sqlite3.h revision 298161
1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef _SQLITE3_H_ 34#define _SQLITE3_H_ 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_STDCALL 58# define SQLITE_STDCALL 59#endif 60 61/* 62** These no-op macros are used in front of interfaces to mark those 63** interfaces as either deprecated or experimental. New applications 64** should not use deprecated interfaces - they are supported for backwards 65** compatibility only. Application writers should be aware that 66** experimental interfaces are subject to change in point releases. 67** 68** These macros used to resolve to various kinds of compiler magic that 69** would generate warning messages when they were used. But that 70** compiler magic ended up generating such a flurry of bug reports 71** that we have taken it all out and gone back to using simple 72** noop macros. 73*/ 74#define SQLITE_DEPRECATED 75#define SQLITE_EXPERIMENTAL 76 77/* 78** Ensure these symbols were not defined by some previous header file. 79*/ 80#ifdef SQLITE_VERSION 81# undef SQLITE_VERSION 82#endif 83#ifdef SQLITE_VERSION_NUMBER 84# undef SQLITE_VERSION_NUMBER 85#endif 86 87/* 88** CAPI3REF: Compile-Time Library Version Numbers 89** 90** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 91** evaluates to a string literal that is the SQLite version in the 92** format "X.Y.Z" where X is the major version number (always 3 for 