputs within a single SQL statement. Most SQL functions are 4859269851Speter** deterministic. The built-in [random()] SQL function is an example of a 4860269851Speter** function that is not deterministic. The SQLite query planner is able to 4861269851Speter** perform additional optimizations on deterministic functions, so use 4862269851Speter** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4863269851Speter** 4864355326Scy** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4865355326Scy** flag, which if present prevents the function from being invoked from 4866355326Scy** within VIEWs or TRIGGERs. For security reasons, the [SQLITE_DIRECTONLY] 4867355326Scy** flag is recommended for any application-defined SQL function that has 4868355326Scy** side-effects. 4869355326Scy** 4870251883Speter** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4871251883Speter** function can gain access to this pointer using [sqlite3_user_data()].)^ 4872251883Speter** 4873342292Scy** ^The sixth, seventh and eighth parameters passed to the three 4874342292Scy** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4875251883Speter** pointers to C-language functions that implement the SQL function or 4876251883Speter** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4877251883Speter** callback only; NULL pointers must be passed as the xStep and xFinal 4878251883Speter** parameters. ^An aggregate SQL function requires an implementation of xStep 4879251883Speter** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4880251883Speter** SQL function or aggregate, pass NULL pointers for all three function 4881251883Speter** callbacks. 4882251883Speter** 4883342292Scy** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4884342292Scy** and xInverse) passed to sqlite3_create_window_function are pointers to 4885342292Scy** C-language callbacks that implement the new function. xStep and xFinal 4886342292Scy** must both be non-NULL. xValue and xInverse may either both be NULL, in 4887342292Scy** which case a regular aggregate function is created, or must both be 4888342292Scy** non-NULL, in which case the new function may be used as either an aggregate 4889342292Scy** or aggregate window function. More details regarding the implementation 4890342292Scy** of aggregate window functions are 4891342292Scy** [user-defined window functions|available here]. 4892251883Speter** 4893342292Scy** ^(If the final parameter to sqlite3_create_function_v2() or 4894342292Scy** sqlite3_create_window_function() is not NULL, then it is destructor for 4895342292Scy** the application data pointer. The destructor is invoked when the function 4896342292Scy** is deleted, either by being overloaded or when the database connection 4897342292Scy** closes.)^ ^The destructor is also invoked if the call to 4898342292Scy** sqlite3_create_function_v2() fails. ^When the destructor callback is 4899342292Scy** invoked, it is passed a single argument which is a copy of the application 4900342292Scy** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4901342292Scy** 4902251883Speter** ^It is permitted to register multiple implementations of the same 4903251883Speter** functions with the same name but with either differing numbers of 4904251883Speter** arguments or differing preferred text encodings. ^SQLite will use 4905251883Speter** the implementation that most closely matches the way in which the 4906251883Speter** SQL function is used. ^A function implementation with a non-negative 4907251883Speter** nArg parameter is a better match than a function implementation with 4908251883Speter** a negative nArg. ^A function where the preferred text encoding 4909251883Speter** matches the database encoding is a better 4910251883Speter** match than a function where the encoding is different. 4911251883Speter** ^A function where the encoding difference is between UTF16le and UTF16be 4912251883Speter** is a closer match than a function where the encoding difference is 4913251883Speter** between UTF8 and UTF16. 4914251883Speter** 4915251883Speter** ^Built-in functions may be overloaded by new application-defined functions. 4916251883Speter** 4917251883Speter** ^An application-defined function is permitted to call other 4918251883Speter** SQLite interfaces. However, such calls must not 4919251883Speter** close the database connection nor finalize or reset the prepared 4920251883Speter** statement in which the function is running. 4921251883Speter*/ 4922322444SpeterSQLITE_API int sqlite3_create_function( 4923251883Speter sqlite3 *db, 4924251883Speter const char *zFunctionName, 4925251883Speter int nArg, 4926251883Speter int eTextRep, 4927251883Speter void *pApp, 4928251883Speter void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4929251883Speter void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4930251883Speter void (*xFinal)(sqlite3_context*) 4931251883Speter); 4932322444SpeterSQLITE_API int sqlite3_create_function16( 4933251883Speter sqlite3 *db, 4934251883Speter const void *zFunctionName, 4935251883Speter int nArg, 4936251883Speter int eTextRep, 4937251883Speter void *pApp, 4938251883Speter void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4939251883Speter void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4940251883Speter void (*xFinal)(sqlite3_context*) 4941251883Speter); 4942322444SpeterSQLITE_API int sqlite3_create_function_v2( 4943251883Speter sqlite3 *db, 4944251883Speter const char *zFunctionName, 4945251883Speter int nArg, 4946251883Speter int eTextRep, 4947251883Speter void *pApp, 4948251883Speter void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4949251883Speter void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4950251883Speter void (*xFinal)(sqlite3_context*), 4951251883Speter void(*xDestroy)(void*) 4952251883Speter); 4953342292ScySQLITE_API int sqlite3_create_window_function( 4954342292Scy sqlite3 *db, 4955342292Scy const char *zFunctionName, 4956342292Scy int nArg, 4957342292Scy int eTextRep, 4958342292Scy void *pApp, 4959342292Scy void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4960342292Scy void (*xFinal)(sqlite3_context*), 4961342292Scy void (*xValue)(sqlite3_context*), 4962342292Scy void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4963342292Scy void(*xDestroy)(void*) 4964342292Scy); 4965251883Speter 4966251883Speter/* 4967251883Speter** CAPI3REF: Text Encodings 4968251883Speter** 4969251883Speter** These constant define integer codes that represent the various 4970251883Speter** text encodings supported by SQLite. 4971251883Speter*/ 4972282328Sbapt#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4973282328Sbapt#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4974282328Sbapt#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4975251883Speter#define SQLITE_UTF16 4 /* Use native byte order */ 4976269851Speter#define SQLITE_ANY 5 /* Deprecated */ 4977251883Speter#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4978251883Speter 4979251883Speter/* 4980269851Speter** CAPI3REF: Function Flags 4981269851Speter** 4982269851Speter** These constants may be ORed together with the 4983269851Speter** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4984269851Speter** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4985269851Speter** [sqlite3_create_function_v2()]. 4986355326Scy** 4987355326Scy** The SQLITE_DETERMINISTIC flag means that the new function will always 4988355326Scy** maps the same inputs into the same output. The abs() function is 4989355326Scy** deterministic, for example, but randomblob() is not. 4990355326Scy** 4991355326Scy** The SQLITE_DIRECTONLY flag means that the function may only be invoked 4992355326Scy** from top-level SQL, and cannot be used in VIEWs or TRIGGERs. This is 4993355326Scy** a security feature which is recommended for all 4994355326Scy** [application-defined SQL functions] that have side-effects. This flag 4995355326Scy** prevents an attacker from adding triggers and views to a schema then 4996355326Scy** tricking a high-privilege application into causing unintended side-effects 4997355326Scy** while performing ordinary queries. 4998355326Scy** 4999355326Scy** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5000355326Scy** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5001355326Scy** Specifying this flag makes no difference for scalar or aggregate user 5002355326Scy** functions. However, if it is not specified for a user-defined window 5003355326Scy** function, then any sub-types belonging to arguments passed to the window 5004355326Scy** function may be discarded before the window function is called (i.e. 5005355326Scy** sqlite3_value_subtype() will always return 0). 5006269851Speter*/ 5007355326Scy#define SQLITE_DETERMINISTIC 0x000000800 5008355326Scy#define SQLITE_DIRECTONLY 0x000080000 5009355326Scy#define SQLITE_SUBTYPE 0x000100000 5010269851Speter 5011269851Speter/* 5012251883Speter** CAPI3REF: Deprecated Functions 5013251883Speter** DEPRECATED 5014251883Speter** 5015251883Speter** These functions are [deprecated]. In order to maintain 5016251883Speter** backwards compatibility with older code, these functions continue 5017251883Speter** to be supported. However, new applications should avoid 5018282328Sbapt** the use of these functions. To encourage programmers to avoid 5019282328Sbapt** these functions, we will not explain what they do. 5020251883Speter*/ 5021251883Speter#ifndef SQLITE_OMIT_DEPRECATED 5022322444SpeterSQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5023322444SpeterSQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5024322444SpeterSQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5025322444SpeterSQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5026322444SpeterSQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5027322444SpeterSQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5028251883Speter void*,sqlite3_int64); 5029251883Speter#endif 5030251883Speter 5031251883Speter/* 5032286510Speter** CAPI3REF: Obtaining SQL Values 5033286510Speter** METHOD: sqlite3_value 5034251883Speter** 5035322444Speter** <b>Summary:</b> 5036322444Speter** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5037322444Speter** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5038322444Speter** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5039322444Speter** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5040322444Speter** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5041322444Speter** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5042322444Speter** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5043322444Speter** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5044322444Speter** the native byteorder 5045322444Speter** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5046322444Speter** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5047322444Speter** <tr><td> <td> <td> 5048322444Speter** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5049322444Speter** or a UTF-8 TEXT in bytes 5050322444Speter** <tr><td><b>sqlite3_value_bytes16 </b> 5051322444Speter** <td>→ <td>Size of UTF-16 5052322444Speter** TEXT in bytes 5053322444Speter** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5054322444Speter** datatype of the value 5055322444Speter** <tr><td><b>sqlite3_value_numeric_type </b> 5056322444Speter** <td>→ <td>Best numeric datatype of the value 5057342292Scy** <tr><td><b>sqlite3_value_nochange </b> 5058342292Scy** <td>→ <td>True if the column is unchanged in an UPDATE 5059342292Scy** against a virtual table. 5060347347Scy** <tr><td><b>sqlite3_value_frombind </b> 5061347347Scy** <td>→ <td>True if value originated from a [bound parameter] 5062322444Speter** </table></blockquote> 5063251883Speter** 5064322444Speter** <b>Details:</b> 5065251883Speter** 5066322444Speter** These routines extract type, size, and content information from 5067322444Speter** [protected sqlite3_value] objects. Protected sqlite3_value objects 5068322444Speter** are used to pass parameter information into implementation of 5069322444Speter** [application-defined SQL functions] and [virtual tables]. 5070322444Speter** 5071251883Speter** These routines work only with [protected sqlite3_value] objects. 5072251883Speter** Any attempt to use these routines on an [unprotected sqlite3_value] 5073322444Speter** is not threadsafe. 5074251883Speter** 5075251883Speter** ^These routines work just like the corresponding [column access functions] 5076274884Sbapt** except that these routines take a single [protected sqlite3_value] object 5077251883Speter** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5078251883Speter** 5079251883Speter** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5080251883Speter** in the native byte-order of the host machine. ^The 5081251883Speter** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5082251883Speter** extract UTF-16 strings as big-endian and little-endian respectively. 5083251883Speter** 5084322444Speter** ^If [sqlite3_value] object V was initialized 5085322444Speter** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5086322444Speter** and if X and Y are strings that compare equal according to strcmp(X,Y), 5087322444Speter** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5088322444Speter** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5089322444Speter** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5090322444Speter** 5091322444Speter** ^(The sqlite3_value_type(V) interface returns the 5092322444Speter** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5093322444Speter** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5094322444Speter** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5095322444Speter** Other interfaces might change the datatype for an sqlite3_value object. 5096322444Speter** For example, if the datatype is initially SQLITE_INTEGER and 5097322444Speter** sqlite3_value_text(V) is called to extract a text value for that 5098322444Speter** integer, then subsequent calls to sqlite3_value_type(V) might return 5099322444Speter** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5100322444Speter** occurs is undefined and may change from one release of SQLite to the next. 5101322444Speter** 5102251883Speter** ^(The sqlite3_value_numeric_type() interface attempts to apply 5103251883Speter** numeric affinity to the value. This means that an attempt is 5104251883Speter** made to convert the value to an integer or floating point. If 5105251883Speter** such a conversion is possible without loss of information (in other 5106251883Speter** words, if the value is a string that looks like a number) 5107251883Speter** then the conversion is performed. Otherwise no conversion occurs. 5108251883Speter** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5109251883Speter** 5110342292Scy** ^Within the [xUpdate] method of a [virtual table], the 5111342292Scy** sqlite3_value_nochange(X) interface returns true if and only if 5112342292Scy** the column corresponding to X is unchanged by the UPDATE operation 5113342292Scy** that the xUpdate method call was invoked to implement and if 5114342292Scy** and the prior [xColumn] method call that was invoked to extracted 5115342292Scy** the value for that column returned without setting a result (probably 5116342292Scy** because it queried [sqlite3_vtab_nochange()] and found that the column 5117342292Scy** was unchanging). ^Within an [xUpdate] method, any value for which 5118342292Scy** sqlite3_value_nochange(X) is true will in all other respects appear 5119342292Scy** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5120342292Scy** than within an [xUpdate] method call for an UPDATE statement, then 5121342292Scy** the return value is arbitrary and meaningless. 5122342292Scy** 5123347347Scy** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5124347347Scy** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5125347347Scy** interfaces. ^If X comes from an SQL literal value, or a table column, 5126347347Scy** and expression, then sqlite3_value_frombind(X) returns zero. 5127347347Scy** 5128251883Speter** Please pay particular attention to the fact that the pointer returned 5129251883Speter** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5130251883Speter** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5131251883Speter** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5132251883Speter** or [sqlite3_value_text16()]. 5133251883Speter** 5134251883Speter** These routines must be called from the same thread as 5135251883Speter** the SQL function that supplied the [sqlite3_value*] parameters. 5136342292Scy** 5137342292Scy** As long as the input parameter is correct, these routines can only 5138342292Scy** fail if an out-of-memory error occurs during a format conversion. 5139342292Scy** Only the following subset of interfaces are subject to out-of-memory 5140342292Scy** errors: 5141342292Scy** 5142342292Scy** <ul> 5143342292Scy** <li> sqlite3_value_blob() 5144342292Scy** <li> sqlite3_value_text() 5145342292Scy** <li> sqlite3_value_text16() 5146342292Scy** <li> sqlite3_value_text16le() 5147342292Scy** <li> sqlite3_value_text16be() 5148342292Scy** <li> sqlite3_value_bytes() 5149342292Scy** <li> sqlite3_value_bytes16() 5150342292Scy** </ul> 5151342292Scy** 5152342292Scy** If an out-of-memory error occurs, then the return value from these 5153342292Scy** routines is the same as if the column had contained an SQL NULL value. 5154342292Scy** Valid SQL NULL returns can be distinguished from out-of-memory errors 5155342292Scy** by invoking the [sqlite3_errcode()] immediately after the suspect 5156342292Scy** return value is obtained and before any 5157342292Scy** other SQLite interface is called on the same [database connection]. 5158251883Speter*/ 5159322444SpeterSQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5160322444SpeterSQLITE_API double sqlite3_value_double(sqlite3_value*); 5161322444SpeterSQLITE_API int sqlite3_value_int(sqlite3_value*); 5162322444SpeterSQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5163322444SpeterSQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5164322444SpeterSQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5165322444SpeterSQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5166322444SpeterSQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5167322444SpeterSQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5168322444SpeterSQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5169322444SpeterSQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5170322444SpeterSQLITE_API int sqlite3_value_type(sqlite3_value*); 5171322444SpeterSQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5172342292ScySQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5173347347ScySQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5174251883Speter 5175251883Speter/* 5176298161Sbapt** CAPI3REF: Finding The Subtype Of SQL Values 5177298161Sbapt** METHOD: sqlite3_value 5178298161Sbapt** 5179298161Sbapt** The sqlite3_value_subtype(V) function returns the subtype for 5180298161Sbapt** an [application-defined SQL function] argument V. The subtype 5181298161Sbapt** information can be used to pass a limited amount of context from 5182298161Sbapt** one SQL function to another. Use the [sqlite3_result_subtype()] 5183298161Sbapt** routine to set the subtype for the return value of an SQL function. 5184298161Sbapt*/ 5185322444SpeterSQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5186298161Sbapt 5187298161Sbapt/* 5188286510Speter** CAPI3REF: Copy And Free SQL Values 5189286510Speter** METHOD: sqlite3_value 5190286510Speter** 5191286510Speter** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5192286510Speter** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5193286510Speter** is a [protected sqlite3_value] object even if the input is not. 5194286510Speter** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5195286510Speter** memory allocation fails. 5196286510Speter** 5197286510Speter** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5198286510Speter** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5199286510Speter** then sqlite3_value_free(V) is a harmless no-op. 5200286510Speter*/ 5201322444SpeterSQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5202322444SpeterSQLITE_API void sqlite3_value_free(sqlite3_value*); 5203286510Speter 5204286510Speter/* 5205251883Speter** CAPI3REF: Obtain Aggregate Function Context 5206286510Speter** METHOD: sqlite3_context 5207251883Speter** 5208251883Speter** Implementations of aggregate SQL functions use this 5209251883Speter** routine to allocate memory for storing their state. 5210251883Speter** 5211251883Speter** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5212251883Speter** for a particular aggregate function, SQLite 5213251883Speter** allocates N of memory, zeroes out that memory, and returns a pointer 5214251883Speter** to the new memory. ^On second and subsequent calls to 5215251883Speter** sqlite3_aggregate_context() for the same aggregate function instance, 5216251883Speter** the same buffer is returned. Sqlite3_aggregate_context() is normally 5217251883Speter** called once for each invocation of the xStep callback and then one 5218251883Speter** last time when the xFinal callback is invoked. ^(When no rows match 5219251883Speter** an aggregate query, the xStep() callback of the aggregate function 5220251883Speter** implementation is never called and xFinal() is called exactly once. 5221251883Speter** In those cases, sqlite3_aggregate_context() might be called for the 5222251883Speter** first time from within xFinal().)^ 5223251883Speter** 5224251883Speter** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5225251883Speter** when first called if N is less than or equal to zero or if a memory 5226251883Speter** allocate error occurs. 5227251883Speter** 5228251883Speter** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5229251883Speter** determined by the N parameter on first successful call. Changing the 5230251883Speter** value of N in subsequent call to sqlite3_aggregate_context() within 5231251883Speter** the same aggregate function instance will not resize the memory 5232251883Speter** allocation.)^ Within the xFinal callback, it is customary to set 5233251883Speter** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5234251883Speter** pointless memory allocations occur. 5235251883Speter** 5236251883Speter** ^SQLite automatically frees the memory allocated by 5237251883Speter** sqlite3_aggregate_context() when the aggregate query concludes. 5238251883Speter** 5239251883Speter** The first parameter must be a copy of the 5240251883Speter** [sqlite3_context | SQL function context] that is the first parameter 5241251883Speter** to the xStep or xFinal callback routine that implements the aggregate 5242251883Speter** function. 5243251883Speter** 5244251883Speter** This routine must be called from the same thread in which 5245251883Speter** the aggregate SQL function is running. 5246251883Speter*/ 5247322444SpeterSQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5248251883Speter 5249251883Speter/* 5250251883Speter** CAPI3REF: User Data For Functions 5251286510Speter** METHOD: sqlite3_context 5252251883Speter** 5253251883Speter** ^The sqlite3_user_data() interface returns a copy of 5254251883Speter** the pointer that was the pUserData parameter (the 5th parameter) 5255251883Speter** of the [sqlite3_create_function()] 5256251883Speter** and [sqlite3_create_function16()] routines that originally 5257251883Speter** registered the application defined function. 5258251883Speter** 5259251883Speter** This routine must be called from the same thread in which 5260251883Speter** the application-defined function is running. 5261251883Speter*/ 5262322444SpeterSQLITE_API void *sqlite3_user_data(sqlite3_context*); 5263251883Speter 5264251883Speter/* 5265251883Speter** CAPI3REF: Database Connection For Functions 5266286510Speter** METHOD: sqlite3_context 5267251883Speter** 5268251883Speter** ^The sqlite3_context_db_handle() interface returns a copy of 5269251883Speter** the pointer to the [database connection] (the 1st parameter) 5270251883Speter** of the [sqlite3_create_function()] 5271251883Speter** and [sqlite3_create_function16()] routines that originally 5272251883Speter** registered the application defined function. 5273251883Speter*/ 5274322444SpeterSQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5275251883Speter 5276251883Speter/* 5277251883Speter** CAPI3REF: Function Auxiliary Data 5278286510Speter** METHOD: sqlite3_context 5279251883Speter** 5280269851Speter** These functions may be used by (non-aggregate) SQL functions to 5281251883Speter** associate metadata with argument values. If the same value is passed to 5282251883Speter** multiple invocations of the same SQL function during query execution, under 5283269851Speter** some circumstances the associated metadata may be preserved. An example 5284269851Speter** of where this might be useful is in a regular-expression matching 5285269851Speter** function. The compiled version of the regular expression can be stored as 5286269851Speter** metadata associated with the pattern string. 5287269851Speter** Then as long as the pattern string remains the same, 5288269851Speter** the compiled regular expression can be reused on multiple 5289269851Speter** invocations of the same function. 5290251883Speter** 5291322444Speter** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5292322444Speter** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5293322444Speter** value to the application-defined function. ^N is zero for the left-most 5294322444Speter** function argument. ^If there is no metadata 5295322444Speter** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5296269851Speter** returns a NULL pointer. 5297251883Speter** 5298269851Speter** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5299269851Speter** argument of the application-defined function. ^Subsequent 5300269851Speter** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5301269851Speter** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5302269851Speter** NULL if the metadata has been discarded. 5303269851Speter** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5304269851Speter** SQLite will invoke the destructor function X with parameter P exactly 5305269851Speter** once, when the metadata is discarded. 5306269851Speter** SQLite is free to discard the metadata at any time, including: <ul> 5307305002Scy** <li> ^(when the corresponding function parameter changes)^, or 5308305002Scy** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5309305002Scy** SQL statement)^, or 5310305002Scy** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5311305002Scy** parameter)^, or 5312305002Scy** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5313305002Scy** allocation error occurs.)^ </ul> 5314251883Speter** 5315269851Speter** Note the last bullet in particular. The destructor X in 5316269851Speter** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5317269851Speter** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5318269851Speter** should be called near the end of the function implementation and the 5319269851Speter** function implementation should not make any use of P after 5320269851Speter** sqlite3_set_auxdata() has been called. 5321251883Speter** 5322251883Speter** ^(In practice, metadata is preserved between function calls for 5323269851Speter** function parameters that are compile-time constants, including literal 5324269851Speter** values and [parameters] and expressions composed from the same.)^ 5325251883Speter** 5326322444Speter** The value of the N parameter to these interfaces should be non-negative. 5327322444Speter** Future enhancements may make use of negative N values to define new 5328322444Speter** kinds of function caching behavior. 5329322444Speter** 5330251883Speter** These routines must be called from the same thread in which 5331251883Speter** the SQL function is running. 5332251883Speter*/ 5333322444SpeterSQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5334322444SpeterSQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5335251883Speter 5336251883Speter 5337251883Speter/* 5338251883Speter** CAPI3REF: Constants Defining Special Destructor Behavior 5339251883Speter** 5340251883Speter** These are special values for the destructor that is passed in as the 5341251883Speter** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5342251883Speter** argument is SQLITE_STATIC, it means that the content pointer is constant 5343251883Speter** and will never change. It does not need to be destroyed. ^The 5344251883Speter** SQLITE_TRANSIENT value means that the content will likely change in 5345251883Speter** the near future and that SQLite should make its own private copy of 5346251883Speter** the content before returning. 5347251883Speter** 5348251883Speter** The typedef is necessary to work around problems in certain 5349251883Speter** C++ compilers. 5350251883Speter*/ 5351251883Spetertypedef void (*sqlite3_destructor_type)(void*); 5352251883Speter#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5353251883Speter#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5354251883Speter 5355251883Speter/* 5356251883Speter** CAPI3REF: Setting The Result Of An SQL Function 5357286510Speter** METHOD: sqlite3_context 5358251883Speter** 5359251883Speter** These routines are used by the xFunc or xFinal callbacks that 5360251883Speter** implement SQL functions and aggregates. See 5361251883Speter** [sqlite3_create_function()] and [sqlite3_create_function16()] 5362251883Speter** for additional information. 5363251883Speter** 5364251883Speter** These functions work very much like the [parameter binding] family of 5365251883Speter** functions used to bind values to host parameters in prepared statements. 5366251883Speter** Refer to the [SQL parameter] documentation for additional information. 5367251883Speter** 5368251883Speter** ^The sqlite3_result_blob() interface sets the result from 5369251883Speter** an application-defined function to be the BLOB whose content is pointed 5370251883Speter** to by the second parameter and which is N bytes long where N is the 5371251883Speter** third parameter. 5372251883Speter** 5373286510Speter** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5374286510Speter** interfaces set the result of the application-defined function to be 5375286510Speter** a BLOB containing all zero bytes and N bytes in size. 5376251883Speter** 5377251883Speter** ^The sqlite3_result_double() interface sets the result from 5378251883Speter** an application-defined function to be a floating point value specified 5379251883Speter** by its 2nd argument. 5380251883Speter** 5381251883Speter** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5382251883Speter** cause the implemented SQL function to throw an exception. 5383251883Speter** ^SQLite uses the string pointed to by the 5384251883Speter** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5385251883Speter** as the text of an error message. ^SQLite interprets the error 5386251883Speter** message string from sqlite3_result_error() as UTF-8. ^SQLite 5387251883Speter** interprets the string from sqlite3_result_error16() as UTF-16 in native 5388251883Speter** byte order. ^If the third parameter to sqlite3_result_error() 5389251883Speter** or sqlite3_result_error16() is negative then SQLite takes as the error 5390251883Speter** message all text up through the first zero character. 5391251883Speter** ^If the third parameter to sqlite3_result_error() or 5392251883Speter** sqlite3_result_error16() is non-negative then SQLite takes that many 5393251883Speter** bytes (not characters) from the 2nd parameter as the error message. 5394251883Speter** ^The sqlite3_result_error() and sqlite3_result_error16() 5395251883Speter** routines make a private copy of the error message text before 5396251883Speter** they return. Hence, the calling function can deallocate or 5397251883Speter** modify the text after they return without harm. 5398251883Speter** ^The sqlite3_result_error_code() function changes the error code 5399251883Speter** returned by SQLite as a result of an error in a function. ^By default, 5400251883Speter** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5401251883Speter** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5402251883Speter** 5403251883Speter** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5404251883Speter** error indicating that a string or BLOB is too long to represent. 5405251883Speter** 5406251883Speter** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5407251883Speter** error indicating that a memory allocation failed. 5408251883Speter** 5409251883Speter** ^The sqlite3_result_int() interface sets the return value 5410251883Speter** of the application-defined function to be the 32-bit signed integer 5411251883Speter** value given in the 2nd argument. 5412251883Speter** ^The sqlite3_result_int64() interface sets the return value 5413251883Speter** of the application-defined function to be the 64-bit signed integer 5414251883Speter** value given in the 2nd argument. 5415251883Speter** 5416251883Speter** ^The sqlite3_result_null() interface sets the return value 5417251883Speter** of the application-defined function to be NULL. 5418251883Speter** 5419251883Speter** ^The sqlite3_result_text(), sqlite3_result_text16(), 5420251883Speter** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5421251883Speter** set the return value of the application-defined function to be 5422251883Speter** a text string which is represented as UTF-8, UTF-16 native byte order, 5423251883Speter** UTF-16 little endian, or UTF-16 big endian, respectively. 5424274884Sbapt** ^The sqlite3_result_text64() interface sets the return value of an 5425274884Sbapt** application-defined function to be a text string in an encoding 5426274884Sbapt** specified by the fifth (and last) parameter, which must be one 5427274884Sbapt** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5428251883Speter** ^SQLite takes the text result from the application from 5429251883Speter** the 2nd parameter of the sqlite3_result_text* interfaces. 5430251883Speter** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5431251883Speter** is negative, then SQLite takes result text from the 2nd parameter 5432251883Speter** through the first zero character. 5433251883Speter** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5434251883Speter** is non-negative, then as many bytes (not characters) of the text 5435251883Speter** pointed to by the 2nd parameter are taken as the application-defined 5436251883Speter** function result. If the 3rd parameter is non-negative, then it 5437251883Speter** must be the byte offset into the string where the NUL terminator would 5438251883Speter** appear if the string where NUL terminated. If any NUL characters occur 5439251883Speter** in the string at a byte offset that is less than the value of the 3rd 5440251883Speter** parameter, then the resulting string will contain embedded NULs and the 5441251883Speter** result of expressions operating on strings with embedded NULs is undefined. 5442251883Speter** ^If the 4th parameter to the sqlite3_result_text* interfaces 5443251883Speter** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5444251883Speter** function as the destructor on the text or BLOB result when it has 5445251883Speter** finished using that result. 5446251883Speter** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5447251883Speter** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5448251883Speter** assumes that the text or BLOB result is in constant space and does not 5449251883Speter** copy the content of the parameter nor call a destructor on the content 5450251883Speter** when it has finished using that result. 5451251883Speter** ^If the 4th parameter to the sqlite3_result_text* interfaces 5452251883Speter** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5453322444Speter** then SQLite makes a copy of the result into space obtained 5454251883Speter** from [sqlite3_malloc()] before it returns. 5455251883Speter** 5456251883Speter** ^The sqlite3_result_value() interface sets the result of 5457286510Speter** the application-defined function to be a copy of the 5458251883Speter** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5459251883Speter** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5460251883Speter** so that the [sqlite3_value] specified in the parameter may change or 5461251883Speter** be deallocated after sqlite3_result_value() returns without harm. 5462251883Speter** ^A [protected sqlite3_value] object may always be used where an 5463251883Speter** [unprotected sqlite3_value] object is required, so either 5464251883Speter** kind of [sqlite3_value] object can be used with this interface. 5465251883Speter** 5466322444Speter** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5467322444Speter** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5468322444Speter** also associates the host-language pointer P or type T with that 5469322444Speter** NULL value such that the pointer can be retrieved within an 5470322444Speter** [application-defined SQL function] using [sqlite3_value_pointer()]. 5471322444Speter** ^If the D parameter is not NULL, then it is a pointer to a destructor 5472322444Speter** for the P parameter. ^SQLite invokes D with P as its only argument 5473322444Speter** when SQLite is finished with P. The T parameter should be a static 5474322444Speter** string and preferably a string literal. The sqlite3_result_pointer() 5475322444Speter** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5476322444Speter** 5477251883Speter** If these routines are called from within the different thread 5478251883Speter** than the one containing the application-defined function that received 5479251883Speter** the [sqlite3_context] pointer, the results are undefined. 5480251883Speter*/ 5481322444SpeterSQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5482322444SpeterSQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5483282328Sbapt sqlite3_uint64,void(*)(void*)); 5484322444SpeterSQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5485322444SpeterSQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5486322444SpeterSQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5487322444SpeterSQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5488322444SpeterSQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5489322444SpeterSQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5490322444SpeterSQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5491322444SpeterSQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5492322444SpeterSQLITE_API void sqlite3_result_null(sqlite3_context*); 5493322444SpeterSQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5494322444SpeterSQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5495274884Sbapt void(*)(void*), unsigned char encoding); 5496322444SpeterSQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5497322444SpeterSQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5498322444SpeterSQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5499322444SpeterSQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5500322444SpeterSQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5501322444SpeterSQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5502322444SpeterSQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5503251883Speter 5504298161Sbapt 5505251883Speter/* 5506298161Sbapt** CAPI3REF: Setting The Subtype Of An SQL Function 5507298161Sbapt** METHOD: sqlite3_context 5508298161Sbapt** 5509298161Sbapt** The sqlite3_result_subtype(C,T) function causes the subtype of 5510298161Sbapt** the result from the [application-defined SQL function] with 5511298161Sbapt** [sqlite3_context] C to be the value T. Only the lower 8 bits 5512298161Sbapt** of the subtype T are preserved in current versions of SQLite; 5513298161Sbapt** higher order bits are discarded. 5514298161Sbapt** The number of subtype bytes preserved by SQLite might increase 5515298161Sbapt** in future releases of SQLite. 5516298161Sbapt*/ 5517322444SpeterSQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5518298161Sbapt 5519298161Sbapt/* 5520251883Speter** CAPI3REF: Define New Collating Sequences 5521286510Speter** METHOD: sqlite3 5522251883Speter** 5523251883Speter** ^These functions add, remove, or modify a [collation] associated 5524251883Speter** with the [database connection] specified as the first argument. 5525251883Speter** 5526251883Speter** ^The name of the collation is a UTF-8 string 5527251883Speter** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5528251883Speter** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5529251883Speter** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5530251883Speter** considered to be the same name. 5531251883Speter** 5532251883Speter** ^(The third argument (eTextRep) must be one of the constants: 5533251883Speter** <ul> 5534251883Speter** <li> [SQLITE_UTF8], 5535251883Speter** <li> [SQLITE_UTF16LE], 5536251883Speter** <li> [SQLITE_UTF16BE], 5537251883Speter** <li> [SQLITE_UTF16], or 5538251883Speter** <li> [SQLITE_UTF16_ALIGNED]. 5539251883Speter** </ul>)^ 5540251883Speter** ^The eTextRep argument determines the encoding of strings passed 5541251883Speter** to the collating function callback, xCallback. 5542251883Speter** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5543251883Speter** force strings to be UTF16 with native byte order. 5544251883Speter** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5545251883Speter** on an even byte address. 5546251883Speter** 5547251883Speter** ^The fourth argument, pArg, is an application data pointer that is passed 5548251883Speter** through as the first argument to the collating function callback. 5549251883Speter** 5550251883Speter** ^The fifth argument, xCallback, is a pointer to the collating function. 5551251883Speter** ^Multiple collating functions can be registered using the same name but 5552251883Speter** with different eTextRep parameters and SQLite will use whichever 5553251883Speter** function requires the least amount of data transformation. 5554251883Speter** ^If the xCallback argument is NULL then the collating function is 5555251883Speter** deleted. ^When all collating functions having the same name are deleted, 5556251883Speter** that collation is no longer usable. 5557251883Speter** 5558251883Speter** ^The collating function callback is invoked with a copy of the pArg 5559251883Speter** application data pointer and with two strings in the encoding specified 5560251883Speter** by the eTextRep argument. The collating function must return an 5561251883Speter** integer that is negative, zero, or positive 5562251883Speter** if the first string is less than, equal to, or greater than the second, 5563251883Speter** respectively. A collating function must always return the same answer 5564251883Speter** given the same inputs. If two or more collating functions are registered 5565251883Speter** to the same collation name (using different eTextRep values) then all 5566251883Speter** must give an equivalent answer when invoked with equivalent strings. 5567251883Speter** The collating function must obey the following properties for all 5568251883Speter** strings A, B, and C: 5569251883Speter** 5570251883Speter** <ol> 5571251883Speter** <li> If A==B then B==A. 5572251883Speter** <li> If A==B and B==C then A==C. 5573251883Speter** <li> If A<B THEN B>A. 5574251883Speter** <li> If A<B and B<C then A<C. 5575251883Speter** </ol> 5576251883Speter** 5577251883Speter** If a collating function fails any of the above constraints and that 5578251883Speter** collating function is registered and used, then the behavior of SQLite 5579251883Speter** is undefined. 5580251883Speter** 5581251883Speter** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5582251883Speter** with the addition that the xDestroy callback is invoked on pArg when 5583251883Speter** the collating function is deleted. 5584251883Speter** ^Collating functions are deleted when they are overridden by later 5585251883Speter** calls to the collation creation functions or when the 5586251883Speter** [database connection] is closed using [sqlite3_close()]. 5587251883Speter** 5588251883Speter** ^The xDestroy callback is <u>not</u> called if the 5589251883Speter** sqlite3_create_collation_v2() function fails. Applications that invoke 5590251883Speter** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5591251883Speter** check the return code and dispose of the application data pointer 5592251883Speter** themselves rather than expecting SQLite to deal with it for them. 5593251883Speter** This is different from every other SQLite interface. The inconsistency 5594251883Speter** is unfortunate but cannot be changed without breaking backwards 5595251883Speter** compatibility. 5596251883Speter** 5597251883Speter** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5598251883Speter*/ 5599322444SpeterSQLITE_API int sqlite3_create_collation( 5600251883Speter sqlite3*, 5601251883Speter const char *zName, 5602251883Speter int eTextRep, 5603251883Speter void *pArg, 5604251883Speter int(*xCompare)(void*,int,const void*,int,const void*) 5605251883Speter); 5606322444SpeterSQLITE_API int sqlite3_create_collation_v2( 5607251883Speter sqlite3*, 5608251883Speter const char *zName, 5609251883Speter int eTextRep, 5610251883Speter void *pArg, 5611251883Speter int(*xCompare)(void*,int,const void*,int,const void*), 5612251883Speter void(*xDestroy)(void*) 5613251883Speter); 5614322444SpeterSQLITE_API int sqlite3_create_collation16( 5615251883Speter sqlite3*, 5616251883Speter const void *zName, 5617251883Speter int eTextRep, 5618251883Speter void *pArg, 5619251883Speter int(*xCompare)(void*,int,const void*,int,const void*) 5620251883Speter); 5621251883Speter 5622251883Speter/* 5623251883Speter** CAPI3REF: Collation Needed Callbacks 5624286510Speter** METHOD: sqlite3 5625251883Speter** 5626251883Speter** ^To avoid having to register all collation sequences before a database 5627251883Speter** can be used, a single callback function may be registered with the 5628251883Speter** [database connection] to be invoked whenever an undefined collation 5629251883Speter** sequence is required. 5630251883Speter** 5631251883Speter** ^If the function is registered using the sqlite3_collation_needed() API, 5632251883Speter** then it is passed the names of undefined collation sequences as strings 5633251883Speter** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5634251883Speter** the names are passed as UTF-16 in machine native byte order. 5635251883Speter** ^A call to either function replaces the existing collation-needed callback. 5636251883Speter** 5637251883Speter** ^(When the callback is invoked, the first argument passed is a copy 5638251883Speter** of the second argument to sqlite3_collation_needed() or 5639251883Speter** sqlite3_collation_needed16(). The second argument is the database 5640251883Speter** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5641251883Speter** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5642251883Speter** sequence function required. The fourth parameter is the name of the 5643251883Speter** required collation sequence.)^ 5644251883Speter** 5645251883Speter** The callback function should register the desired collation using 5646251883Speter** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5647251883Speter** [sqlite3_create_collation_v2()]. 5648251883Speter*/ 5649322444SpeterSQLITE_API int sqlite3_collation_needed( 5650251883Speter sqlite3*, 5651251883Speter void*, 5652251883Speter void(*)(void*,sqlite3*,int eTextRep,const char*) 5653251883Speter); 5654322444SpeterSQLITE_API int sqlite3_collation_needed16( 5655251883Speter sqlite3*, 5656251883Speter void*, 5657251883Speter void(*)(void*,sqlite3*,int eTextRep,const void*) 5658251883Speter); 5659251883Speter 5660251883Speter#ifdef SQLITE_HAS_CODEC 5661251883Speter/* 5662251883Speter** Specify the key for an encrypted database. This routine should be 5663251883Speter** called right after sqlite3_open(). 5664251883Speter** 5665251883Speter** The code to implement this API is not available in the public release 5666251883Speter** of SQLite. 5667251883Speter*/ 5668322444SpeterSQLITE_API int sqlite3_key( 5669251883Speter sqlite3 *db, /* Database to be rekeyed */ 5670251883Speter const void *pKey, int nKey /* The key */ 5671251883Speter); 5672322444SpeterSQLITE_API int sqlite3_key_v2( 5673269851Speter sqlite3 *db, /* Database to be rekeyed */ 5674269851Speter const char *zDbName, /* Name of the database */ 5675269851Speter const void *pKey, int nKey /* The key */ 5676269851Speter); 5677251883Speter 5678251883Speter/* 5679251883Speter** Change the key on an open database. If the current database is not 5680251883Speter** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5681251883Speter** database is decrypted. 5682251883Speter** 5683251883Speter** The code to implement this API is not available in the public release 5684251883Speter** of SQLite. 5685251883Speter*/ 5686322444SpeterSQLITE_API int sqlite3_rekey( 5687251883Speter sqlite3 *db, /* Database to be rekeyed */ 5688251883Speter const void *pKey, int nKey /* The new key */ 5689251883Speter); 5690322444SpeterSQLITE_API int sqlite3_rekey_v2( 5691269851Speter sqlite3 *db, /* Database to be rekeyed */ 5692269851Speter const char *zDbName, /* Name of the database */ 5693269851Speter const void *pKey, int nKey /* The new key */ 5694269851Speter); 5695251883Speter 5696251883Speter/* 5697251883Speter** Specify the activation key for a SEE database. Unless 5698251883Speter** activated, none of the SEE routines will work. 5699251883Speter*/ 5700322444SpeterSQLITE_API void sqlite3_activate_see( 5701251883Speter const char *zPassPhrase /* Activation phrase */ 5702251883Speter); 5703251883Speter#endif 5704251883Speter 5705251883Speter#ifdef SQLITE_ENABLE_CEROD 5706251883Speter/* 5707251883Speter** Specify the activation key for a CEROD database. Unless 5708251883Speter** activated, none of the CEROD routines will work. 5709251883Speter*/ 5710322444SpeterSQLITE_API void sqlite3_activate_cerod( 5711251883Speter const char *zPassPhrase /* Activation phrase */ 5712251883Speter); 5713251883Speter#endif 5714251883Speter 5715251883Speter/* 5716251883Speter** CAPI3REF: Suspend Execution For A Short Time 5717251883Speter** 5718251883Speter** The sqlite3_sleep() function causes the current thread to suspend execution 5719251883Speter** for at least a number of milliseconds specified in its parameter. 5720251883Speter** 5721251883Speter** If the operating system does not support sleep requests with 5722251883Speter** millisecond time resolution, then the time will be rounded up to 5723251883Speter** the nearest second. The number of milliseconds of sleep actually 5724251883Speter** requested from the operating system is returned. 5725251883Speter** 5726251883Speter** ^SQLite implements this interface by calling the xSleep() 5727251883Speter** method of the default [sqlite3_vfs] object. If the xSleep() method 5728251883Speter** of the default VFS is not implemented correctly, or not implemented at 5729251883Speter** all, then the behavior of sqlite3_sleep() may deviate from the description 5730251883Speter** in the previous paragraphs. 5731251883Speter*/ 5732322444SpeterSQLITE_API int sqlite3_sleep(int); 5733251883Speter 5734251883Speter/* 5735251883Speter** CAPI3REF: Name Of The Folder Holding Temporary Files 5736251883Speter** 5737251883Speter** ^(If this global variable is made to point to a string which is 5738251883Speter** the name of a folder (a.k.a. directory), then all temporary files 5739251883Speter** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5740251883Speter** will be placed in that directory.)^ ^If this variable 5741251883Speter** is a NULL pointer, then SQLite performs a search for an appropriate 5742251883Speter** temporary file directory. 5743251883Speter** 5744274884Sbapt** Applications are strongly discouraged from using this global variable. 5745274884Sbapt** It is required to set a temporary folder on Windows Runtime (WinRT). 5746274884Sbapt** But for all other platforms, it is highly recommended that applications 5747274884Sbapt** neither read nor write this variable. This global variable is a relic 5748274884Sbapt** that exists for backwards compatibility of legacy applications and should 5749274884Sbapt** be avoided in new projects. 5750274884Sbapt** 5751251883Speter** It is not safe to read or modify this variable in more than one 5752251883Speter** thread at a time. It is not safe to read or modify this variable 5753251883Speter** if a [database connection] is being used at the same time in a separate 5754251883Speter** thread. 5755251883Speter** It is intended that this variable be set once 5756251883Speter** as part of process initialization and before any SQLite interface 5757251883Speter** routines have been called and that this variable remain unchanged 5758251883Speter** thereafter. 5759251883Speter** 5760251883Speter** ^The [temp_store_directory pragma] may modify this variable and cause 5761251883Speter** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5762251883Speter** the [temp_store_directory pragma] always assumes that any string 5763251883Speter** that this variable points to is held in memory obtained from 5764251883Speter** [sqlite3_malloc] and the pragma may attempt to free that memory 5765251883Speter** using [sqlite3_free]. 5766251883Speter** Hence, if this variable is modified directly, either it should be 5767251883Speter** made NULL or made to point to memory obtained from [sqlite3_malloc] 5768251883Speter** or else the use of the [temp_store_directory pragma] should be avoided. 5769274884Sbapt** Except when requested by the [temp_store_directory pragma], SQLite 5770274884Sbapt** does not free the memory that sqlite3_temp_directory points to. If 5771274884Sbapt** the application wants that memory to be freed, it must do 5772274884Sbapt** so itself, taking care to only do so after all [database connection] 5773274884Sbapt** objects have been destroyed. 5774251883Speter** 5775251883Speter** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5776251883Speter** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5777251883Speter** features that require the use of temporary files may fail. Here is an 5778251883Speter** example of how to do this using C++ with the Windows Runtime: 5779251883Speter** 5780251883Speter** <blockquote><pre> 5781251883Speter** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5782251883Speter** TemporaryFolder->Path->Data(); 5783251883Speter** char zPathBuf[MAX_PATH + 1]; 5784251883Speter** memset(zPathBuf, 0, sizeof(zPathBuf)); 5785251883Speter** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5786251883Speter** NULL, NULL); 5787251883Speter** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5788251883Speter** </pre></blockquote> 5789251883Speter*/ 5790251883SpeterSQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5791251883Speter 5792251883Speter/* 5793251883Speter** CAPI3REF: Name Of The Folder Holding Database Files 5794251883Speter** 5795251883Speter** ^(If this global variable is made to point to a string which is 5796251883Speter** the name of a folder (a.k.a. directory), then all database files 5797251883Speter** specified with a relative pathname and created or accessed by 5798251883Speter** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5799251883Speter** to be relative to that directory.)^ ^If this variable is a NULL 5800251883Speter** pointer, then SQLite assumes that all database files specified 5801251883Speter** with a relative pathname are relative to the current directory 5802251883Speter** for the process. Only the windows VFS makes use of this global 5803251883Speter** variable; it is ignored by the unix VFS. 5804251883Speter** 5805251883Speter** Changing the value of this variable while a database connection is 5806251883Speter** open can result in a corrupt database. 5807251883Speter** 5808251883Speter** It is not safe to read or modify this variable in more than one 5809251883Speter** thread at a time. It is not safe to read or modify this variable 5810251883Speter** if a [database connection] is being used at the same time in a separate 5811251883Speter** thread. 5812251883Speter** It is intended that this variable be set once 5813251883Speter** as part of process initialization and before any SQLite interface 5814251883Speter** routines have been called and that this variable remain unchanged 5815251883Speter** thereafter. 5816251883Speter** 5817251883Speter** ^The [data_store_directory pragma] may modify this variable and cause 5818251883Speter** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5819251883Speter** the [data_store_directory pragma] always assumes that any string 5820251883Speter** that this variable points to is held in memory obtained from 5821251883Speter** [sqlite3_malloc] and the pragma may attempt to free that memory 5822251883Speter** using [sqlite3_free]. 5823251883Speter** Hence, if this variable is modified directly, either it should be 5824251883Speter** made NULL or made to point to memory obtained from [sqlite3_malloc] 5825251883Speter** or else the use of the [data_store_directory pragma] should be avoided. 5826251883Speter*/ 5827251883SpeterSQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5828251883Speter 5829251883Speter/* 5830342292Scy** CAPI3REF: Win32 Specific Interface 5831342292Scy** 5832342292Scy** These interfaces are available only on Windows. The 5833342292Scy** [sqlite3_win32_set_directory] interface is used to set the value associated 5834342292Scy** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5835342292Scy** zValue, depending on the value of the type parameter. The zValue parameter 5836342292Scy** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5837342292Scy** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5838342292Scy** prior to being used. The [sqlite3_win32_set_directory] interface returns 5839342292Scy** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5840342292Scy** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5841342292Scy** [sqlite3_data_directory] variable is intended to act as a replacement for 5842342292Scy** the current directory on the sub-platforms of Win32 where that concept is 5843342292Scy** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5844342292Scy** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5845342292Scy** sqlite3_win32_set_directory interface except the string parameter must be 5846342292Scy** UTF-8 or UTF-16, respectively. 5847342292Scy*/ 5848342292ScySQLITE_API int sqlite3_win32_set_directory( 5849342292Scy unsigned long type, /* Identifier for directory being set or reset */ 5850342292Scy void *zValue /* New value for directory being set or reset */ 5851342292Scy); 5852342292ScySQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5853342292ScySQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5854342292Scy 5855342292Scy/* 5856342292Scy** CAPI3REF: Win32 Directory Types 5857342292Scy** 5858342292Scy** These macros are only available on Windows. They define the allowed values 5859342292Scy** for the type argument to the [sqlite3_win32_set_directory] interface. 5860342292Scy*/ 5861342292Scy#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5862342292Scy#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5863342292Scy 5864342292Scy/* 5865251883Speter** CAPI3REF: Test For Auto-Commit Mode 5866251883Speter** KEYWORDS: {autocommit mode} 5867286510Speter** METHOD: sqlite3 5868251883Speter** 5869251883Speter** ^The sqlite3_get_autocommit() interface returns non-zero or 5870251883Speter** zero if the given database connection is or is not in autocommit mode, 5871251883Speter** respectively. ^Autocommit mode is on by default. 5872251883Speter** ^Autocommit mode is disabled by a [BEGIN] statement. 5873251883Speter** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5874251883Speter** 5875251883Speter** If certain kinds of errors occur on a statement within a multi-statement 5876251883Speter** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5877251883Speter** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5878251883Speter** transaction might be rolled back automatically. The only way to 5879251883Speter** find out whether SQLite automatically rolled back the transaction after 5880251883Speter** an error is to use this function. 5881251883Speter** 5882251883Speter** If another thread changes the autocommit status of the database 5883251883Speter** connection while this routine is running, then the return value 5884251883Speter** is undefined. 5885251883Speter*/ 5886322444SpeterSQLITE_API int sqlite3_get_autocommit(sqlite3*); 5887251883Speter 5888251883Speter/* 5889251883Speter** CAPI3REF: Find The Database Handle Of A Prepared Statement 5890286510Speter** METHOD: sqlite3_stmt 5891251883Speter** 5892251883Speter** ^The sqlite3_db_handle interface returns the [database connection] handle 5893251883Speter** to which a [prepared statement] belongs. ^The [database connection] 5894251883Speter** returned by sqlite3_db_handle is the same [database connection] 5895251883Speter** that was the first argument 5896251883Speter** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5897251883Speter** create the statement in the first place. 5898251883Speter*/ 5899322444SpeterSQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5900251883Speter 5901251883Speter/* 5902251883Speter** CAPI3REF: Return The Filename For A Database Connection 5903286510Speter** METHOD: sqlite3 5904251883Speter** 5905251883Speter** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5906251883Speter** associated with database N of connection D. ^The main database file 5907251883Speter** has the name "main". If there is no attached database N on the database 5908251883Speter** connection D, or if database N is a temporary or in-memory database, then 5909347347Scy** this function will return either a NULL pointer or an empty string. 5910251883Speter** 5911251883Speter** ^The filename returned by this function is the output of the 5912251883Speter** xFullPathname method of the [VFS]. ^In other words, the filename 5913251883Speter** will be an absolute pathname, even if the filename used 5914251883Speter** to open the database originally was a URI or relative pathname. 5915251883Speter*/ 5916322444SpeterSQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5917251883Speter 5918251883Speter/* 5919251883Speter** CAPI3REF: Determine if a database is read-only 5920286510Speter** METHOD: sqlite3 5921251883Speter** 5922251883Speter** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5923251883Speter** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5924251883Speter** the name of a database on connection D. 5925251883Speter*/ 5926322444SpeterSQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5927251883Speter 5928251883Speter/* 5929251883Speter** CAPI3REF: Find the next prepared statement 5930286510Speter** METHOD: sqlite3 5931251883Speter** 5932251883Speter** ^This interface returns a pointer to the next [prepared statement] after 5933251883Speter** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5934251883Speter** then this interface returns a pointer to the first prepared statement 5935251883Speter** associated with the database connection pDb. ^If no prepared statement 5936251883Speter** satisfies the conditions of this routine, it returns NULL. 5937251883Speter** 5938251883Speter** The [database connection] pointer D in a call to 5939251883Speter** [sqlite3_next_stmt(D,S)] must refer to an open database 5940251883Speter** connection and in particular must not be a NULL pointer. 5941251883Speter*/ 5942322444SpeterSQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5943251883Speter 5944251883Speter/* 5945251883Speter** CAPI3REF: Commit And Rollback Notification Callbacks 5946286510Speter** METHOD: sqlite3 5947251883Speter** 5948251883Speter** ^The sqlite3_commit_hook() interface registers a callback 5949251883Speter** function to be invoked whenever a transaction is [COMMIT | committed]. 5950251883Speter** ^Any callback set by a previous call to sqlite3_commit_hook() 5951251883Speter** for the same database connection is overridden. 5952251883Speter** ^The sqlite3_rollback_hook() interface registers a callback 5953251883Speter** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5954251883Speter** ^Any callback set by a previous call to sqlite3_rollback_hook() 5955251883Speter** for the same database connection is overridden. 5956251883Speter** ^The pArg argument is passed through to the callback. 5957251883Speter** ^If the callback on a commit hook function returns non-zero, 5958251883Speter** then the commit is converted into a rollback. 5959251883Speter** 5960251883Speter** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5961251883Speter** return the P argument from the previous call of the same function 5962251883Speter** on the same [database connection] D, or NULL for 5963251883Speter** the first call for each function on D. 5964251883Speter** 5965251883Speter** The commit and rollback hook callbacks are not reentrant. 5966251883Speter** The callback implementation must not do anything that will modify 5967251883Speter** the database connection that invoked the callback. Any actions 5968251883Speter** to modify the database connection must be deferred until after the 5969251883Speter** completion of the [sqlite3_step()] call that triggered the commit 5970251883Speter** or rollback hook in the first place. 5971251883Speter** Note that running any other SQL statements, including SELECT statements, 5972251883Speter** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5973251883Speter** the database connections for the meaning of "modify" in this paragraph. 5974251883Speter** 5975251883Speter** ^Registering a NULL function disables the callback. 5976251883Speter** 5977251883Speter** ^When the commit hook callback routine returns zero, the [COMMIT] 5978251883Speter** operation is allowed to continue normally. ^If the commit hook 5979251883Speter** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5980251883Speter** ^The rollback hook is invoked on a rollback that results from a commit 5981251883Speter** hook returning non-zero, just as it would be with any other rollback. 5982251883Speter** 5983251883Speter** ^For the purposes of this API, a transaction is said to have been 5984251883Speter** rolled back if an explicit "ROLLBACK" statement is executed, or 5985251883Speter** an error or constraint causes an implicit rollback to occur. 5986251883Speter** ^The rollback callback is not invoked if a transaction is 5987251883Speter** automatically rolled back because the database connection is closed. 5988251883Speter** 5989251883Speter** See also the [sqlite3_update_hook()] interface. 5990251883Speter*/ 5991322444SpeterSQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5992322444SpeterSQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5993251883Speter 5994251883Speter/* 5995251883Speter** CAPI3REF: Data Change Notification Callbacks 5996286510Speter** METHOD: sqlite3 5997251883Speter** 5998251883Speter** ^The sqlite3_update_hook() interface registers a callback function 5999251883Speter** with the [database connection] identified by the first argument 6000269851Speter** to be invoked whenever a row is updated, inserted or deleted in 6001305002Scy** a [rowid table]. 6002251883Speter** ^Any callback set by a previous call to this function 6003251883Speter** for the same database connection is overridden. 6004251883Speter** 6005251883Speter** ^The second argument is a pointer to the function to invoke when a 6006269851Speter** row is updated, inserted or deleted in a rowid table. 6007251883Speter** ^The first argument to the callback is a copy of the third argument 6008251883Speter** to sqlite3_update_hook(). 6009251883Speter** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6010251883Speter** or [SQLITE_UPDATE], depending on the operation that caused the callback 6011251883Speter** to be invoked. 6012251883Speter** ^The third and fourth arguments to the callback contain pointers to the 6013251883Speter** database and table name containing the affected row. 6014251883Speter** ^The final callback parameter is the [rowid] of the row. 6015251883Speter** ^In the case of an update, this is the [rowid] after the update takes place. 6016251883Speter** 6017251883Speter** ^(The update hook is not invoked when internal system tables are 6018251883Speter** modified (i.e. sqlite_master and sqlite_sequence).)^ 6019269851Speter** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6020251883Speter** 6021251883Speter** ^In the current implementation, the update hook 6022322444Speter** is not invoked when conflicting rows are deleted because of an 6023251883Speter** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6024251883Speter** invoked when rows are deleted using the [truncate optimization]. 6025251883Speter** The exceptions defined in this paragraph might change in a future 6026251883Speter** release of SQLite. 6027251883Speter** 6028251883Speter** The update hook implementation must not do anything that will modify 6029251883Speter** the database connection that invoked the update hook. Any actions 6030251883Speter** to modify the database connection must be deferred until after the 6031251883Speter** completion of the [sqlite3_step()] call that triggered the update hook. 6032251883Speter** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6033251883Speter** database connections for the meaning of "modify" in this paragraph. 6034251883Speter** 6035251883Speter** ^The sqlite3_update_hook(D,C,P) function 6036251883Speter** returns the P argument from the previous call 6037251883Speter** on the same [database connection] D, or NULL for 6038251883Speter** the first call on D. 6039251883Speter** 6040305002Scy** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6041305002Scy** and [sqlite3_preupdate_hook()] interfaces. 6042251883Speter*/ 6043322444SpeterSQLITE_API void *sqlite3_update_hook( 6044251883Speter sqlite3*, 6045251883Speter void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6046251883Speter void* 6047251883Speter); 6048251883Speter 6049251883Speter/* 6050251883Speter** CAPI3REF: Enable Or Disable Shared Pager Cache 6051251883Speter** 6052251883Speter** ^(This routine enables or disables the sharing of the database cache 6053251883Speter** and schema data structures between [database connection | connections] 6054251883Speter** to the same database. Sharing is enabled if the argument is true 6055251883Speter** and disabled if the argument is false.)^ 6056251883Speter** 6057251883Speter** ^Cache sharing is enabled and disabled for an entire process. 6058322444Speter** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6059322444Speter** In prior versions of SQLite, 6060251883Speter** sharing was enabled or disabled for each thread separately. 6061251883Speter** 6062251883Speter** ^(The cache sharing mode set by this interface effects all subsequent 6063251883Speter** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6064251883Speter** Existing database connections continue use the sharing mode 6065251883Speter** that was in effect at the time they were opened.)^ 6066251883Speter** 6067251883Speter** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6068251883Speter** successfully. An [error code] is returned otherwise.)^ 6069251883Speter** 6070251883Speter** ^Shared cache is disabled by default. But this might change in 6071251883Speter** future releases of SQLite. Applications that care about shared 6072251883Speter** cache setting should set it explicitly. 6073251883Speter** 6074282328Sbapt** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6075282328Sbapt** and will always return SQLITE_MISUSE. On those systems, 6076282328Sbapt** shared cache mode should be enabled per-database connection via 6077282328Sbapt** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6078282328Sbapt** 6079251883Speter** This interface is threadsafe on processors where writing a 6080251883Speter** 32-bit integer is atomic. 6081251883Speter** 6082251883Speter** See Also: [SQLite Shared-Cache Mode] 6083251883Speter*/ 6084322444SpeterSQLITE_API int sqlite3_enable_shared_cache(int); 6085251883Speter 6086251883Speter/* 6087251883Speter** CAPI3REF: Attempt To Free Heap Memory 6088251883Speter** 6089251883Speter** ^The sqlite3_release_memory() interface attempts to free N bytes 6090251883Speter** of heap memory by deallocating non-essential memory allocations 6091251883Speter** held by the database library. Memory used to cache database 6092251883Speter** pages to improve performance is an example of non-essential memory. 6093251883Speter** ^sqlite3_release_memory() returns the number of bytes actually freed, 6094251883Speter** which might be more or less than the amount requested. 6095251883Speter** ^The sqlite3_release_memory() routine is a no-op returning zero 6096251883Speter** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6097251883Speter** 6098251883Speter** See also: [sqlite3_db_release_memory()] 6099251883Speter*/ 6100322444SpeterSQLITE_API int sqlite3_release_memory(int); 6101251883Speter 6102251883Speter/* 6103251883Speter** CAPI3REF: Free Memory Used By A Database Connection 6104286510Speter** METHOD: sqlite3 6105251883Speter** 6106251883Speter** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6107251883Speter** memory as possible from database connection D. Unlike the 6108269851Speter** [sqlite3_release_memory()] interface, this interface is in effect even 6109269851Speter** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6110251883Speter** omitted. 6111251883Speter** 6112251883Speter** See also: [sqlite3_release_memory()] 6113251883Speter*/ 6114322444SpeterSQLITE_API int sqlite3_db_release_memory(sqlite3*); 6115251883Speter 6116251883Speter/* 6117251883Speter** CAPI3REF: Impose A Limit On Heap Size 6118251883Speter** 6119251883Speter** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6120251883Speter** soft limit on the amount of heap memory that may be allocated by SQLite. 6121251883Speter** ^SQLite strives to keep heap memory utilization below the soft heap 6122251883Speter** limit by reducing the number of pages held in the page cache 6123251883Speter** as heap memory usages approaches the limit. 6124251883Speter** ^The soft heap limit is "soft" because even though SQLite strives to stay 6125251883Speter** below the limit, it will exceed the limit rather than generate 6126251883Speter** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6127251883Speter** is advisory only. 6128251883Speter** 6129251883Speter** ^The return value from sqlite3_soft_heap_limit64() is the size of 6130251883Speter** the soft heap limit prior to the call, or negative in the case of an 6131251883Speter** error. ^If the argument N is negative 6132251883Speter** then no change is made to the soft heap limit. Hence, the current 6133251883Speter** size of the soft heap limit can be determined by invoking 6134251883Speter** sqlite3_soft_heap_limit64() with a negative argument. 6135251883Speter** 6136251883Speter** ^If the argument N is zero then the soft heap limit is disabled. 6137251883Speter** 6138251883Speter** ^(The soft heap limit is not enforced in the current implementation 6139251883Speter** if one or more of following conditions are true: 6140251883Speter** 6141251883Speter** <ul> 6142251883Speter** <li> The soft heap limit is set to zero. 6143251883Speter** <li> Memory accounting is disabled using a combination of the 6144251883Speter** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6145251883Speter** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6146251883Speter** <li> An alternative page cache implementation is specified using 6147251883Speter** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6148251883Speter** <li> The page cache allocates from its own memory pool supplied 6149251883Speter** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6150251883Speter** from the heap. 6151251883Speter** </ul>)^ 6152251883Speter** 6153322444Speter** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 6154322444Speter** the soft heap limit is enforced 6155251883Speter** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 6156251883Speter** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 6157251883Speter** the soft heap limit is enforced on every memory allocation. Without 6158251883Speter** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 6159251883Speter** when memory is allocated by the page cache. Testing suggests that because 6160251883Speter** the page cache is the predominate memory user in SQLite, most 6161251883Speter** applications will achieve adequate soft heap limit enforcement without 6162251883Speter** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6163251883Speter** 6164251883Speter** The circumstances under which SQLite will enforce the soft heap limit may 6165251883Speter** changes in future releases of SQLite. 6166251883Speter*/ 6167322444SpeterSQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6168251883Speter 6169251883Speter/* 6170251883Speter** CAPI3REF: Deprecated Soft Heap Limit Interface 6171251883Speter** DEPRECATED 6172251883Speter** 6173251883Speter** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6174251883Speter** interface. This routine is provided for historical compatibility 6175251883Speter** only. All new applications should use the 6176251883Speter** [sqlite3_soft_heap_limit64()] interface rather than this one. 6177251883Speter*/ 6178322444SpeterSQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6179251883Speter 6180251883Speter 6181251883Speter/* 6182251883Speter** CAPI3REF: Extract Metadata About A Column Of A Table 6183286510Speter** METHOD: sqlite3 6184251883Speter** 6185282328Sbapt** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6186282328Sbapt** information about column C of table T in database D 6187282328Sbapt** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6188282328Sbapt** interface returns SQLITE_OK and fills in the non-NULL pointers in 6189282328Sbapt** the final five arguments with appropriate values if the specified 6190282328Sbapt** column exists. ^The sqlite3_table_column_metadata() interface returns 6191282328Sbapt** SQLITE_ERROR and if the specified column does not exist. 6192282328Sbapt** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6193305002Scy** NULL pointer, then this routine simply checks for the existence of the 6194282328Sbapt** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6195322444Speter** does not. If the table name parameter T in a call to 6196322444Speter** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6197322444Speter** undefined behavior. 6198251883Speter** 6199251883Speter** ^The column is identified by the second, third and fourth parameters to 6200282328Sbapt** this function. ^(The second parameter is either the name of the database 6201251883Speter** (i.e. "main", "temp", or an attached database) containing the specified 6202282328Sbapt** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6203251883Speter** for the table using the same algorithm used by the database engine to 6204251883Speter** resolve unqualified table references. 6205251883Speter** 6206251883Speter** ^The third and fourth parameters to this function are the table and column 6207282328Sbapt** name of the desired column, respectively. 6208251883Speter** 6209251883Speter** ^Metadata is returned by writing to the memory locations passed as the 5th 6210251883Speter** and subsequent parameters to this function. ^Any of these arguments may be 6211251883Speter** NULL, in which case the corresponding element of metadata is omitted. 6212251883Speter** 6213251883Speter** ^(<blockquote> 6214251883Speter** <table border="1"> 6215251883Speter** <tr><th> Parameter <th> Output<br>Type <th> Description 6216251883Speter** 6217251883Speter** <tr><td> 5th <td> const char* <td> Data type 6218251883Speter** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6219251883Speter** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6220251883Speter** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6221251883Speter** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6222251883Speter** </table> 6223251883Speter** </blockquote>)^ 6224251883Speter** 6225251883Speter** ^The memory pointed to by the character pointers returned for the 6226282328Sbapt** declaration type and collation sequence is valid until the next 6227251883Speter** call to any SQLite API function. 6228251883Speter** 6229251883Speter** ^If the specified table is actually a view, an [error code] is returned. 6230251883Speter** 6231282328Sbapt** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6232282328Sbapt** is not a [WITHOUT ROWID] table and an 6233251883Speter** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6234251883Speter** parameters are set for the explicitly declared column. ^(If there is no 6235282328Sbapt** [INTEGER PRIMARY KEY] column, then the outputs 6236282328Sbapt** for the [rowid] are set as follows: 6237251883Speter** 6238251883Speter** <pre> 6239251883Speter** data type: "INTEGER" 6240251883Speter** collation sequence: "BINARY" 6241251883Speter** not null: 0 6242251883Speter** primary key: 1 6243251883Speter** auto increment: 0 6244251883Speter** </pre>)^ 6245251883Speter** 6246282328Sbapt** ^This function causes all database schemas to be read from disk and 6247282328Sbapt** parsed, if that has not already been done, and returns an error if 6248282328Sbapt** any errors are encountered while loading the schema. 6249251883Speter*/ 6250322444SpeterSQLITE_API int sqlite3_table_column_metadata( 6251251883Speter sqlite3 *db, /* Connection handle */ 6252251883Speter const char *zDbName, /* Database name or NULL */ 6253251883Speter const char *zTableName, /* Table name */ 6254251883Speter const char *zColumnName, /* Column name */ 6255251883Speter char const **pzDataType, /* OUTPUT: Declared data type */ 6256251883Speter char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6257251883Speter int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6258251883Speter int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6259251883Speter int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6260251883Speter); 6261251883Speter 6262251883Speter/* 6263251883Speter** CAPI3REF: Load An Extension 6264286510Speter** METHOD: sqlite3 6265251883Speter** 6266251883Speter** ^This interface loads an SQLite extension library from the named file. 6267251883Speter** 6268251883Speter** ^The sqlite3_load_extension() interface attempts to load an 6269251883Speter** [SQLite extension] library contained in the file zFile. If 6270251883Speter** the file cannot be loaded directly, attempts are made to load 6271251883Speter** with various operating-system specific extensions added. 6272251883Speter** So for example, if "samplelib" cannot be loaded, then names like 6273251883Speter** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6274251883Speter** be tried also. 6275251883Speter** 6276251883Speter** ^The entry point is zProc. 6277251883Speter** ^(zProc may be 0, in which case SQLite will try to come up with an 6278251883Speter** entry point name on its own. It first tries "sqlite3_extension_init". 6279251883Speter** If that does not work, it constructs a name "sqlite3_X_init" where the 6280251883Speter** X is consists of the lower-case equivalent of all ASCII alphabetic 6281251883Speter** characters in the filename from the last "/" to the first following 6282251883Speter** "." and omitting any initial "lib".)^ 6283251883Speter** ^The sqlite3_load_extension() interface returns 6284251883Speter** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6285251883Speter** ^If an error occurs and pzErrMsg is not 0, then the 6286251883Speter** [sqlite3_load_extension()] interface shall attempt to 6287251883Speter** fill *pzErrMsg with error message text stored in memory 6288251883Speter** obtained from [sqlite3_malloc()]. The calling function 6289251883Speter** should free this memory by calling [sqlite3_free()]. 6290251883Speter** 6291251883Speter** ^Extension loading must be enabled using 6292305002Scy** [sqlite3_enable_load_extension()] or 6293305002Scy** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6294305002Scy** prior to calling this API, 6295251883Speter** otherwise an error will be returned. 6296251883Speter** 6297305002Scy** <b>Security warning:</b> It is recommended that the 6298305002Scy** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6299305002Scy** interface. The use of the [sqlite3_enable_load_extension()] interface 6300305002Scy** should be avoided. This will keep the SQL function [load_extension()] 6301305002Scy** disabled and prevent SQL injections from giving attackers 6302305002Scy** access to extension loading capabilities. 6303305002Scy** 6304251883Speter** See also the [load_extension() SQL function]. 6305251883Speter*/ 6306322444SpeterSQLITE_API int sqlite3_load_extension( 6307251883Speter sqlite3 *db, /* Load the extension into this database connection */ 6308251883Speter const char *zFile, /* Name of the shared library containing extension */ 6309251883Speter const char *zProc, /* Entry point. Derived from zFile if 0 */ 6310251883Speter char **pzErrMsg /* Put error message here if not 0 */ 6311251883Speter); 6312251883Speter 6313251883Speter/* 6314251883Speter** CAPI3REF: Enable Or Disable Extension Loading 6315286510Speter** METHOD: sqlite3 6316251883Speter** 6317251883Speter** ^So as not to open security holes in older applications that are 6318251883Speter** unprepared to deal with [extension loading], and as a means of disabling 6319251883Speter** [extension loading] while evaluating user-entered SQL, the following API 6320251883Speter** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6321251883Speter** 6322251883Speter** ^Extension loading is off by default. 6323251883Speter** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6324251883Speter** to turn extension loading on and call it with onoff==0 to turn 6325251883Speter** it back off again. 6326305002Scy** 6327305002Scy** ^This interface enables or disables both the C-API 6328305002Scy** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6329305002Scy** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6330305002Scy** to enable or disable only the C-API.)^ 6331305002Scy** 6332305002Scy** <b>Security warning:</b> It is recommended that extension loading 6333305002Scy** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6334305002Scy** rather than this interface, so the [load_extension()] SQL function 6335305002Scy** remains disabled. This will prevent SQL injections from giving attackers 6336305002Scy** access to extension loading capabilities. 6337251883Speter*/ 6338322444SpeterSQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6339251883Speter 6340251883Speter/* 6341251883Speter** CAPI3REF: Automatically Load Statically Linked Extensions 6342251883Speter** 6343251883Speter** ^This interface causes the xEntryPoint() function to be invoked for 6344251883Speter** each new [database connection] that is created. The idea here is that 6345251883Speter** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6346251883Speter** that is to be automatically loaded into all new database connections. 6347251883Speter** 6348251883Speter** ^(Even though the function prototype shows that xEntryPoint() takes 6349251883Speter** no arguments and returns void, SQLite invokes xEntryPoint() with three 6350305002Scy** arguments and expects an integer result as if the signature of the 6351251883Speter** entry point where as follows: 6352251883Speter** 6353251883Speter** <blockquote><pre> 6354251883Speter** int xEntryPoint( 6355251883Speter** sqlite3 *db, 6356251883Speter** const char **pzErrMsg, 6357251883Speter** const struct sqlite3_api_routines *pThunk 6358251883Speter** ); 6359251883Speter** </pre></blockquote>)^ 6360251883Speter** 6361251883Speter** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6362251883Speter** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6363251883Speter** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6364251883Speter** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6365251883Speter** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6366251883Speter** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6367251883Speter** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6368251883Speter** 6369251883Speter** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6370251883Speter** on the list of automatic extensions is a harmless no-op. ^No entry point 6371251883Speter** will be called more than once for each database connection that is opened. 6372251883Speter** 6373269851Speter** See also: [sqlite3_reset_auto_extension()] 6374269851Speter** and [sqlite3_cancel_auto_extension()] 6375251883Speter*/ 6376322444SpeterSQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6377251883Speter 6378251883Speter/* 6379269851Speter** CAPI3REF: Cancel Automatic Extension Loading 6380269851Speter** 6381269851Speter** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6382269851Speter** initialization routine X that was registered using a prior call to 6383269851Speter** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6384269851Speter** routine returns 1 if initialization routine X was successfully 6385269851Speter** unregistered and it returns 0 if X was not on the list of initialization 6386269851Speter** routines. 6387269851Speter*/ 6388322444SpeterSQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6389269851Speter 6390269851Speter/* 6391251883Speter** CAPI3REF: Reset Automatic Extension Loading 6392251883Speter** 6393251883Speter** ^This interface disables all automatic extensions previously 6394251883Speter** registered using [sqlite3_auto_extension()]. 6395251883Speter*/ 6396322444SpeterSQLITE_API void sqlite3_reset_auto_extension(void); 6397251883Speter 6398251883Speter/* 6399251883Speter** The interface to the virtual-table mechanism is currently considered 6400251883Speter** to be experimental. The interface might change in incompatible ways. 6401251883Speter** If this is a problem for you, do not use the interface at this time. 6402251883Speter** 6403251883Speter** When the virtual-table mechanism stabilizes, we will declare the 6404251883Speter** interface fixed, support it indefinitely, and remove this comment. 6405251883Speter*/ 6406251883Speter 6407251883Speter/* 6408251883Speter** Structures used by the virtual table interface 6409251883Speter*/ 6410251883Spetertypedef struct sqlite3_vtab sqlite3_vtab; 6411251883Spetertypedef struct sqlite3_index_info sqlite3_index_info; 6412251883Spetertypedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6413251883Spetertypedef struct sqlite3_module sqlite3_module; 6414251883Speter 6415251883Speter/* 6416251883Speter** CAPI3REF: Virtual Table Object 6417251883Speter** KEYWORDS: sqlite3_module {virtual table module} 6418251883Speter** 6419251883Speter** This structure, sometimes called a "virtual table module", 6420251883Speter** defines the implementation of a [virtual tables]. 6421251883Speter** This structure consists mostly of methods for the module. 6422251883Speter** 6423251883Speter** ^A virtual table module is created by filling in a persistent 6424251883Speter** instance of this structure and passing a pointer to that instance 6425251883Speter** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6426251883Speter** ^The registration remains valid until it is replaced by a different 6427251883Speter** module or until the [database connection] closes. The content 6428251883Speter** of this structure must not change while it is registered with 6429251883Speter** any database connection. 6430251883Speter*/ 6431251883Speterstruct sqlite3_module { 6432251883Speter int iVersion; 6433251883Speter int (*xCreate)(sqlite3*, void *pAux, 6434251883Speter int argc, const char *const*argv, 6435251883Speter sqlite3_vtab **ppVTab, char**); 6436251883Speter int (*xConnect)(sqlite3*, void *pAux, 6437251883Speter int argc, const char *const*argv, 6438251883Speter sqlite3_vtab **ppVTab, char**); 6439251883Speter int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6440251883Speter int (*xDisconnect)(sqlite3_vtab *pVTab); 6441251883Speter int (*xDestroy)(sqlite3_vtab *pVTab); 6442251883Speter int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6443251883Speter int (*xClose)(sqlite3_vtab_cursor*); 6444251883Speter int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6445251883Speter int argc, sqlite3_value **argv); 6446251883Speter int (*xNext)(sqlite3_vtab_cursor*); 6447251883Speter int (*xEof)(sqlite3_vtab_cursor*); 6448251883Speter int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6449251883Speter int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6450251883Speter int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6451251883Speter int (*xBegin)(sqlite3_vtab *pVTab); 6452251883Speter int (*xSync)(sqlite3_vtab *pVTab); 6453251883Speter int (*xCommit)(sqlite3_vtab *pVTab); 6454251883Speter int (*xRollback)(sqlite3_vtab *pVTab); 6455251883Speter int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6456251883Speter void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6457251883Speter void **ppArg); 6458251883Speter int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6459251883Speter /* The methods above are in version 1 of the sqlite_module object. Those 6460251883Speter ** below are for version 2 and greater. */ 6461251883Speter int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6462251883Speter int (*xRelease)(sqlite3_vtab *pVTab, int); 6463251883Speter int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6464342292Scy /* The methods above are in versions 1 and 2 of the sqlite_module object. 6465342292Scy ** Those below are for version 3 and greater. */ 6466342292Scy int (*xShadowName)(const char*); 6467251883Speter}; 6468251883Speter 6469251883Speter/* 6470251883Speter** CAPI3REF: Virtual Table Indexing Information 6471251883Speter** KEYWORDS: sqlite3_index_info 6472251883Speter** 6473251883Speter** The sqlite3_index_info structure and its substructures is used as part 6474251883Speter** of the [virtual table] interface to 6475251883Speter** pass information into and receive the reply from the [xBestIndex] 6476251883Speter** method of a [virtual table module]. The fields under **Inputs** are the 6477251883Speter** inputs to xBestIndex and are read-only. xBestIndex inserts its 6478251883Speter** results into the **Outputs** fields. 6479251883Speter** 6480251883Speter** ^(The aConstraint[] array records WHERE clause constraints of the form: 6481251883Speter** 6482251883Speter** <blockquote>column OP expr</blockquote> 6483251883Speter** 6484251883Speter** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6485251883Speter** stored in aConstraint[].op using one of the 6486251883Speter** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6487251883Speter** ^(The index of the column is stored in 6488251883Speter** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6489251883Speter** expr on the right-hand side can be evaluated (and thus the constraint 6490251883Speter** is usable) and false if it cannot.)^ 6491251883Speter** 6492251883Speter** ^The optimizer automatically inverts terms of the form "expr OP column" 6493251883Speter** and makes other simplifications to the WHERE clause in an attempt to 6494251883Speter** get as many WHERE clause terms into the form shown above as possible. 6495251883Speter** ^The aConstraint[] array only reports WHERE clause terms that are 6496251883Speter** relevant to the particular virtual table being queried. 6497251883Speter** 6498251883Speter** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6499251883Speter** ^Each term of aOrderBy records a column of the ORDER BY clause. 6500251883Speter** 6501298161Sbapt** The colUsed field indicates which columns of the virtual table may be 6502298161Sbapt** required by the current scan. Virtual table columns are numbered from 6503298161Sbapt** zero in the order in which they appear within the CREATE TABLE statement 6504298161Sbapt** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6505298161Sbapt** the corresponding bit is set within the colUsed mask if the column may be 6506298161Sbapt** required by SQLite. If the table has at least 64 columns and any column 6507298161Sbapt** to the right of the first 63 is required, then bit 63 of colUsed is also 6508298161Sbapt** set. In other words, column iCol may be required if the expression 6509298161Sbapt** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6510298161Sbapt** non-zero. 6511298161Sbapt** 6512251883Speter** The [xBestIndex] method must fill aConstraintUsage[] with information 6513251883Speter** about what parameters to pass to xFilter. ^If argvIndex>0 then 6514251883Speter** the right-hand side of the corresponding aConstraint[] is evaluated 6515251883Speter** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6516251883Speter** is true, then the constraint is assumed to be fully handled by the 6517251883Speter** virtual table and is not checked again by SQLite.)^ 6518251883Speter** 6519251883Speter** ^The idxNum and idxPtr values are recorded and passed into the 6520251883Speter** [xFilter] method. 6521251883Speter** ^[sqlite3_free()] is used to free idxPtr if and only if 6522251883Speter** needToFreeIdxPtr is true. 6523251883Speter** 6524251883Speter** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6525251883Speter** the correct order to satisfy the ORDER BY clause so that no separate 6526251883Speter** sorting step is required. 6527251883Speter** 6528269851Speter** ^The estimatedCost value is an estimate of the cost of a particular 6529269851Speter** strategy. A cost of N indicates that the cost of the strategy is similar 6530269851Speter** to a linear scan of an SQLite table with N rows. A cost of log(N) 6531269851Speter** indicates that the expense of the operation is similar to that of a 6532269851Speter** binary search on a unique indexed field of an SQLite table with N rows. 6533269851Speter** 6534269851Speter** ^The estimatedRows value is an estimate of the number of rows that 6535269851Speter** will be returned by the strategy. 6536269851Speter** 6537298161Sbapt** The xBestIndex method may optionally populate the idxFlags field with a 6538298161Sbapt** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6539298161Sbapt** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6540298161Sbapt** assumes that the strategy may visit at most one row. 6541298161Sbapt** 6542298161Sbapt** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6543298161Sbapt** SQLite also assumes that if a call to the xUpdate() method is made as 6544298161Sbapt** part of the same statement to delete or update a virtual table row and the 6545298161Sbapt** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6546298161Sbapt** any database changes. In other words, if the xUpdate() returns 6547298161Sbapt** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6548298161Sbapt** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6549298161Sbapt** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6550298161Sbapt** the xUpdate method are automatically rolled back by SQLite. 6551298161Sbapt** 6552269851Speter** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6553322444Speter** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6554322444Speter** If a virtual table extension is 6555269851Speter** used with an SQLite version earlier than 3.8.2, the results of attempting 6556269851Speter** to read or write the estimatedRows field are undefined (but are likely 6557269851Speter** to included crashing the application). The estimatedRows field should 6558269851Speter** therefore only be used if [sqlite3_libversion_number()] returns a 6559298161Sbapt** value greater than or equal to 3008002. Similarly, the idxFlags field 6560322444Speter** was added for [version 3.9.0] ([dateof:3.9.0]). 6561322444Speter** It may therefore only be used if 6562298161Sbapt** sqlite3_libversion_number() returns a value greater than or equal to 6563298161Sbapt** 3009000. 6564251883Speter*/ 6565251883Speterstruct sqlite3_index_info { 6566251883Speter /* Inputs */ 6567251883Speter int nConstraint; /* Number of entries in aConstraint */ 6568251883Speter struct sqlite3_index_constraint { 6569298161Sbapt int iColumn; /* Column constrained. -1 for ROWID */ 6570251883Speter unsigned char op; /* Constraint operator */ 6571251883Speter unsigned char usable; /* True if this constraint is usable */ 6572251883Speter int iTermOffset; /* Used internally - xBestIndex should ignore */ 6573251883Speter } *aConstraint; /* Table of WHERE clause constraints */ 6574251883Speter int nOrderBy; /* Number of terms in the ORDER BY clause */ 6575251883Speter struct sqlite3_index_orderby { 6576251883Speter int iColumn; /* Column number */ 6577251883Speter unsigned char desc; /* True for DESC. False for ASC. */ 6578251883Speter } *aOrderBy; /* The ORDER BY clause */ 6579251883Speter /* Outputs */ 6580251883Speter struct sqlite3_index_constraint_usage { 6581251883Speter int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6582251883Speter unsigned char omit; /* Do not code a test for this constraint */ 6583251883Speter } *aConstraintUsage; 6584251883Speter int idxNum; /* Number used to identify the index */ 6585251883Speter char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6586251883Speter int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6587251883Speter int orderByConsumed; /* True if output is already ordered */ 6588269851Speter double estimatedCost; /* Estimated cost of using this index */ 6589269851Speter /* Fields below are only available in SQLite 3.8.2 and later */ 6590269851Speter sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6591298161Sbapt /* Fields below are only available in SQLite 3.9.0 and later */ 6592298161Sbapt int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6593298161Sbapt /* Fields below are only available in SQLite 3.10.0 and later */ 6594298161Sbapt sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6595251883Speter}; 6596251883Speter 6597251883Speter/* 6598298161Sbapt** CAPI3REF: Virtual Table Scan Flags 6599342292Scy** 6600342292Scy** Virtual table implementations are allowed to set the 6601342292Scy** [sqlite3_index_info].idxFlags field to some combination of 6602342292Scy** these bits. 6603298161Sbapt*/ 6604298161Sbapt#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6605298161Sbapt 6606298161Sbapt/* 6607251883Speter** CAPI3REF: Virtual Table Constraint Operator Codes 6608251883Speter** 6609251883Speter** These macros defined the allowed values for the 6610251883Speter** [sqlite3_index_info].aConstraint[].op field. Each value represents 6611251883Speter** an operator that is part of a constraint term in the wHERE clause of 6612251883Speter** a query that uses a [virtual table]. 6613251883Speter*/ 6614342292Scy#define SQLITE_INDEX_CONSTRAINT_EQ 2 6615342292Scy#define SQLITE_INDEX_CONSTRAINT_GT 4 6616342292Scy#define SQLITE_INDEX_CONSTRAINT_LE 8 6617342292Scy#define SQLITE_INDEX_CONSTRAINT_LT 16 6618342292Scy#define SQLITE_INDEX_CONSTRAINT_GE 32 6619342292Scy#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6620342292Scy#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6621342292Scy#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6622342292Scy#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6623342292Scy#define SQLITE_INDEX_CONSTRAINT_NE 68 6624342292Scy#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6625342292Scy#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6626342292Scy#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6627342292Scy#define SQLITE_INDEX_CONSTRAINT_IS 72 6628342292Scy#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6629251883Speter 6630251883Speter/* 6631251883Speter** CAPI3REF: Register A Virtual Table Implementation 6632286510Speter** METHOD: sqlite3 6633251883Speter** 6634251883Speter** ^These routines are used to register a new [virtual table module] name. 6635251883Speter** ^Module names must be registered before 6636251883Speter** creating a new [virtual table] using the module and before using a 6637251883Speter** preexisting [virtual table] for the module. 6638251883Speter** 6639251883Speter** ^The module name is registered on the [database connection] specified 6640251883Speter** by the first parameter. ^The name of the module is given by the 6641251883Speter** second parameter. ^The third parameter is a pointer to 6642251883Speter** the implementation of the [virtual table module]. ^The fourth 6643251883Speter** parameter is an arbitrary client data pointer that is passed through 6644251883Speter** into the [xCreate] and [xConnect] methods of the virtual table module 6645251883Speter** when a new virtual table is be being created or reinitialized. 6646251883Speter** 6647251883Speter** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6648251883Speter** is a pointer to a destructor for the pClientData. ^SQLite will 6649251883Speter** invoke the destructor function (if it is not NULL) when SQLite 6650251883Speter** no longer needs the pClientData pointer. ^The destructor will also 6651251883Speter** be invoked if the call to sqlite3_create_module_v2() fails. 6652251883Speter** ^The sqlite3_create_module() 6653251883Speter** interface is equivalent to sqlite3_create_module_v2() with a NULL 6654251883Speter** destructor. 6655355326Scy** 6656355326Scy** ^If the third parameter (the pointer to the sqlite3_module object) is 6657355326Scy** NULL then no new module is create and any existing modules with the 6658355326Scy** same name are dropped. 6659355326Scy** 6660355326Scy** See also: [sqlite3_drop_modules()] 6661251883Speter*/ 6662322444SpeterSQLITE_API int sqlite3_create_module( 6663251883Speter sqlite3 *db, /* SQLite connection to register module with */ 6664251883Speter const char *zName, /* Name of the module */ 6665251883Speter const sqlite3_module *p, /* Methods for the module */ 6666251883Speter void *pClientData /* Client data for xCreate/xConnect */ 6667251883Speter); 6668322444SpeterSQLITE_API int sqlite3_create_module_v2( 6669251883Speter sqlite3 *db, /* SQLite connection to register module with */ 6670251883Speter const char *zName, /* Name of the module */ 6671251883Speter const sqlite3_module *p, /* Methods for the module */ 6672251883Speter void *pClientData, /* Client data for xCreate/xConnect */ 6673251883Speter void(*xDestroy)(void*) /* Module destructor function */ 6674251883Speter); 6675251883Speter 6676251883Speter/* 6677355326Scy** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6678355326Scy** METHOD: sqlite3 6679355326Scy** 6680355326Scy** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6681355326Scy** table modules from database connection D except those named on list L. 6682355326Scy** The L parameter must be either NULL or a pointer to an array of pointers 6683355326Scy** to strings where the array is terminated by a single NULL pointer. 6684355326Scy** ^If the L parameter is NULL, then all virtual table modules are removed. 6685355326Scy** 6686355326Scy** See also: [sqlite3_create_module()] 6687355326Scy*/ 6688355326ScySQLITE_API int sqlite3_drop_modules( 6689355326Scy sqlite3 *db, /* Remove modules from this connection */ 6690355326Scy const char **azKeep /* Except, do not remove the ones named here */ 6691355326Scy); 6692355326Scy 6693355326Scy/* 6694251883Speter** CAPI3REF: Virtual Table Instance Object 6695251883Speter** KEYWORDS: sqlite3_vtab 6696251883Speter** 6697251883Speter** Every [virtual table module] implementation uses a subclass 6698251883Speter** of this object to describe a particular instance 6699251883Speter** of the [virtual table]. Each subclass will 6700251883Speter** be tailored to the specific needs of the module implementation. 6701251883Speter** The purpose of this superclass is to define certain fields that are 6702251883Speter** common to all module implementations. 6703251883Speter** 6704251883Speter** ^Virtual tables methods can set an error message by assigning a 6705251883Speter** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6706251883Speter** take care that any prior string is freed by a call to [sqlite3_free()] 6707251883Speter** prior to assigning a new string to zErrMsg. ^After the error message 6708251883Speter** is delivered up to the client application, the string will be automatically 6709251883Speter** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6710251883Speter*/ 6711251883Speterstruct sqlite3_vtab { 6712251883Speter const sqlite3_module *pModule; /* The module for this virtual table */ 6713282328Sbapt int nRef; /* Number of open cursors */ 6714251883Speter char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6715251883Speter /* Virtual table implementations will typically add additional fields */ 6716251883Speter}; 6717251883Speter 6718251883Speter/* 6719251883Speter** CAPI3REF: Virtual Table Cursor Object 6720251883Speter** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6721251883Speter** 6722251883Speter** Every [virtual table module] implementation uses a subclass of the 6723251883Speter** following structure to describe cursors that point into the 6724251883Speter** [virtual table] and are used 6725251883Speter** to loop through the virtual table. Cursors are created using the 6726251883Speter** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6727251883Speter** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6728251883Speter** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6729251883Speter** of the module. Each module implementation will define 6730251883Speter** the content of a cursor structure to suit its own needs. 6731251883Speter** 6732251883Speter** This superclass exists in order to define fields of the cursor that 6733251883Speter** are common to all implementations. 6734251883Speter*/ 6735251883Speterstruct sqlite3_vtab_cursor { 6736251883Speter sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6737251883Speter /* Virtual table implementations will typically add additional fields */ 6738251883Speter}; 6739251883Speter 6740251883Speter/* 6741251883Speter** CAPI3REF: Declare The Schema Of A Virtual Table 6742251883Speter** 6743251883Speter** ^The [xCreate] and [xConnect] methods of a 6744251883Speter** [virtual table module] call this interface 6745251883Speter** to declare the format (the names and datatypes of the columns) of 6746251883Speter** the virtual tables they implement. 6747251883Speter*/ 6748322444SpeterSQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6749251883Speter 6750251883Speter/* 6751251883Speter** CAPI3REF: Overload A Function For A Virtual Table 6752286510Speter** METHOD: sqlite3 6753251883Speter** 6754251883Speter** ^(Virtual tables can provide alternative implementations of functions 6755251883Speter** using the [xFindFunction] method of the [virtual table module]. 6756251883Speter** But global versions of those functions 6757251883Speter** must exist in order to be overloaded.)^ 6758251883Speter** 6759251883Speter** ^(This API makes sure a global version of a function with a particular 6760251883Speter** name and number of parameters exists. If no such function exists 6761251883Speter** before this API is called, a new function is created.)^ ^The implementation 6762251883Speter** of the new function always causes an exception to be thrown. So 6763251883Speter** the new function is not good for anything by itself. Its only 6764251883Speter** purpose is to be a placeholder function that can be overloaded 6765251883Speter** by a [virtual table]. 6766251883Speter*/ 6767322444SpeterSQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6768251883Speter 6769251883Speter/* 6770251883Speter** The interface to the virtual-table mechanism defined above (back up 6771251883Speter** to a comment remarkably similar to this one) is currently considered 6772251883Speter** to be experimental. The interface might change in incompatible ways. 6773251883Speter** If this is a problem for you, do not use the interface at this time. 6774251883Speter** 6775251883Speter** When the virtual-table mechanism stabilizes, we will declare the 6776251883Speter** interface fixed, support it indefinitely, and remove this comment. 6777251883Speter*/ 6778251883Speter 6779251883Speter/* 6780251883Speter** CAPI3REF: A Handle To An Open BLOB 6781251883Speter** KEYWORDS: {BLOB handle} {BLOB handles} 6782251883Speter** 6783251883Speter** An instance of this object represents an open BLOB on which 6784251883Speter** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6785251883Speter** ^Objects of this type are created by [sqlite3_blob_open()] 6786251883Speter** and destroyed by [sqlite3_blob_close()]. 6787251883Speter** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6788251883Speter** can be used to read or write small subsections of the BLOB. 6789251883Speter** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6790251883Speter*/ 6791251883Spetertypedef struct sqlite3_blob sqlite3_blob; 6792251883Speter 6793251883Speter/* 6794251883Speter** CAPI3REF: Open A BLOB For Incremental I/O 6795286510Speter** METHOD: sqlite3 6796286510Speter** CONSTRUCTOR: sqlite3_blob 6797251883Speter** 6798251883Speter** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6799251883Speter** in row iRow, column zColumn, table zTable in database zDb; 6800251883Speter** in other words, the same BLOB that would be selected by: 6801251883Speter** 6802251883Speter** <pre> 6803251883Speter** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6804251883Speter** </pre>)^ 6805251883Speter** 6806282328Sbapt** ^(Parameter zDb is not the filename that contains the database, but 6807282328Sbapt** rather the symbolic name of the database. For attached databases, this is 6808282328Sbapt** the name that appears after the AS keyword in the [ATTACH] statement. 6809282328Sbapt** For the main database file, the database name is "main". For TEMP 6810282328Sbapt** tables, the database name is "temp".)^ 6811282328Sbapt** 6812251883Speter** ^If the flags parameter is non-zero, then the BLOB is opened for read 6813282328Sbapt** and write access. ^If the flags parameter is zero, the BLOB is opened for 6814282328Sbapt** read-only access. 6815251883Speter** 6816282328Sbapt** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6817282328Sbapt** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6818282328Sbapt** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6819282328Sbapt** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6820282328Sbapt** on *ppBlob after this function it returns. 6821251883Speter** 6822282328Sbapt** This function fails with SQLITE_ERROR if any of the following are true: 6823282328Sbapt** <ul> 6824282328Sbapt** <li> ^(Database zDb does not exist)^, 6825282328Sbapt** <li> ^(Table zTable does not exist within database zDb)^, 6826282328Sbapt** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6827282328Sbapt** <li> ^(Column zColumn does not exist)^, 6828282328Sbapt** <li> ^(Row iRow is not present in the table)^, 6829282328Sbapt** <li> ^(The specified column of row iRow contains a value that is not 6830282328Sbapt** a TEXT or BLOB value)^, 6831282328Sbapt** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6832282328Sbapt** constraint and the blob is being opened for read/write access)^, 6833282328Sbapt** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6834282328Sbapt** column zColumn is part of a [child key] definition and the blob is 6835282328Sbapt** being opened for read/write access)^. 6836282328Sbapt** </ul> 6837251883Speter** 6838282328Sbapt** ^Unless it returns SQLITE_MISUSE, this function sets the 6839282328Sbapt** [database connection] error code and message accessible via 6840282328Sbapt** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6841282328Sbapt** 6842322444Speter** A BLOB referenced by sqlite3_blob_open() may be read using the 6843322444Speter** [sqlite3_blob_read()] interface and modified by using 6844322444Speter** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6845322444Speter** different row of the same table using the [sqlite3_blob_reopen()] 6846322444Speter** interface. However, the column, table, or database of a [BLOB handle] 6847322444Speter** cannot be changed after the [BLOB handle] is opened. 6848282328Sbapt** 6849251883Speter** ^(If the row that a BLOB handle points to is modified by an 6850251883Speter** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6851251883Speter** then the BLOB handle is marked as "expired". 6852251883Speter** This is true if any column of the row is changed, even a column 6853251883Speter** other than the one the BLOB handle is open on.)^ 6854251883Speter** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6855251883Speter** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6856251883Speter** ^(Changes written into a BLOB prior to the BLOB expiring are not 6857251883Speter** rolled back by the expiration of the BLOB. Such changes will eventually 6858251883Speter** commit if the transaction continues to completion.)^ 6859251883Speter** 6860251883Speter** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6861251883Speter** the opened blob. ^The size of a blob may not be changed by this 6862251883Speter** interface. Use the [UPDATE] SQL command to change the size of a 6863251883Speter** blob. 6864251883Speter** 6865251883Speter** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6866282328Sbapt** and the built-in [zeroblob] SQL function may be used to create a 6867282328Sbapt** zero-filled blob to read or write using the incremental-blob interface. 6868251883Speter** 6869251883Speter** To avoid a resource leak, every open [BLOB handle] should eventually 6870251883Speter** be released by a call to [sqlite3_blob_close()]. 6871322444Speter** 6872322444Speter** See also: [sqlite3_blob_close()], 6873322444Speter** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6874322444Speter** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6875251883Speter*/ 6876322444SpeterSQLITE_API int sqlite3_blob_open( 6877251883Speter sqlite3*, 6878251883Speter const char *zDb, 6879251883Speter const char *zTable, 6880251883Speter const char *zColumn, 6881251883Speter sqlite3_int64 iRow, 6882251883Speter int flags, 6883251883Speter sqlite3_blob **ppBlob 6884251883Speter); 6885251883Speter 6886251883Speter/* 6887251883Speter** CAPI3REF: Move a BLOB Handle to a New Row 6888286510Speter** METHOD: sqlite3_blob 6889251883Speter** 6890322444Speter** ^This function is used to move an existing [BLOB handle] so that it points 6891251883Speter** to a different row of the same database table. ^The new row is identified 6892251883Speter** by the rowid value passed as the second argument. Only the row can be 6893251883Speter** changed. ^The database, table and column on which the blob handle is open 6894322444Speter** remain the same. Moving an existing [BLOB handle] to a new row is 6895251883Speter** faster than closing the existing handle and opening a new one. 6896251883Speter** 6897251883Speter** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6898251883Speter** it must exist and there must be either a blob or text value stored in 6899251883Speter** the nominated column.)^ ^If the new row is not present in the table, or if 6900251883Speter** it does not contain a blob or text value, or if another error occurs, an 6901251883Speter** SQLite error code is returned and the blob handle is considered aborted. 6902251883Speter** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6903251883Speter** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6904251883Speter** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6905251883Speter** always returns zero. 6906251883Speter** 6907251883Speter** ^This function sets the database handle error code and message. 6908251883Speter*/ 6909322444SpeterSQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6910251883Speter 6911251883Speter/* 6912251883Speter** CAPI3REF: Close A BLOB Handle 6913286510Speter** DESTRUCTOR: sqlite3_blob 6914251883Speter** 6915282328Sbapt** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6916282328Sbapt** unconditionally. Even if this routine returns an error code, the 6917282328Sbapt** handle is still closed.)^ 6918251883Speter** 6919282328Sbapt** ^If the blob handle being closed was opened for read-write access, and if 6920282328Sbapt** the database is in auto-commit mode and there are no other open read-write 6921282328Sbapt** blob handles or active write statements, the current transaction is 6922282328Sbapt** committed. ^If an error occurs while committing the transaction, an error 6923282328Sbapt** code is returned and the transaction rolled back. 6924251883Speter** 6925282328Sbapt** Calling this function with an argument that is not a NULL pointer or an 6926282328Sbapt** open blob handle results in undefined behaviour. ^Calling this routine 6927282328Sbapt** with a null pointer (such as would be returned by a failed call to 6928282328Sbapt** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6929282328Sbapt** is passed a valid open blob handle, the values returned by the 6930282328Sbapt** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6931251883Speter*/ 6932322444SpeterSQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6933251883Speter 6934251883Speter/* 6935251883Speter** CAPI3REF: Return The Size Of An Open BLOB 6936286510Speter** METHOD: sqlite3_blob 6937251883Speter** 6938251883Speter** ^Returns the size in bytes of the BLOB accessible via the 6939251883Speter** successfully opened [BLOB handle] in its only argument. ^The 6940251883Speter** incremental blob I/O routines can only read or overwriting existing 6941251883Speter** blob content; they cannot change the size of a blob. 6942251883Speter** 6943251883Speter** This routine only works on a [BLOB handle] which has been created 6944251883Speter** by a prior successful call to [sqlite3_blob_open()] and which has not 6945251883Speter** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6946251883Speter** to this routine results in undefined and probably undesirable behavior. 6947251883Speter*/ 6948322444SpeterSQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6949251883Speter 6950251883Speter/* 6951251883Speter** CAPI3REF: Read Data From A BLOB Incrementally 6952286510Speter** METHOD: sqlite3_blob 6953251883Speter** 6954251883Speter** ^(This function is used to read data from an open [BLOB handle] into a 6955251883Speter** caller-supplied buffer. N bytes of data are copied into buffer Z 6956251883Speter** from the open BLOB, starting at offset iOffset.)^ 6957251883Speter** 6958251883Speter** ^If offset iOffset is less than N bytes from the end of the BLOB, 6959251883Speter** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6960251883Speter** less than zero, [SQLITE_ERROR] is returned and no data is read. 6961251883Speter** ^The size of the blob (and hence the maximum value of N+iOffset) 6962251883Speter** can be determined using the [sqlite3_blob_bytes()] interface. 6963251883Speter** 6964251883Speter** ^An attempt to read from an expired [BLOB handle] fails with an 6965251883Speter** error code of [SQLITE_ABORT]. 6966251883Speter** 6967251883Speter** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6968251883Speter** Otherwise, an [error code] or an [extended error code] is returned.)^ 6969251883Speter** 6970251883Speter** This routine only works on a [BLOB handle] which has been created 6971251883Speter** by a prior successful call to [sqlite3_blob_open()] and which has not 6972251883Speter** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6973251883Speter** to this routine results in undefined and probably undesirable behavior. 6974251883Speter** 6975251883Speter** See also: [sqlite3_blob_write()]. 6976251883Speter*/ 6977322444SpeterSQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6978251883Speter 6979251883Speter/* 6980251883Speter** CAPI3REF: Write Data Into A BLOB Incrementally 6981286510Speter** METHOD: sqlite3_blob 6982251883Speter** 6983282328Sbapt** ^(This function is used to write data into an open [BLOB handle] from a 6984282328Sbapt** caller-supplied buffer. N bytes of data are copied from the buffer Z 6985282328Sbapt** into the open BLOB, starting at offset iOffset.)^ 6986251883Speter** 6987282328Sbapt** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6988282328Sbapt** Otherwise, an [error code] or an [extended error code] is returned.)^ 6989282328Sbapt** ^Unless SQLITE_MISUSE is returned, this function sets the 6990282328Sbapt** [database connection] error code and message accessible via 6991282328Sbapt** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6992282328Sbapt** 6993251883Speter** ^If the [BLOB handle] passed as the first argument was not opened for 6994251883Speter** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6995251883Speter** this function returns [SQLITE_READONLY]. 6996251883Speter** 6997282328Sbapt** This function may only modify the contents of the BLOB; it is 6998251883Speter** not possible to increase the size of a BLOB using this API. 6999251883Speter** ^If offset iOffset is less than N bytes from the end of the BLOB, 7000282328Sbapt** [SQLITE_ERROR] is returned and no data is written. The size of the 7001282328Sbapt** BLOB (and hence the maximum value of N+iOffset) can be determined 7002282328Sbapt** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7003282328Sbapt** than zero [SQLITE_ERROR] is returned and no data is written. 7004251883Speter** 7005251883Speter** ^An attempt to write to an expired [BLOB handle] fails with an 7006251883Speter** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7007251883Speter** before the [BLOB handle] expired are not rolled back by the 7008251883Speter** expiration of the handle, though of course those changes might 7009251883Speter** have been overwritten by the statement that expired the BLOB handle 7010251883Speter** or by other independent statements. 7011251883Speter** 7012251883Speter** This routine only works on a [BLOB handle] which has been created 7013251883Speter** by a prior successful call to [sqlite3_blob_open()] and which has not 7014251883Speter** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7015251883Speter** to this routine results in undefined and probably undesirable behavior. 7016251883Speter** 7017251883Speter** See also: [sqlite3_blob_read()]. 7018251883Speter*/ 7019322444SpeterSQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7020251883Speter 7021251883Speter/* 7022251883Speter** CAPI3REF: Virtual File System Objects 7023251883Speter** 7024251883Speter** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7025251883Speter** that SQLite uses to interact 7026251883Speter** with the underlying operating system. Most SQLite builds come with a 7027251883Speter** single default VFS that is appropriate for the host computer. 7028251883Speter** New VFSes can be registered and existing VFSes can be unregistered. 7029251883Speter** The following interfaces are provided. 7030251883Speter** 7031251883Speter** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7032251883Speter** ^Names are case sensitive. 7033251883Speter** ^Names are zero-terminated UTF-8 strings. 7034251883Speter** ^If there is no match, a NULL pointer is returned. 7035251883Speter** ^If zVfsName is NULL then the default VFS is returned. 7036251883Speter** 7037251883Speter** ^New VFSes are registered with sqlite3_vfs_register(). 7038251883Speter** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7039251883Speter** ^The same VFS can be registered multiple times without injury. 7040251883Speter** ^To make an existing VFS into the default VFS, register it again 7041251883Speter** with the makeDflt flag set. If two different VFSes with the 7042251883Speter** same name are registered, the behavior is undefined. If a 7043251883Speter** VFS is registered with a name that is NULL or an empty string, 7044251883Speter** then the behavior is undefined. 7045251883Speter** 7046251883Speter** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7047251883Speter** ^(If the default VFS is unregistered, another VFS is chosen as 7048251883Speter** the default. The choice for the new VFS is arbitrary.)^ 7049251883Speter*/ 7050322444SpeterSQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7051322444SpeterSQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7052322444SpeterSQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7053251883Speter 7054251883Speter/* 7055251883Speter** CAPI3REF: Mutexes 7056251883Speter** 7057251883Speter** The SQLite core uses these routines for thread 7058251883Speter** synchronization. Though they are intended for internal 7059251883Speter** use by SQLite, code that links against SQLite is 7060251883Speter** permitted to use any of these routines. 7061251883Speter** 7062251883Speter** The SQLite source code contains multiple implementations 7063251883Speter** of these mutex routines. An appropriate implementation 7064282328Sbapt** is selected automatically at compile-time. The following 7065251883Speter** implementations are available in the SQLite core: 7066251883Speter** 7067251883Speter** <ul> 7068251883Speter** <li> SQLITE_MUTEX_PTHREADS 7069251883Speter** <li> SQLITE_MUTEX_W32 7070251883Speter** <li> SQLITE_MUTEX_NOOP 7071282328Sbapt** </ul> 7072251883Speter** 7073282328Sbapt** The SQLITE_MUTEX_NOOP implementation is a set of routines 7074251883Speter** that does no real locking and is appropriate for use in 7075282328Sbapt** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7076251883Speter** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7077251883Speter** and Windows. 7078251883Speter** 7079282328Sbapt** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7080251883Speter** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7081251883Speter** implementation is included with the library. In this case the 7082251883Speter** application must supply a custom mutex implementation using the 7083251883Speter** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7084251883Speter** before calling sqlite3_initialize() or any other public sqlite3_ 7085282328Sbapt** function that calls sqlite3_initialize(). 7086251883Speter** 7087251883Speter** ^The sqlite3_mutex_alloc() routine allocates a new 7088282328Sbapt** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7089282328Sbapt** routine returns NULL if it is unable to allocate the requested 7090282328Sbapt** mutex. The argument to sqlite3_mutex_alloc() must one of these 7091282328Sbapt** integer constants: 7092251883Speter** 7093251883Speter** <ul> 7094251883Speter** <li> SQLITE_MUTEX_FAST 7095251883Speter** <li> SQLITE_MUTEX_RECURSIVE 7096251883Speter** <li> SQLITE_MUTEX_STATIC_MASTER 7097251883Speter** <li> SQLITE_MUTEX_STATIC_MEM 7098274884Sbapt** <li> SQLITE_MUTEX_STATIC_OPEN 7099251883Speter** <li> SQLITE_MUTEX_STATIC_PRNG 7100251883Speter** <li> SQLITE_MUTEX_STATIC_LRU 7101274884Sbapt** <li> SQLITE_MUTEX_STATIC_PMEM 7102274884Sbapt** <li> SQLITE_MUTEX_STATIC_APP1 7103274884Sbapt** <li> SQLITE_MUTEX_STATIC_APP2 7104282328Sbapt** <li> SQLITE_MUTEX_STATIC_APP3 7105298161Sbapt** <li> SQLITE_MUTEX_STATIC_VFS1 7106298161Sbapt** <li> SQLITE_MUTEX_STATIC_VFS2 7107298161Sbapt** <li> SQLITE_MUTEX_STATIC_VFS3 7108282328Sbapt** </ul> 7109251883Speter** 7110251883Speter** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7111251883Speter** cause sqlite3_mutex_alloc() to create 7112251883Speter** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7113251883Speter** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7114251883Speter** The mutex implementation does not need to make a distinction 7115251883Speter** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7116282328Sbapt** not want to. SQLite will only request a recursive mutex in 7117282328Sbapt** cases where it really needs one. If a faster non-recursive mutex 7118251883Speter** implementation is available on the host platform, the mutex subsystem 7119251883Speter** might return such a mutex in response to SQLITE_MUTEX_FAST. 7120251883Speter** 7121251883Speter** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7122251883Speter** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7123282328Sbapt** a pointer to a static preexisting mutex. ^Nine static mutexes are 7124251883Speter** used by the current version of SQLite. Future versions of SQLite 7125251883Speter** may add additional static mutexes. Static mutexes are for internal 7126251883Speter** use by SQLite only. Applications that use SQLite mutexes should 7127251883Speter** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7128251883Speter** SQLITE_MUTEX_RECURSIVE. 7129251883Speter** 7130251883Speter** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7131251883Speter** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7132282328Sbapt** returns a different mutex on every call. ^For the static 7133251883Speter** mutex types, the same mutex is returned on every call that has 7134251883Speter** the same type number. 7135251883Speter** 7136251883Speter** ^The sqlite3_mutex_free() routine deallocates a previously 7137282328Sbapt** allocated dynamic mutex. Attempting to deallocate a static 7138282328Sbapt** mutex results in undefined behavior. 7139251883Speter** 7140251883Speter** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7141251883Speter** to enter a mutex. ^If another thread is already within the mutex, 7142251883Speter** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7143251883Speter** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7144251883Speter** upon successful entry. ^(Mutexes created using 7145251883Speter** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7146282328Sbapt** In such cases, the 7147251883Speter** mutex must be exited an equal number of times before another thread 7148282328Sbapt** can enter.)^ If the same thread tries to enter any mutex other 7149282328Sbapt** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7150251883Speter** 7151251883Speter** ^(Some systems (for example, Windows 95) do not support the operation 7152251883Speter** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7153282328Sbapt** will always return SQLITE_BUSY. The SQLite core only ever uses 7154282328Sbapt** sqlite3_mutex_try() as an optimization so this is acceptable 7155282328Sbapt** behavior.)^ 7156251883Speter** 7157251883Speter** ^The sqlite3_mutex_leave() routine exits a mutex that was 7158282328Sbapt** previously entered by the same thread. The behavior 7159251883Speter** is undefined if the mutex is not currently entered by the 7160282328Sbapt** calling thread or is not currently allocated. 7161251883Speter** 7162251883Speter** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7163251883Speter** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7164251883Speter** behave as no-ops. 7165251883Speter** 7166251883Speter** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7167251883Speter*/ 7168322444SpeterSQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7169322444SpeterSQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7170322444SpeterSQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7171322444SpeterSQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7172322444SpeterSQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7173251883Speter 7174251883Speter/* 7175251883Speter** CAPI3REF: Mutex Methods Object 7176251883Speter** 7177251883Speter** An instance of this structure defines the low-level routines 7178251883Speter** used to allocate and use mutexes. 7179251883Speter** 7180251883Speter** Usually, the default mutex implementations provided by SQLite are 7181282328Sbapt** sufficient, however the application has the option of substituting a custom 7182251883Speter** implementation for specialized deployments or systems for which SQLite 7183282328Sbapt** does not provide a suitable implementation. In this case, the application 7184251883Speter** creates and populates an instance of this structure to pass 7185251883Speter** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7186251883Speter** Additionally, an instance of this structure can be used as an 7187251883Speter** output variable when querying the system for the current mutex 7188251883Speter** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7189251883Speter** 7190251883Speter** ^The xMutexInit method defined by this structure is invoked as 7191251883Speter** part of system initialization by the sqlite3_initialize() function. 7192251883Speter** ^The xMutexInit routine is called by SQLite exactly once for each 7193251883Speter** effective call to [sqlite3_initialize()]. 7194251883Speter** 7195251883Speter** ^The xMutexEnd method defined by this structure is invoked as 7196251883Speter** part of system shutdown by the sqlite3_shutdown() function. The 7197251883Speter** implementation of this method is expected to release all outstanding 7198251883Speter** resources obtained by the mutex methods implementation, especially 7199251883Speter** those obtained by the xMutexInit method. ^The xMutexEnd() 7200251883Speter** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7201251883Speter** 7202251883Speter** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7203251883Speter** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7204251883Speter** xMutexNotheld) implement the following interfaces (respectively): 7205251883Speter** 7206251883Speter** <ul> 7207251883Speter** <li> [sqlite3_mutex_alloc()] </li> 7208251883Speter** <li> [sqlite3_mutex_free()] </li> 7209251883Speter** <li> [sqlite3_mutex_enter()] </li> 7210251883Speter** <li> [sqlite3_mutex_try()] </li> 7211251883Speter** <li> [sqlite3_mutex_leave()] </li> 7212251883Speter** <li> [sqlite3_mutex_held()] </li> 7213251883Speter** <li> [sqlite3_mutex_notheld()] </li> 7214251883Speter** </ul>)^ 7215251883Speter** 7216251883Speter** The only difference is that the public sqlite3_XXX functions enumerated 7217251883Speter** above silently ignore any invocations that pass a NULL pointer instead 7218251883Speter** of a valid mutex handle. The implementations of the methods defined 7219251883Speter** by this structure are not required to handle this case, the results 7220251883Speter** of passing a NULL pointer instead of a valid mutex handle are undefined 7221251883Speter** (i.e. it is acceptable to provide an implementation that segfaults if 7222251883Speter** it is passed a NULL pointer). 7223251883Speter** 7224282328Sbapt** The xMutexInit() method must be threadsafe. It must be harmless to 7225251883Speter** invoke xMutexInit() multiple times within the same process and without 7226251883Speter** intervening calls to xMutexEnd(). Second and subsequent calls to 7227251883Speter** xMutexInit() must be no-ops. 7228251883Speter** 7229282328Sbapt** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7230282328Sbapt** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7231251883Speter** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7232251883Speter** memory allocation for a fast or recursive mutex. 7233251883Speter** 7234251883Speter** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7235251883Speter** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7236251883Speter** If xMutexInit fails in any way, it is expected to clean up after itself 7237251883Speter** prior to returning. 7238251883Speter*/ 7239251883Spetertypedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7240251883Speterstruct sqlite3_mutex_methods { 7241251883Speter int (*xMutexInit)(void); 7242251883Speter int (*xMutexEnd)(void); 7243251883Speter sqlite3_mutex *(*xMutexAlloc)(int); 7244251883Speter void (*xMutexFree)(sqlite3_mutex *); 7245251883Speter void (*xMutexEnter)(sqlite3_mutex *); 7246251883Speter int (*xMutexTry)(sqlite3_mutex *); 7247251883Speter void (*xMutexLeave)(sqlite3_mutex *); 7248251883Speter int (*xMutexHeld)(sqlite3_mutex *); 7249251883Speter int (*xMutexNotheld)(sqlite3_mutex *); 7250251883Speter}; 7251251883Speter 7252251883Speter/* 7253251883Speter** CAPI3REF: Mutex Verification Routines 7254251883Speter** 7255251883Speter** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7256282328Sbapt** are intended for use inside assert() statements. The SQLite core 7257251883Speter** never uses these routines except inside an assert() and applications 7258282328Sbapt** are advised to follow the lead of the core. The SQLite core only 7259251883Speter** provides implementations for these routines when it is compiled 7260282328Sbapt** with the SQLITE_DEBUG flag. External mutex implementations 7261251883Speter** are only required to provide these routines if SQLITE_DEBUG is 7262251883Speter** defined and if NDEBUG is not defined. 7263251883Speter** 7264282328Sbapt** These routines should return true if the mutex in their argument 7265251883Speter** is held or not held, respectively, by the calling thread. 7266251883Speter** 7267282328Sbapt** The implementation is not required to provide versions of these 7268251883Speter** routines that actually work. If the implementation does not provide working 7269251883Speter** versions of these routines, it should at least provide stubs that always 7270251883Speter** return true so that one does not get spurious assertion failures. 7271251883Speter** 7272282328Sbapt** If the argument to sqlite3_mutex_held() is a NULL pointer then 7273251883Speter** the routine should return 1. This seems counter-intuitive since 7274251883Speter** clearly the mutex cannot be held if it does not exist. But 7275251883Speter** the reason the mutex does not exist is because the build is not 7276251883Speter** using mutexes. And we do not want the assert() containing the 7277251883Speter** call to sqlite3_mutex_held() to fail, so a non-zero return is 7278282328Sbapt** the appropriate thing to do. The sqlite3_mutex_notheld() 7279251883Speter** interface should also return 1 when given a NULL pointer. 7280251883Speter*/ 7281251883Speter#ifndef NDEBUG 7282322444SpeterSQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7283322444SpeterSQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7284251883Speter#endif 7285251883Speter 7286251883Speter/* 7287251883Speter** CAPI3REF: Mutex Types 7288251883Speter** 7289251883Speter** The [sqlite3_mutex_alloc()] interface takes a single argument 7290251883Speter** which is one of these integer constants. 7291251883Speter** 7292251883Speter** The set of static mutexes may change from one SQLite release to the 7293251883Speter** next. Applications that override the built-in mutex logic must be 7294251883Speter** prepared to accommodate additional static mutexes. 7295251883Speter*/ 7296251883Speter#define SQLITE_MUTEX_FAST 0 7297251883Speter#define SQLITE_MUTEX_RECURSIVE 1 7298251883Speter#define SQLITE_MUTEX_STATIC_MASTER 2 7299251883Speter#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7300251883Speter#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7301251883Speter#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7302322444Speter#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7303251883Speter#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7304251883Speter#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7305251883Speter#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7306274884Sbapt#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7307274884Sbapt#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7308274884Sbapt#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7309286510Speter#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7310286510Speter#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7311286510Speter#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7312251883Speter 7313251883Speter/* 7314251883Speter** CAPI3REF: Retrieve the mutex for a database connection 7315286510Speter** METHOD: sqlite3 7316251883Speter** 7317251883Speter** ^This interface returns a pointer the [sqlite3_mutex] object that 7318251883Speter** serializes access to the [database connection] given in the argument 7319251883Speter** when the [threading mode] is Serialized. 7320251883Speter** ^If the [threading mode] is Single-thread or Multi-thread then this 7321251883Speter** routine returns a NULL pointer. 7322251883Speter*/ 7323322444SpeterSQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7324251883Speter 7325251883Speter/* 7326251883Speter** CAPI3REF: Low-Level Control Of Database Files 7327286510Speter** METHOD: sqlite3 7328342292Scy** KEYWORDS: {file control} 7329251883Speter** 7330251883Speter** ^The [sqlite3_file_control()] interface makes a direct call to the 7331251883Speter** xFileControl method for the [sqlite3_io_methods] object associated 7332251883Speter** with a particular database identified by the second argument. ^The 7333251883Speter** name of the database is "main" for the main database or "temp" for the 7334251883Speter** TEMP database, or the name that appears after the AS keyword for 7335251883Speter** databases that are added using the [ATTACH] SQL command. 7336251883Speter** ^A NULL pointer can be used in place of "main" to refer to the 7337251883Speter** main database file. 7338251883Speter** ^The third and fourth parameters to this routine 7339251883Speter** are passed directly through to the second and third parameters of 7340251883Speter** the xFileControl method. ^The return value of the xFileControl 7341251883Speter** method becomes the return value of this routine. 7342251883Speter** 7343342292Scy** A few opcodes for [sqlite3_file_control()] are handled directly 7344342292Scy** by the SQLite core and never invoke the 7345342292Scy** sqlite3_io_methods.xFileControl method. 7346342292Scy** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7347251883Speter** a pointer to the underlying [sqlite3_file] object to be written into 7348342292Scy** the space pointed to by the 4th parameter. The 7349342292Scy** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7350342292Scy** the [sqlite3_file] object associated with the journal file instead of 7351342292Scy** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7352342292Scy** a pointer to the underlying [sqlite3_vfs] object for the file. 7353342292Scy** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7354342292Scy** from the pager. 7355251883Speter** 7356251883Speter** ^If the second parameter (zDbName) does not match the name of any 7357251883Speter** open database file, then SQLITE_ERROR is returned. ^This error 7358251883Speter** code is not remembered and will not be recalled by [sqlite3_errcode()] 7359251883Speter** or [sqlite3_errmsg()]. The underlying xFileControl method might 7360251883Speter** also return SQLITE_ERROR. There is no way to distinguish between 7361251883Speter** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7362251883Speter** xFileControl method. 7363251883Speter** 7364342292Scy** See also: [file control opcodes] 7365251883Speter*/ 7366322444SpeterSQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7367251883Speter 7368251883Speter/* 7369251883Speter** CAPI3REF: Testing Interface 7370251883Speter** 7371251883Speter** ^The sqlite3_test_control() interface is used to read out internal 7372251883Speter** state of SQLite and to inject faults into SQLite for testing 7373251883Speter** purposes. ^The first parameter is an operation code that determines 7374251883Speter** the number, meaning, and operation of all subsequent parameters. 7375251883Speter** 7376251883Speter** This interface is not for use by applications. It exists solely 7377251883Speter** for verifying the correct operation of the SQLite library. Depending 7378251883Speter** on how the SQLite library is compiled, this interface might not exist. 7379251883Speter** 7380251883Speter** The details of the operation codes, their meanings, the parameters 7381251883Speter** they take, and what they do are all subject to change without notice. 7382251883Speter** Unlike most of the SQLite API, this function is not guaranteed to 7383251883Speter** operate consistently from one release to the next. 7384251883Speter*/ 7385322444SpeterSQLITE_API int sqlite3_test_control(int op, ...); 7386251883Speter 7387251883Speter/* 7388251883Speter** CAPI3REF: Testing Interface Operation Codes 7389251883Speter** 7390251883Speter** These constants are the valid operation code parameters used 7391251883Speter** as the first argument to [sqlite3_test_control()]. 7392251883Speter** 7393251883Speter** These parameters and their meanings are subject to change 7394251883Speter** without notice. These values are for testing purposes only. 7395251883Speter** Applications should not use any of these parameters or the 7396251883Speter** [sqlite3_test_control()] interface. 7397251883Speter*/ 7398251883Speter#define SQLITE_TESTCTRL_FIRST 5 7399251883Speter#define SQLITE_TESTCTRL_PRNG_SAVE 5 7400251883Speter#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7401355326Scy#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7402251883Speter#define SQLITE_TESTCTRL_BITVEC_TEST 8 7403251883Speter#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7404251883Speter#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7405251883Speter#define SQLITE_TESTCTRL_PENDING_BYTE 11 7406251883Speter#define SQLITE_TESTCTRL_ASSERT 12 7407251883Speter#define SQLITE_TESTCTRL_ALWAYS 13 7408251883Speter#define SQLITE_TESTCTRL_RESERVE 14 7409251883Speter#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7410342292Scy#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7411342292Scy#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7412342292Scy#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7413251883Speter#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7414274884Sbapt#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7415322444Speter#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7416269851Speter#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7417269851Speter#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7418269851Speter#define SQLITE_TESTCTRL_BYTEORDER 22 7419274884Sbapt#define SQLITE_TESTCTRL_ISINIT 23 7420274884Sbapt#define SQLITE_TESTCTRL_SORTER_MMAP 24 7421282328Sbapt#define SQLITE_TESTCTRL_IMPOSTER 25 7422342292Scy#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7423351633Scy#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7424355326Scy#define SQLITE_TESTCTRL_PRNG_SEED 28 7425355326Scy#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7426355326Scy#define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7427251883Speter 7428251883Speter/* 7429342292Scy** CAPI3REF: SQL Keyword Checking 7430342292Scy** 7431342292Scy** These routines provide access to the set of SQL language keywords 7432342292Scy** recognized by SQLite. Applications can uses these routines to determine 7433342292Scy** whether or not a specific identifier needs to be escaped (for example, 7434342292Scy** by enclosing in double-quotes) so as not to confuse the parser. 7435342292Scy** 7436342292Scy** The sqlite3_keyword_count() interface returns the number of distinct 7437342292Scy** keywords understood by SQLite. 7438342292Scy** 7439342292Scy** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7440342292Scy** makes *Z point to that keyword expressed as UTF8 and writes the number 7441342292Scy** of bytes in the keyword into *L. The string that *Z points to is not 7442342292Scy** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7443342292Scy** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7444342292Scy** or L are NULL or invalid pointers then calls to 7445342292Scy** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7446342292Scy** 7447342292Scy** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7448342292Scy** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7449342292Scy** if it is and zero if not. 7450342292Scy** 7451342292Scy** The parser used by SQLite is forgiving. It is often possible to use 7452342292Scy** a keyword as an identifier as long as such use does not result in a 7453342292Scy** parsing ambiguity. For example, the statement 7454342292Scy** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7455342292Scy** creates a new table named "BEGIN" with three columns named 7456342292Scy** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7457342292Scy** using keywords as identifiers. Common techniques used to avoid keyword 7458342292Scy** name collisions include: 7459342292Scy** <ul> 7460342292Scy** <li> Put all identifier names inside double-quotes. This is the official 7461342292Scy** SQL way to escape identifier names. 7462342292Scy** <li> Put identifier names inside [...]. This is not standard SQL, 7463342292Scy** but it is what SQL Server does and so lots of programmers use this 7464342292Scy** technique. 7465342292Scy** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7466342292Scy** with "Z". 7467342292Scy** <li> Include a digit somewhere in every identifier name. 7468342292Scy** </ul> 7469342292Scy** 7470342292Scy** Note that the number of keywords understood by SQLite can depend on 7471342292Scy** compile-time options. For example, "VACUUM" is not a keyword if 7472342292Scy** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7473342292Scy** new keywords may be added to future releases of SQLite. 7474342292Scy*/ 7475342292ScySQLITE_API int sqlite3_keyword_count(void); 7476342292ScySQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7477342292ScySQLITE_API int sqlite3_keyword_check(const char*,int); 7478342292Scy 7479342292Scy/* 7480342292Scy** CAPI3REF: Dynamic String Object 7481342292Scy** KEYWORDS: {dynamic string} 7482342292Scy** 7483342292Scy** An instance of the sqlite3_str object contains a dynamically-sized 7484342292Scy** string under construction. 7485342292Scy** 7486342292Scy** The lifecycle of an sqlite3_str object is as follows: 7487342292Scy** <ol> 7488342292Scy** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7489342292Scy** <li> ^Text is appended to the sqlite3_str object using various 7490342292Scy** methods, such as [sqlite3_str_appendf()]. 7491342292Scy** <li> ^The sqlite3_str object is destroyed and the string it created 7492342292Scy** is returned using the [sqlite3_str_finish()] interface. 7493342292Scy** </ol> 7494342292Scy*/ 7495342292Scytypedef struct sqlite3_str sqlite3_str; 7496342292Scy 7497342292Scy/* 7498342292Scy** CAPI3REF: Create A New Dynamic String Object 7499342292Scy** CONSTRUCTOR: sqlite3_str 7500342292Scy** 7501342292Scy** ^The [sqlite3_str_new(D)] interface allocates and initializes 7502342292Scy** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7503342292Scy** [sqlite3_str_new()] must be freed by a subsequent call to 7504342292Scy** [sqlite3_str_finish(X)]. 7505342292Scy** 7506342292Scy** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7507342292Scy** valid [sqlite3_str] object, though in the event of an out-of-memory 7508342292Scy** error the returned object might be a special singleton that will 7509342292Scy** silently reject new text, always return SQLITE_NOMEM from 7510342292Scy** [sqlite3_str_errcode()], always return 0 for 7511342292Scy** [sqlite3_str_length()], and always return NULL from 7512342292Scy** [sqlite3_str_finish(X)]. It is always safe to use the value 7513342292Scy** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7514342292Scy** to any of the other [sqlite3_str] methods. 7515342292Scy** 7516342292Scy** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7517342292Scy** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7518342292Scy** length of the string contained in the [sqlite3_str] object will be 7519342292Scy** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7520342292Scy** of [SQLITE_MAX_LENGTH]. 7521342292Scy*/ 7522342292ScySQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7523342292Scy 7524342292Scy/* 7525342292Scy** CAPI3REF: Finalize A Dynamic String 7526342292Scy** DESTRUCTOR: sqlite3_str 7527342292Scy** 7528342292Scy** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7529342292Scy** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7530342292Scy** that contains the constructed string. The calling application should 7531342292Scy** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7532342292Scy** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7533342292Scy** errors were encountered during construction of the string. ^The 7534342292Scy** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7535342292Scy** string in [sqlite3_str] object X is zero bytes long. 7536342292Scy*/ 7537342292ScySQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7538342292Scy 7539342292Scy/* 7540342292Scy** CAPI3REF: Add Content To A Dynamic String 7541342292Scy** METHOD: sqlite3_str 7542342292Scy** 7543342292Scy** These interfaces add content to an sqlite3_str object previously obtained 7544342292Scy** from [sqlite3_str_new()]. 7545342292Scy** 7546342292Scy** ^The [sqlite3_str_appendf(X,F,...)] and 7547342292Scy** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7548342292Scy** functionality of SQLite to append formatted text onto the end of 7549342292Scy** [sqlite3_str] object X. 7550342292Scy** 7551342292Scy** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7552342292Scy** onto the end of the [sqlite3_str] object X. N must be non-negative. 7553342292Scy** S must contain at least N non-zero bytes of content. To append a 7554342292Scy** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7555342292Scy** method instead. 7556342292Scy** 7557342292Scy** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7558342292Scy** zero-terminated string S onto the end of [sqlite3_str] object X. 7559342292Scy** 7560342292Scy** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7561342292Scy** single-byte character C onto the end of [sqlite3_str] object X. 7562342292Scy** ^This method can be used, for example, to add whitespace indentation. 7563342292Scy** 7564342292Scy** ^The [sqlite3_str_reset(X)] method resets the string under construction 7565342292Scy** inside [sqlite3_str] object X back to zero bytes in length. 7566342292Scy** 7567342292Scy** These methods do not return a result code. ^If an error occurs, that fact 7568342292Scy** is recorded in the [sqlite3_str] object and can be recovered by a 7569342292Scy** subsequent call to [sqlite3_str_errcode(X)]. 7570342292Scy*/ 7571342292ScySQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7572342292ScySQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7573342292ScySQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7574342292ScySQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7575342292ScySQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7576342292ScySQLITE_API void sqlite3_str_reset(sqlite3_str*); 7577342292Scy 7578342292Scy/* 7579342292Scy** CAPI3REF: Status Of A Dynamic String 7580342292Scy** METHOD: sqlite3_str 7581342292Scy** 7582342292Scy** These interfaces return the current status of an [sqlite3_str] object. 7583342292Scy** 7584342292Scy** ^If any prior errors have occurred while constructing the dynamic string 7585342292Scy** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7586342292Scy** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7587342292Scy** [SQLITE_NOMEM] following any out-of-memory error, or 7588342292Scy** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7589342292Scy** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7590342292Scy** 7591342292Scy** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7592342292Scy** of the dynamic string under construction in [sqlite3_str] object X. 7593342292Scy** ^The length returned by [sqlite3_str_length(X)] does not include the 7594342292Scy** zero-termination byte. 7595342292Scy** 7596342292Scy** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7597342292Scy** content of the dynamic string under construction in X. The value 7598342292Scy** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7599342292Scy** and might be freed or altered by any subsequent method on the same 7600342292Scy** [sqlite3_str] object. Applications must not used the pointer returned 7601342292Scy** [sqlite3_str_value(X)] after any subsequent method call on the same 7602342292Scy** object. ^Applications may change the content of the string returned 7603342292Scy** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7604342292Scy** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7605342292Scy** write any byte after any subsequent sqlite3_str method call. 7606342292Scy*/ 7607342292ScySQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7608342292ScySQLITE_API int sqlite3_str_length(sqlite3_str*); 7609342292ScySQLITE_API char *sqlite3_str_value(sqlite3_str*); 7610342292Scy 7611342292Scy/* 7612251883Speter** CAPI3REF: SQLite Runtime Status 7613251883Speter** 7614282328Sbapt** ^These interfaces are used to retrieve runtime status information 7615251883Speter** about the performance of SQLite, and optionally to reset various 7616251883Speter** highwater marks. ^The first argument is an integer code for 7617251883Speter** the specific parameter to measure. ^(Recognized integer codes 7618251883Speter** are of the form [status parameters | SQLITE_STATUS_...].)^ 7619251883Speter** ^The current value of the parameter is returned into *pCurrent. 7620251883Speter** ^The highest recorded value is returned in *pHighwater. ^If the 7621251883Speter** resetFlag is true, then the highest record value is reset after 7622251883Speter** *pHighwater is written. ^(Some parameters do not record the highest 7623251883Speter** value. For those parameters 7624251883Speter** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7625251883Speter** ^(Other parameters record only the highwater mark and not the current 7626251883Speter** value. For these latter parameters nothing is written into *pCurrent.)^ 7627251883Speter** 7628282328Sbapt** ^The sqlite3_status() and sqlite3_status64() routines return 7629282328Sbapt** SQLITE_OK on success and a non-zero [error code] on failure. 7630251883Speter** 7631282328Sbapt** If either the current value or the highwater mark is too large to 7632282328Sbapt** be represented by a 32-bit integer, then the values returned by 7633282328Sbapt** sqlite3_status() are undefined. 7634251883Speter** 7635251883Speter** See also: [sqlite3_db_status()] 7636251883Speter*/ 7637322444SpeterSQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7638322444SpeterSQLITE_API int sqlite3_status64( 7639282328Sbapt int op, 7640282328Sbapt sqlite3_int64 *pCurrent, 7641282328Sbapt sqlite3_int64 *pHighwater, 7642282328Sbapt int resetFlag 7643282328Sbapt); 7644251883Speter 7645251883Speter 7646251883Speter/* 7647251883Speter** CAPI3REF: Status Parameters 7648251883Speter** KEYWORDS: {status parameters} 7649251883Speter** 7650251883Speter** These integer constants designate various run-time status parameters 7651251883Speter** that can be returned by [sqlite3_status()]. 7652251883Speter** 7653251883Speter** <dl> 7654251883Speter** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7655251883Speter** <dd>This parameter is the current amount of memory checked out 7656251883Speter** using [sqlite3_malloc()], either directly or indirectly. The 7657251883Speter** figure includes calls made to [sqlite3_malloc()] by the application 7658342292Scy** and internal memory usage by the SQLite library. Auxiliary page-cache 7659251883Speter** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7660251883Speter** this parameter. The amount returned is the sum of the allocation 7661251883Speter** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7662251883Speter** 7663251883Speter** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7664251883Speter** <dd>This parameter records the largest memory allocation request 7665251883Speter** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7666251883Speter** internal equivalents). Only the value returned in the 7667251883Speter** *pHighwater parameter to [sqlite3_status()] is of interest. 7668251883Speter** The value written into the *pCurrent parameter is undefined.</dd>)^ 7669251883Speter** 7670251883Speter** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7671251883Speter** <dd>This parameter records the number of separate memory allocations 7672251883Speter** currently checked out.</dd>)^ 7673251883Speter** 7674251883Speter** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7675251883Speter** <dd>This parameter returns the number of pages used out of the 7676251883Speter** [pagecache memory allocator] that was configured using 7677251883Speter** [SQLITE_CONFIG_PAGECACHE]. The 7678251883Speter** value returned is in pages, not in bytes.</dd>)^ 7679251883Speter** 7680251883Speter** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7681251883Speter** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7682251883Speter** <dd>This parameter returns the number of bytes of page cache 7683251883Speter** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7684251883Speter** buffer and where forced to overflow to [sqlite3_malloc()]. The 7685251883Speter** returned value includes allocations that overflowed because they 7686251883Speter** where too large (they were larger than the "sz" parameter to 7687251883Speter** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7688251883Speter** no space was left in the page cache.</dd>)^ 7689251883Speter** 7690251883Speter** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7691251883Speter** <dd>This parameter records the largest memory allocation request 7692251883Speter** handed to [pagecache memory allocator]. Only the value returned in the 7693251883Speter** *pHighwater parameter to [sqlite3_status()] is of interest. 7694251883Speter** The value written into the *pCurrent parameter is undefined.</dd>)^ 7695251883Speter** 7696342292Scy** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7697342292Scy** <dd>No longer used.</dd> 7698251883Speter** 7699251883Speter** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7700342292Scy** <dd>No longer used.</dd> 7701251883Speter** 7702342292Scy** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7703342292Scy** <dd>No longer used.</dd> 7704251883Speter** 7705251883Speter** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7706298161Sbapt** <dd>The *pHighwater parameter records the deepest parser stack. 7707298161Sbapt** The *pCurrent value is undefined. The *pHighwater value is only 7708251883Speter** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7709251883Speter** </dl> 7710251883Speter** 7711251883Speter** New status parameters may be added from time to time. 7712251883Speter*/ 7713251883Speter#define SQLITE_STATUS_MEMORY_USED 0 7714251883Speter#define SQLITE_STATUS_PAGECACHE_USED 1 7715251883Speter#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7716342292Scy#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7717342292Scy#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7718251883Speter#define SQLITE_STATUS_MALLOC_SIZE 5 7719251883Speter#define SQLITE_STATUS_PARSER_STACK 6 7720251883Speter#define SQLITE_STATUS_PAGECACHE_SIZE 7 7721342292Scy#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7722251883Speter#define SQLITE_STATUS_MALLOC_COUNT 9 7723251883Speter 7724251883Speter/* 7725251883Speter** CAPI3REF: Database Connection Status 7726286510Speter** METHOD: sqlite3 7727251883Speter** 7728251883Speter** ^This interface is used to retrieve runtime status information 7729251883Speter** about a single [database connection]. ^The first argument is the 7730251883Speter** database connection object to be interrogated. ^The second argument 7731251883Speter** is an integer constant, taken from the set of 7732251883Speter** [SQLITE_DBSTATUS options], that 7733251883Speter** determines the parameter to interrogate. The set of 7734251883Speter** [SQLITE_DBSTATUS options] is likely 7735251883Speter** to grow in future releases of SQLite. 7736251883Speter** 7737251883Speter** ^The current value of the requested parameter is written into *pCur 7738251883Speter** and the highest instantaneous value is written into *pHiwtr. ^If 7739251883Speter** the resetFlg is true, then the highest instantaneous value is 7740251883Speter** reset back down to the current value. 7741251883Speter** 7742251883Speter** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7743251883Speter** non-zero [error code] on failure. 7744251883Speter** 7745251883Speter** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7746251883Speter*/ 7747322444SpeterSQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7748251883Speter 7749251883Speter/* 7750251883Speter** CAPI3REF: Status Parameters for database connections 7751251883Speter** KEYWORDS: {SQLITE_DBSTATUS options} 7752251883Speter** 7753251883Speter** These constants are the available integer "verbs" that can be passed as 7754251883Speter** the second argument to the [sqlite3_db_status()] interface. 7755251883Speter** 7756251883Speter** New verbs may be added in future releases of SQLite. Existing verbs 7757251883Speter** might be discontinued. Applications should check the return code from 7758251883Speter** [sqlite3_db_status()] to make sure that the call worked. 7759251883Speter** The [sqlite3_db_status()] interface will return a non-zero error code 7760251883Speter** if a discontinued or unsupported verb is invoked. 7761251883Speter** 7762251883Speter** <dl> 7763251883Speter** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7764251883Speter** <dd>This parameter returns the number of lookaside memory slots currently 7765251883Speter** checked out.</dd>)^ 7766251883Speter** 7767251883Speter** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7768251883Speter** <dd>This parameter returns the number malloc attempts that were 7769251883Speter** satisfied using lookaside memory. Only the high-water value is meaningful; 7770251883Speter** the current value is always zero.)^ 7771251883Speter** 7772251883Speter** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7773251883Speter** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7774251883Speter** <dd>This parameter returns the number malloc attempts that might have 7775251883Speter** been satisfied using lookaside memory but failed due to the amount of 7776251883Speter** memory requested being larger than the lookaside slot size. 7777251883Speter** Only the high-water value is meaningful; 7778251883Speter** the current value is always zero.)^ 7779251883Speter** 7780251883Speter** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7781251883Speter** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7782251883Speter** <dd>This parameter returns the number malloc attempts that might have 7783251883Speter** been satisfied using lookaside memory but failed due to all lookaside 7784251883Speter** memory already being in use. 7785251883Speter** Only the high-water value is meaningful; 7786251883Speter** the current value is always zero.)^ 7787251883Speter** 7788251883Speter** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7789274884Sbapt** <dd>This parameter returns the approximate number of bytes of heap 7790251883Speter** memory used by all pager caches associated with the database connection.)^ 7791251883Speter** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7792251883Speter** 7793305002Scy** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7794305002Scy** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7795305002Scy** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7796305002Scy** pager cache is shared between two or more connections the bytes of heap 7797305002Scy** memory used by that pager cache is divided evenly between the attached 7798305002Scy** connections.)^ In other words, if none of the pager caches associated 7799305002Scy** with the database connection are shared, this request returns the same 7800305002Scy** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7801305002Scy** shared, the value returned by this call will be smaller than that returned 7802305002Scy** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7803305002Scy** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7804305002Scy** 7805251883Speter** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7806274884Sbapt** <dd>This parameter returns the approximate number of bytes of heap 7807251883Speter** memory used to store the schema for all databases associated 7808251883Speter** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7809251883Speter** ^The full amount of memory used by the schemas is reported, even if the 7810251883Speter** schema memory is shared with other database connections due to 7811251883Speter** [shared cache mode] being enabled. 7812251883Speter** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7813251883Speter** 7814251883Speter** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7815274884Sbapt** <dd>This parameter returns the approximate number of bytes of heap 7816251883Speter** and lookaside memory used by all prepared statements associated with 7817251883Speter** the database connection.)^ 7818251883Speter** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7819251883Speter** </dd> 7820251883Speter** 7821251883Speter** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7822251883Speter** <dd>This parameter returns the number of pager cache hits that have 7823251883Speter** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7824251883Speter** is always 0. 7825251883Speter** </dd> 7826251883Speter** 7827251883Speter** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7828251883Speter** <dd>This parameter returns the number of pager cache misses that have 7829251883Speter** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7830251883Speter** is always 0. 7831251883Speter** </dd> 7832251883Speter** 7833251883Speter** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7834251883Speter** <dd>This parameter returns the number of dirty cache entries that have 7835251883Speter** been written to disk. Specifically, the number of pages written to the 7836251883Speter** wal file in wal mode databases, or the number of pages written to the 7837251883Speter** database file in rollback mode databases. Any pages written as part of 7838251883Speter** transaction rollback or database recovery operations are not included. 7839251883Speter** If an IO or other error occurs while writing a page to disk, the effect 7840251883Speter** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7841251883Speter** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7842251883Speter** </dd> 7843269851Speter** 7844342292Scy** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7845342292Scy** <dd>This parameter returns the number of dirty cache entries that have 7846342292Scy** been written to disk in the middle of a transaction due to the page 7847342292Scy** cache overflowing. Transactions are more efficient if they are written 7848342292Scy** to disk all at once. When pages spill mid-transaction, that introduces 7849342292Scy** additional overhead. This parameter can be used help identify 7850342292Scy** inefficiencies that can be resolve by increasing the cache size. 7851342292Scy** </dd> 7852342292Scy** 7853269851Speter** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7854269851Speter** <dd>This parameter returns zero for the current value if and only if 7855269851Speter** all foreign key constraints (deferred or immediate) have been 7856269851Speter** resolved.)^ ^The highwater mark is always 0. 7857269851Speter** </dd> 7858251883Speter** </dl> 7859251883Speter*/ 7860251883Speter#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7861251883Speter#define SQLITE_DBSTATUS_CACHE_USED 1 7862251883Speter#define SQLITE_DBSTATUS_SCHEMA_USED 2 7863251883Speter#define SQLITE_DBSTATUS_STMT_USED 3 7864251883Speter#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7865251883Speter#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7866251883Speter#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7867251883Speter#define SQLITE_DBSTATUS_CACHE_HIT 7 7868251883Speter#define SQLITE_DBSTATUS_CACHE_MISS 8 7869251883Speter#define SQLITE_DBSTATUS_CACHE_WRITE 9 7870269851Speter#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7871305002Scy#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7872342292Scy#define SQLITE_DBSTATUS_CACHE_SPILL 12 7873342292Scy#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7874251883Speter 7875251883Speter 7876251883Speter/* 7877251883Speter** CAPI3REF: Prepared Statement Status 7878286510Speter** METHOD: sqlite3_stmt 7879251883Speter** 7880251883Speter** ^(Each prepared statement maintains various 7881251883Speter** [SQLITE_STMTSTATUS counters] that measure the number 7882251883Speter** of times it has performed specific operations.)^ These counters can 7883251883Speter** be used to monitor the performance characteristics of the prepared 7884251883Speter** statements. For example, if the number of table steps greatly exceeds 7885251883Speter** the number of table searches or result rows, that would tend to indicate 7886251883Speter** that the prepared statement is using a full table scan rather than 7887251883Speter** an index. 7888251883Speter** 7889251883Speter** ^(This interface is used to retrieve and reset counter values from 7890251883Speter** a [prepared statement]. The first argument is the prepared statement 7891251883Speter** object to be interrogated. The second argument 7892251883Speter** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7893251883Speter** to be interrogated.)^ 7894251883Speter** ^The current value of the requested counter is returned. 7895251883Speter** ^If the resetFlg is true, then the counter is reset to zero after this 7896251883Speter** interface call returns. 7897251883Speter** 7898251883Speter** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7899251883Speter*/ 7900322444SpeterSQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7901251883Speter 7902251883Speter/* 7903251883Speter** CAPI3REF: Status Parameters for prepared statements 7904251883Speter** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7905251883Speter** 7906251883Speter** These preprocessor macros define integer codes that name counter 7907251883Speter** values associated with the [sqlite3_stmt_status()] interface. 7908251883Speter** The meanings of the various counters are as follows: 7909251883Speter** 7910251883Speter** <dl> 7911251883Speter** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7912251883Speter** <dd>^This is the number of times that SQLite has stepped forward in 7913251883Speter** a table as part of a full table scan. Large numbers for this counter 7914251883Speter** may indicate opportunities for performance improvement through 7915251883Speter** careful use of indices.</dd> 7916251883Speter** 7917251883Speter** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7918251883Speter** <dd>^This is the number of sort operations that have occurred. 7919251883Speter** A non-zero value in this counter may indicate an opportunity to 7920251883Speter** improvement performance through careful use of indices.</dd> 7921251883Speter** 7922251883Speter** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7923251883Speter** <dd>^This is the number of rows inserted into transient indices that 7924251883Speter** were created automatically in order to help joins run faster. 7925251883Speter** A non-zero value in this counter may indicate an opportunity to 7926251883Speter** improvement performance by adding permanent indices that do not 7927251883Speter** need to be reinitialized each time the statement is run.</dd> 7928269851Speter** 7929269851Speter** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7930269851Speter** <dd>^This is the number of virtual machine operations executed 7931269851Speter** by the prepared statement if that number is less than or equal 7932269851Speter** to 2147483647. The number of virtual machine operations can be 7933269851Speter** used as a proxy for the total work done by the prepared statement. 7934269851Speter** If the number of virtual machine operations exceeds 2147483647 7935269851Speter** then the value returned by this statement status code is undefined. 7936322444Speter** 7937322444Speter** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7938322444Speter** <dd>^This is the number of times that the prepare statement has been 7939322444Speter** automatically regenerated due to schema changes or change to 7940322444Speter** [bound parameters] that might affect the query plan. 7941322444Speter** 7942322444Speter** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7943322444Speter** <dd>^This is the number of times that the prepared statement has 7944322444Speter** been run. A single "run" for the purposes of this counter is one 7945322444Speter** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7946322444Speter** The counter is incremented on the first [sqlite3_step()] call of each 7947322444Speter** cycle. 7948322444Speter** 7949322444Speter** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7950322444Speter** <dd>^This is the approximate number of bytes of heap memory 7951322444Speter** used to store the prepared statement. ^This value is not actually 7952322444Speter** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7953322444Speter** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7954269851Speter** </dd> 7955251883Speter** </dl> 7956251883Speter*/ 7957251883Speter#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7958251883Speter#define SQLITE_STMTSTATUS_SORT 2 7959251883Speter#define SQLITE_STMTSTATUS_AUTOINDEX 3 7960269851Speter#define SQLITE_STMTSTATUS_VM_STEP 4 7961322444Speter#define SQLITE_STMTSTATUS_REPREPARE 5 7962322444Speter#define SQLITE_STMTSTATUS_RUN 6 7963322444Speter#define SQLITE_STMTSTATUS_MEMUSED 99 7964251883Speter 7965251883Speter/* 7966251883Speter** CAPI3REF: Custom Page Cache Object 7967251883Speter** 7968251883Speter** The sqlite3_pcache type is opaque. It is implemented by 7969251883Speter** the pluggable module. The SQLite core has no knowledge of 7970251883Speter** its size or internal structure and never deals with the 7971251883Speter** sqlite3_pcache object except by holding and passing pointers 7972251883Speter** to the object. 7973251883Speter** 7974251883Speter** See [sqlite3_pcache_methods2] for additional information. 7975251883Speter*/ 7976251883Spetertypedef struct sqlite3_pcache sqlite3_pcache; 7977251883Speter 7978251883Speter/* 7979251883Speter** CAPI3REF: Custom Page Cache Object 7980251883Speter** 7981251883Speter** The sqlite3_pcache_page object represents a single page in the 7982251883Speter** page cache. The page cache will allocate instances of this 7983251883Speter** object. Various methods of the page cache use pointers to instances 7984251883Speter** of this object as parameters or as their return value. 7985251883Speter** 7986251883Speter** See [sqlite3_pcache_methods2] for additional information. 7987251883Speter*/ 7988251883Spetertypedef struct sqlite3_pcache_page sqlite3_pcache_page; 7989251883Speterstruct sqlite3_pcache_page { 7990251883Speter void *pBuf; /* The content of the page */ 7991251883Speter void *pExtra; /* Extra information associated with the page */ 7992251883Speter}; 7993251883Speter 7994251883Speter/* 7995251883Speter** CAPI3REF: Application Defined Page Cache. 7996251883Speter** KEYWORDS: {page cache} 7997251883Speter** 7998251883Speter** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7999251883Speter** register an alternative page cache implementation by passing in an 8000251883Speter** instance of the sqlite3_pcache_methods2 structure.)^ 8001251883Speter** In many applications, most of the heap memory allocated by 8002251883Speter** SQLite is used for the page cache. 8003251883Speter** By implementing a 8004251883Speter** custom page cache using this API, an application can better control 8005251883Speter** the amount of memory consumed by SQLite, the way in which 8006251883Speter** that memory is allocated and released, and the policies used to 8007251883Speter** determine exactly which parts of a database file are cached and for 8008251883Speter** how long. 8009251883Speter** 8010251883Speter** The alternative page cache mechanism is an 8011251883Speter** extreme measure that is only needed by the most demanding applications. 8012251883Speter** The built-in page cache is recommended for most uses. 8013251883Speter** 8014251883Speter** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8015251883Speter** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8016251883Speter** the application may discard the parameter after the call to 8017251883Speter** [sqlite3_config()] returns.)^ 8018251883Speter** 8019251883Speter** [[the xInit() page cache method]] 8020251883Speter** ^(The xInit() method is called once for each effective 8021251883Speter** call to [sqlite3_initialize()])^ 8022251883Speter** (usually only once during the lifetime of the process). ^(The xInit() 8023251883Speter** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8024251883Speter** The intent of the xInit() method is to set up global data structures 8025251883Speter** required by the custom page cache implementation. 8026251883Speter** ^(If the xInit() method is NULL, then the 8027251883Speter** built-in default page cache is used instead of the application defined 8028251883Speter** page cache.)^ 8029251883Speter** 8030251883Speter** [[the xShutdown() page cache method]] 8031251883Speter** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8032251883Speter** It can be used to clean up 8033251883Speter** any outstanding resources before process shutdown, if required. 8034251883Speter** ^The xShutdown() method may be NULL. 8035251883Speter** 8036251883Speter** ^SQLite automatically serializes calls to the xInit method, 8037251883Speter** so the xInit method need not be threadsafe. ^The 8038251883Speter** xShutdown method is only called from [sqlite3_shutdown()] so it does 8039251883Speter** not need to be threadsafe either. All other methods must be threadsafe 8040251883Speter** in multithreaded applications. 8041251883Speter** 8042251883Speter** ^SQLite will never invoke xInit() more than once without an intervening 8043251883Speter** call to xShutdown(). 8044251883Speter** 8045251883Speter** [[the xCreate() page cache methods]] 8046251883Speter** ^SQLite invokes the xCreate() method to construct a new cache instance. 8047251883Speter** SQLite will typically create one cache instance for each open database file, 8048251883Speter** though this is not guaranteed. ^The 8049251883Speter** first parameter, szPage, is the size in bytes of the pages that must 8050251883Speter** be allocated by the cache. ^szPage will always a power of two. ^The 8051251883Speter** second parameter szExtra is a number of bytes of extra storage 8052251883Speter** associated with each page cache entry. ^The szExtra parameter will 8053251883Speter** a number less than 250. SQLite will use the 8054251883Speter** extra szExtra bytes on each page to store metadata about the underlying 8055251883Speter** database page on disk. The value passed into szExtra depends 8056251883Speter** on the SQLite version, the target platform, and how SQLite was compiled. 8057251883Speter** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8058251883Speter** created will be used to cache database pages of a file stored on disk, or 8059251883Speter** false if it is used for an in-memory database. The cache implementation 8060251883Speter** does not have to do anything special based with the value of bPurgeable; 8061251883Speter** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8062251883Speter** never invoke xUnpin() except to deliberately delete a page. 8063251883Speter** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8064251883Speter** false will always have the "discard" flag set to true. 8065251883Speter** ^Hence, a cache created with bPurgeable false will 8066251883Speter** never contain any unpinned pages. 8067251883Speter** 8068251883Speter** [[the xCachesize() page cache method]] 8069251883Speter** ^(The xCachesize() method may be called at any time by SQLite to set the 8070251883Speter** suggested maximum cache-size (number of pages stored by) the cache 8071251883Speter** instance passed as the first argument. This is the value configured using 8072251883Speter** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8073251883Speter** parameter, the implementation is not required to do anything with this 8074251883Speter** value; it is advisory only. 8075251883Speter** 8076251883Speter** [[the xPagecount() page cache methods]] 8077251883Speter** The xPagecount() method must return the number of pages currently 8078251883Speter** stored in the cache, both pinned and unpinned. 8079251883Speter** 8080251883Speter** [[the xFetch() page cache methods]] 8081251883Speter** The xFetch() method locates a page in the cache and returns a pointer to 8082251883Speter** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8083251883Speter** The pBuf element of the returned sqlite3_pcache_page object will be a 8084251883Speter** pointer to a buffer of szPage bytes used to store the content of a 8085251883Speter** single database page. The pExtra element of sqlite3_pcache_page will be 8086251883Speter** a pointer to the szExtra bytes of extra storage that SQLite has requested 8087251883Speter** for each entry in the page cache. 8088251883Speter** 8089251883Speter** The page to be fetched is determined by the key. ^The minimum key value 8090251883Speter** is 1. After it has been retrieved using xFetch, the page is considered 8091251883Speter** to be "pinned". 8092251883Speter** 8093251883Speter** If the requested page is already in the page cache, then the page cache 8094251883Speter** implementation must return a pointer to the page buffer with its content 8095251883Speter** intact. If the requested page is not already in the cache, then the 8096251883Speter** cache implementation should use the value of the createFlag 8097251883Speter** parameter to help it determined what action to take: 8098251883Speter** 8099251883Speter** <table border=1 width=85% align=center> 8100251883Speter** <tr><th> createFlag <th> Behavior when page is not already in cache 8101251883Speter** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8102251883Speter** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8103251883Speter** Otherwise return NULL. 8104251883Speter** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8105251883Speter** NULL if allocating a new page is effectively impossible. 8106251883Speter** </table> 8107251883Speter** 8108251883Speter** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8109251883Speter** will only use a createFlag of 2 after a prior call with a createFlag of 1 8110251883Speter** failed.)^ In between the to xFetch() calls, SQLite may 8111251883Speter** attempt to unpin one or more cache pages by spilling the content of 8112251883Speter** pinned pages to disk and synching the operating system disk cache. 8113251883Speter** 8114251883Speter** [[the xUnpin() page cache method]] 8115251883Speter** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8116251883Speter** as its second argument. If the third parameter, discard, is non-zero, 8117251883Speter** then the page must be evicted from the cache. 8118251883Speter** ^If the discard parameter is 8119251883Speter** zero, then the page may be discarded or retained at the discretion of 8120251883Speter** page cache implementation. ^The page cache implementation 8121251883Speter** may choose to evict unpinned pages at any time. 8122251883Speter** 8123251883Speter** The cache must not perform any reference counting. A single 8124251883Speter** call to xUnpin() unpins the page regardless of the number of prior calls 8125251883Speter** to xFetch(). 8126251883Speter** 8127251883Speter** [[the xRekey() page cache methods]] 8128251883Speter** The xRekey() method is used to change the key value associated with the 8129251883Speter** page passed as the second argument. If the cache 8130251883Speter** previously contains an entry associated with newKey, it must be 8131251883Speter** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8132251883Speter** to be pinned. 8133251883Speter** 8134251883Speter** When SQLite calls the xTruncate() method, the cache must discard all 8135251883Speter** existing cache entries with page numbers (keys) greater than or equal 8136251883Speter** to the value of the iLimit parameter passed to xTruncate(). If any 8137251883Speter** of these pages are pinned, they are implicitly unpinned, meaning that 8138251883Speter** they can be safely discarded. 8139251883Speter** 8140251883Speter** [[the xDestroy() page cache method]] 8141251883Speter** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8142251883Speter** All resources associated with the specified cache should be freed. ^After 8143251883Speter** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8144251883Speter** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8145251883Speter** functions. 8146251883Speter** 8147251883Speter** [[the xShrink() page cache method]] 8148251883Speter** ^SQLite invokes the xShrink() method when it wants the page cache to 8149251883Speter** free up as much of heap memory as possible. The page cache implementation 8150251883Speter** is not obligated to free any memory, but well-behaved implementations should 8151251883Speter** do their best. 8152251883Speter*/ 8153251883Spetertypedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8154251883Speterstruct sqlite3_pcache_methods2 { 8155251883Speter int iVersion; 8156251883Speter void *pArg; 8157251883Speter int (*xInit)(void*); 8158251883Speter void (*xShutdown)(void*); 8159251883Speter sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8160251883Speter void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8161251883Speter int (*xPagecount)(sqlite3_pcache*); 8162251883Speter sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8163251883Speter void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8164251883Speter void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8165251883Speter unsigned oldKey, unsigned newKey); 8166251883Speter void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8167251883Speter void (*xDestroy)(sqlite3_pcache*); 8168251883Speter void (*xShrink)(sqlite3_pcache*); 8169251883Speter}; 8170251883Speter 8171251883Speter/* 8172251883Speter** This is the obsolete pcache_methods object that has now been replaced 8173251883Speter** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8174251883Speter** retained in the header file for backwards compatibility only. 8175251883Speter*/ 8176251883Spetertypedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8177251883Speterstruct sqlite3_pcache_methods { 8178251883Speter void *pArg; 8179251883Speter int (*xInit)(void*); 8180251883Speter void (*xShutdown)(void*); 8181251883Speter sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8182251883Speter void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8183251883Speter int (*xPagecount)(sqlite3_pcache*); 8184251883Speter void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8185251883Speter void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8186251883Speter void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8187251883Speter void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8188251883Speter void (*xDestroy)(sqlite3_pcache*); 8189251883Speter}; 8190251883Speter 8191251883Speter 8192251883Speter/* 8193251883Speter** CAPI3REF: Online Backup Object 8194251883Speter** 8195251883Speter** The sqlite3_backup object records state information about an ongoing 8196251883Speter** online backup operation. ^The sqlite3_backup object is created by 8197251883Speter** a call to [sqlite3_backup_init()] and is destroyed by a call to 8198251883Speter** [sqlite3_backup_finish()]. 8199251883Speter** 8200251883Speter** See Also: [Using the SQLite Online Backup API] 8201251883Speter*/ 8202251883Spetertypedef struct sqlite3_backup sqlite3_backup; 8203251883Speter 8204251883Speter/* 8205251883Speter** CAPI3REF: Online Backup API. 8206251883Speter** 8207251883Speter** The backup API copies the content of one database into another. 8208251883Speter** It is useful either for creating backups of databases or 8209251883Speter** for copying in-memory databases to or from persistent files. 8210251883Speter** 8211251883Speter** See Also: [Using the SQLite Online Backup API] 8212251883Speter** 8213251883Speter** ^SQLite holds a write transaction open on the destination database file 8214251883Speter** for the duration of the backup operation. 8215251883Speter** ^The source database is read-locked only while it is being read; 8216251883Speter** it is not locked continuously for the entire backup operation. 8217251883Speter** ^Thus, the backup may be performed on a live source database without 8218251883Speter** preventing other database connections from 8219251883Speter** reading or writing to the source database while the backup is underway. 8220251883Speter** 8221251883Speter** ^(To perform a backup operation: 8222251883Speter** <ol> 8223251883Speter** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8224251883Speter** backup, 8225251883Speter** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8226251883Speter** the data between the two databases, and finally 8227251883Speter** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8228251883Speter** associated with the backup operation. 8229251883Speter** </ol>)^ 8230251883Speter** There should be exactly one call to sqlite3_backup_finish() for each 8231251883Speter** successful call to sqlite3_backup_init(). 8232251883Speter** 8233251883Speter** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8234251883Speter** 8235251883Speter** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8236251883Speter** [database connection] associated with the destination database 8237251883Speter** and the database name, respectively. 8238251883Speter** ^The database name is "main" for the main database, "temp" for the 8239251883Speter** temporary database, or the name specified after the AS keyword in 8240251883Speter** an [ATTACH] statement for an attached database. 8241251883Speter** ^The S and M arguments passed to 8242251883Speter** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8243251883Speter** and database name of the source database, respectively. 8244251883Speter** ^The source and destination [database connections] (parameters S and D) 8245251883Speter** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8246251883Speter** an error. 8247251883Speter** 8248305002Scy** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8249282328Sbapt** there is already a read or read-write transaction open on the 8250282328Sbapt** destination database. 8251282328Sbapt** 8252251883Speter** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8253251883Speter** returned and an error code and error message are stored in the 8254251883Speter** destination [database connection] D. 8255251883Speter** ^The error code and message for the failed call to sqlite3_backup_init() 8256251883Speter** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8257251883Speter** [sqlite3_errmsg16()] functions. 8258251883Speter** ^A successful call to sqlite3_backup_init() returns a pointer to an 8259251883Speter** [sqlite3_backup] object. 8260251883Speter** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8261251883Speter** sqlite3_backup_finish() functions to perform the specified backup 8262251883Speter** operation. 8263251883Speter** 8264251883Speter** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8265251883Speter** 8266251883Speter** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8267251883Speter** the source and destination databases specified by [sqlite3_backup] object B. 8268251883Speter** ^If N is negative, all remaining source pages are copied. 8269251883Speter** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8270251883Speter** are still more pages to be copied, then the function returns [SQLITE_OK]. 8271251883Speter** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8272251883Speter** from source to destination, then it returns [SQLITE_DONE]. 8273251883Speter** ^If an error occurs while running sqlite3_backup_step(B,N), 8274251883Speter** then an [error code] is returned. ^As well as [SQLITE_OK] and 8275251883Speter** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8276251883Speter** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8277251883Speter** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8278251883Speter** 8279251883Speter** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8280251883Speter** <ol> 8281251883Speter** <li> the destination database was opened read-only, or 8282251883Speter** <li> the destination database is using write-ahead-log journaling 8283251883Speter** and the destination and source page sizes differ, or 8284251883Speter** <li> the destination database is an in-memory database and the 8285251883Speter** destination and source page sizes differ. 8286251883Speter** </ol>)^ 8287251883Speter** 8288251883Speter** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8289251883Speter** the [sqlite3_busy_handler | busy-handler function] 8290251883Speter** is invoked (if one is specified). ^If the 8291251883Speter** busy-handler returns non-zero before the lock is available, then 8292251883Speter** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8293251883Speter** sqlite3_backup_step() can be retried later. ^If the source 8294251883Speter** [database connection] 8295251883Speter** is being used to write to the source database when sqlite3_backup_step() 8296251883Speter** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8297251883Speter** case the call to sqlite3_backup_step() can be retried later on. ^(If 8298251883Speter** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8299251883Speter** [SQLITE_READONLY] is returned, then 8300251883Speter** there is no point in retrying the call to sqlite3_backup_step(). These 8301251883Speter** errors are considered fatal.)^ The application must accept 8302251883Speter** that the backup operation has failed and pass the backup operation handle 8303251883Speter** to the sqlite3_backup_finish() to release associated resources. 8304251883Speter** 8305251883Speter** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8306251883Speter** on the destination file. ^The exclusive lock is not released until either 8307251883Speter** sqlite3_backup_finish() is called or the backup operation is complete 8308251883Speter** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8309251883Speter** sqlite3_backup_step() obtains a [shared lock] on the source database that 8310251883Speter** lasts for the duration of the sqlite3_backup_step() call. 8311251883Speter** ^Because the source database is not locked between calls to 8312251883Speter** sqlite3_backup_step(), the source database may be modified mid-way 8313251883Speter** through the backup process. ^If the source database is modified by an 8314251883Speter** external process or via a database connection other than the one being 8315251883Speter** used by the backup operation, then the backup will be automatically 8316251883Speter** restarted by the next call to sqlite3_backup_step(). ^If the source 8317251883Speter** database is modified by the using the same database connection as is used 8318251883Speter** by the backup operation, then the backup database is automatically 8319251883Speter** updated at the same time. 8320251883Speter** 8321251883Speter** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8322251883Speter** 8323251883Speter** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8324251883Speter** application wishes to abandon the backup operation, the application 8325251883Speter** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8326251883Speter** ^The sqlite3_backup_finish() interfaces releases all 8327251883Speter** resources associated with the [sqlite3_backup] object. 8328251883Speter** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8329251883Speter** active write-transaction on the destination database is rolled back. 8330251883Speter** The [sqlite3_backup] object is invalid 8331251883Speter** and may not be used following a call to sqlite3_backup_finish(). 8332251883Speter** 8333251883Speter** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8334251883Speter** sqlite3_backup_step() errors occurred, regardless or whether or not 8335251883Speter** sqlite3_backup_step() completed. 8336251883Speter** ^If an out-of-memory condition or IO error occurred during any prior 8337251883Speter** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8338251883Speter** sqlite3_backup_finish() returns the corresponding [error code]. 8339251883Speter** 8340251883Speter** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8341251883Speter** is not a permanent error and does not affect the return value of 8342251883Speter** sqlite3_backup_finish(). 8343251883Speter** 8344282328Sbapt** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8345251883Speter** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8346251883Speter** 8347282328Sbapt** ^The sqlite3_backup_remaining() routine returns the number of pages still 8348282328Sbapt** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8349282328Sbapt** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8350282328Sbapt** in the source database at the conclusion of the most recent 8351282328Sbapt** sqlite3_backup_step(). 8352282328Sbapt** ^(The values returned by these functions are only updated by 8353282328Sbapt** sqlite3_backup_step(). If the source database is modified in a way that 8354282328Sbapt** changes the size of the source database or the number of pages remaining, 8355282328Sbapt** those changes are not reflected in the output of sqlite3_backup_pagecount() 8356282328Sbapt** and sqlite3_backup_remaining() until after the next 8357282328Sbapt** sqlite3_backup_step().)^ 8358251883Speter** 8359251883Speter** <b>Concurrent Usage of Database Handles</b> 8360251883Speter** 8361251883Speter** ^The source [database connection] may be used by the application for other 8362251883Speter** purposes while a backup operation is underway or being initialized. 8363251883Speter** ^If SQLite is compiled and configured to support threadsafe database 8364251883Speter** connections, then the source database connection may be used concurrently 8365251883Speter** from within other threads. 8366251883Speter** 8367251883Speter** However, the application must guarantee that the destination 8368251883Speter** [database connection] is not passed to any other API (by any thread) after 8369251883Speter** sqlite3_backup_init() is called and before the corresponding call to 8370251883Speter** sqlite3_backup_finish(). SQLite does not currently check to see 8371251883Speter** if the application incorrectly accesses the destination [database connection] 8372251883Speter** and so no error code is reported, but the operations may malfunction 8373251883Speter** nevertheless. Use of the destination database connection while a 8374251883Speter** backup is in progress might also also cause a mutex deadlock. 8375251883Speter** 8376251883Speter** If running in [shared cache mode], the application must 8377251883Speter** guarantee that the shared cache used by the destination database 8378251883Speter** is not accessed while the backup is running. In practice this means 8379251883Speter** that the application must guarantee that the disk file being 8380251883Speter** backed up to is not accessed by any connection within the process, 8381251883Speter** not just the specific connection that was passed to sqlite3_backup_init(). 8382251883Speter** 8383251883Speter** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8384251883Speter** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8385251883Speter** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8386251883Speter** APIs are not strictly speaking threadsafe. If they are invoked at the 8387251883Speter** same time as another thread is invoking sqlite3_backup_step() it is 8388251883Speter** possible that they return invalid values. 8389251883Speter*/ 8390322444SpeterSQLITE_API sqlite3_backup *sqlite3_backup_init( 8391251883Speter sqlite3 *pDest, /* Destination database handle */ 8392251883Speter const char *zDestName, /* Destination database name */ 8393251883Speter sqlite3 *pSource, /* Source database handle */ 8394251883Speter const char *zSourceName /* Source database name */ 8395251883Speter); 8396322444SpeterSQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8397322444SpeterSQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8398322444SpeterSQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8399322444SpeterSQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8400251883Speter 8401251883Speter/* 8402251883Speter** CAPI3REF: Unlock Notification 8403286510Speter** METHOD: sqlite3 8404251883Speter** 8405251883Speter** ^When running in shared-cache mode, a database operation may fail with 8406251883Speter** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8407251883Speter** individual tables within the shared-cache cannot be obtained. See 8408251883Speter** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8409251883Speter** ^This API may be used to register a callback that SQLite will invoke 8410251883Speter** when the connection currently holding the required lock relinquishes it. 8411251883Speter** ^This API is only available if the library was compiled with the 8412251883Speter** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8413251883Speter** 8414251883Speter** See Also: [Using the SQLite Unlock Notification Feature]. 8415251883Speter** 8416251883Speter** ^Shared-cache locks are released when a database connection concludes 8417251883Speter** its current transaction, either by committing it or rolling it back. 8418251883Speter** 8419251883Speter** ^When a connection (known as the blocked connection) fails to obtain a 8420251883Speter** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8421251883Speter** identity of the database connection (the blocking connection) that 8422251883Speter** has locked the required resource is stored internally. ^After an 8423251883Speter** application receives an SQLITE_LOCKED error, it may call the 8424251883Speter** sqlite3_unlock_notify() method with the blocked connection handle as 8425251883Speter** the first argument to register for a callback that will be invoked 8426251883Speter** when the blocking connections current transaction is concluded. ^The 8427251883Speter** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8428251883Speter** call that concludes the blocking connections transaction. 8429251883Speter** 8430251883Speter** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8431251883Speter** there is a chance that the blocking connection will have already 8432251883Speter** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8433251883Speter** If this happens, then the specified callback is invoked immediately, 8434251883Speter** from within the call to sqlite3_unlock_notify().)^ 8435251883Speter** 8436251883Speter** ^If the blocked connection is attempting to obtain a write-lock on a 8437251883Speter** shared-cache table, and more than one other connection currently holds 8438251883Speter** a read-lock on the same table, then SQLite arbitrarily selects one of 8439251883Speter** the other connections to use as the blocking connection. 8440251883Speter** 8441251883Speter** ^(There may be at most one unlock-notify callback registered by a 8442251883Speter** blocked connection. If sqlite3_unlock_notify() is called when the 8443251883Speter** blocked connection already has a registered unlock-notify callback, 8444251883Speter** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8445251883Speter** called with a NULL pointer as its second argument, then any existing 8446251883Speter** unlock-notify callback is canceled. ^The blocked connections 8447251883Speter** unlock-notify callback may also be canceled by closing the blocked 8448251883Speter** connection using [sqlite3_close()]. 8449251883Speter** 8450251883Speter** The unlock-notify callback is not reentrant. If an application invokes 8451251883Speter** any sqlite3_xxx API functions from within an unlock-notify callback, a 8452251883Speter** crash or deadlock may be the result. 8453251883Speter** 8454251883Speter** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8455251883Speter** returns SQLITE_OK. 8456251883Speter** 8457251883Speter** <b>Callback Invocation Details</b> 8458251883Speter** 8459251883Speter** When an unlock-notify callback is registered, the application provides a 8460251883Speter** single void* pointer that is passed to the callback when it is invoked. 8461251883Speter** However, the signature of the callback function allows SQLite to pass 8462251883Speter** it an array of void* context pointers. The first argument passed to 8463251883Speter** an unlock-notify callback is a pointer to an array of void* pointers, 8464251883Speter** and the second is the number of entries in the array. 8465251883Speter** 8466251883Speter** When a blocking connections transaction is concluded, there may be 8467251883Speter** more than one blocked connection that has registered for an unlock-notify 8468251883Speter** callback. ^If two or more such blocked connections have specified the 8469251883Speter** same callback function, then instead of invoking the callback function 8470251883Speter** multiple times, it is invoked once with the set of void* context pointers 8471251883Speter** specified by the blocked connections bundled together into an array. 8472251883Speter** This gives the application an opportunity to prioritize any actions 8473251883Speter** related to the set of unblocked database connections. 8474251883Speter** 8475251883Speter** <b>Deadlock Detection</b> 8476251883Speter** 8477251883Speter** Assuming that after registering for an unlock-notify callback a 8478251883Speter** database waits for the callback to be issued before taking any further 8479251883Speter** action (a reasonable assumption), then using this API may cause the 8480251883Speter** application to deadlock. For example, if connection X is waiting for 8481251883Speter** connection Y's transaction to be concluded, and similarly connection 8482251883Speter** Y is waiting on connection X's transaction, then neither connection 8483251883Speter** will proceed and the system may remain deadlocked indefinitely. 8484251883Speter** 8485251883Speter** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8486251883Speter** detection. ^If a given call to sqlite3_unlock_notify() would put the 8487251883Speter** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8488251883Speter** unlock-notify callback is registered. The system is said to be in 8489251883Speter** a deadlocked state if connection A has registered for an unlock-notify 8490251883Speter** callback on the conclusion of connection B's transaction, and connection 8491251883Speter** B has itself registered for an unlock-notify callback when connection 8492251883Speter** A's transaction is concluded. ^Indirect deadlock is also detected, so 8493251883Speter** the system is also considered to be deadlocked if connection B has 8494251883Speter** registered for an unlock-notify callback on the conclusion of connection 8495251883Speter** C's transaction, where connection C is waiting on connection A. ^Any 8496251883Speter** number of levels of indirection are allowed. 8497251883Speter** 8498251883Speter** <b>The "DROP TABLE" Exception</b> 8499251883Speter** 8500251883Speter** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8501251883Speter** always appropriate to call sqlite3_unlock_notify(). There is however, 8502251883Speter** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8503251883Speter** SQLite checks if there are any currently executing SELECT statements 8504251883Speter** that belong to the same connection. If there are, SQLITE_LOCKED is 8505251883Speter** returned. In this case there is no "blocking connection", so invoking 8506251883Speter** sqlite3_unlock_notify() results in the unlock-notify callback being 8507251883Speter** invoked immediately. If the application then re-attempts the "DROP TABLE" 8508251883Speter** or "DROP INDEX" query, an infinite loop might be the result. 8509251883Speter** 8510251883Speter** One way around this problem is to check the extended error code returned 8511251883Speter** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8512251883Speter** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8513251883Speter** the special "DROP TABLE/INDEX" case, the extended error code is just 8514251883Speter** SQLITE_LOCKED.)^ 8515251883Speter*/ 8516322444SpeterSQLITE_API int sqlite3_unlock_notify( 8517251883Speter sqlite3 *pBlocked, /* Waiting connection */ 8518251883Speter void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8519251883Speter void *pNotifyArg /* Argument to pass to xNotify */ 8520251883Speter); 8521251883Speter 8522251883Speter 8523251883Speter/* 8524251883Speter** CAPI3REF: String Comparison 8525251883Speter** 8526251883Speter** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8527251883Speter** and extensions to compare the contents of two buffers containing UTF-8 8528251883Speter** strings in a case-independent fashion, using the same definition of "case 8529251883Speter** independence" that SQLite uses internally when comparing identifiers. 8530251883Speter*/ 8531322444SpeterSQLITE_API int sqlite3_stricmp(const char *, const char *); 8532322444SpeterSQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8533251883Speter 8534251883Speter/* 8535251883Speter** CAPI3REF: String Globbing 8536251883Speter* 8537298161Sbapt** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8538298161Sbapt** string X matches the [GLOB] pattern P. 8539298161Sbapt** ^The definition of [GLOB] pattern matching used in 8540251883Speter** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8541298161Sbapt** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8542298161Sbapt** is case sensitive. 8543251883Speter** 8544251883Speter** Note that this routine returns zero on a match and non-zero if the strings 8545251883Speter** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8546298161Sbapt** 8547298161Sbapt** See also: [sqlite3_strlike()]. 8548251883Speter*/ 8549322444SpeterSQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8550251883Speter 8551251883Speter/* 8552298161Sbapt** CAPI3REF: String LIKE Matching 8553298161Sbapt* 8554298161Sbapt** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8555298161Sbapt** string X matches the [LIKE] pattern P with escape character E. 8556298161Sbapt** ^The definition of [LIKE] pattern matching used in 8557298161Sbapt** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8558298161Sbapt** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8559298161Sbapt** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8560298161Sbapt** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8561298161Sbapt** insensitive - equivalent upper and lower case ASCII characters match 8562298161Sbapt** one another. 8563298161Sbapt** 8564298161Sbapt** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8565298161Sbapt** only ASCII characters are case folded. 8566298161Sbapt** 8567298161Sbapt** Note that this routine returns zero on a match and non-zero if the strings 8568298161Sbapt** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8569298161Sbapt** 8570298161Sbapt** See also: [sqlite3_strglob()]. 8571298161Sbapt*/ 8572322444SpeterSQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8573298161Sbapt 8574298161Sbapt/* 8575251883Speter** CAPI3REF: Error Logging Interface 8576251883Speter** 8577251883Speter** ^The [sqlite3_log()] interface writes a message into the [error log] 8578251883Speter** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8579251883Speter** ^If logging is enabled, the zFormat string and subsequent arguments are 8580251883Speter** used with [sqlite3_snprintf()] to generate the final output string. 8581251883Speter** 8582251883Speter** The sqlite3_log() interface is intended for use by extensions such as 8583251883Speter** virtual tables, collating functions, and SQL functions. While there is 8584251883Speter** nothing to prevent an application from calling sqlite3_log(), doing so 8585251883Speter** is considered bad form. 8586251883Speter** 8587251883Speter** The zFormat string must not be NULL. 8588251883Speter** 8589251883Speter** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8590251883Speter** will not use dynamically allocated memory. The log message is stored in 8591251883Speter** a fixed-length buffer on the stack. If the log message is longer than 8592251883Speter** a few hundred characters, it will be truncated to the length of the 8593251883Speter** buffer. 8594251883Speter*/ 8595322444SpeterSQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8596251883Speter 8597251883Speter/* 8598251883Speter** CAPI3REF: Write-Ahead Log Commit Hook 8599286510Speter** METHOD: sqlite3 8600251883Speter** 8601251883Speter** ^The [sqlite3_wal_hook()] function is used to register a callback that 8602282328Sbapt** is invoked each time data is committed to a database in wal mode. 8603251883Speter** 8604282328Sbapt** ^(The callback is invoked by SQLite after the commit has taken place and 8605282328Sbapt** the associated write-lock on the database released)^, so the implementation 8606251883Speter** may read, write or [checkpoint] the database as required. 8607251883Speter** 8608251883Speter** ^The first parameter passed to the callback function when it is invoked 8609251883Speter** is a copy of the third parameter passed to sqlite3_wal_hook() when 8610251883Speter** registering the callback. ^The second is a copy of the database handle. 8611251883Speter** ^The third parameter is the name of the database that was written to - 8612251883Speter** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8613251883Speter** is the number of pages currently in the write-ahead log file, 8614251883Speter** including those that were just committed. 8615251883Speter** 8616251883Speter** The callback function should normally return [SQLITE_OK]. ^If an error 8617251883Speter** code is returned, that error will propagate back up through the 8618251883Speter** SQLite code base to cause the statement that provoked the callback 8619251883Speter** to report an error, though the commit will have still occurred. If the 8620251883Speter** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8621251883Speter** that does not correspond to any valid SQLite error code, the results 8622251883Speter** are undefined. 8623251883Speter** 8624251883Speter** A single database handle may have at most a single write-ahead log callback 8625251883Speter** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8626251883Speter** previously registered write-ahead log callback. ^Note that the 8627251883Speter** [sqlite3_wal_autocheckpoint()] interface and the 8628251883Speter** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8629298161Sbapt** overwrite any prior [sqlite3_wal_hook()] settings. 8630251883Speter*/ 8631322444SpeterSQLITE_API void *sqlite3_wal_hook( 8632251883Speter sqlite3*, 8633251883Speter int(*)(void *,sqlite3*,const char*,int), 8634251883Speter void* 8635251883Speter); 8636251883Speter 8637251883Speter/* 8638251883Speter** CAPI3REF: Configure an auto-checkpoint 8639286510Speter** METHOD: sqlite3 8640251883Speter** 8641251883Speter** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8642251883Speter** [sqlite3_wal_hook()] that causes any database on [database connection] D 8643251883Speter** to automatically [checkpoint] 8644251883Speter** after committing a transaction if there are N or 8645251883Speter** more frames in the [write-ahead log] file. ^Passing zero or 8646251883Speter** a negative value as the nFrame parameter disables automatic 8647251883Speter** checkpoints entirely. 8648251883Speter** 8649251883Speter** ^The callback registered by this function replaces any existing callback 8650251883Speter** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8651251883Speter** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8652251883Speter** configured by this function. 8653251883Speter** 8654251883Speter** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8655251883Speter** from SQL. 8656251883Speter** 8657274884Sbapt** ^Checkpoints initiated by this mechanism are 8658274884Sbapt** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8659274884Sbapt** 8660251883Speter** ^Every new [database connection] defaults to having the auto-checkpoint 8661251883Speter** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8662251883Speter** pages. The use of this interface 8663251883Speter** is only necessary if the default setting is found to be suboptimal 8664251883Speter** for a particular application. 8665251883Speter*/ 8666322444SpeterSQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8667251883Speter 8668251883Speter/* 8669251883Speter** CAPI3REF: Checkpoint a database 8670286510Speter** METHOD: sqlite3 8671251883Speter** 8672282328Sbapt** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8673282328Sbapt** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8674251883Speter** 8675282328Sbapt** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8676282328Sbapt** [write-ahead log] for database X on [database connection] D to be 8677282328Sbapt** transferred into the database file and for the write-ahead log to 8678282328Sbapt** be reset. See the [checkpointing] documentation for addition 8679282328Sbapt** information. 8680251883Speter** 8681282328Sbapt** This interface used to be the only way to cause a checkpoint to 8682282328Sbapt** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8683282328Sbapt** interface was added. This interface is retained for backwards 8684282328Sbapt** compatibility and as a convenience for applications that need to manually 8685282328Sbapt** start a callback but which do not need the full power (and corresponding 8686282328Sbapt** complication) of [sqlite3_wal_checkpoint_v2()]. 8687251883Speter*/ 8688322444SpeterSQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8689251883Speter 8690251883Speter/* 8691251883Speter** CAPI3REF: Checkpoint a database 8692286510Speter** METHOD: sqlite3 8693251883Speter** 8694282328Sbapt** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8695282328Sbapt** operation on database X of [database connection] D in mode M. Status 8696282328Sbapt** information is written back into integers pointed to by L and C.)^ 8697282328Sbapt** ^(The M parameter must be a valid [checkpoint mode]:)^ 8698251883Speter** 8699251883Speter** <dl> 8700251883Speter** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8701282328Sbapt** ^Checkpoint as many frames as possible without waiting for any database 8702282328Sbapt** readers or writers to finish, then sync the database file if all frames 8703282328Sbapt** in the log were checkpointed. ^The [busy-handler callback] 8704282328Sbapt** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8705282328Sbapt** ^On the other hand, passive mode might leave the checkpoint unfinished 8706282328Sbapt** if there are concurrent readers or writers. 8707251883Speter** 8708251883Speter** <dt>SQLITE_CHECKPOINT_FULL<dd> 8709282328Sbapt** ^This mode blocks (it invokes the 8710274884Sbapt** [sqlite3_busy_handler|busy-handler callback]) until there is no 8711251883Speter** database writer and all readers are reading from the most recent database 8712282328Sbapt** snapshot. ^It then checkpoints all frames in the log file and syncs the 8713282328Sbapt** database file. ^This mode blocks new database writers while it is pending, 8714282328Sbapt** but new database readers are allowed to continue unimpeded. 8715251883Speter** 8716251883Speter** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8717282328Sbapt** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8718282328Sbapt** that after checkpointing the log file it blocks (calls the 8719282328Sbapt** [busy-handler callback]) 8720282328Sbapt** until all readers are reading from the database file only. ^This ensures 8721282328Sbapt** that the next writer will restart the log file from the beginning. 8722282328Sbapt** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8723282328Sbapt** database writer attempts while it is pending, but does not impede readers. 8724282328Sbapt** 8725282328Sbapt** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8726282328Sbapt** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8727282328Sbapt** addition that it also truncates the log file to zero bytes just prior 8728282328Sbapt** to a successful return. 8729251883Speter** </dl> 8730251883Speter** 8731282328Sbapt** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8732282328Sbapt** the log file or to -1 if the checkpoint could not run because 8733282328Sbapt** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8734282328Sbapt** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8735282328Sbapt** log file (including any that were already checkpointed before the function 8736282328Sbapt** was called) or to -1 if the checkpoint could not run due to an error or 8737282328Sbapt** because the database is not in WAL mode. ^Note that upon successful 8738282328Sbapt** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8739282328Sbapt** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8740251883Speter** 8741282328Sbapt** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8742251883Speter** any other process is running a checkpoint operation at the same time, the 8743282328Sbapt** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8744251883Speter** busy-handler configured, it will not be invoked in this case. 8745251883Speter** 8746282328Sbapt** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8747282328Sbapt** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8748282328Sbapt** obtained immediately, and a busy-handler is configured, it is invoked and 8749282328Sbapt** the writer lock retried until either the busy-handler returns 0 or the lock 8750282328Sbapt** is successfully obtained. ^The busy-handler is also invoked while waiting for 8751282328Sbapt** database readers as described above. ^If the busy-handler returns 0 before 8752251883Speter** the writer lock is obtained or while waiting for database readers, the 8753251883Speter** checkpoint operation proceeds from that point in the same way as 8754251883Speter** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8755282328Sbapt** without blocking any further. ^SQLITE_BUSY is returned in this case. 8756251883Speter** 8757282328Sbapt** ^If parameter zDb is NULL or points to a zero length string, then the 8758282328Sbapt** specified operation is attempted on all WAL databases [attached] to 8759282328Sbapt** [database connection] db. In this case the 8760282328Sbapt** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8761251883Speter** an SQLITE_BUSY error is encountered when processing one or more of the 8762251883Speter** attached WAL databases, the operation is still attempted on any remaining 8763282328Sbapt** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8764251883Speter** error occurs while processing an attached database, processing is abandoned 8765282328Sbapt** and the error code is returned to the caller immediately. ^If no error 8766251883Speter** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8767251883Speter** databases, SQLITE_OK is returned. 8768251883Speter** 8769282328Sbapt** ^If database zDb is the name of an attached database that is not in WAL 8770282328Sbapt** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8771251883Speter** zDb is not NULL (or a zero length string) and is not the name of any 8772251883Speter** attached database, SQLITE_ERROR is returned to the caller. 8773282328Sbapt** 8774282328Sbapt** ^Unless it returns SQLITE_MISUSE, 8775282328Sbapt** the sqlite3_wal_checkpoint_v2() interface 8776282328Sbapt** sets the error information that is queried by 8777282328Sbapt** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8778282328Sbapt** 8779282328Sbapt** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8780282328Sbapt** from SQL. 8781251883Speter*/ 8782322444SpeterSQLITE_API int sqlite3_wal_checkpoint_v2( 8783251883Speter sqlite3 *db, /* Database handle */ 8784251883Speter const char *zDb, /* Name of attached database (or NULL) */ 8785251883Speter int eMode, /* SQLITE_CHECKPOINT_* value */ 8786251883Speter int *pnLog, /* OUT: Size of WAL log in frames */ 8787251883Speter int *pnCkpt /* OUT: Total number of frames checkpointed */ 8788251883Speter); 8789251883Speter 8790251883Speter/* 8791282328Sbapt** CAPI3REF: Checkpoint Mode Values 8792282328Sbapt** KEYWORDS: {checkpoint mode} 8793251883Speter** 8794282328Sbapt** These constants define all valid values for the "checkpoint mode" passed 8795282328Sbapt** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8796282328Sbapt** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8797282328Sbapt** meaning of each of these checkpoint modes. 8798251883Speter*/ 8799282328Sbapt#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8800282328Sbapt#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8801282328Sbapt#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8802282328Sbapt#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8803251883Speter 8804251883Speter/* 8805251883Speter** CAPI3REF: Virtual Table Interface Configuration 8806251883Speter** 8807251883Speter** This function may be called by either the [xConnect] or [xCreate] method 8808251883Speter** of a [virtual table] implementation to configure 8809251883Speter** various facets of the virtual table interface. 8810251883Speter** 8811251883Speter** If this interface is invoked outside the context of an xConnect or 8812251883Speter** xCreate virtual table method then the behavior is undefined. 8813251883Speter** 8814251883Speter** At present, there is only one option that may be configured using 8815251883Speter** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8816251883Speter** may be added in the future. 8817251883Speter*/ 8818322444SpeterSQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8819251883Speter 8820251883Speter/* 8821251883Speter** CAPI3REF: Virtual Table Configuration Options 8822251883Speter** 8823251883Speter** These macros define the various options to the 8824251883Speter** [sqlite3_vtab_config()] interface that [virtual table] implementations 8825251883Speter** can use to customize and optimize their behavior. 8826251883Speter** 8827251883Speter** <dl> 8828342292Scy** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8829251883Speter** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8830251883Speter** <dd>Calls of the form 8831251883Speter** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8832251883Speter** where X is an integer. If X is zero, then the [virtual table] whose 8833251883Speter** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8834251883Speter** support constraints. In this configuration (which is the default) if 8835251883Speter** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8836251883Speter** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8837251883Speter** specified as part of the users SQL statement, regardless of the actual 8838251883Speter** ON CONFLICT mode specified. 8839251883Speter** 8840251883Speter** If X is non-zero, then the virtual table implementation guarantees 8841251883Speter** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8842251883Speter** any modifications to internal or persistent data structures have been made. 8843251883Speter** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8844251883Speter** is able to roll back a statement or database transaction, and abandon 8845251883Speter** or continue processing the current SQL statement as appropriate. 8846251883Speter** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8847251883Speter** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8848251883Speter** had been ABORT. 8849251883Speter** 8850251883Speter** Virtual table implementations that are required to handle OR REPLACE 8851251883Speter** must do so within the [xUpdate] method. If a call to the 8852251883Speter** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8853251883Speter** CONFLICT policy is REPLACE, the virtual table implementation should 8854251883Speter** silently replace the appropriate rows within the xUpdate callback and 8855251883Speter** return SQLITE_OK. Or, if this is not possible, it may return 8856251883Speter** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8857251883Speter** constraint handling. 8858251883Speter** </dl> 8859251883Speter*/ 8860251883Speter#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8861251883Speter 8862251883Speter/* 8863251883Speter** CAPI3REF: Determine The Virtual Table Conflict Policy 8864251883Speter** 8865251883Speter** This function may only be called from within a call to the [xUpdate] method 8866251883Speter** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8867251883Speter** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8868251883Speter** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8869251883Speter** of the SQL statement that triggered the call to the [xUpdate] method of the 8870251883Speter** [virtual table]. 8871251883Speter*/ 8872322444SpeterSQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8873251883Speter 8874251883Speter/* 8875342292Scy** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8876342292Scy** 8877342292Scy** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8878342292Scy** method of a [virtual table], then it returns true if and only if the 8879342292Scy** column is being fetched as part of an UPDATE operation during which the 8880342292Scy** column value will not change. Applications might use this to substitute 8881342292Scy** a return value that is less expensive to compute and that the corresponding 8882342292Scy** [xUpdate] method understands as a "no-change" value. 8883342292Scy** 8884342292Scy** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8885342292Scy** the column is not changed by the UPDATE statement, then the xColumn 8886342292Scy** method can optionally return without setting a result, without calling 8887342292Scy** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8888342292Scy** In that case, [sqlite3_value_nochange(X)] will return true for the 8889342292Scy** same column in the [xUpdate] method. 8890342292Scy*/ 8891342292ScySQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8892342292Scy 8893342292Scy/* 8894342292Scy** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8895342292Scy** 8896342292Scy** This function may only be called from within a call to the [xBestIndex] 8897342292Scy** method of a [virtual table]. 8898342292Scy** 8899342292Scy** The first argument must be the sqlite3_index_info object that is the 8900342292Scy** first parameter to the xBestIndex() method. The second argument must be 8901342292Scy** an index into the aConstraint[] array belonging to the sqlite3_index_info 8902342292Scy** structure passed to xBestIndex. This function returns a pointer to a buffer 8903342292Scy** containing the name of the collation sequence for the corresponding 8904342292Scy** constraint. 8905342292Scy*/ 8906342292ScySQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8907342292Scy 8908342292Scy/* 8909251883Speter** CAPI3REF: Conflict resolution modes 8910274884Sbapt** KEYWORDS: {conflict resolution mode} 8911251883Speter** 8912251883Speter** These constants are returned by [sqlite3_vtab_on_conflict()] to 8913251883Speter** inform a [virtual table] implementation what the [ON CONFLICT] mode 8914251883Speter** is for the SQL statement being evaluated. 8915251883Speter** 8916251883Speter** Note that the [SQLITE_IGNORE] constant is also used as a potential 8917251883Speter** return value from the [sqlite3_set_authorizer()] callback and that 8918251883Speter** [SQLITE_ABORT] is also a [result code]. 8919251883Speter*/ 8920251883Speter#define SQLITE_ROLLBACK 1 8921251883Speter/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8922251883Speter#define SQLITE_FAIL 3 8923251883Speter/* #define SQLITE_ABORT 4 // Also an error code */ 8924251883Speter#define SQLITE_REPLACE 5 8925251883Speter 8926282328Sbapt/* 8927282328Sbapt** CAPI3REF: Prepared Statement Scan Status Opcodes 8928282328Sbapt** KEYWORDS: {scanstatus options} 8929282328Sbapt** 8930282328Sbapt** The following constants can be used for the T parameter to the 8931282328Sbapt** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8932282328Sbapt** different metric for sqlite3_stmt_scanstatus() to return. 8933282328Sbapt** 8934282328Sbapt** When the value returned to V is a string, space to hold that string is 8935282328Sbapt** managed by the prepared statement S and will be automatically freed when 8936282328Sbapt** S is finalized. 8937282328Sbapt** 8938282328Sbapt** <dl> 8939282328Sbapt** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8940282328Sbapt** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8941282328Sbapt** set to the total number of times that the X-th loop has run.</dd> 8942282328Sbapt** 8943282328Sbapt** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8944282328Sbapt** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8945282328Sbapt** to the total number of rows examined by all iterations of the X-th loop.</dd> 8946282328Sbapt** 8947282328Sbapt** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8948282328Sbapt** <dd>^The "double" variable pointed to by the T parameter will be set to the 8949282328Sbapt** query planner's estimate for the average number of rows output from each 8950282328Sbapt** iteration of the X-th loop. If the query planner's estimates was accurate, 8951282328Sbapt** then this value will approximate the quotient NVISIT/NLOOP and the 8952282328Sbapt** product of this value for all prior loops with the same SELECTID will 8953282328Sbapt** be the NLOOP value for the current loop. 8954282328Sbapt** 8955282328Sbapt** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8956282328Sbapt** <dd>^The "const char *" variable pointed to by the T parameter will be set 8957282328Sbapt** to a zero-terminated UTF-8 string containing the name of the index or table 8958282328Sbapt** used for the X-th loop. 8959282328Sbapt** 8960282328Sbapt** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8961282328Sbapt** <dd>^The "const char *" variable pointed to by the T parameter will be set 8962282328Sbapt** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8963282328Sbapt** description for the X-th loop. 8964282328Sbapt** 8965282328Sbapt** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8966282328Sbapt** <dd>^The "int" variable pointed to by the T parameter will be set to the 8967282328Sbapt** "select-id" for the X-th loop. The select-id identifies which query or 8968282328Sbapt** subquery the loop is part of. The main query has a select-id of zero. 8969282328Sbapt** The select-id is the same value as is output in the first column 8970282328Sbapt** of an [EXPLAIN QUERY PLAN] query. 8971282328Sbapt** </dl> 8972282328Sbapt*/ 8973282328Sbapt#define SQLITE_SCANSTAT_NLOOP 0 8974282328Sbapt#define SQLITE_SCANSTAT_NVISIT 1 8975282328Sbapt#define SQLITE_SCANSTAT_EST 2 8976282328Sbapt#define SQLITE_SCANSTAT_NAME 3 8977282328Sbapt#define SQLITE_SCANSTAT_EXPLAIN 4 8978282328Sbapt#define SQLITE_SCANSTAT_SELECTID 5 8979251883Speter 8980282328Sbapt/* 8981282328Sbapt** CAPI3REF: Prepared Statement Scan Status 8982286510Speter** METHOD: sqlite3_stmt 8983282328Sbapt** 8984282328Sbapt** This interface returns information about the predicted and measured 8985282328Sbapt** performance for pStmt. Advanced applications can use this 8986282328Sbapt** interface to compare the predicted and the measured performance and 8987282328Sbapt** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8988282328Sbapt** 8989282328Sbapt** Since this interface is expected to be rarely used, it is only 8990282328Sbapt** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8991282328Sbapt** compile-time option. 8992282328Sbapt** 8993282328Sbapt** The "iScanStatusOp" parameter determines which status information to return. 8994282328Sbapt** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8995282328Sbapt** of this interface is undefined. 8996282328Sbapt** ^The requested measurement is written into a variable pointed to by 8997282328Sbapt** the "pOut" parameter. 8998282328Sbapt** Parameter "idx" identifies the specific loop to retrieve statistics for. 8999282328Sbapt** Loops are numbered starting from zero. ^If idx is out of range - less than 9000282328Sbapt** zero or greater than or equal to the total number of loops used to implement 9001282328Sbapt** the statement - a non-zero value is returned and the variable that pOut 9002282328Sbapt** points to is unchanged. 9003282328Sbapt** 9004282328Sbapt** ^Statistics might not be available for all loops in all statements. ^In cases 9005282328Sbapt** where there exist loops with no available statistics, this function behaves 9006282328Sbapt** as if the loop did not exist - it returns non-zero and leave the variable 9007282328Sbapt** that pOut points to unchanged. 9008282328Sbapt** 9009282328Sbapt** See also: [sqlite3_stmt_scanstatus_reset()] 9010282328Sbapt*/ 9011322444SpeterSQLITE_API int sqlite3_stmt_scanstatus( 9012282328Sbapt sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9013282328Sbapt int idx, /* Index of loop to report on */ 9014282328Sbapt int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9015282328Sbapt void *pOut /* Result written here */ 9016282328Sbapt); 9017251883Speter 9018251883Speter/* 9019282328Sbapt** CAPI3REF: Zero Scan-Status Counters 9020286510Speter** METHOD: sqlite3_stmt 9021282328Sbapt** 9022282328Sbapt** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9023282328Sbapt** 9024282328Sbapt** This API is only available if the library is built with pre-processor 9025282328Sbapt** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9026282328Sbapt*/ 9027322444SpeterSQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9028282328Sbapt 9029298161Sbapt/* 9030298161Sbapt** CAPI3REF: Flush caches to disk mid-transaction 9031298161Sbapt** 9032298161Sbapt** ^If a write-transaction is open on [database connection] D when the 9033298161Sbapt** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9034298161Sbapt** pages in the pager-cache that are not currently in use are written out 9035298161Sbapt** to disk. A dirty page may be in use if a database cursor created by an 9036298161Sbapt** active SQL statement is reading from it, or if it is page 1 of a database 9037298161Sbapt** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9038298161Sbapt** interface flushes caches for all schemas - "main", "temp", and 9039298161Sbapt** any [attached] databases. 9040298161Sbapt** 9041298161Sbapt** ^If this function needs to obtain extra database locks before dirty pages 9042298161Sbapt** can be flushed to disk, it does so. ^If those locks cannot be obtained 9043298161Sbapt** immediately and there is a busy-handler callback configured, it is invoked 9044298161Sbapt** in the usual manner. ^If the required lock still cannot be obtained, then 9045298161Sbapt** the database is skipped and an attempt made to flush any dirty pages 9046298161Sbapt** belonging to the next (if any) database. ^If any databases are skipped 9047298161Sbapt** because locks cannot be obtained, but no other error occurs, this 9048298161Sbapt** function returns SQLITE_BUSY. 9049298161Sbapt** 9050298161Sbapt** ^If any other error occurs while flushing dirty pages to disk (for 9051298161Sbapt** example an IO error or out-of-memory condition), then processing is 9052298161Sbapt** abandoned and an SQLite [error code] is returned to the caller immediately. 9053298161Sbapt** 9054298161Sbapt** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9055298161Sbapt** 9056298161Sbapt** ^This function does not set the database handle error code or message 9057298161Sbapt** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9058298161Sbapt*/ 9059322444SpeterSQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9060282328Sbapt 9061282328Sbapt/* 9062305002Scy** CAPI3REF: The pre-update hook. 9063305002Scy** 9064305002Scy** ^These interfaces are only available if SQLite is compiled using the 9065305002Scy** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9066305002Scy** 9067305002Scy** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9068305002Scy** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9069322444Speter** on a database table. 9070305002Scy** ^At most one preupdate hook may be registered at a time on a single 9071305002Scy** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9072305002Scy** the previous setting. 9073305002Scy** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9074305002Scy** with a NULL pointer as the second parameter. 9075305002Scy** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9076305002Scy** the first parameter to callbacks. 9077305002Scy** 9078322444Speter** ^The preupdate hook only fires for changes to real database tables; the 9079322444Speter** preupdate hook is not invoked for changes to [virtual tables] or to 9080322444Speter** system tables like sqlite_master or sqlite_stat1. 9081305002Scy** 9082305002Scy** ^The second parameter to the preupdate callback is a pointer to 9083305002Scy** the [database connection] that registered the preupdate hook. 9084305002Scy** ^The third parameter to the preupdate callback is one of the constants 9085305002Scy** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9086305002Scy** kind of update operation that is about to occur. 9087305002Scy** ^(The fourth parameter to the preupdate callback is the name of the 9088305002Scy** database within the database connection that is being modified. This 9089305002Scy** will be "main" for the main database or "temp" for TEMP tables or 9090305002Scy** the name given after the AS keyword in the [ATTACH] statement for attached 9091305002Scy** databases.)^ 9092305002Scy** ^The fifth parameter to the preupdate callback is the name of the 9093305002Scy** table that is being modified. 9094305002Scy** 9095322444Speter** For an UPDATE or DELETE operation on a [rowid table], the sixth 9096322444Speter** parameter passed to the preupdate callback is the initial [rowid] of the 9097322444Speter** row being modified or deleted. For an INSERT operation on a rowid table, 9098322444Speter** or any operation on a WITHOUT ROWID table, the value of the sixth 9099322444Speter** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9100322444Speter** seventh parameter is the final rowid value of the row being inserted 9101322444Speter** or updated. The value of the seventh parameter passed to the callback 9102322444Speter** function is not defined for operations on WITHOUT ROWID tables, or for 9103322444Speter** INSERT operations on rowid tables. 9104322444Speter** 9105305002Scy** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9106305002Scy** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9107305002Scy** provide additional information about a preupdate event. These routines 9108305002Scy** may only be called from within a preupdate callback. Invoking any of 9109305002Scy** these routines from outside of a preupdate callback or with a 9110305002Scy** [database connection] pointer that is different from the one supplied 9111305002Scy** to the preupdate callback results in undefined and probably undesirable 9112305002Scy** behavior. 9113305002Scy** 9114305002Scy** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9115305002Scy** in the row that is being inserted, updated, or deleted. 9116305002Scy** 9117305002Scy** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9118305002Scy** a [protected sqlite3_value] that contains the value of the Nth column of 9119305002Scy** the table row before it is updated. The N parameter must be between 0 9120305002Scy** and one less than the number of columns or the behavior will be 9121305002Scy** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9122305002Scy** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9123305002Scy** behavior is undefined. The [sqlite3_value] that P points to 9124305002Scy** will be destroyed when the preupdate callback returns. 9125305002Scy** 9126305002Scy** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9127305002Scy** a [protected sqlite3_value] that contains the value of the Nth column of 9128305002Scy** the table row after it is updated. The N parameter must be between 0 9129305002Scy** and one less than the number of columns or the behavior will be 9130305002Scy** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9131305002Scy** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9132305002Scy** behavior is undefined. The [sqlite3_value] that P points to 9133305002Scy** will be destroyed when the preupdate callback returns. 9134305002Scy** 9135305002Scy** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9136305002Scy** callback was invoked as a result of a direct insert, update, or delete 9137305002Scy** operation; or 1 for inserts, updates, or deletes invoked by top-level 9138305002Scy** triggers; or 2 for changes resulting from triggers called by top-level 9139305002Scy** triggers; and so forth. 9140305002Scy** 9141305002Scy** See also: [sqlite3_update_hook()] 9142305002Scy*/ 9143322444Speter#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9144322444SpeterSQLITE_API void *sqlite3_preupdate_hook( 9145305002Scy sqlite3 *db, 9146305002Scy void(*xPreUpdate)( 9147305002Scy void *pCtx, /* Copy of third arg to preupdate_hook() */ 9148305002Scy sqlite3 *db, /* Database handle */ 9149305002Scy int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9150305002Scy char const *zDb, /* Database name */ 9151305002Scy char const *zName, /* Table name */ 9152305002Scy sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9153305002Scy sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9154305002Scy ), 9155305002Scy void* 9156305002Scy); 9157322444SpeterSQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9158322444SpeterSQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9159322444SpeterSQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9160322444SpeterSQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9161322444Speter#endif 9162305002Scy 9163305002Scy/* 9164298161Sbapt** CAPI3REF: Low-level system error code 9165298161Sbapt** 9166298161Sbapt** ^Attempt to return the underlying operating system error code or error 9167305002Scy** number that caused the most recent I/O error or failure to open a file. 9168298161Sbapt** The return value is OS-dependent. For example, on unix systems, after 9169298161Sbapt** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9170298161Sbapt** called to get back the underlying "errno" that caused the problem, such 9171298161Sbapt** as ENOSPC, EAUTH, EISDIR, and so forth. 9172298161Sbapt*/ 9173322444SpeterSQLITE_API int sqlite3_system_errno(sqlite3*); 9174298161Sbapt 9175298161Sbapt/* 9176298161Sbapt** CAPI3REF: Database Snapshot 9177322444Speter** KEYWORDS: {snapshot} {sqlite3_snapshot} 9178298161Sbapt** 9179298161Sbapt** An instance of the snapshot object records the state of a [WAL mode] 9180298161Sbapt** database for some specific point in history. 9181298161Sbapt** 9182298161Sbapt** In [WAL mode], multiple [database connections] that are open on the 9183298161Sbapt** same database file can each be reading a different historical version 9184298161Sbapt** of the database file. When a [database connection] begins a read 9185298161Sbapt** transaction, that connection sees an unchanging copy of the database 9186298161Sbapt** as it existed for the point in time when the transaction first started. 9187298161Sbapt** Subsequent changes to the database from other connections are not seen 9188298161Sbapt** by the reader until a new read transaction is started. 9189298161Sbapt** 9190298161Sbapt** The sqlite3_snapshot object records state information about an historical 9191298161Sbapt** version of the database file so that it is possible to later open a new read 9192298161Sbapt** transaction that sees that historical version of the database rather than 9193298161Sbapt** the most recent version. 9194298161Sbapt*/ 9195322444Spetertypedef struct sqlite3_snapshot { 9196322444Speter unsigned char hidden[48]; 9197322444Speter} sqlite3_snapshot; 9198298161Sbapt 9199298161Sbapt/* 9200298161Sbapt** CAPI3REF: Record A Database Snapshot 9201342292Scy** CONSTRUCTOR: sqlite3_snapshot 9202298161Sbapt** 9203298161Sbapt** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9204298161Sbapt** new [sqlite3_snapshot] object that records the current state of 9205298161Sbapt** schema S in database connection D. ^On success, the 9206298161Sbapt** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9207298161Sbapt** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9208322444Speter** If there is not already a read-transaction open on schema S when 9209322444Speter** this function is called, one is opened automatically. 9210298161Sbapt** 9211322444Speter** The following must be true for this function to succeed. If any of 9212322444Speter** the following statements are false when sqlite3_snapshot_get() is 9213322444Speter** called, SQLITE_ERROR is returned. The final value of *P is undefined 9214322444Speter** in this case. 9215322444Speter** 9216322444Speter** <ul> 9217342292Scy** <li> The database handle must not be in [autocommit mode]. 9218322444Speter** 9219322444Speter** <li> Schema S of [database connection] D must be a [WAL mode] database. 9220322444Speter** 9221322444Speter** <li> There must not be a write transaction open on schema S of database 9222322444Speter** connection D. 9223322444Speter** 9224322444Speter** <li> One or more transactions must have been written to the current wal 9225322444Speter** file since it was created on disk (by any connection). This means 9226322444Speter** that a snapshot cannot be taken on a wal mode database with no wal 9227322444Speter** file immediately after it is first opened. At least one transaction 9228322444Speter** must be written to it first. 9229322444Speter** </ul> 9230322444Speter** 9231322444Speter** This function may also return SQLITE_NOMEM. If it is called with the 9232322444Speter** database handle in autocommit mode but fails for some other reason, 9233322444Speter** whether or not a read transaction is opened on schema S is undefined. 9234322444Speter** 9235298161Sbapt** The [sqlite3_snapshot] object returned from a successful call to 9236298161Sbapt** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9237298161Sbapt** to avoid a memory leak. 9238298161Sbapt** 9239298161Sbapt** The [sqlite3_snapshot_get()] interface is only available when the 9240342292Scy** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9241298161Sbapt*/ 9242322444SpeterSQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9243298161Sbapt sqlite3 *db, 9244298161Sbapt const char *zSchema, 9245298161Sbapt sqlite3_snapshot **ppSnapshot 9246298161Sbapt); 9247298161Sbapt 9248298161Sbapt/* 9249298161Sbapt** CAPI3REF: Start a read transaction on an historical snapshot 9250342292Scy** METHOD: sqlite3_snapshot 9251298161Sbapt** 9252342292Scy** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9253342292Scy** transaction or upgrades an existing one for schema S of 9254342292Scy** [database connection] D such that the read transaction refers to 9255342292Scy** historical [snapshot] P, rather than the most recent change to the 9256342292Scy** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9257342292Scy** on success or an appropriate [error code] if it fails. 9258298161Sbapt** 9259342292Scy** ^In order to succeed, the database connection must not be in 9260342292Scy** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9261342292Scy** is already a read transaction open on schema S, then the database handle 9262342292Scy** must have no active statements (SELECT statements that have been passed 9263342292Scy** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9264342292Scy** SQLITE_ERROR is returned if either of these conditions is violated, or 9265342292Scy** if schema S does not exist, or if the snapshot object is invalid. 9266342292Scy** 9267342292Scy** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9268342292Scy** snapshot has been overwritten by a [checkpoint]. In this case 9269342292Scy** SQLITE_ERROR_SNAPSHOT is returned. 9270342292Scy** 9271342292Scy** If there is already a read transaction open when this function is 9272342292Scy** invoked, then the same read transaction remains open (on the same 9273342292Scy** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9274342292Scy** is returned. If another error code - for example SQLITE_PROTOCOL or an 9275342292Scy** SQLITE_IOERR error code - is returned, then the final state of the 9276342292Scy** read transaction is undefined. If SQLITE_OK is returned, then the 9277342292Scy** read transaction is now open on database snapshot P. 9278342292Scy** 9279305002Scy** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9280305002Scy** database connection D does not know that the database file for 9281305002Scy** schema S is in [WAL mode]. A database connection might not know 9282305002Scy** that the database file is in [WAL mode] if there has been no prior 9283305002Scy** I/O on that database connection, or if the database entered [WAL mode] 9284305002Scy** after the most recent I/O on the database connection.)^ 9285305002Scy** (Hint: Run "[PRAGMA application_id]" against a newly opened 9286298161Sbapt** database connection in order to make it ready to use snapshots.) 9287298161Sbapt** 9288298161Sbapt** The [sqlite3_snapshot_open()] interface is only available when the 9289342292Scy** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9290298161Sbapt*/ 9291322444SpeterSQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9292298161Sbapt sqlite3 *db, 9293298161Sbapt const char *zSchema, 9294298161Sbapt sqlite3_snapshot *pSnapshot 9295298161Sbapt); 9296298161Sbapt 9297298161Sbapt/* 9298298161Sbapt** CAPI3REF: Destroy a snapshot 9299342292Scy** DESTRUCTOR: sqlite3_snapshot 9300298161Sbapt** 9301298161Sbapt** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9302298161Sbapt** The application must eventually free every [sqlite3_snapshot] object 9303298161Sbapt** using this routine to avoid a memory leak. 9304298161Sbapt** 9305298161Sbapt** The [sqlite3_snapshot_free()] interface is only available when the 9306342292Scy** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9307298161Sbapt*/ 9308322444SpeterSQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9309298161Sbapt 9310298161Sbapt/* 9311305002Scy** CAPI3REF: Compare the ages of two snapshot handles. 9312342292Scy** METHOD: sqlite3_snapshot 9313305002Scy** 9314305002Scy** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9315305002Scy** of two valid snapshot handles. 9316305002Scy** 9317305002Scy** If the two snapshot handles are not associated with the same database 9318305002Scy** file, the result of the comparison is undefined. 9319305002Scy** 9320305002Scy** Additionally, the result of the comparison is only valid if both of the 9321305002Scy** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9322305002Scy** last time the wal file was deleted. The wal file is deleted when the 9323305002Scy** database is changed back to rollback mode or when the number of database 9324305002Scy** clients drops to zero. If either snapshot handle was obtained before the 9325305002Scy** wal file was last deleted, the value returned by this function 9326305002Scy** is undefined. 9327305002Scy** 9328305002Scy** Otherwise, this API returns a negative value if P1 refers to an older 9329305002Scy** snapshot than P2, zero if the two handles refer to the same database 9330305002Scy** snapshot, and a positive value if P1 is a newer snapshot than P2. 9331342292Scy** 9332342292Scy** This interface is only available if SQLite is compiled with the 9333342292Scy** [SQLITE_ENABLE_SNAPSHOT] option. 9334305002Scy*/ 9335322444SpeterSQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9336305002Scy sqlite3_snapshot *p1, 9337305002Scy sqlite3_snapshot *p2 9338305002Scy); 9339305002Scy 9340305002Scy/* 9341322444Speter** CAPI3REF: Recover snapshots from a wal file 9342342292Scy** METHOD: sqlite3_snapshot 9343322444Speter** 9344342292Scy** If a [WAL file] remains on disk after all database connections close 9345342292Scy** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9346342292Scy** or because the last process to have the database opened exited without 9347342292Scy** calling [sqlite3_close()]) and a new connection is subsequently opened 9348342292Scy** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9349342292Scy** will only be able to open the last transaction added to the WAL file 9350342292Scy** even though the WAL file contains other valid transactions. 9351322444Speter** 9352342292Scy** This function attempts to scan the WAL file associated with database zDb 9353322444Speter** of database handle db and make all valid snapshots available to 9354322444Speter** sqlite3_snapshot_open(). It is an error if there is already a read 9355342292Scy** transaction open on the database, or if the database is not a WAL mode 9356322444Speter** database. 9357322444Speter** 9358322444Speter** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9359342292Scy** 9360342292Scy** This interface is only available if SQLite is compiled with the 9361342292Scy** [SQLITE_ENABLE_SNAPSHOT] option. 9362322444Speter*/ 9363322444SpeterSQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9364322444Speter 9365322444Speter/* 9366342292Scy** CAPI3REF: Serialize a database 9367342292Scy** 9368342292Scy** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9369342292Scy** that is a serialization of the S database on [database connection] D. 9370342292Scy** If P is not a NULL pointer, then the size of the database in bytes 9371342292Scy** is written into *P. 9372342292Scy** 9373342292Scy** For an ordinary on-disk database file, the serialization is just a 9374342292Scy** copy of the disk file. For an in-memory database or a "TEMP" database, 9375342292Scy** the serialization is the same sequence of bytes which would be written 9376342292Scy** to disk if that database where backed up to disk. 9377342292Scy** 9378342292Scy** The usual case is that sqlite3_serialize() copies the serialization of 9379342292Scy** the database into memory obtained from [sqlite3_malloc64()] and returns 9380342292Scy** a pointer to that memory. The caller is responsible for freeing the 9381342292Scy** returned value to avoid a memory leak. However, if the F argument 9382342292Scy** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9383342292Scy** are made, and the sqlite3_serialize() function will return a pointer 9384342292Scy** to the contiguous memory representation of the database that SQLite 9385342292Scy** is currently using for that database, or NULL if the no such contiguous 9386342292Scy** memory representation of the database exists. A contiguous memory 9387342292Scy** representation of the database will usually only exist if there has 9388342292Scy** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9389342292Scy** values of D and S. 9390342292Scy** The size of the database is written into *P even if the 9391342292Scy** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9392342292Scy** of the database exists. 9393342292Scy** 9394342292Scy** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9395342292Scy** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9396342292Scy** allocation error occurs. 9397342292Scy** 9398342292Scy** This interface is only available if SQLite is compiled with the 9399342292Scy** [SQLITE_ENABLE_DESERIALIZE] option. 9400342292Scy*/ 9401342292ScySQLITE_API unsigned char *sqlite3_serialize( 9402342292Scy sqlite3 *db, /* The database connection */ 9403342292Scy const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9404342292Scy sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9405342292Scy unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9406342292Scy); 9407342292Scy 9408342292Scy/* 9409342292Scy** CAPI3REF: Flags for sqlite3_serialize 9410342292Scy** 9411342292Scy** Zero or more of the following constants can be OR-ed together for 9412342292Scy** the F argument to [sqlite3_serialize(D,S,P,F)]. 9413342292Scy** 9414342292Scy** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9415342292Scy** a pointer to contiguous in-memory database that it is currently using, 9416342292Scy** without making a copy of the database. If SQLite is not currently using 9417342292Scy** a contiguous in-memory database, then this option causes 9418342292Scy** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9419342292Scy** using a contiguous in-memory database if it has been initialized by a 9420342292Scy** prior call to [sqlite3_deserialize()]. 9421342292Scy*/ 9422342292Scy#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9423342292Scy 9424342292Scy/* 9425342292Scy** CAPI3REF: Deserialize a database 9426342292Scy** 9427342292Scy** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9428342292Scy** [database connection] D to disconnect from database S and then 9429342292Scy** reopen S as an in-memory database based on the serialization contained 9430342292Scy** in P. The serialized database P is N bytes in size. M is the size of 9431342292Scy** the buffer P, which might be larger than N. If M is larger than N, and 9432342292Scy** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9433342292Scy** permitted to add content to the in-memory database as long as the total 9434342292Scy** size does not exceed M bytes. 9435342292Scy** 9436342292Scy** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9437342292Scy** invoke sqlite3_free() on the serialization buffer when the database 9438342292Scy** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9439342292Scy** SQLite will try to increase the buffer size using sqlite3_realloc64() 9440342292Scy** if writes on the database cause it to grow larger than M bytes. 9441342292Scy** 9442342292Scy** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9443342292Scy** database is currently in a read transaction or is involved in a backup 9444342292Scy** operation. 9445342292Scy** 9446342292Scy** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9447342292Scy** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9448342292Scy** [sqlite3_free()] is invoked on argument P prior to returning. 9449342292Scy** 9450342292Scy** This interface is only available if SQLite is compiled with the 9451342292Scy** [SQLITE_ENABLE_DESERIALIZE] option. 9452342292Scy*/ 9453342292ScySQLITE_API int sqlite3_deserialize( 9454342292Scy sqlite3 *db, /* The database connection */ 9455342292Scy const char *zSchema, /* Which DB to reopen with the deserialization */ 9456342292Scy unsigned char *pData, /* The serialized database content */ 9457342292Scy sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9458342292Scy sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9459342292Scy unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9460342292Scy); 9461342292Scy 9462342292Scy/* 9463342292Scy** CAPI3REF: Flags for sqlite3_deserialize() 9464342292Scy** 9465342292Scy** The following are allowed values for 6th argument (the F argument) to 9466342292Scy** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9467342292Scy** 9468342292Scy** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9469342292Scy** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9470342292Scy** and that SQLite should take ownership of this memory and automatically 9471342292Scy** free it when it has finished using it. Without this flag, the caller 9472342292Scy** is responsible for freeing any dynamically allocated memory. 9473342292Scy** 9474342292Scy** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9475342292Scy** grow the size of the database using calls to [sqlite3_realloc64()]. This 9476342292Scy** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9477342292Scy** Without this flag, the deserialized database cannot increase in size beyond 9478342292Scy** the number of bytes specified by the M parameter. 9479342292Scy** 9480342292Scy** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9481342292Scy** should be treated as read-only. 9482342292Scy*/ 9483342292Scy#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9484342292Scy#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9485342292Scy#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9486342292Scy 9487342292Scy/* 9488251883Speter** Undo the hack that converts floating point types to integer for 9489251883Speter** builds on processors without floating point support. 9490251883Speter*/ 9491251883Speter#ifdef SQLITE_OMIT_FLOATING_POINT 9492251883Speter# undef double 9493251883Speter#endif 9494251883Speter 9495251883Speter#ifdef __cplusplus 9496251883Speter} /* End of the 'extern "C"' block */ 9497251883Speter#endif 9498305002Scy#endif /* SQLITE3_H */ 9499251883Speter 9500305002Scy/******** Begin file sqlite3rtree.h *********/ 9501251883Speter/* 9502251883Speter** 2010 August 30 9503251883Speter** 9504251883Speter** The author disclaims copyright to this source code. In place of 9505251883Speter** a legal notice, here is a blessing: 9506251883Speter** 9507251883Speter** May you do good and not evil. 9508251883Speter** May you find forgiveness for yourself and forgive others. 9509251883Speter** May you share freely, never taking more than you give. 9510251883Speter** 9511251883Speter************************************************************************* 9512251883Speter*/ 9513251883Speter 9514251883Speter#ifndef _SQLITE3RTREE_H_ 9515251883Speter#define _SQLITE3RTREE_H_ 9516251883Speter 9517251883Speter 9518251883Speter#ifdef __cplusplus 9519251883Speterextern "C" { 9520251883Speter#endif 9521251883Speter 9522251883Spetertypedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9523269851Spetertypedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9524251883Speter 9525269851Speter/* The double-precision datatype used by RTree depends on the 9526269851Speter** SQLITE_RTREE_INT_ONLY compile-time option. 9527269851Speter*/ 9528269851Speter#ifdef SQLITE_RTREE_INT_ONLY 9529269851Speter typedef sqlite3_int64 sqlite3_rtree_dbl; 9530269851Speter#else 9531269851Speter typedef double sqlite3_rtree_dbl; 9532269851Speter#endif 9533269851Speter 9534251883Speter/* 9535251883Speter** Register a geometry callback named zGeom that can be used as part of an 9536251883Speter** R-Tree geometry query as follows: 9537251883Speter** 9538251883Speter** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9539251883Speter*/ 9540322444SpeterSQLITE_API int sqlite3_rtree_geometry_callback( 9541251883Speter sqlite3 *db, 9542251883Speter const char *zGeom, 9543269851Speter int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9544251883Speter void *pContext 9545251883Speter); 9546251883Speter 9547251883Speter 9548251883Speter/* 9549251883Speter** A pointer to a structure of the following type is passed as the first 9550251883Speter** argument to callbacks registered using rtree_geometry_callback(). 9551251883Speter*/ 9552251883Speterstruct sqlite3_rtree_geometry { 9553251883Speter void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9554251883Speter int nParam; /* Size of array aParam[] */ 9555269851Speter sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9556251883Speter void *pUser; /* Callback implementation user data */ 9557251883Speter void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9558251883Speter}; 9559251883Speter 9560269851Speter/* 9561269851Speter** Register a 2nd-generation geometry callback named zScore that can be 9562269851Speter** used as part of an R-Tree geometry query as follows: 9563269851Speter** 9564269851Speter** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9565269851Speter*/ 9566322444SpeterSQLITE_API int sqlite3_rtree_query_callback( 9567269851Speter sqlite3 *db, 9568269851Speter const char *zQueryFunc, 9569269851Speter int (*xQueryFunc)(sqlite3_rtree_query_info*), 9570269851Speter void *pContext, 9571269851Speter void (*xDestructor)(void*) 9572269851Speter); 9573251883Speter 9574269851Speter 9575269851Speter/* 9576269851Speter** A pointer to a structure of the following type is passed as the 9577269851Speter** argument to scored geometry callback registered using 9578269851Speter** sqlite3_rtree_query_callback(). 9579269851Speter** 9580269851Speter** Note that the first 5 fields of this structure are identical to 9581269851Speter** sqlite3_rtree_geometry. This structure is a subclass of 9582269851Speter** sqlite3_rtree_geometry. 9583269851Speter*/ 9584269851Speterstruct sqlite3_rtree_query_info { 9585269851Speter void *pContext; /* pContext from when function registered */ 9586269851Speter int nParam; /* Number of function parameters */ 9587269851Speter sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9588269851Speter void *pUser; /* callback can use this, if desired */ 9589269851Speter void (*xDelUser)(void*); /* function to free pUser */ 9590269851Speter sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9591269851Speter unsigned int *anQueue; /* Number of pending entries in the queue */ 9592269851Speter int nCoord; /* Number of coordinates */ 9593269851Speter int iLevel; /* Level of current node or entry */ 9594269851Speter int mxLevel; /* The largest iLevel value in the tree */ 9595269851Speter sqlite3_int64 iRowid; /* Rowid for current entry */ 9596269851Speter sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9597269851Speter int eParentWithin; /* Visibility of parent node */ 9598342292Scy int eWithin; /* OUT: Visibility */ 9599269851Speter sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9600286510Speter /* The following fields are only available in 3.8.11 and later */ 9601286510Speter sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9602269851Speter}; 9603269851Speter 9604269851Speter/* 9605269851Speter** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9606269851Speter*/ 9607269851Speter#define NOT_WITHIN 0 /* Object completely outside of query region */ 9608269851Speter#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9609269851Speter#define FULLY_WITHIN 2 /* Object fully contained within query region */ 9610269851Speter 9611269851Speter 9612251883Speter#ifdef __cplusplus 9613251883Speter} /* end of the 'extern "C"' block */ 9614251883Speter#endif 9615251883Speter 9616251883Speter#endif /* ifndef _SQLITE3RTREE_H_ */ 9617251883Speter 9618305002Scy/******** End of sqlite3rtree.h *********/ 9619305002Scy/******** Begin file sqlite3session.h *********/ 9620305002Scy 9621305002Scy#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9622305002Scy#define __SQLITESESSION_H_ 1 9623305002Scy 9624298161Sbapt/* 9625305002Scy** Make sure we can call this stuff from C++. 9626305002Scy*/ 9627305002Scy#ifdef __cplusplus 9628305002Scyextern "C" { 9629305002Scy#endif 9630305002Scy 9631305002Scy 9632305002Scy/* 9633305002Scy** CAPI3REF: Session Object Handle 9634342292Scy** 9635342292Scy** An instance of this object is a [session] that can be used to 9636342292Scy** record changes to a database. 9637305002Scy*/ 9638305002Scytypedef struct sqlite3_session sqlite3_session; 9639305002Scy 9640305002Scy/* 9641305002Scy** CAPI3REF: Changeset Iterator Handle 9642342292Scy** 9643342292Scy** An instance of this object acts as a cursor for iterating 9644342292Scy** over the elements of a [changeset] or [patchset]. 9645305002Scy*/ 9646305002Scytypedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9647305002Scy 9648305002Scy/* 9649305002Scy** CAPI3REF: Create A New Session Object 9650342292Scy** CONSTRUCTOR: sqlite3_session 9651305002Scy** 9652305002Scy** Create a new session object attached to database handle db. If successful, 9653305002Scy** a pointer to the new object is written to *ppSession and SQLITE_OK is 9654305002Scy** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9655305002Scy** error code (e.g. SQLITE_NOMEM) is returned. 9656305002Scy** 9657305002Scy** It is possible to create multiple session objects attached to a single 9658305002Scy** database handle. 9659305002Scy** 9660305002Scy** Session objects created using this function should be deleted using the 9661305002Scy** [sqlite3session_delete()] function before the database handle that they 9662305002Scy** are attached to is itself closed. If the database handle is closed before 9663305002Scy** the session object is deleted, then the results of calling any session 9664305002Scy** module function, including [sqlite3session_delete()] on the session object 9665305002Scy** are undefined. 9666305002Scy** 9667305002Scy** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9668305002Scy** is not possible for an application to register a pre-update hook on a 9669305002Scy** database handle that has one or more session objects attached. Nor is 9670305002Scy** it possible to create a session object attached to a database handle for 9671305002Scy** which a pre-update hook is already defined. The results of attempting 9672305002Scy** either of these things are undefined. 9673305002Scy** 9674305002Scy** The session object will be used to create changesets for tables in 9675305002Scy** database zDb, where zDb is either "main", or "temp", or the name of an 9676305002Scy** attached database. It is not an error if database zDb is not attached 9677305002Scy** to the database when the session object is created. 9678305002Scy*/ 9679322444SpeterSQLITE_API int sqlite3session_create( 9680305002Scy sqlite3 *db, /* Database handle */ 9681305002Scy const char *zDb, /* Name of db (e.g. "main") */ 9682305002Scy sqlite3_session **ppSession /* OUT: New session object */ 9683305002Scy); 9684305002Scy 9685305002Scy/* 9686305002Scy** CAPI3REF: Delete A Session Object 9687342292Scy** DESTRUCTOR: sqlite3_session 9688305002Scy** 9689305002Scy** Delete a session object previously allocated using 9690305002Scy** [sqlite3session_create()]. Once a session object has been deleted, the 9691305002Scy** results of attempting to use pSession with any other session module 9692305002Scy** function are undefined. 9693305002Scy** 9694305002Scy** Session objects must be deleted before the database handle to which they 9695305002Scy** are attached is closed. Refer to the documentation for 9696305002Scy** [sqlite3session_create()] for details. 9697305002Scy*/ 9698322444SpeterSQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9699305002Scy 9700305002Scy 9701305002Scy/* 9702305002Scy** CAPI3REF: Enable Or Disable A Session Object 9703342292Scy** METHOD: sqlite3_session 9704305002Scy** 9705305002Scy** Enable or disable the recording of changes by a session object. When 9706305002Scy** enabled, a session object records changes made to the database. When 9707305002Scy** disabled - it does not. A newly created session object is enabled. 9708305002Scy** Refer to the documentation for [sqlite3session_changeset()] for further 9709305002Scy** details regarding how enabling and disabling a session object affects 9710305002Scy** the eventual changesets. 9711305002Scy** 9712305002Scy** Passing zero to this function disables the session. Passing a value 9713305002Scy** greater than zero enables it. Passing a value less than zero is a 9714305002Scy** no-op, and may be used to query the current state of the session. 9715305002Scy** 9716305002Scy** The return value indicates the final state of the session object: 0 if 9717305002Scy** the session is disabled, or 1 if it is enabled. 9718305002Scy*/ 9719322444SpeterSQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9720305002Scy 9721305002Scy/* 9722305002Scy** CAPI3REF: Set Or Clear the Indirect Change Flag 9723342292Scy** METHOD: sqlite3_session 9724305002Scy** 9725305002Scy** Each change recorded by a session object is marked as either direct or 9726305002Scy** indirect. A change is marked as indirect if either: 9727305002Scy** 9728305002Scy** <ul> 9729305002Scy** <li> The session object "indirect" flag is set when the change is 9730305002Scy** made, or 9731305002Scy** <li> The change is made by an SQL trigger or foreign key action 9732305002Scy** instead of directly as a result of a users SQL statement. 9733305002Scy** </ul> 9734305002Scy** 9735305002Scy** If a single row is affected by more than one operation within a session, 9736305002Scy** then the change is considered indirect if all operations meet the criteria 9737305002Scy** for an indirect change above, or direct otherwise. 9738305002Scy** 9739305002Scy** This function is used to set, clear or query the session object indirect 9740305002Scy** flag. If the second argument passed to this function is zero, then the 9741305002Scy** indirect flag is cleared. If it is greater than zero, the indirect flag 9742305002Scy** is set. Passing a value less than zero does not modify the current value 9743305002Scy** of the indirect flag, and may be used to query the current state of the 9744305002Scy** indirect flag for the specified session object. 9745305002Scy** 9746305002Scy** The return value indicates the final state of the indirect flag: 0 if 9747305002Scy** it is clear, or 1 if it is set. 9748305002Scy*/ 9749322444SpeterSQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9750305002Scy 9751305002Scy/* 9752305002Scy** CAPI3REF: Attach A Table To A Session Object 9753342292Scy** METHOD: sqlite3_session 9754305002Scy** 9755305002Scy** If argument zTab is not NULL, then it is the name of a table to attach 9756305002Scy** to the session object passed as the first argument. All subsequent changes 9757305002Scy** made to the table while the session object is enabled will be recorded. See 9758305002Scy** documentation for [sqlite3session_changeset()] for further details. 9759305002Scy** 9760305002Scy** Or, if argument zTab is NULL, then changes are recorded for all tables 9761305002Scy** in the database. If additional tables are added to the database (by 9762305002Scy** executing "CREATE TABLE" statements) after this call is made, changes for 9763305002Scy** the new tables are also recorded. 9764305002Scy** 9765305002Scy** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9766305002Scy** defined as part of their CREATE TABLE statement. It does not matter if the 9767305002Scy** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9768305002Scy** KEY may consist of a single column, or may be a composite key. 9769305002Scy** 9770305002Scy** It is not an error if the named table does not exist in the database. Nor 9771305002Scy** is it an error if the named table does not have a PRIMARY KEY. However, 9772305002Scy** no changes will be recorded in either of these scenarios. 9773305002Scy** 9774305002Scy** Changes are not recorded for individual rows that have NULL values stored 9775305002Scy** in one or more of their PRIMARY KEY columns. 9776305002Scy** 9777305002Scy** SQLITE_OK is returned if the call completes without error. Or, if an error 9778305002Scy** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9779342292Scy** 9780342292Scy** <h3>Special sqlite_stat1 Handling</h3> 9781342292Scy** 9782342292Scy** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9783342292Scy** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9784342292Scy** <pre> 9785342292Scy** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9786342292Scy** </pre> 9787342292Scy** 9788342292Scy** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9789342292Scy** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9790342292Scy** are recorded for rows for which (idx IS NULL) is true. However, for such 9791342292Scy** rows a zero-length blob (SQL value X'') is stored in the changeset or 9792342292Scy** patchset instead of a NULL value. This allows such changesets to be 9793342292Scy** manipulated by legacy implementations of sqlite3changeset_invert(), 9794342292Scy** concat() and similar. 9795342292Scy** 9796342292Scy** The sqlite3changeset_apply() function automatically converts the 9797342292Scy** zero-length blob back to a NULL value when updating the sqlite_stat1 9798342292Scy** table. However, if the application calls sqlite3changeset_new(), 9799342292Scy** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9800342292Scy** iterator directly (including on a changeset iterator passed to a 9801342292Scy** conflict-handler callback) then the X'' value is returned. The application 9802342292Scy** must translate X'' to NULL itself if required. 9803342292Scy** 9804342292Scy** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9805342292Scy** changes made to the sqlite_stat1 table. Legacy versions of the 9806342292Scy** sqlite3changeset_apply() function silently ignore any modifications to the 9807342292Scy** sqlite_stat1 table that are part of a changeset or patchset. 9808305002Scy*/ 9809322444SpeterSQLITE_API int sqlite3session_attach( 9810305002Scy sqlite3_session *pSession, /* Session object */ 9811305002Scy const char *zTab /* Table name */ 9812305002Scy); 9813305002Scy 9814305002Scy/* 9815305002Scy** CAPI3REF: Set a table filter on a Session Object. 9816342292Scy** METHOD: sqlite3_session 9817305002Scy** 9818305002Scy** The second argument (xFilter) is the "filter callback". For changes to rows 9819322444Speter** in tables that are not attached to the Session object, the filter is called 9820305002Scy** to determine whether changes to the table's rows should be tracked or not. 9821305002Scy** If xFilter returns 0, changes is not tracked. Note that once a table is 9822305002Scy** attached, xFilter will not be called again. 9823305002Scy*/ 9824322444SpeterSQLITE_API void sqlite3session_table_filter( 9825305002Scy sqlite3_session *pSession, /* Session object */ 9826305002Scy int(*xFilter)( 9827305002Scy void *pCtx, /* Copy of third arg to _filter_table() */ 9828305002Scy const char *zTab /* Table name */ 9829305002Scy ), 9830305002Scy void *pCtx /* First argument passed to xFilter */ 9831305002Scy); 9832305002Scy 9833305002Scy/* 9834305002Scy** CAPI3REF: Generate A Changeset From A Session Object 9835342292Scy** METHOD: sqlite3_session 9836305002Scy** 9837305002Scy** Obtain a changeset containing changes to the tables attached to the 9838305002Scy** session object passed as the first argument. If successful, 9839305002Scy** set *ppChangeset to point to a buffer containing the changeset 9840305002Scy** and *pnChangeset to the size of the changeset in bytes before returning 9841305002Scy** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9842305002Scy** zero and return an SQLite error code. 9843305002Scy** 9844305002Scy** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9845305002Scy** each representing a change to a single row of an attached table. An INSERT 9846305002Scy** change contains the values of each field of a new database row. A DELETE 9847305002Scy** contains the original values of each field of a deleted database row. An 9848305002Scy** UPDATE change contains the original values of each field of an updated 9849305002Scy** database row along with the updated values for each updated non-primary-key 9850305002Scy** column. It is not possible for an UPDATE change to represent a change that 9851305002Scy** modifies the values of primary key columns. If such a change is made, it 9852305002Scy** is represented in a changeset as a DELETE followed by an INSERT. 9853305002Scy** 9854305002Scy** Changes are not recorded for rows that have NULL values stored in one or 9855305002Scy** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9856305002Scy** no corresponding change is present in the changesets returned by this 9857305002Scy** function. If an existing row with one or more NULL values stored in 9858305002Scy** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9859305002Scy** only an INSERT is appears in the changeset. Similarly, if an existing row 9860305002Scy** with non-NULL PRIMARY KEY values is updated so that one or more of its 9861305002Scy** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9862305002Scy** DELETE change only. 9863305002Scy** 9864305002Scy** The contents of a changeset may be traversed using an iterator created 9865305002Scy** using the [sqlite3changeset_start()] API. A changeset may be applied to 9866305002Scy** a database with a compatible schema using the [sqlite3changeset_apply()] 9867305002Scy** API. 9868305002Scy** 9869305002Scy** Within a changeset generated by this function, all changes related to a 9870305002Scy** single table are grouped together. In other words, when iterating through 9871305002Scy** a changeset or when applying a changeset to a database, all changes related 9872305002Scy** to a single table are processed before moving on to the next table. Tables 9873305002Scy** are sorted in the same order in which they were attached (or auto-attached) 9874305002Scy** to the sqlite3_session object. The order in which the changes related to 9875305002Scy** a single table are stored is undefined. 9876305002Scy** 9877305002Scy** Following a successful call to this function, it is the responsibility of 9878305002Scy** the caller to eventually free the buffer that *ppChangeset points to using 9879305002Scy** [sqlite3_free()]. 9880305002Scy** 9881305002Scy** <h3>Changeset Generation</h3> 9882305002Scy** 9883305002Scy** Once a table has been attached to a session object, the session object 9884305002Scy** records the primary key values of all new rows inserted into the table. 9885305002Scy** It also records the original primary key and other column values of any 9886305002Scy** deleted or updated rows. For each unique primary key value, data is only 9887305002Scy** recorded once - the first time a row with said primary key is inserted, 9888305002Scy** updated or deleted in the lifetime of the session. 9889305002Scy** 9890305002Scy** There is one exception to the previous paragraph: when a row is inserted, 9891305002Scy** updated or deleted, if one or more of its primary key columns contain a 9892305002Scy** NULL value, no record of the change is made. 9893305002Scy** 9894305002Scy** The session object therefore accumulates two types of records - those 9895305002Scy** that consist of primary key values only (created when the user inserts 9896305002Scy** a new record) and those that consist of the primary key values and the 9897305002Scy** original values of other table columns (created when the users deletes 9898305002Scy** or updates a record). 9899305002Scy** 9900305002Scy** When this function is called, the requested changeset is created using 9901305002Scy** both the accumulated records and the current contents of the database 9902305002Scy** file. Specifically: 9903305002Scy** 9904305002Scy** <ul> 9905305002Scy** <li> For each record generated by an insert, the database is queried 9906305002Scy** for a row with a matching primary key. If one is found, an INSERT 9907305002Scy** change is added to the changeset. If no such row is found, no change 9908305002Scy** is added to the changeset. 9909305002Scy** 9910305002Scy** <li> For each record generated by an update or delete, the database is 9911305002Scy** queried for a row with a matching primary key. If such a row is 9912305002Scy** found and one or more of the non-primary key fields have been 9913305002Scy** modified from their original values, an UPDATE change is added to 9914305002Scy** the changeset. Or, if no such row is found in the table, a DELETE 9915305002Scy** change is added to the changeset. If there is a row with a matching 9916305002Scy** primary key in the database, but all fields contain their original 9917305002Scy** values, no change is added to the changeset. 9918305002Scy** </ul> 9919305002Scy** 9920305002Scy** This means, amongst other things, that if a row is inserted and then later 9921305002Scy** deleted while a session object is active, neither the insert nor the delete 9922305002Scy** will be present in the changeset. Or if a row is deleted and then later a 9923305002Scy** row with the same primary key values inserted while a session object is 9924305002Scy** active, the resulting changeset will contain an UPDATE change instead of 9925305002Scy** a DELETE and an INSERT. 9926305002Scy** 9927305002Scy** When a session object is disabled (see the [sqlite3session_enable()] API), 9928305002Scy** it does not accumulate records when rows are inserted, updated or deleted. 9929305002Scy** This may appear to have some counter-intuitive effects if a single row 9930305002Scy** is written to more than once during a session. For example, if a row 9931305002Scy** is inserted while a session object is enabled, then later deleted while 9932305002Scy** the same session object is disabled, no INSERT record will appear in the 9933305002Scy** changeset, even though the delete took place while the session was disabled. 9934305002Scy** Or, if one field of a row is updated while a session is disabled, and 9935305002Scy** another field of the same row is updated while the session is enabled, the 9936305002Scy** resulting changeset will contain an UPDATE change that updates both fields. 9937305002Scy*/ 9938322444SpeterSQLITE_API int sqlite3session_changeset( 9939305002Scy sqlite3_session *pSession, /* Session object */ 9940305002Scy int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9941305002Scy void **ppChangeset /* OUT: Buffer containing changeset */ 9942305002Scy); 9943305002Scy 9944305002Scy/* 9945342292Scy** CAPI3REF: Load The Difference Between Tables Into A Session 9946342292Scy** METHOD: sqlite3_session 9947305002Scy** 9948305002Scy** If it is not already attached to the session object passed as the first 9949305002Scy** argument, this function attaches table zTbl in the same manner as the 9950305002Scy** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9951305002Scy** does not have a primary key, this function is a no-op (but does not return 9952305002Scy** an error). 9953305002Scy** 9954305002Scy** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9955305002Scy** attached to the same database handle as the session object that contains 9956305002Scy** a table compatible with the table attached to the session by this function. 9957305002Scy** A table is considered compatible if it: 9958305002Scy** 9959305002Scy** <ul> 9960305002Scy** <li> Has the same name, 9961305002Scy** <li> Has the same set of columns declared in the same order, and 9962305002Scy** <li> Has the same PRIMARY KEY definition. 9963305002Scy** </ul> 9964305002Scy** 9965305002Scy** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9966305002Scy** are compatible but do not have any PRIMARY KEY columns, it is not an error 9967305002Scy** but no changes are added to the session object. As with other session 9968305002Scy** APIs, tables without PRIMARY KEYs are simply ignored. 9969305002Scy** 9970305002Scy** This function adds a set of changes to the session object that could be 9971305002Scy** used to update the table in database zFrom (call this the "from-table") 9972305002Scy** so that its content is the same as the table attached to the session 9973305002Scy** object (call this the "to-table"). Specifically: 9974305002Scy** 9975305002Scy** <ul> 9976305002Scy** <li> For each row (primary key) that exists in the to-table but not in 9977305002Scy** the from-table, an INSERT record is added to the session object. 9978305002Scy** 9979305002Scy** <li> For each row (primary key) that exists in the to-table but not in 9980305002Scy** the from-table, a DELETE record is added to the session object. 9981305002Scy** 9982305002Scy** <li> For each row (primary key) that exists in both tables, but features 9983322444Speter** different non-PK values in each, an UPDATE record is added to the 9984322444Speter** session. 9985305002Scy** </ul> 9986305002Scy** 9987305002Scy** To clarify, if this function is called and then a changeset constructed 9988305002Scy** using [sqlite3session_changeset()], then after applying that changeset to 9989305002Scy** database zFrom the contents of the two compatible tables would be 9990305002Scy** identical. 9991305002Scy** 9992305002Scy** It an error if database zFrom does not exist or does not contain the 9993305002Scy** required compatible table. 9994305002Scy** 9995305002Scy** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9996305002Scy** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9997305002Scy** may be set to point to a buffer containing an English language error 9998305002Scy** message. It is the responsibility of the caller to free this buffer using 9999305002Scy** sqlite3_free(). 10000305002Scy*/ 10001322444SpeterSQLITE_API int sqlite3session_diff( 10002305002Scy sqlite3_session *pSession, 10003305002Scy const char *zFromDb, 10004305002Scy const char *zTbl, 10005305002Scy char **pzErrMsg 10006305002Scy); 10007305002Scy 10008305002Scy 10009305002Scy/* 10010305002Scy** CAPI3REF: Generate A Patchset From A Session Object 10011342292Scy** METHOD: sqlite3_session 10012305002Scy** 10013305002Scy** The differences between a patchset and a changeset are that: 10014305002Scy** 10015305002Scy** <ul> 10016305002Scy** <li> DELETE records consist of the primary key fields only. The 10017305002Scy** original values of other fields are omitted. 10018305002Scy** <li> The original values of any modified fields are omitted from 10019305002Scy** UPDATE records. 10020305002Scy** </ul> 10021305002Scy** 10022305002Scy** A patchset blob may be used with up to date versions of all 10023305002Scy** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10024305002Scy** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10025305002Scy** attempting to use a patchset blob with old versions of the 10026305002Scy** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10027305002Scy** 10028305002Scy** Because the non-primary key "old.*" fields are omitted, no 10029305002Scy** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10030305002Scy** is passed to the sqlite3changeset_apply() API. Other conflict types work 10031305002Scy** in the same way as for changesets. 10032305002Scy** 10033305002Scy** Changes within a patchset are ordered in the same way as for changesets 10034305002Scy** generated by the sqlite3session_changeset() function (i.e. all changes for 10035305002Scy** a single table are grouped together, tables appear in the order in which 10036305002Scy** they were attached to the session object). 10037305002Scy*/ 10038322444SpeterSQLITE_API int sqlite3session_patchset( 10039305002Scy sqlite3_session *pSession, /* Session object */ 10040342292Scy int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10041342292Scy void **ppPatchset /* OUT: Buffer containing patchset */ 10042305002Scy); 10043305002Scy 10044305002Scy/* 10045305002Scy** CAPI3REF: Test if a changeset has recorded any changes. 10046305002Scy** 10047305002Scy** Return non-zero if no changes to attached tables have been recorded by 10048305002Scy** the session object passed as the first argument. Otherwise, if one or 10049305002Scy** more changes have been recorded, return zero. 10050305002Scy** 10051305002Scy** Even if this function returns zero, it is possible that calling 10052305002Scy** [sqlite3session_changeset()] on the session handle may still return a 10053305002Scy** changeset that contains no changes. This can happen when a row in 10054305002Scy** an attached table is modified and then later on the original values 10055305002Scy** are restored. However, if this function returns non-zero, then it is 10056305002Scy** guaranteed that a call to sqlite3session_changeset() will return a 10057305002Scy** changeset containing zero changes. 10058305002Scy*/ 10059322444SpeterSQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10060305002Scy 10061305002Scy/* 10062305002Scy** CAPI3REF: Create An Iterator To Traverse A Changeset 10063342292Scy** CONSTRUCTOR: sqlite3_changeset_iter 10064305002Scy** 10065305002Scy** Create an iterator used to iterate through the contents of a changeset. 10066305002Scy** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10067305002Scy** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10068305002Scy** SQLite error code is returned. 10069305002Scy** 10070305002Scy** The following functions can be used to advance and query a changeset 10071305002Scy** iterator created by this function: 10072305002Scy** 10073305002Scy** <ul> 10074305002Scy** <li> [sqlite3changeset_next()] 10075305002Scy** <li> [sqlite3changeset_op()] 10076305002Scy** <li> [sqlite3changeset_new()] 10077305002Scy** <li> [sqlite3changeset_old()] 10078305002Scy** </ul> 10079305002Scy** 10080305002Scy** It is the responsibility of the caller to eventually destroy the iterator 10081305002Scy** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10082305002Scy** changeset (pChangeset) must remain valid until after the iterator is 10083305002Scy** destroyed. 10084305002Scy** 10085305002Scy** Assuming the changeset blob was created by one of the 10086305002Scy** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10087305002Scy** [sqlite3changeset_invert()] functions, all changes within the changeset 10088305002Scy** that apply to a single table are grouped together. This means that when 10089305002Scy** an application iterates through a changeset using an iterator created by 10090322444Speter** this function, all changes that relate to a single table are visited 10091305002Scy** consecutively. There is no chance that the iterator will visit a change 10092305002Scy** the applies to table X, then one for table Y, and then later on visit 10093305002Scy** another change for table X. 10094342292Scy** 10095342292Scy** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10096342292Scy** may be modified by passing a combination of 10097342292Scy** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10098342292Scy** 10099342292Scy** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10100342292Scy** and therefore subject to change. 10101305002Scy*/ 10102322444SpeterSQLITE_API int sqlite3changeset_start( 10103305002Scy sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10104305002Scy int nChangeset, /* Size of changeset blob in bytes */ 10105305002Scy void *pChangeset /* Pointer to blob containing changeset */ 10106305002Scy); 10107342292ScySQLITE_API int sqlite3changeset_start_v2( 10108342292Scy sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10109342292Scy int nChangeset, /* Size of changeset blob in bytes */ 10110342292Scy void *pChangeset, /* Pointer to blob containing changeset */ 10111342292Scy int flags /* SESSION_CHANGESETSTART_* flags */ 10112342292Scy); 10113305002Scy 10114342292Scy/* 10115342292Scy** CAPI3REF: Flags for sqlite3changeset_start_v2 10116342292Scy** 10117342292Scy** The following flags may passed via the 4th parameter to 10118342292Scy** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10119342292Scy** 10120342292Scy** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10121342292Scy** Invert the changeset while iterating through it. This is equivalent to 10122342292Scy** inverting a changeset using sqlite3changeset_invert() before applying it. 10123342292Scy** It is an error to specify this flag with a patchset. 10124342292Scy*/ 10125342292Scy#define SQLITE_CHANGESETSTART_INVERT 0x0002 10126305002Scy 10127342292Scy 10128305002Scy/* 10129305002Scy** CAPI3REF: Advance A Changeset Iterator 10130342292Scy** METHOD: sqlite3_changeset_iter 10131305002Scy** 10132305002Scy** This function may only be used with iterators created by function 10133305002Scy** [sqlite3changeset_start()]. If it is called on an iterator passed to 10134305002Scy** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10135305002Scy** is returned and the call has no effect. 10136305002Scy** 10137305002Scy** Immediately after an iterator is created by sqlite3changeset_start(), it 10138305002Scy** does not point to any change in the changeset. Assuming the changeset 10139305002Scy** is not empty, the first call to this function advances the iterator to 10140305002Scy** point to the first change in the changeset. Each subsequent call advances 10141305002Scy** the iterator to point to the next change in the changeset (if any). If 10142305002Scy** no error occurs and the iterator points to a valid change after a call 10143305002Scy** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10144305002Scy** Otherwise, if all changes in the changeset have already been visited, 10145305002Scy** SQLITE_DONE is returned. 10146305002Scy** 10147305002Scy** If an error occurs, an SQLite error code is returned. Possible error 10148305002Scy** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10149305002Scy** SQLITE_NOMEM. 10150305002Scy*/ 10151322444SpeterSQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10152305002Scy 10153305002Scy/* 10154305002Scy** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10155342292Scy** METHOD: sqlite3_changeset_iter 10156305002Scy** 10157305002Scy** The pIter argument passed to this function may either be an iterator 10158305002Scy** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10159305002Scy** created by [sqlite3changeset_start()]. In the latter case, the most recent 10160305002Scy** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10161305002Scy** is not the case, this function returns [SQLITE_MISUSE]. 10162305002Scy** 10163305002Scy** If argument pzTab is not NULL, then *pzTab is set to point to a 10164305002Scy** nul-terminated utf-8 encoded string containing the name of the table 10165305002Scy** affected by the current change. The buffer remains valid until either 10166305002Scy** sqlite3changeset_next() is called on the iterator or until the 10167305002Scy** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 10168305002Scy** set to the number of columns in the table affected by the change. If 10169346442Scy** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10170305002Scy** is an indirect change, or false (0) otherwise. See the documentation for 10171305002Scy** [sqlite3session_indirect()] for a description of direct and indirect 10172305002Scy** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10173305002Scy** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10174305002Scy** type of change that the iterator currently points to. 10175305002Scy** 10176305002Scy** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10177305002Scy** SQLite error code is returned. The values of the output variables may not 10178305002Scy** be trusted in this case. 10179305002Scy*/ 10180322444SpeterSQLITE_API int sqlite3changeset_op( 10181305002Scy sqlite3_changeset_iter *pIter, /* Iterator object */ 10182305002Scy const char **pzTab, /* OUT: Pointer to table name */ 10183305002Scy int *pnCol, /* OUT: Number of columns in table */ 10184305002Scy int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10185305002Scy int *pbIndirect /* OUT: True for an 'indirect' change */ 10186305002Scy); 10187305002Scy 10188305002Scy/* 10189305002Scy** CAPI3REF: Obtain The Primary Key Definition Of A Table 10190342292Scy** METHOD: sqlite3_changeset_iter 10191305002Scy** 10192305002Scy** For each modified table, a changeset includes the following: 10193305002Scy** 10194305002Scy** <ul> 10195305002Scy** <li> The number of columns in the table, and 10196305002Scy** <li> Which of those columns make up the tables PRIMARY KEY. 10197305002Scy** </ul> 10198305002Scy** 10199305002Scy** This function is used to find which columns comprise the PRIMARY KEY of 10200305002Scy** the table modified by the change that iterator pIter currently points to. 10201305002Scy** If successful, *pabPK is set to point to an array of nCol entries, where 10202305002Scy** nCol is the number of columns in the table. Elements of *pabPK are set to 10203305002Scy** 0x01 if the corresponding column is part of the tables primary key, or 10204305002Scy** 0x00 if it is not. 10205305002Scy** 10206322444Speter** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10207305002Scy** in the table. 10208305002Scy** 10209305002Scy** If this function is called when the iterator does not point to a valid 10210305002Scy** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10211305002Scy** SQLITE_OK is returned and the output variables populated as described 10212305002Scy** above. 10213305002Scy*/ 10214322444SpeterSQLITE_API int sqlite3changeset_pk( 10215305002Scy sqlite3_changeset_iter *pIter, /* Iterator object */ 10216305002Scy unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10217305002Scy int *pnCol /* OUT: Number of entries in output array */ 10218305002Scy); 10219305002Scy 10220305002Scy/* 10221305002Scy** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10222342292Scy** METHOD: sqlite3_changeset_iter 10223305002Scy** 10224305002Scy** The pIter argument passed to this function may either be an iterator 10225305002Scy** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10226305002Scy** created by [sqlite3changeset_start()]. In the latter case, the most recent 10227305002Scy** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10228305002Scy** Furthermore, it may only be called if the type of change that the iterator 10229305002Scy** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10230305002Scy** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10231305002Scy** 10232305002Scy** Argument iVal must be greater than or equal to 0, and less than the number 10233305002Scy** of columns in the table affected by the current change. Otherwise, 10234305002Scy** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10235305002Scy** 10236305002Scy** If successful, this function sets *ppValue to point to a protected 10237305002Scy** sqlite3_value object containing the iVal'th value from the vector of 10238305002Scy** original row values stored as part of the UPDATE or DELETE change and 10239305002Scy** returns SQLITE_OK. The name of the function comes from the fact that this 10240305002Scy** is similar to the "old.*" columns available to update or delete triggers. 10241305002Scy** 10242305002Scy** If some other error occurs (e.g. an OOM condition), an SQLite error code 10243305002Scy** is returned and *ppValue is set to NULL. 10244305002Scy*/ 10245322444SpeterSQLITE_API int sqlite3changeset_old( 10246305002Scy sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10247305002Scy int iVal, /* Column number */ 10248305002Scy sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10249305002Scy); 10250305002Scy 10251305002Scy/* 10252305002Scy** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10253342292Scy** METHOD: sqlite3_changeset_iter 10254305002Scy** 10255305002Scy** The pIter argument passed to this function may either be an iterator 10256305002Scy** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10257305002Scy** created by [sqlite3changeset_start()]. In the latter case, the most recent 10258305002Scy** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10259305002Scy** Furthermore, it may only be called if the type of change that the iterator 10260305002Scy** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10261305002Scy** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10262305002Scy** 10263305002Scy** Argument iVal must be greater than or equal to 0, and less than the number 10264305002Scy** of columns in the table affected by the current change. Otherwise, 10265305002Scy** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10266305002Scy** 10267305002Scy** If successful, this function sets *ppValue to point to a protected 10268305002Scy** sqlite3_value object containing the iVal'th value from the vector of 10269305002Scy** new row values stored as part of the UPDATE or INSERT change and 10270305002Scy** returns SQLITE_OK. If the change is an UPDATE and does not include 10271305002Scy** a new value for the requested column, *ppValue is set to NULL and 10272305002Scy** SQLITE_OK returned. The name of the function comes from the fact that 10273305002Scy** this is similar to the "new.*" columns available to update or delete 10274305002Scy** triggers. 10275305002Scy** 10276305002Scy** If some other error occurs (e.g. an OOM condition), an SQLite error code 10277305002Scy** is returned and *ppValue is set to NULL. 10278305002Scy*/ 10279322444SpeterSQLITE_API int sqlite3changeset_new( 10280305002Scy sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10281305002Scy int iVal, /* Column number */ 10282305002Scy sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10283305002Scy); 10284305002Scy 10285305002Scy/* 10286305002Scy** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10287342292Scy** METHOD: sqlite3_changeset_iter 10288305002Scy** 10289305002Scy** This function should only be used with iterator objects passed to a 10290305002Scy** conflict-handler callback by [sqlite3changeset_apply()] with either 10291305002Scy** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10292305002Scy** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10293305002Scy** is set to NULL. 10294305002Scy** 10295305002Scy** Argument iVal must be greater than or equal to 0, and less than the number 10296305002Scy** of columns in the table affected by the current change. Otherwise, 10297305002Scy** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10298305002Scy** 10299305002Scy** If successful, this function sets *ppValue to point to a protected 10300305002Scy** sqlite3_value object containing the iVal'th value from the 10301305002Scy** "conflicting row" associated with the current conflict-handler callback 10302305002Scy** and returns SQLITE_OK. 10303305002Scy** 10304305002Scy** If some other error occurs (e.g. an OOM condition), an SQLite error code 10305305002Scy** is returned and *ppValue is set to NULL. 10306305002Scy*/ 10307322444SpeterSQLITE_API int sqlite3changeset_conflict( 10308305002Scy sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10309305002Scy int iVal, /* Column number */ 10310305002Scy sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10311305002Scy); 10312305002Scy 10313305002Scy/* 10314305002Scy** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10315342292Scy** METHOD: sqlite3_changeset_iter 10316305002Scy** 10317305002Scy** This function may only be called with an iterator passed to an 10318305002Scy** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10319305002Scy** it sets the output variable to the total number of known foreign key 10320305002Scy** violations in the destination database and returns SQLITE_OK. 10321305002Scy** 10322305002Scy** In all other cases this function returns SQLITE_MISUSE. 10323305002Scy*/ 10324322444SpeterSQLITE_API int sqlite3changeset_fk_conflicts( 10325305002Scy sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10326305002Scy int *pnOut /* OUT: Number of FK violations */ 10327305002Scy); 10328305002Scy 10329305002Scy 10330305002Scy/* 10331305002Scy** CAPI3REF: Finalize A Changeset Iterator 10332342292Scy** METHOD: sqlite3_changeset_iter 10333305002Scy** 10334305002Scy** This function is used to finalize an iterator allocated with 10335305002Scy** [sqlite3changeset_start()]. 10336305002Scy** 10337305002Scy** This function should only be called on iterators created using the 10338305002Scy** [sqlite3changeset_start()] function. If an application calls this 10339305002Scy** function with an iterator passed to a conflict-handler by 10340305002Scy** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10341305002Scy** call has no effect. 10342305002Scy** 10343305002Scy** If an error was encountered within a call to an sqlite3changeset_xxx() 10344305002Scy** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10345305002Scy** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10346305002Scy** to that error is returned by this function. Otherwise, SQLITE_OK is 10347305002Scy** returned. This is to allow the following pattern (pseudo-code): 10348305002Scy** 10349342292Scy** <pre> 10350305002Scy** sqlite3changeset_start(); 10351305002Scy** while( SQLITE_ROW==sqlite3changeset_next() ){ 10352305002Scy** // Do something with change. 10353305002Scy** } 10354305002Scy** rc = sqlite3changeset_finalize(); 10355305002Scy** if( rc!=SQLITE_OK ){ 10356305002Scy** // An error has occurred 10357305002Scy** } 10358342292Scy** </pre> 10359305002Scy*/ 10360322444SpeterSQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10361305002Scy 10362305002Scy/* 10363305002Scy** CAPI3REF: Invert A Changeset 10364305002Scy** 10365305002Scy** This function is used to "invert" a changeset object. Applying an inverted 10366305002Scy** changeset to a database reverses the effects of applying the uninverted 10367305002Scy** changeset. Specifically: 10368305002Scy** 10369305002Scy** <ul> 10370305002Scy** <li> Each DELETE change is changed to an INSERT, and 10371305002Scy** <li> Each INSERT change is changed to a DELETE, and 10372305002Scy** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10373305002Scy** </ul> 10374305002Scy** 10375305002Scy** This function does not change the order in which changes appear within 10376305002Scy** the changeset. It merely reverses the sense of each individual change. 10377305002Scy** 10378305002Scy** If successful, a pointer to a buffer containing the inverted changeset 10379305002Scy** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10380305002Scy** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10381305002Scy** zeroed and an SQLite error code returned. 10382305002Scy** 10383305002Scy** It is the responsibility of the caller to eventually call sqlite3_free() 10384305002Scy** on the *ppOut pointer to free the buffer allocation following a successful 10385305002Scy** call to this function. 10386305002Scy** 10387305002Scy** WARNING/TODO: This function currently assumes that the input is a valid 10388305002Scy** changeset. If it is not, the results are undefined. 10389305002Scy*/ 10390322444SpeterSQLITE_API int sqlite3changeset_invert( 10391305002Scy int nIn, const void *pIn, /* Input changeset */ 10392305002Scy int *pnOut, void **ppOut /* OUT: Inverse of input */ 10393305002Scy); 10394305002Scy 10395305002Scy/* 10396305002Scy** CAPI3REF: Concatenate Two Changeset Objects 10397305002Scy** 10398305002Scy** This function is used to concatenate two changesets, A and B, into a 10399305002Scy** single changeset. The result is a changeset equivalent to applying 10400305002Scy** changeset A followed by changeset B. 10401305002Scy** 10402305002Scy** This function combines the two input changesets using an 10403305002Scy** sqlite3_changegroup object. Calling it produces similar results as the 10404305002Scy** following code fragment: 10405305002Scy** 10406342292Scy** <pre> 10407305002Scy** sqlite3_changegroup *pGrp; 10408305002Scy** rc = sqlite3_changegroup_new(&pGrp); 10409305002Scy** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10410305002Scy** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10411305002Scy** if( rc==SQLITE_OK ){ 10412305002Scy** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10413305002Scy** }else{ 10414305002Scy** *ppOut = 0; 10415305002Scy** *pnOut = 0; 10416305002Scy** } 10417342292Scy** </pre> 10418305002Scy** 10419305002Scy** Refer to the sqlite3_changegroup documentation below for details. 10420305002Scy*/ 10421322444SpeterSQLITE_API int sqlite3changeset_concat( 10422305002Scy int nA, /* Number of bytes in buffer pA */ 10423305002Scy void *pA, /* Pointer to buffer containing changeset A */ 10424305002Scy int nB, /* Number of bytes in buffer pB */ 10425305002Scy void *pB, /* Pointer to buffer containing changeset B */ 10426305002Scy int *pnOut, /* OUT: Number of bytes in output changeset */ 10427305002Scy void **ppOut /* OUT: Buffer containing output changeset */ 10428305002Scy); 10429305002Scy 10430305002Scy 10431305002Scy/* 10432322444Speter** CAPI3REF: Changegroup Handle 10433342292Scy** 10434342292Scy** A changegroup is an object used to combine two or more 10435342292Scy** [changesets] or [patchsets] 10436305002Scy*/ 10437305002Scytypedef struct sqlite3_changegroup sqlite3_changegroup; 10438305002Scy 10439305002Scy/* 10440322444Speter** CAPI3REF: Create A New Changegroup Object 10441342292Scy** CONSTRUCTOR: sqlite3_changegroup 10442305002Scy** 10443305002Scy** An sqlite3_changegroup object is used to combine two or more changesets 10444305002Scy** (or patchsets) into a single changeset (or patchset). A single changegroup 10445305002Scy** object may combine changesets or patchsets, but not both. The output is 10446305002Scy** always in the same format as the input. 10447305002Scy** 10448305002Scy** If successful, this function returns SQLITE_OK and populates (*pp) with 10449305002Scy** a pointer to a new sqlite3_changegroup object before returning. The caller 10450305002Scy** should eventually free the returned object using a call to 10451305002Scy** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10452305002Scy** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10453305002Scy** 10454305002Scy** The usual usage pattern for an sqlite3_changegroup object is as follows: 10455305002Scy** 10456305002Scy** <ul> 10457305002Scy** <li> It is created using a call to sqlite3changegroup_new(). 10458305002Scy** 10459305002Scy** <li> Zero or more changesets (or patchsets) are added to the object 10460305002Scy** by calling sqlite3changegroup_add(). 10461305002Scy** 10462305002Scy** <li> The result of combining all input changesets together is obtained 10463305002Scy** by the application via a call to sqlite3changegroup_output(). 10464305002Scy** 10465305002Scy** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10466305002Scy** </ul> 10467305002Scy** 10468305002Scy** Any number of calls to add() and output() may be made between the calls to 10469305002Scy** new() and delete(), and in any order. 10470305002Scy** 10471305002Scy** As well as the regular sqlite3changegroup_add() and 10472305002Scy** sqlite3changegroup_output() functions, also available are the streaming 10473305002Scy** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10474305002Scy*/ 10475322444SpeterSQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10476305002Scy 10477305002Scy/* 10478322444Speter** CAPI3REF: Add A Changeset To A Changegroup 10479342292Scy** METHOD: sqlite3_changegroup 10480322444Speter** 10481305002Scy** Add all changes within the changeset (or patchset) in buffer pData (size 10482305002Scy** nData bytes) to the changegroup. 10483305002Scy** 10484305002Scy** If the buffer contains a patchset, then all prior calls to this function 10485305002Scy** on the same changegroup object must also have specified patchsets. Or, if 10486305002Scy** the buffer contains a changeset, so must have the earlier calls to this 10487305002Scy** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10488305002Scy** to the changegroup. 10489305002Scy** 10490305002Scy** Rows within the changeset and changegroup are identified by the values in 10491305002Scy** their PRIMARY KEY columns. A change in the changeset is considered to 10492305002Scy** apply to the same row as a change already present in the changegroup if 10493305002Scy** the two rows have the same primary key. 10494305002Scy** 10495322444Speter** Changes to rows that do not already appear in the changegroup are 10496305002Scy** simply copied into it. Or, if both the new changeset and the changegroup 10497305002Scy** contain changes that apply to a single row, the final contents of the 10498305002Scy** changegroup depends on the type of each change, as follows: 10499305002Scy** 10500305002Scy** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10501305002Scy** <tr><th style="white-space:pre">Existing Change </th> 10502305002Scy** <th style="white-space:pre">New Change </th> 10503305002Scy** <th>Output Change 10504305002Scy** <tr><td>INSERT <td>INSERT <td> 10505305002Scy** The new change is ignored. This case does not occur if the new 10506305002Scy** changeset was recorded immediately after the changesets already 10507305002Scy** added to the changegroup. 10508305002Scy** <tr><td>INSERT <td>UPDATE <td> 10509305002Scy** The INSERT change remains in the changegroup. The values in the 10510305002Scy** INSERT change are modified as if the row was inserted by the 10511305002Scy** existing change and then updated according to the new change. 10512305002Scy** <tr><td>INSERT <td>DELETE <td> 10513305002Scy** The existing INSERT is removed from the changegroup. The DELETE is 10514305002Scy** not added. 10515305002Scy** <tr><td>UPDATE <td>INSERT <td> 10516305002Scy** The new change is ignored. This case does not occur if the new 10517305002Scy** changeset was recorded immediately after the changesets already 10518305002Scy** added to the changegroup. 10519305002Scy** <tr><td>UPDATE <td>UPDATE <td> 10520305002Scy** The existing UPDATE remains within the changegroup. It is amended 10521305002Scy** so that the accompanying values are as if the row was updated once 10522305002Scy** by the existing change and then again by the new change. 10523305002Scy** <tr><td>UPDATE <td>DELETE <td> 10524305002Scy** The existing UPDATE is replaced by the new DELETE within the 10525305002Scy** changegroup. 10526305002Scy** <tr><td>DELETE <td>INSERT <td> 10527305002Scy** If one or more of the column values in the row inserted by the 10528305002Scy** new change differ from those in the row deleted by the existing 10529305002Scy** change, the existing DELETE is replaced by an UPDATE within the 10530305002Scy** changegroup. Otherwise, if the inserted row is exactly the same 10531305002Scy** as the deleted row, the existing DELETE is simply discarded. 10532305002Scy** <tr><td>DELETE <td>UPDATE <td> 10533305002Scy** The new change is ignored. This case does not occur if the new 10534305002Scy** changeset was recorded immediately after the changesets already 10535305002Scy** added to the changegroup. 10536305002Scy** <tr><td>DELETE <td>DELETE <td> 10537305002Scy** The new change is ignored. This case does not occur if the new 10538305002Scy** changeset was recorded immediately after the changesets already 10539305002Scy** added to the changegroup. 10540305002Scy** </table> 10541305002Scy** 10542305002Scy** If the new changeset contains changes to a table that is already present 10543305002Scy** in the changegroup, then the number of columns and the position of the 10544305002Scy** primary key columns for the table must be consistent. If this is not the 10545305002Scy** case, this function fails with SQLITE_SCHEMA. If the input changeset 10546305002Scy** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10547305002Scy** returned. Or, if an out-of-memory condition occurs during processing, this 10548305002Scy** function returns SQLITE_NOMEM. In all cases, if an error occurs the 10549305002Scy** final contents of the changegroup is undefined. 10550305002Scy** 10551305002Scy** If no error occurs, SQLITE_OK is returned. 10552305002Scy*/ 10553322444SpeterSQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10554305002Scy 10555305002Scy/* 10556322444Speter** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10557342292Scy** METHOD: sqlite3_changegroup 10558322444Speter** 10559305002Scy** Obtain a buffer containing a changeset (or patchset) representing the 10560305002Scy** current contents of the changegroup. If the inputs to the changegroup 10561305002Scy** were themselves changesets, the output is a changeset. Or, if the 10562305002Scy** inputs were patchsets, the output is also a patchset. 10563305002Scy** 10564305002Scy** As with the output of the sqlite3session_changeset() and 10565305002Scy** sqlite3session_patchset() functions, all changes related to a single 10566305002Scy** table are grouped together in the output of this function. Tables appear 10567305002Scy** in the same order as for the very first changeset added to the changegroup. 10568305002Scy** If the second or subsequent changesets added to the changegroup contain 10569305002Scy** changes for tables that do not appear in the first changeset, they are 10570305002Scy** appended onto the end of the output changeset, again in the order in 10571305002Scy** which they are first encountered. 10572305002Scy** 10573305002Scy** If an error occurs, an SQLite error code is returned and the output 10574305002Scy** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10575305002Scy** is returned and the output variables are set to the size of and a 10576305002Scy** pointer to the output buffer, respectively. In this case it is the 10577305002Scy** responsibility of the caller to eventually free the buffer using a 10578305002Scy** call to sqlite3_free(). 10579305002Scy*/ 10580322444SpeterSQLITE_API int sqlite3changegroup_output( 10581305002Scy sqlite3_changegroup*, 10582305002Scy int *pnData, /* OUT: Size of output buffer in bytes */ 10583305002Scy void **ppData /* OUT: Pointer to output buffer */ 10584305002Scy); 10585305002Scy 10586305002Scy/* 10587322444Speter** CAPI3REF: Delete A Changegroup Object 10588342292Scy** DESTRUCTOR: sqlite3_changegroup 10589305002Scy*/ 10590322444SpeterSQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10591305002Scy 10592305002Scy/* 10593305002Scy** CAPI3REF: Apply A Changeset To A Database 10594305002Scy** 10595342292Scy** Apply a changeset or patchset to a database. These functions attempt to 10596342292Scy** update the "main" database attached to handle db with the changes found in 10597342292Scy** the changeset passed via the second and third arguments. 10598305002Scy** 10599342292Scy** The fourth argument (xFilter) passed to these functions is the "filter 10600305002Scy** callback". If it is not NULL, then for each table affected by at least one 10601305002Scy** change in the changeset, the filter callback is invoked with 10602305002Scy** the table name as the second argument, and a copy of the context pointer 10603342292Scy** passed as the sixth argument as the first. If the "filter callback" 10604342292Scy** returns zero, then no attempt is made to apply any changes to the table. 10605342292Scy** Otherwise, if the return value is non-zero or the xFilter argument to 10606342292Scy** is NULL, all changes related to the table are attempted. 10607305002Scy** 10608305002Scy** For each table that is not excluded by the filter callback, this function 10609305002Scy** tests that the target database contains a compatible table. A table is 10610305002Scy** considered compatible if all of the following are true: 10611305002Scy** 10612305002Scy** <ul> 10613305002Scy** <li> The table has the same name as the name recorded in the 10614305002Scy** changeset, and 10615322444Speter** <li> The table has at least as many columns as recorded in the 10616305002Scy** changeset, and 10617305002Scy** <li> The table has primary key columns in the same position as 10618305002Scy** recorded in the changeset. 10619305002Scy** </ul> 10620305002Scy** 10621305002Scy** If there is no compatible table, it is not an error, but none of the 10622305002Scy** changes associated with the table are applied. A warning message is issued 10623305002Scy** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10624305002Scy** one such warning is issued for each table in the changeset. 10625305002Scy** 10626305002Scy** For each change for which there is a compatible table, an attempt is made 10627305002Scy** to modify the table contents according to the UPDATE, INSERT or DELETE 10628305002Scy** change. If a change cannot be applied cleanly, the conflict handler 10629305002Scy** function passed as the fifth argument to sqlite3changeset_apply() may be 10630305002Scy** invoked. A description of exactly when the conflict handler is invoked for 10631305002Scy** each type of change is below. 10632305002Scy** 10633305002Scy** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10634305002Scy** of passing anything other than a valid function pointer as the xConflict 10635305002Scy** argument are undefined. 10636305002Scy** 10637305002Scy** Each time the conflict handler function is invoked, it must return one 10638305002Scy** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10639305002Scy** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10640305002Scy** if the second argument passed to the conflict handler is either 10641305002Scy** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10642305002Scy** returns an illegal value, any changes already made are rolled back and 10643305002Scy** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10644305002Scy** actions are taken by sqlite3changeset_apply() depending on the value 10645305002Scy** returned by each invocation of the conflict-handler function. Refer to 10646305002Scy** the documentation for the three 10647305002Scy** [SQLITE_CHANGESET_OMIT|available return values] for details. 10648305002Scy** 10649305002Scy** <dl> 10650305002Scy** <dt>DELETE Changes<dd> 10651342292Scy** For each DELETE change, the function checks if the target database 10652305002Scy** contains a row with the same primary key value (or values) as the 10653305002Scy** original row values stored in the changeset. If it does, and the values 10654305002Scy** stored in all non-primary key columns also match the values stored in 10655305002Scy** the changeset the row is deleted from the target database. 10656305002Scy** 10657305002Scy** If a row with matching primary key values is found, but one or more of 10658305002Scy** the non-primary key fields contains a value different from the original 10659305002Scy** row value stored in the changeset, the conflict-handler function is 10660322444Speter** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10661322444Speter** database table has more columns than are recorded in the changeset, 10662322444Speter** only the values of those non-primary key fields are compared against 10663322444Speter** the current database contents - any trailing database table columns 10664322444Speter** are ignored. 10665305002Scy** 10666305002Scy** If no row with matching primary key values is found in the database, 10667305002Scy** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10668305002Scy** passed as the second argument. 10669305002Scy** 10670305002Scy** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10671305002Scy** (which can only happen if a foreign key constraint is violated), the 10672305002Scy** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10673305002Scy** passed as the second argument. This includes the case where the DELETE 10674305002Scy** operation is attempted because an earlier call to the conflict handler 10675305002Scy** function returned [SQLITE_CHANGESET_REPLACE]. 10676305002Scy** 10677305002Scy** <dt>INSERT Changes<dd> 10678305002Scy** For each INSERT change, an attempt is made to insert the new row into 10679322444Speter** the database. If the changeset row contains fewer fields than the 10680322444Speter** database table, the trailing fields are populated with their default 10681322444Speter** values. 10682305002Scy** 10683305002Scy** If the attempt to insert the row fails because the database already 10684305002Scy** contains a row with the same primary key values, the conflict handler 10685305002Scy** function is invoked with the second argument set to 10686305002Scy** [SQLITE_CHANGESET_CONFLICT]. 10687305002Scy** 10688305002Scy** If the attempt to insert the row fails because of some other constraint 10689305002Scy** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10690305002Scy** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10691305002Scy** This includes the case where the INSERT operation is re-attempted because 10692305002Scy** an earlier call to the conflict handler function returned 10693305002Scy** [SQLITE_CHANGESET_REPLACE]. 10694305002Scy** 10695305002Scy** <dt>UPDATE Changes<dd> 10696342292Scy** For each UPDATE change, the function checks if the target database 10697305002Scy** contains a row with the same primary key value (or values) as the 10698305002Scy** original row values stored in the changeset. If it does, and the values 10699322444Speter** stored in all modified non-primary key columns also match the values 10700322444Speter** stored in the changeset the row is updated within the target database. 10701305002Scy** 10702305002Scy** If a row with matching primary key values is found, but one or more of 10703322444Speter** the modified non-primary key fields contains a value different from an 10704322444Speter** original row value stored in the changeset, the conflict-handler function 10705322444Speter** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10706305002Scy** UPDATE changes only contain values for non-primary key fields that are 10707305002Scy** to be modified, only those fields need to match the original values to 10708305002Scy** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10709305002Scy** 10710305002Scy** If no row with matching primary key values is found in the database, 10711305002Scy** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10712305002Scy** passed as the second argument. 10713305002Scy** 10714305002Scy** If the UPDATE operation is attempted, but SQLite returns 10715305002Scy** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10716305002Scy** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10717305002Scy** This includes the case where the UPDATE operation is attempted after 10718305002Scy** an earlier call to the conflict handler function returned 10719305002Scy** [SQLITE_CHANGESET_REPLACE]. 10720305002Scy** </dl> 10721305002Scy** 10722305002Scy** It is safe to execute SQL statements, including those that write to the 10723305002Scy** table that the callback related to, from within the xConflict callback. 10724305002Scy** This can be used to further customize the applications conflict 10725305002Scy** resolution strategy. 10726305002Scy** 10727342292Scy** All changes made by these functions are enclosed in a savepoint transaction. 10728305002Scy** If any other error (aside from a constraint failure when attempting to 10729305002Scy** write to the target database) occurs, then the savepoint transaction is 10730305002Scy** rolled back, restoring the target database to its original state, and an 10731305002Scy** SQLite error code returned. 10732342292Scy** 10733342292Scy** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10734342292Scy** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10735342292Scy** may set (*ppRebase) to point to a "rebase" that may be used with the 10736342292Scy** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10737342292Scy** is set to the size of the buffer in bytes. It is the responsibility of the 10738342292Scy** caller to eventually free any such buffer using sqlite3_free(). The buffer 10739342292Scy** is only allocated and populated if one or more conflicts were encountered 10740342292Scy** while applying the patchset. See comments surrounding the sqlite3_rebaser 10741342292Scy** APIs for further details. 10742342292Scy** 10743342292Scy** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10744342292Scy** may be modified by passing a combination of 10745342292Scy** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10746342292Scy** 10747342292Scy** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10748342292Scy** and therefore subject to change. 10749305002Scy*/ 10750322444SpeterSQLITE_API int sqlite3changeset_apply( 10751305002Scy sqlite3 *db, /* Apply change to "main" db of this handle */ 10752305002Scy int nChangeset, /* Size of changeset in bytes */ 10753305002Scy void *pChangeset, /* Changeset blob */ 10754305002Scy int(*xFilter)( 10755305002Scy void *pCtx, /* Copy of sixth arg to _apply() */ 10756305002Scy const char *zTab /* Table name */ 10757305002Scy ), 10758305002Scy int(*xConflict)( 10759305002Scy void *pCtx, /* Copy of sixth arg to _apply() */ 10760305002Scy int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10761305002Scy sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10762305002Scy ), 10763305002Scy void *pCtx /* First argument passed to xConflict */ 10764305002Scy); 10765342292ScySQLITE_API int sqlite3changeset_apply_v2( 10766342292Scy sqlite3 *db, /* Apply change to "main" db of this handle */ 10767342292Scy int nChangeset, /* Size of changeset in bytes */ 10768342292Scy void *pChangeset, /* Changeset blob */ 10769342292Scy int(*xFilter)( 10770342292Scy void *pCtx, /* Copy of sixth arg to _apply() */ 10771342292Scy const char *zTab /* Table name */ 10772342292Scy ), 10773342292Scy int(*xConflict)( 10774342292Scy void *pCtx, /* Copy of sixth arg to _apply() */ 10775342292Scy int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10776342292Scy sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10777342292Scy ), 10778342292Scy void *pCtx, /* First argument passed to xConflict */ 10779342292Scy void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10780342292Scy int flags /* SESSION_CHANGESETAPPLY_* flags */ 10781342292Scy); 10782305002Scy 10783342292Scy/* 10784342292Scy** CAPI3REF: Flags for sqlite3changeset_apply_v2 10785342292Scy** 10786342292Scy** The following flags may passed via the 9th parameter to 10787342292Scy** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10788342292Scy** 10789342292Scy** <dl> 10790342292Scy** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10791342292Scy** Usually, the sessions module encloses all operations performed by 10792342292Scy** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10793342292Scy** SAVEPOINT is committed if the changeset or patchset is successfully 10794342292Scy** applied, or rolled back if an error occurs. Specifying this flag 10795342292Scy** causes the sessions module to omit this savepoint. In this case, if the 10796342292Scy** caller has an open transaction or savepoint when apply_v2() is called, 10797342292Scy** it may revert the partially applied changeset by rolling it back. 10798342292Scy** 10799342292Scy** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10800342292Scy** Invert the changeset before applying it. This is equivalent to inverting 10801342292Scy** a changeset using sqlite3changeset_invert() before applying it. It is 10802342292Scy** an error to specify this flag with a patchset. 10803342292Scy*/ 10804342292Scy#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10805342292Scy#define SQLITE_CHANGESETAPPLY_INVERT 0x0002 10806342292Scy 10807305002Scy/* 10808305002Scy** CAPI3REF: Constants Passed To The Conflict Handler 10809305002Scy** 10810305002Scy** Values that may be passed as the second argument to a conflict-handler. 10811305002Scy** 10812305002Scy** <dl> 10813305002Scy** <dt>SQLITE_CHANGESET_DATA<dd> 10814305002Scy** The conflict handler is invoked with CHANGESET_DATA as the second argument 10815305002Scy** when processing a DELETE or UPDATE change if a row with the required 10816305002Scy** PRIMARY KEY fields is present in the database, but one or more other 10817305002Scy** (non primary-key) fields modified by the update do not contain the 10818305002Scy** expected "before" values. 10819305002Scy** 10820305002Scy** The conflicting row, in this case, is the database row with the matching 10821305002Scy** primary key. 10822305002Scy** 10823305002Scy** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10824305002Scy** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10825305002Scy** argument when processing a DELETE or UPDATE change if a row with the 10826305002Scy** required PRIMARY KEY fields is not present in the database. 10827305002Scy** 10828305002Scy** There is no conflicting row in this case. The results of invoking the 10829305002Scy** sqlite3changeset_conflict() API are undefined. 10830305002Scy** 10831305002Scy** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10832305002Scy** CHANGESET_CONFLICT is passed as the second argument to the conflict 10833305002Scy** handler while processing an INSERT change if the operation would result 10834305002Scy** in duplicate primary key values. 10835305002Scy** 10836305002Scy** The conflicting row in this case is the database row with the matching 10837305002Scy** primary key. 10838305002Scy** 10839305002Scy** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10840305002Scy** If foreign key handling is enabled, and applying a changeset leaves the 10841305002Scy** database in a state containing foreign key violations, the conflict 10842305002Scy** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10843305002Scy** exactly once before the changeset is committed. If the conflict handler 10844305002Scy** returns CHANGESET_OMIT, the changes, including those that caused the 10845305002Scy** foreign key constraint violation, are committed. Or, if it returns 10846305002Scy** CHANGESET_ABORT, the changeset is rolled back. 10847305002Scy** 10848305002Scy** No current or conflicting row information is provided. The only function 10849305002Scy** it is possible to call on the supplied sqlite3_changeset_iter handle 10850305002Scy** is sqlite3changeset_fk_conflicts(). 10851305002Scy** 10852305002Scy** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10853305002Scy** If any other constraint violation occurs while applying a change (i.e. 10854305002Scy** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10855305002Scy** invoked with CHANGESET_CONSTRAINT as the second argument. 10856305002Scy** 10857305002Scy** There is no conflicting row in this case. The results of invoking the 10858305002Scy** sqlite3changeset_conflict() API are undefined. 10859305002Scy** 10860305002Scy** </dl> 10861305002Scy*/ 10862305002Scy#define SQLITE_CHANGESET_DATA 1 10863305002Scy#define SQLITE_CHANGESET_NOTFOUND 2 10864305002Scy#define SQLITE_CHANGESET_CONFLICT 3 10865305002Scy#define SQLITE_CHANGESET_CONSTRAINT 4 10866305002Scy#define SQLITE_CHANGESET_FOREIGN_KEY 5 10867305002Scy 10868305002Scy/* 10869305002Scy** CAPI3REF: Constants Returned By The Conflict Handler 10870305002Scy** 10871305002Scy** A conflict handler callback must return one of the following three values. 10872305002Scy** 10873305002Scy** <dl> 10874305002Scy** <dt>SQLITE_CHANGESET_OMIT<dd> 10875305002Scy** If a conflict handler returns this value no special action is taken. The 10876305002Scy** change that caused the conflict is not applied. The session module 10877305002Scy** continues to the next change in the changeset. 10878305002Scy** 10879305002Scy** <dt>SQLITE_CHANGESET_REPLACE<dd> 10880305002Scy** This value may only be returned if the second argument to the conflict 10881305002Scy** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10882305002Scy** is not the case, any changes applied so far are rolled back and the 10883305002Scy** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10884305002Scy** 10885305002Scy** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10886305002Scy** handler, then the conflicting row is either updated or deleted, depending 10887305002Scy** on the type of change. 10888305002Scy** 10889305002Scy** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10890305002Scy** handler, then the conflicting row is removed from the database and a 10891305002Scy** second attempt to apply the change is made. If this second attempt fails, 10892305002Scy** the original row is restored to the database before continuing. 10893305002Scy** 10894305002Scy** <dt>SQLITE_CHANGESET_ABORT<dd> 10895305002Scy** If this value is returned, any changes applied so far are rolled back 10896305002Scy** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10897305002Scy** </dl> 10898305002Scy*/ 10899305002Scy#define SQLITE_CHANGESET_OMIT 0 10900305002Scy#define SQLITE_CHANGESET_REPLACE 1 10901305002Scy#define SQLITE_CHANGESET_ABORT 2 10902305002Scy 10903342292Scy/* 10904342292Scy** CAPI3REF: Rebasing changesets 10905342292Scy** EXPERIMENTAL 10906342292Scy** 10907342292Scy** Suppose there is a site hosting a database in state S0. And that 10908342292Scy** modifications are made that move that database to state S1 and a 10909342292Scy** changeset recorded (the "local" changeset). Then, a changeset based 10910342292Scy** on S0 is received from another site (the "remote" changeset) and 10911342292Scy** applied to the database. The database is then in state 10912342292Scy** (S1+"remote"), where the exact state depends on any conflict 10913342292Scy** resolution decisions (OMIT or REPLACE) made while applying "remote". 10914342292Scy** Rebasing a changeset is to update it to take those conflict 10915342292Scy** resolution decisions into account, so that the same conflicts 10916342292Scy** do not have to be resolved elsewhere in the network. 10917342292Scy** 10918342292Scy** For example, if both the local and remote changesets contain an 10919342292Scy** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10920342292Scy** 10921342292Scy** local: INSERT INTO t1 VALUES(1, 'v1'); 10922342292Scy** remote: INSERT INTO t1 VALUES(1, 'v2'); 10923342292Scy** 10924342292Scy** and the conflict resolution is REPLACE, then the INSERT change is 10925342292Scy** removed from the local changeset (it was overridden). Or, if the 10926342292Scy** conflict resolution was "OMIT", then the local changeset is modified 10927342292Scy** to instead contain: 10928342292Scy** 10929342292Scy** UPDATE t1 SET b = 'v2' WHERE a=1; 10930342292Scy** 10931342292Scy** Changes within the local changeset are rebased as follows: 10932342292Scy** 10933342292Scy** <dl> 10934342292Scy** <dt>Local INSERT<dd> 10935342292Scy** This may only conflict with a remote INSERT. If the conflict 10936342292Scy** resolution was OMIT, then add an UPDATE change to the rebased 10937342292Scy** changeset. Or, if the conflict resolution was REPLACE, add 10938342292Scy** nothing to the rebased changeset. 10939342292Scy** 10940342292Scy** <dt>Local DELETE<dd> 10941342292Scy** This may conflict with a remote UPDATE or DELETE. In both cases the 10942342292Scy** only possible resolution is OMIT. If the remote operation was a 10943342292Scy** DELETE, then add no change to the rebased changeset. If the remote 10944342292Scy** operation was an UPDATE, then the old.* fields of change are updated 10945342292Scy** to reflect the new.* values in the UPDATE. 10946342292Scy** 10947342292Scy** <dt>Local UPDATE<dd> 10948342292Scy** This may conflict with a remote UPDATE or DELETE. If it conflicts 10949342292Scy** with a DELETE, and the conflict resolution was OMIT, then the update 10950342292Scy** is changed into an INSERT. Any undefined values in the new.* record 10951342292Scy** from the update change are filled in using the old.* values from 10952342292Scy** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10953342292Scy** the UPDATE change is simply omitted from the rebased changeset. 10954342292Scy** 10955342292Scy** If conflict is with a remote UPDATE and the resolution is OMIT, then 10956342292Scy** the old.* values are rebased using the new.* values in the remote 10957342292Scy** change. Or, if the resolution is REPLACE, then the change is copied 10958342292Scy** into the rebased changeset with updates to columns also updated by 10959342292Scy** the conflicting remote UPDATE removed. If this means no columns would 10960342292Scy** be updated, the change is omitted. 10961342292Scy** </dl> 10962342292Scy** 10963342292Scy** A local change may be rebased against multiple remote changes 10964342292Scy** simultaneously. If a single key is modified by multiple remote 10965342292Scy** changesets, they are combined as follows before the local changeset 10966342292Scy** is rebased: 10967342292Scy** 10968342292Scy** <ul> 10969342292Scy** <li> If there has been one or more REPLACE resolutions on a 10970342292Scy** key, it is rebased according to a REPLACE. 10971342292Scy** 10972342292Scy** <li> If there have been no REPLACE resolutions on a key, then 10973342292Scy** the local changeset is rebased according to the most recent 10974342292Scy** of the OMIT resolutions. 10975342292Scy** </ul> 10976342292Scy** 10977342292Scy** Note that conflict resolutions from multiple remote changesets are 10978342292Scy** combined on a per-field basis, not per-row. This means that in the 10979342292Scy** case of multiple remote UPDATE operations, some fields of a single 10980342292Scy** local change may be rebased for REPLACE while others are rebased for 10981342292Scy** OMIT. 10982342292Scy** 10983342292Scy** In order to rebase a local changeset, the remote changeset must first 10984342292Scy** be applied to the local database using sqlite3changeset_apply_v2() and 10985342292Scy** the buffer of rebase information captured. Then: 10986342292Scy** 10987342292Scy** <ol> 10988342292Scy** <li> An sqlite3_rebaser object is created by calling 10989342292Scy** sqlite3rebaser_create(). 10990342292Scy** <li> The new object is configured with the rebase buffer obtained from 10991342292Scy** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10992342292Scy** If the local changeset is to be rebased against multiple remote 10993342292Scy** changesets, then sqlite3rebaser_configure() should be called 10994342292Scy** multiple times, in the same order that the multiple 10995342292Scy** sqlite3changeset_apply_v2() calls were made. 10996342292Scy** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10997342292Scy** <li> The sqlite3_rebaser object is deleted by calling 10998342292Scy** sqlite3rebaser_delete(). 10999342292Scy** </ol> 11000342292Scy*/ 11001342292Scytypedef struct sqlite3_rebaser sqlite3_rebaser; 11002342292Scy 11003305002Scy/* 11004342292Scy** CAPI3REF: Create a changeset rebaser object. 11005342292Scy** EXPERIMENTAL 11006342292Scy** 11007342292Scy** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11008342292Scy** point to the new object and return SQLITE_OK. Otherwise, if an error 11009342292Scy** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11010342292Scy** to NULL. 11011342292Scy*/ 11012342292ScySQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11013342292Scy 11014342292Scy/* 11015342292Scy** CAPI3REF: Configure a changeset rebaser object. 11016342292Scy** EXPERIMENTAL 11017342292Scy** 11018342292Scy** Configure the changeset rebaser object to rebase changesets according 11019342292Scy** to the conflict resolutions described by buffer pRebase (size nRebase 11020342292Scy** bytes), which must have been obtained from a previous call to 11021342292Scy** sqlite3changeset_apply_v2(). 11022342292Scy*/ 11023342292ScySQLITE_API int sqlite3rebaser_configure( 11024342292Scy sqlite3_rebaser*, 11025342292Scy int nRebase, const void *pRebase 11026342292Scy); 11027342292Scy 11028342292Scy/* 11029342292Scy** CAPI3REF: Rebase a changeset 11030342292Scy** EXPERIMENTAL 11031342292Scy** 11032342292Scy** Argument pIn must point to a buffer containing a changeset nIn bytes 11033342292Scy** in size. This function allocates and populates a buffer with a copy 11034342292Scy** of the changeset rebased rebased according to the configuration of the 11035342292Scy** rebaser object passed as the first argument. If successful, (*ppOut) 11036347347Scy** is set to point to the new buffer containing the rebased changeset and 11037342292Scy** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11038342292Scy** responsibility of the caller to eventually free the new buffer using 11039342292Scy** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11040342292Scy** are set to zero and an SQLite error code returned. 11041342292Scy*/ 11042342292ScySQLITE_API int sqlite3rebaser_rebase( 11043342292Scy sqlite3_rebaser*, 11044342292Scy int nIn, const void *pIn, 11045342292Scy int *pnOut, void **ppOut 11046342292Scy); 11047342292Scy 11048342292Scy/* 11049342292Scy** CAPI3REF: Delete a changeset rebaser object. 11050342292Scy** EXPERIMENTAL 11051342292Scy** 11052342292Scy** Delete the changeset rebaser object and all associated resources. There 11053342292Scy** should be one call to this function for each successful invocation 11054342292Scy** of sqlite3rebaser_create(). 11055342292Scy*/ 11056342292ScySQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11057342292Scy 11058342292Scy/* 11059305002Scy** CAPI3REF: Streaming Versions of API functions. 11060305002Scy** 11061305002Scy** The six streaming API xxx_strm() functions serve similar purposes to the 11062305002Scy** corresponding non-streaming API functions: 11063305002Scy** 11064305002Scy** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11065305002Scy** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11066342292Scy** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11067342292Scy** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11068342292Scy** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11069342292Scy** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11070342292Scy** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11071342292Scy** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11072342292Scy** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11073305002Scy** </table> 11074305002Scy** 11075305002Scy** Non-streaming functions that accept changesets (or patchsets) as input 11076305002Scy** require that the entire changeset be stored in a single buffer in memory. 11077305002Scy** Similarly, those that return a changeset or patchset do so by returning 11078305002Scy** a pointer to a single large buffer allocated using sqlite3_malloc(). 11079305002Scy** Normally this is convenient. However, if an application running in a 11080305002Scy** low-memory environment is required to handle very large changesets, the 11081305002Scy** large contiguous memory allocations required can become onerous. 11082305002Scy** 11083305002Scy** In order to avoid this problem, instead of a single large buffer, input 11084305002Scy** is passed to a streaming API functions by way of a callback function that 11085305002Scy** the sessions module invokes to incrementally request input data as it is 11086305002Scy** required. In all cases, a pair of API function parameters such as 11087305002Scy** 11088305002Scy** <pre> 11089305002Scy** int nChangeset, 11090305002Scy** void *pChangeset, 11091305002Scy** </pre> 11092305002Scy** 11093305002Scy** Is replaced by: 11094305002Scy** 11095305002Scy** <pre> 11096305002Scy** int (*xInput)(void *pIn, void *pData, int *pnData), 11097305002Scy** void *pIn, 11098305002Scy** </pre> 11099305002Scy** 11100305002Scy** Each time the xInput callback is invoked by the sessions module, the first 11101305002Scy** argument passed is a copy of the supplied pIn context pointer. The second 11102305002Scy** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11103305002Scy** error occurs the xInput method should copy up to (*pnData) bytes of data 11104305002Scy** into the buffer and set (*pnData) to the actual number of bytes copied 11105305002Scy** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11106305002Scy** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11107305002Scy** error code should be returned. In all cases, if an xInput callback returns 11108305002Scy** an error, all processing is abandoned and the streaming API function 11109305002Scy** returns a copy of the error code to the caller. 11110305002Scy** 11111305002Scy** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11112305002Scy** invoked by the sessions module at any point during the lifetime of the 11113305002Scy** iterator. If such an xInput callback returns an error, the iterator enters 11114305002Scy** an error state, whereby all subsequent calls to iterator functions 11115305002Scy** immediately fail with the same error code as returned by xInput. 11116305002Scy** 11117305002Scy** Similarly, streaming API functions that return changesets (or patchsets) 11118305002Scy** return them in chunks by way of a callback function instead of via a 11119305002Scy** pointer to a single large buffer. In this case, a pair of parameters such 11120305002Scy** as: 11121305002Scy** 11122305002Scy** <pre> 11123305002Scy** int *pnChangeset, 11124305002Scy** void **ppChangeset, 11125305002Scy** </pre> 11126305002Scy** 11127305002Scy** Is replaced by: 11128305002Scy** 11129305002Scy** <pre> 11130305002Scy** int (*xOutput)(void *pOut, const void *pData, int nData), 11131305002Scy** void *pOut 11132305002Scy** </pre> 11133305002Scy** 11134305002Scy** The xOutput callback is invoked zero or more times to return data to 11135305002Scy** the application. The first parameter passed to each call is a copy of the 11136305002Scy** pOut pointer supplied by the application. The second parameter, pData, 11137305002Scy** points to a buffer nData bytes in size containing the chunk of output 11138305002Scy** data being returned. If the xOutput callback successfully processes the 11139305002Scy** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11140305002Scy** it should return some other SQLite error code. In this case processing 11141305002Scy** is immediately abandoned and the streaming API function returns a copy 11142305002Scy** of the xOutput error code to the application. 11143305002Scy** 11144305002Scy** The sessions module never invokes an xOutput callback with the third 11145305002Scy** parameter set to a value less than or equal to zero. Other than this, 11146305002Scy** no guarantees are made as to the size of the chunks of data returned. 11147305002Scy*/ 11148322444SpeterSQLITE_API int sqlite3changeset_apply_strm( 11149305002Scy sqlite3 *db, /* Apply change to "main" db of this handle */ 11150305002Scy int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11151305002Scy void *pIn, /* First arg for xInput */ 11152305002Scy int(*xFilter)( 11153305002Scy void *pCtx, /* Copy of sixth arg to _apply() */ 11154305002Scy const char *zTab /* Table name */ 11155305002Scy ), 11156305002Scy int(*xConflict)( 11157305002Scy void *pCtx, /* Copy of sixth arg to _apply() */ 11158305002Scy int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11159305002Scy sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11160305002Scy ), 11161305002Scy void *pCtx /* First argument passed to xConflict */ 11162305002Scy); 11163342292ScySQLITE_API int sqlite3changeset_apply_v2_strm( 11164342292Scy sqlite3 *db, /* Apply change to "main" db of this handle */ 11165342292Scy int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11166342292Scy void *pIn, /* First arg for xInput */ 11167342292Scy int(*xFilter)( 11168342292Scy void *pCtx, /* Copy of sixth arg to _apply() */ 11169342292Scy const char *zTab /* Table name */ 11170342292Scy ), 11171342292Scy int(*xConflict)( 11172342292Scy void *pCtx, /* Copy of sixth arg to _apply() */ 11173342292Scy int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11174342292Scy sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11175342292Scy ), 11176342292Scy void *pCtx, /* First argument passed to xConflict */ 11177342292Scy void **ppRebase, int *pnRebase, 11178342292Scy int flags 11179342292Scy); 11180322444SpeterSQLITE_API int sqlite3changeset_concat_strm( 11181305002Scy int (*xInputA)(void *pIn, void *pData, int *pnData), 11182305002Scy void *pInA, 11183305002Scy int (*xInputB)(void *pIn, void *pData, int *pnData), 11184305002Scy void *pInB, 11185305002Scy int (*xOutput)(void *pOut, const void *pData, int nData), 11186305002Scy void *pOut 11187305002Scy); 11188322444SpeterSQLITE_API int sqlite3changeset_invert_strm( 11189305002Scy int (*xInput)(void *pIn, void *pData, int *pnData), 11190305002Scy void *pIn, 11191305002Scy int (*xOutput)(void *pOut, const void *pData, int nData), 11192305002Scy void *pOut 11193305002Scy); 11194322444SpeterSQLITE_API int sqlite3changeset_start_strm( 11195305002Scy sqlite3_changeset_iter **pp, 11196305002Scy int (*xInput)(void *pIn, void *pData, int *pnData), 11197305002Scy void *pIn 11198305002Scy); 11199342292ScySQLITE_API int sqlite3changeset_start_v2_strm( 11200342292Scy sqlite3_changeset_iter **pp, 11201342292Scy int (*xInput)(void *pIn, void *pData, int *pnData), 11202342292Scy void *pIn, 11203342292Scy int flags 11204342292Scy); 11205322444SpeterSQLITE_API int sqlite3session_changeset_strm( 11206305002Scy sqlite3_session *pSession, 11207305002Scy int (*xOutput)(void *pOut, const void *pData, int nData), 11208305002Scy void *pOut 11209305002Scy); 11210322444SpeterSQLITE_API int sqlite3session_patchset_strm( 11211305002Scy sqlite3_session *pSession, 11212305002Scy int (*xOutput)(void *pOut, const void *pData, int nData), 11213305002Scy void *pOut 11214305002Scy); 11215322444SpeterSQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11216305002Scy int (*xInput)(void *pIn, void *pData, int *pnData), 11217305002Scy void *pIn 11218305002Scy); 11219322444SpeterSQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11220305002Scy int (*xOutput)(void *pOut, const void *pData, int nData), 11221305002Scy void *pOut 11222305002Scy); 11223342292ScySQLITE_API int sqlite3rebaser_rebase_strm( 11224342292Scy sqlite3_rebaser *pRebaser, 11225342292Scy int (*xInput)(void *pIn, void *pData, int *pnData), 11226342292Scy void *pIn, 11227342292Scy int (*xOutput)(void *pOut, const void *pData, int nData), 11228342292Scy void *pOut 11229342292Scy); 11230305002Scy 11231342292Scy/* 11232342292Scy** CAPI3REF: Configure global parameters 11233342292Scy** 11234342292Scy** The sqlite3session_config() interface is used to make global configuration 11235342292Scy** changes to the sessions module in order to tune it to the specific needs 11236342292Scy** of the application. 11237342292Scy** 11238342292Scy** The sqlite3session_config() interface is not threadsafe. If it is invoked 11239342292Scy** while any other thread is inside any other sessions method then the 11240342292Scy** results are undefined. Furthermore, if it is invoked after any sessions 11241342292Scy** related objects have been created, the results are also undefined. 11242342292Scy** 11243342292Scy** The first argument to the sqlite3session_config() function must be one 11244342292Scy** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11245342292Scy** interpretation of the (void*) value passed as the second parameter and 11246342292Scy** the effect of calling this function depends on the value of the first 11247342292Scy** parameter. 11248342292Scy** 11249342292Scy** <dl> 11250342292Scy** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11251342292Scy** By default, the sessions module streaming interfaces attempt to input 11252342292Scy** and output data in approximately 1 KiB chunks. This operand may be used 11253342292Scy** to set and query the value of this configuration setting. The pointer 11254342292Scy** passed as the second argument must point to a value of type (int). 11255342292Scy** If this value is greater than 0, it is used as the new streaming data 11256342292Scy** chunk size for both input and output. Before returning, the (int) value 11257342292Scy** pointed to by pArg is set to the final value of the streaming interface 11258342292Scy** chunk size. 11259342292Scy** </dl> 11260342292Scy** 11261342292Scy** This function returns SQLITE_OK if successful, or an SQLite error code 11262342292Scy** otherwise. 11263342292Scy*/ 11264342292ScySQLITE_API int sqlite3session_config(int op, void *pArg); 11265305002Scy 11266305002Scy/* 11267342292Scy** CAPI3REF: Values for sqlite3session_config(). 11268342292Scy*/ 11269342292Scy#define SQLITE_SESSION_CONFIG_STRMSIZE 1 11270342292Scy 11271342292Scy/* 11272305002Scy** Make sure we can call this stuff from C++. 11273305002Scy*/ 11274305002Scy#ifdef __cplusplus 11275305002Scy} 11276305002Scy#endif 11277305002Scy 11278305002Scy#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11279305002Scy 11280305002Scy/******** End of sqlite3session.h *********/ 11281305002Scy/******** Begin file fts5.h *********/ 11282305002Scy/* 11283298161Sbapt** 2014 May 31 11284298161Sbapt** 11285298161Sbapt** The author disclaims copyright to this source code. In place of 11286298161Sbapt** a legal notice, here is a blessing: 11287298161Sbapt** 11288298161Sbapt** May you do good and not evil. 11289298161Sbapt** May you find forgiveness for yourself and forgive others. 11290298161Sbapt** May you share freely, never taking more than you give. 11291298161Sbapt** 11292298161Sbapt****************************************************************************** 11293298161Sbapt** 11294298161Sbapt** Interfaces to extend FTS5. Using the interfaces defined in this file, 11295298161Sbapt** FTS5 may be extended with: 11296298161Sbapt** 11297298161Sbapt** * custom tokenizers, and 11298298161Sbapt** * custom auxiliary functions. 11299298161Sbapt*/ 11300298161Sbapt 11301298161Sbapt 11302298161Sbapt#ifndef _FTS5_H 11303298161Sbapt#define _FTS5_H 11304298161Sbapt 11305298161Sbapt 11306298161Sbapt#ifdef __cplusplus 11307298161Sbaptextern "C" { 11308298161Sbapt#endif 11309298161Sbapt 11310298161Sbapt/************************************************************************* 11311298161Sbapt** CUSTOM AUXILIARY FUNCTIONS 11312298161Sbapt** 11313298161Sbapt** Virtual table implementations may overload SQL functions by implementing 11314298161Sbapt** the sqlite3_module.xFindFunction() method. 11315298161Sbapt*/ 11316298161Sbapt 11317298161Sbapttypedef struct Fts5ExtensionApi Fts5ExtensionApi; 11318298161Sbapttypedef struct Fts5Context Fts5Context; 11319298161Sbapttypedef struct Fts5PhraseIter Fts5PhraseIter; 11320298161Sbapt 11321298161Sbapttypedef void (*fts5_extension_function)( 11322298161Sbapt const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11323298161Sbapt Fts5Context *pFts, /* First arg to pass to pApi functions */ 11324298161Sbapt sqlite3_context *pCtx, /* Context for returning result/error */ 11325298161Sbapt int nVal, /* Number of values in apVal[] array */ 11326298161Sbapt sqlite3_value **apVal /* Array of trailing arguments */ 11327298161Sbapt); 11328298161Sbapt 11329298161Sbaptstruct Fts5PhraseIter { 11330298161Sbapt const unsigned char *a; 11331298161Sbapt const unsigned char *b; 11332298161Sbapt}; 11333298161Sbapt 11334298161Sbapt/* 11335298161Sbapt** EXTENSION API FUNCTIONS 11336298161Sbapt** 11337298161Sbapt** xUserData(pFts): 11338298161Sbapt** Return a copy of the context pointer the extension function was 11339298161Sbapt** registered with. 11340298161Sbapt** 11341298161Sbapt** xColumnTotalSize(pFts, iCol, pnToken): 11342298161Sbapt** If parameter iCol is less than zero, set output variable *pnToken 11343298161Sbapt** to the total number of tokens in the FTS5 table. Or, if iCol is 11344298161Sbapt** non-negative but less than the number of columns in the table, return 11345298161Sbapt** the total number of tokens in column iCol, considering all rows in 11346298161Sbapt** the FTS5 table. 11347298161Sbapt** 11348298161Sbapt** If parameter iCol is greater than or equal to the number of columns 11349298161Sbapt** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11350298161Sbapt** an OOM condition or IO error), an appropriate SQLite error code is 11351298161Sbapt** returned. 11352298161Sbapt** 11353298161Sbapt** xColumnCount(pFts): 11354298161Sbapt** Return the number of columns in the table. 11355298161Sbapt** 11356298161Sbapt** xColumnSize(pFts, iCol, pnToken): 11357298161Sbapt** If parameter iCol is less than zero, set output variable *pnToken 11358298161Sbapt** to the total number of tokens in the current row. Or, if iCol is 11359298161Sbapt** non-negative but less than the number of columns in the table, set 11360298161Sbapt** *pnToken to the number of tokens in column iCol of the current row. 11361298161Sbapt** 11362298161Sbapt** If parameter iCol is greater than or equal to the number of columns 11363298161Sbapt** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11364298161Sbapt** an OOM condition or IO error), an appropriate SQLite error code is 11365298161Sbapt** returned. 11366298161Sbapt** 11367298161Sbapt** This function may be quite inefficient if used with an FTS5 table 11368298161Sbapt** created with the "columnsize=0" option. 11369298161Sbapt** 11370298161Sbapt** xColumnText: 11371298161Sbapt** This function attempts to retrieve the text of column iCol of the 11372298161Sbapt** current document. If successful, (*pz) is set to point to a buffer 11373298161Sbapt** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11374298161Sbapt** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11375298161Sbapt** if an error occurs, an SQLite error code is returned and the final values 11376298161Sbapt** of (*pz) and (*pn) are undefined. 11377298161Sbapt** 11378298161Sbapt** xPhraseCount: 11379298161Sbapt** Returns the number of phrases in the current query expression. 11380298161Sbapt** 11381298161Sbapt** xPhraseSize: 11382298161Sbapt** Returns the number of tokens in phrase iPhrase of the query. Phrases 11383298161Sbapt** are numbered starting from zero. 11384298161Sbapt** 11385298161Sbapt** xInstCount: 11386298161Sbapt** Set *pnInst to the total number of occurrences of all phrases within 11387298161Sbapt** the query within the current row. Return SQLITE_OK if successful, or 11388298161Sbapt** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11389298161Sbapt** 11390298161Sbapt** This API can be quite slow if used with an FTS5 table created with the 11391298161Sbapt** "detail=none" or "detail=column" option. If the FTS5 table is created 11392298161Sbapt** with either "detail=none" or "detail=column" and "content=" option 11393298161Sbapt** (i.e. if it is a contentless table), then this API always returns 0. 11394298161Sbapt** 11395298161Sbapt** xInst: 11396298161Sbapt** Query for the details of phrase match iIdx within the current row. 11397298161Sbapt** Phrase matches are numbered starting from zero, so the iIdx argument 11398298161Sbapt** should be greater than or equal to zero and smaller than the value 11399298161Sbapt** output by xInstCount(). 11400298161Sbapt** 11401298161Sbapt** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11402298161Sbapt** to the column in which it occurs and *piOff the token offset of the 11403346442Scy** first token of the phrase. Returns SQLITE_OK if successful, or an error 11404346442Scy** code (i.e. SQLITE_NOMEM) if an error occurs. 11405298161Sbapt** 11406298161Sbapt** This API can be quite slow if used with an FTS5 table created with the 11407298161Sbapt** "detail=none" or "detail=column" option. 11408298161Sbapt** 11409298161Sbapt** xRowid: 11410298161Sbapt** Returns the rowid of the current row. 11411298161Sbapt** 11412298161Sbapt** xTokenize: 11413298161Sbapt** Tokenize text using the tokenizer belonging to the FTS5 table. 11414298161Sbapt** 11415298161Sbapt** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11416298161Sbapt** This API function is used to query the FTS table for phrase iPhrase 11417298161Sbapt** of the current query. Specifically, a query equivalent to: 11418298161Sbapt** 11419298161Sbapt** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11420298161Sbapt** 11421298161Sbapt** with $p set to a phrase equivalent to the phrase iPhrase of the 11422305002Scy** current query is executed. Any column filter that applies to 11423305002Scy** phrase iPhrase of the current query is included in $p. For each 11424305002Scy** row visited, the callback function passed as the fourth argument 11425305002Scy** is invoked. The context and API objects passed to the callback 11426305002Scy** function may be used to access the properties of each matched row. 11427305002Scy** Invoking Api.xUserData() returns a copy of the pointer passed as 11428305002Scy** the third argument to pUserData. 11429298161Sbapt** 11430298161Sbapt** If the callback function returns any value other than SQLITE_OK, the 11431298161Sbapt** query is abandoned and the xQueryPhrase function returns immediately. 11432298161Sbapt** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11433298161Sbapt** Otherwise, the error code is propagated upwards. 11434298161Sbapt** 11435298161Sbapt** If the query runs to completion without incident, SQLITE_OK is returned. 11436298161Sbapt** Or, if some error occurs before the query completes or is aborted by 11437298161Sbapt** the callback, an SQLite error code is returned. 11438298161Sbapt** 11439298161Sbapt** 11440298161Sbapt** xSetAuxdata(pFts5, pAux, xDelete) 11441298161Sbapt** 11442298161Sbapt** Save the pointer passed as the second argument as the extension functions 11443298161Sbapt** "auxiliary data". The pointer may then be retrieved by the current or any 11444298161Sbapt** future invocation of the same fts5 extension function made as part of 11445347347Scy** the same MATCH query using the xGetAuxdata() API. 11446298161Sbapt** 11447298161Sbapt** Each extension function is allocated a single auxiliary data slot for 11448298161Sbapt** each FTS query (MATCH expression). If the extension function is invoked 11449298161Sbapt** more than once for a single FTS query, then all invocations share a 11450298161Sbapt** single auxiliary data context. 11451298161Sbapt** 11452298161Sbapt** If there is already an auxiliary data pointer when this function is 11453298161Sbapt** invoked, then it is replaced by the new pointer. If an xDelete callback 11454298161Sbapt** was specified along with the original pointer, it is invoked at this 11455298161Sbapt** point. 11456298161Sbapt** 11457298161Sbapt** The xDelete callback, if one is specified, is also invoked on the 11458298161Sbapt** auxiliary data pointer after the FTS5 query has finished. 11459298161Sbapt** 11460347347Scy** If an error (e.g. an OOM condition) occurs within this function, 11461298161Sbapt** the auxiliary data is set to NULL and an error code returned. If the 11462298161Sbapt** xDelete parameter was not NULL, it is invoked on the auxiliary data 11463298161Sbapt** pointer before returning. 11464298161Sbapt** 11465298161Sbapt** 11466298161Sbapt** xGetAuxdata(pFts5, bClear) 11467298161Sbapt** 11468298161Sbapt** Returns the current auxiliary data pointer for the fts5 extension 11469298161Sbapt** function. See the xSetAuxdata() method for details. 11470298161Sbapt** 11471298161Sbapt** If the bClear argument is non-zero, then the auxiliary data is cleared 11472298161Sbapt** (set to NULL) before this function returns. In this case the xDelete, 11473298161Sbapt** if any, is not invoked. 11474298161Sbapt** 11475298161Sbapt** 11476298161Sbapt** xRowCount(pFts5, pnRow) 11477298161Sbapt** 11478298161Sbapt** This function is used to retrieve the total number of rows in the table. 11479298161Sbapt** In other words, the same value that would be returned by: 11480298161Sbapt** 11481298161Sbapt** SELECT count(*) FROM ftstable; 11482298161Sbapt** 11483298161Sbapt** xPhraseFirst() 11484298161Sbapt** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11485298161Sbapt** method, to iterate through all instances of a single query phrase within 11486298161Sbapt** the current row. This is the same information as is accessible via the 11487298161Sbapt** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11488298161Sbapt** to use, this API may be faster under some circumstances. To iterate 11489298161Sbapt** through instances of phrase iPhrase, use the following code: 11490298161Sbapt** 11491298161Sbapt** Fts5PhraseIter iter; 11492298161Sbapt** int iCol, iOff; 11493298161Sbapt** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11494298161Sbapt** iCol>=0; 11495298161Sbapt** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11496298161Sbapt** ){ 11497298161Sbapt** // An instance of phrase iPhrase at offset iOff of column iCol 11498298161Sbapt** } 11499298161Sbapt** 11500298161Sbapt** The Fts5PhraseIter structure is defined above. Applications should not 11501298161Sbapt** modify this structure directly - it should only be used as shown above 11502298161Sbapt** with the xPhraseFirst() and xPhraseNext() API methods (and by 11503298161Sbapt** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11504298161Sbapt** 11505298161Sbapt** This API can be quite slow if used with an FTS5 table created with the 11506298161Sbapt** "detail=none" or "detail=column" option. If the FTS5 table is created 11507298161Sbapt** with either "detail=none" or "detail=column" and "content=" option 11508298161Sbapt** (i.e. if it is a contentless table), then this API always iterates 11509298161Sbapt** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11510298161Sbapt** 11511298161Sbapt** xPhraseNext() 11512298161Sbapt** See xPhraseFirst above. 11513298161Sbapt** 11514298161Sbapt** xPhraseFirstColumn() 11515298161Sbapt** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11516298161Sbapt** and xPhraseNext() APIs described above. The difference is that instead 11517298161Sbapt** of iterating through all instances of a phrase in the current row, these 11518298161Sbapt** APIs are used to iterate through the set of columns in the current row 11519298161Sbapt** that contain one or more instances of a specified phrase. For example: 11520298161Sbapt** 11521298161Sbapt** Fts5PhraseIter iter; 11522298161Sbapt** int iCol; 11523298161Sbapt** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11524298161Sbapt** iCol>=0; 11525298161Sbapt** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11526298161Sbapt** ){ 11527298161Sbapt** // Column iCol contains at least one instance of phrase iPhrase 11528298161Sbapt** } 11529298161Sbapt** 11530298161Sbapt** This API can be quite slow if used with an FTS5 table created with the 11531298161Sbapt** "detail=none" option. If the FTS5 table is created with either 11532298161Sbapt** "detail=none" "content=" option (i.e. if it is a contentless table), 11533298161Sbapt** then this API always iterates through an empty set (all calls to 11534298161Sbapt** xPhraseFirstColumn() set iCol to -1). 11535298161Sbapt** 11536298161Sbapt** The information accessed using this API and its companion 11537298161Sbapt** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11538298161Sbapt** (or xInst/xInstCount). The chief advantage of this API is that it is 11539298161Sbapt** significantly more efficient than those alternatives when used with 11540298161Sbapt** "detail=column" tables. 11541298161Sbapt** 11542298161Sbapt** xPhraseNextColumn() 11543298161Sbapt** See xPhraseFirstColumn above. 11544298161Sbapt*/ 11545298161Sbaptstruct Fts5ExtensionApi { 11546298161Sbapt int iVersion; /* Currently always set to 3 */ 11547298161Sbapt 11548298161Sbapt void *(*xUserData)(Fts5Context*); 11549298161Sbapt 11550298161Sbapt int (*xColumnCount)(Fts5Context*); 11551298161Sbapt int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11552298161Sbapt int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11553298161Sbapt 11554298161Sbapt int (*xTokenize)(Fts5Context*, 11555298161Sbapt const char *pText, int nText, /* Text to tokenize */ 11556298161Sbapt void *pCtx, /* Context passed to xToken() */ 11557298161Sbapt int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11558298161Sbapt ); 11559298161Sbapt 11560298161Sbapt int (*xPhraseCount)(Fts5Context*); 11561298161Sbapt int (*xPhraseSize)(Fts5Context*, int iPhrase); 11562298161Sbapt 11563298161Sbapt int (*xInstCount)(Fts5Context*, int *pnInst); 11564298161Sbapt int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11565298161Sbapt 11566298161Sbapt sqlite3_int64 (*xRowid)(Fts5Context*); 11567298161Sbapt int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11568298161Sbapt int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11569298161Sbapt 11570298161Sbapt int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11571298161Sbapt int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11572298161Sbapt ); 11573298161Sbapt int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11574298161Sbapt void *(*xGetAuxdata)(Fts5Context*, int bClear); 11575298161Sbapt 11576298161Sbapt int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11577298161Sbapt void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11578298161Sbapt 11579298161Sbapt int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11580298161Sbapt void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11581298161Sbapt}; 11582298161Sbapt 11583298161Sbapt/* 11584298161Sbapt** CUSTOM AUXILIARY FUNCTIONS 11585298161Sbapt*************************************************************************/ 11586298161Sbapt 11587298161Sbapt/************************************************************************* 11588298161Sbapt** CUSTOM TOKENIZERS 11589298161Sbapt** 11590298161Sbapt** Applications may also register custom tokenizer types. A tokenizer 11591298161Sbapt** is registered by providing fts5 with a populated instance of the 11592298161Sbapt** following structure. All structure methods must be defined, setting 11593298161Sbapt** any member of the fts5_tokenizer struct to NULL leads to undefined 11594298161Sbapt** behaviour. The structure methods are expected to function as follows: 11595298161Sbapt** 11596298161Sbapt** xCreate: 11597305002Scy** This function is used to allocate and initialize a tokenizer instance. 11598298161Sbapt** A tokenizer instance is required to actually tokenize text. 11599298161Sbapt** 11600298161Sbapt** The first argument passed to this function is a copy of the (void*) 11601298161Sbapt** pointer provided by the application when the fts5_tokenizer object 11602298161Sbapt** was registered with FTS5 (the third argument to xCreateTokenizer()). 11603298161Sbapt** The second and third arguments are an array of nul-terminated strings 11604298161Sbapt** containing the tokenizer arguments, if any, specified following the 11605298161Sbapt** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11606298161Sbapt** to create the FTS5 table. 11607298161Sbapt** 11608298161Sbapt** The final argument is an output variable. If successful, (*ppOut) 11609298161Sbapt** should be set to point to the new tokenizer handle and SQLITE_OK 11610298161Sbapt** returned. If an error occurs, some value other than SQLITE_OK should 11611298161Sbapt** be returned. In this case, fts5 assumes that the final value of *ppOut 11612298161Sbapt** is undefined. 11613298161Sbapt** 11614298161Sbapt** xDelete: 11615298161Sbapt** This function is invoked to delete a tokenizer handle previously 11616298161Sbapt** allocated using xCreate(). Fts5 guarantees that this function will 11617298161Sbapt** be invoked exactly once for each successful call to xCreate(). 11618298161Sbapt** 11619298161Sbapt** xTokenize: 11620298161Sbapt** This function is expected to tokenize the nText byte string indicated 11621298161Sbapt** by argument pText. pText may or may not be nul-terminated. The first 11622298161Sbapt** argument passed to this function is a pointer to an Fts5Tokenizer object 11623298161Sbapt** returned by an earlier call to xCreate(). 11624298161Sbapt** 11625298161Sbapt** The second argument indicates the reason that FTS5 is requesting 11626298161Sbapt** tokenization of the supplied text. This is always one of the following 11627298161Sbapt** four values: 11628298161Sbapt** 11629298161Sbapt** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11630298161Sbapt** or removed from the FTS table. The tokenizer is being invoked to 11631298161Sbapt** determine the set of tokens to add to (or delete from) the 11632298161Sbapt** FTS index. 11633298161Sbapt** 11634298161Sbapt** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11635298161Sbapt** against the FTS index. The tokenizer is being called to tokenize 11636298161Sbapt** a bareword or quoted string specified as part of the query. 11637298161Sbapt** 11638298161Sbapt** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11639298161Sbapt** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11640298161Sbapt** followed by a "*" character, indicating that the last token 11641298161Sbapt** returned by the tokenizer will be treated as a token prefix. 11642298161Sbapt** 11643298161Sbapt** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11644298161Sbapt** satisfy an fts5_api.xTokenize() request made by an auxiliary 11645298161Sbapt** function. Or an fts5_api.xColumnSize() request made by the same 11646298161Sbapt** on a columnsize=0 database. 11647298161Sbapt** </ul> 11648298161Sbapt** 11649298161Sbapt** For each token in the input string, the supplied callback xToken() must 11650298161Sbapt** be invoked. The first argument to it should be a copy of the pointer 11651298161Sbapt** passed as the second argument to xTokenize(). The third and fourth 11652298161Sbapt** arguments are a pointer to a buffer containing the token text, and the 11653298161Sbapt** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11654298161Sbapt** of the first byte of and first byte immediately following the text from 11655298161Sbapt** which the token is derived within the input. 11656298161Sbapt** 11657298161Sbapt** The second argument passed to the xToken() callback ("tflags") should 11658298161Sbapt** normally be set to 0. The exception is if the tokenizer supports 11659298161Sbapt** synonyms. In this case see the discussion below for details. 11660298161Sbapt** 11661298161Sbapt** FTS5 assumes the xToken() callback is invoked for each token in the 11662298161Sbapt** order that they occur within the input text. 11663298161Sbapt** 11664298161Sbapt** If an xToken() callback returns any value other than SQLITE_OK, then 11665298161Sbapt** the tokenization should be abandoned and the xTokenize() method should 11666298161Sbapt** immediately return a copy of the xToken() return value. Or, if the 11667298161Sbapt** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11668298161Sbapt** if an error occurs with the xTokenize() implementation itself, it 11669298161Sbapt** may abandon the tokenization and return any error code other than 11670298161Sbapt** SQLITE_OK or SQLITE_DONE. 11671298161Sbapt** 11672298161Sbapt** SYNONYM SUPPORT 11673298161Sbapt** 11674298161Sbapt** Custom tokenizers may also support synonyms. Consider a case in which a 11675298161Sbapt** user wishes to query for a phrase such as "first place". Using the 11676298161Sbapt** built-in tokenizers, the FTS5 query 'first + place' will match instances 11677298161Sbapt** of "first place" within the document set, but not alternative forms 11678298161Sbapt** such as "1st place". In some applications, it would be better to match 11679298161Sbapt** all instances of "first place" or "1st place" regardless of which form 11680298161Sbapt** the user specified in the MATCH query text. 11681298161Sbapt** 11682298161Sbapt** There are several ways to approach this in FTS5: 11683298161Sbapt** 11684298161Sbapt** <ol><li> By mapping all synonyms to a single token. In this case, the 11685298161Sbapt** In the above example, this means that the tokenizer returns the 11686298161Sbapt** same token for inputs "first" and "1st". Say that token is in 11687298161Sbapt** fact "first", so that when the user inserts the document "I won 11688298161Sbapt** 1st place" entries are added to the index for tokens "i", "won", 11689298161Sbapt** "first" and "place". If the user then queries for '1st + place', 11690298161Sbapt** the tokenizer substitutes "first" for "1st" and the query works 11691298161Sbapt** as expected. 11692298161Sbapt** 11693346442Scy** <li> By querying the index for all synonyms of each query term 11694346442Scy** separately. In this case, when tokenizing query text, the 11695346442Scy** tokenizer may provide multiple synonyms for a single term 11696346442Scy** within the document. FTS5 then queries the index for each 11697346442Scy** synonym individually. For example, faced with the query: 11698298161Sbapt** 11699298161Sbapt** <codeblock> 11700298161Sbapt** ... MATCH 'first place'</codeblock> 11701298161Sbapt** 11702298161Sbapt** the tokenizer offers both "1st" and "first" as synonyms for the 11703298161Sbapt** first token in the MATCH query and FTS5 effectively runs a query 11704298161Sbapt** similar to: 11705298161Sbapt** 11706298161Sbapt** <codeblock> 11707298161Sbapt** ... MATCH '(first OR 1st) place'</codeblock> 11708298161Sbapt** 11709298161Sbapt** except that, for the purposes of auxiliary functions, the query 11710298161Sbapt** still appears to contain just two phrases - "(first OR 1st)" 11711298161Sbapt** being treated as a single phrase. 11712298161Sbapt** 11713298161Sbapt** <li> By adding multiple synonyms for a single term to the FTS index. 11714298161Sbapt** Using this method, when tokenizing document text, the tokenizer 11715298161Sbapt** provides multiple synonyms for each token. So that when a 11716298161Sbapt** document such as "I won first place" is tokenized, entries are 11717298161Sbapt** added to the FTS index for "i", "won", "first", "1st" and 11718298161Sbapt** "place". 11719298161Sbapt** 11720298161Sbapt** This way, even if the tokenizer does not provide synonyms 11721346442Scy** when tokenizing query text (it should not - to do so would be 11722298161Sbapt** inefficient), it doesn't matter if the user queries for 11723342292Scy** 'first + place' or '1st + place', as there are entries in the 11724298161Sbapt** FTS index corresponding to both forms of the first token. 11725298161Sbapt** </ol> 11726298161Sbapt** 11727298161Sbapt** Whether it is parsing document or query text, any call to xToken that 11728298161Sbapt** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11729298161Sbapt** is considered to supply a synonym for the previous token. For example, 11730298161Sbapt** when parsing the document "I won first place", a tokenizer that supports 11731298161Sbapt** synonyms would call xToken() 5 times, as follows: 11732298161Sbapt** 11733298161Sbapt** <codeblock> 11734298161Sbapt** xToken(pCtx, 0, "i", 1, 0, 1); 11735298161Sbapt** xToken(pCtx, 0, "won", 3, 2, 5); 11736298161Sbapt** xToken(pCtx, 0, "first", 5, 6, 11); 11737298161Sbapt** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11738298161Sbapt** xToken(pCtx, 0, "place", 5, 12, 17); 11739298161Sbapt**</codeblock> 11740298161Sbapt** 11741298161Sbapt** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11742298161Sbapt** xToken() is called. Multiple synonyms may be specified for a single token 11743298161Sbapt** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11744298161Sbapt** There is no limit to the number of synonyms that may be provided for a 11745298161Sbapt** single token. 11746298161Sbapt** 11747298161Sbapt** In many cases, method (1) above is the best approach. It does not add 11748298161Sbapt** extra data to the FTS index or require FTS5 to query for multiple terms, 11749298161Sbapt** so it is efficient in terms of disk space and query speed. However, it 11750298161Sbapt** does not support prefix queries very well. If, as suggested above, the 11751342292Scy** token "first" is substituted for "1st" by the tokenizer, then the query: 11752298161Sbapt** 11753298161Sbapt** <codeblock> 11754298161Sbapt** ... MATCH '1s*'</codeblock> 11755298161Sbapt** 11756298161Sbapt** will not match documents that contain the token "1st" (as the tokenizer 11757298161Sbapt** will probably not map "1s" to any prefix of "first"). 11758298161Sbapt** 11759298161Sbapt** For full prefix support, method (3) may be preferred. In this case, 11760298161Sbapt** because the index contains entries for both "first" and "1st", prefix 11761298161Sbapt** queries such as 'fi*' or '1s*' will match correctly. However, because 11762298161Sbapt** extra entries are added to the FTS index, this method uses more space 11763298161Sbapt** within the database. 11764298161Sbapt** 11765298161Sbapt** Method (2) offers a midpoint between (1) and (3). Using this method, 11766298161Sbapt** a query such as '1s*' will match documents that contain the literal 11767298161Sbapt** token "1st", but not "first" (assuming the tokenizer is not able to 11768298161Sbapt** provide synonyms for prefixes). However, a non-prefix query like '1st' 11769298161Sbapt** will match against "1st" and "first". This method does not require 11770298161Sbapt** extra disk space, as no extra entries are added to the FTS index. 11771298161Sbapt** On the other hand, it may require more CPU cycles to run MATCH queries, 11772298161Sbapt** as separate queries of the FTS index are required for each synonym. 11773298161Sbapt** 11774298161Sbapt** When using methods (2) or (3), it is important that the tokenizer only 11775298161Sbapt** provide synonyms when tokenizing document text (method (2)) or query 11776298161Sbapt** text (method (3)), not both. Doing so will not cause any errors, but is 11777298161Sbapt** inefficient. 11778298161Sbapt*/ 11779298161Sbapttypedef struct Fts5Tokenizer Fts5Tokenizer; 11780298161Sbapttypedef struct fts5_tokenizer fts5_tokenizer; 11781298161Sbaptstruct fts5_tokenizer { 11782298161Sbapt int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11783298161Sbapt void (*xDelete)(Fts5Tokenizer*); 11784298161Sbapt int (*xTokenize)(Fts5Tokenizer*, 11785298161Sbapt void *pCtx, 11786298161Sbapt int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11787298161Sbapt const char *pText, int nText, 11788298161Sbapt int (*xToken)( 11789298161Sbapt void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11790298161Sbapt int tflags, /* Mask of FTS5_TOKEN_* flags */ 11791298161Sbapt const char *pToken, /* Pointer to buffer containing token */ 11792298161Sbapt int nToken, /* Size of token in bytes */ 11793298161Sbapt int iStart, /* Byte offset of token within input text */ 11794298161Sbapt int iEnd /* Byte offset of end of token within input text */ 11795298161Sbapt ) 11796298161Sbapt ); 11797298161Sbapt}; 11798298161Sbapt 11799298161Sbapt/* Flags that may be passed as the third argument to xTokenize() */ 11800298161Sbapt#define FTS5_TOKENIZE_QUERY 0x0001 11801298161Sbapt#define FTS5_TOKENIZE_PREFIX 0x0002 11802298161Sbapt#define FTS5_TOKENIZE_DOCUMENT 0x0004 11803298161Sbapt#define FTS5_TOKENIZE_AUX 0x0008 11804298161Sbapt 11805298161Sbapt/* Flags that may be passed by the tokenizer implementation back to FTS5 11806298161Sbapt** as the third argument to the supplied xToken callback. */ 11807298161Sbapt#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11808298161Sbapt 11809298161Sbapt/* 11810298161Sbapt** END OF CUSTOM TOKENIZERS 11811298161Sbapt*************************************************************************/ 11812298161Sbapt 11813298161Sbapt/************************************************************************* 11814298161Sbapt** FTS5 EXTENSION REGISTRATION API 11815298161Sbapt*/ 11816298161Sbapttypedef struct fts5_api fts5_api; 11817298161Sbaptstruct fts5_api { 11818298161Sbapt int iVersion; /* Currently always set to 2 */ 11819298161Sbapt 11820298161Sbapt /* Create a new tokenizer */ 11821298161Sbapt int (*xCreateTokenizer)( 11822298161Sbapt fts5_api *pApi, 11823298161Sbapt const char *zName, 11824298161Sbapt void *pContext, 11825298161Sbapt fts5_tokenizer *pTokenizer, 11826298161Sbapt void (*xDestroy)(void*) 11827298161Sbapt ); 11828298161Sbapt 11829298161Sbapt /* Find an existing tokenizer */ 11830298161Sbapt int (*xFindTokenizer)( 11831298161Sbapt fts5_api *pApi, 11832298161Sbapt const char *zName, 11833298161Sbapt void **ppContext, 11834298161Sbapt fts5_tokenizer *pTokenizer 11835298161Sbapt ); 11836298161Sbapt 11837298161Sbapt /* Create a new auxiliary function */ 11838298161Sbapt int (*xCreateFunction)( 11839298161Sbapt fts5_api *pApi, 11840298161Sbapt const char *zName, 11841298161Sbapt void *pContext, 11842298161Sbapt fts5_extension_function xFunction, 11843298161Sbapt void (*xDestroy)(void*) 11844298161Sbapt ); 11845298161Sbapt}; 11846298161Sbapt 11847298161Sbapt/* 11848298161Sbapt** END OF REGISTRATION API 11849298161Sbapt*************************************************************************/ 11850298161Sbapt 11851298161Sbapt#ifdef __cplusplus 11852298161Sbapt} /* end of the 'extern "C"' block */ 11853298161Sbapt#endif 11854298161Sbapt 11855298161Sbapt#endif /* _FTS5_H */ 11856298161Sbapt 11857305002Scy/******** End of fts5.h *********/ 11858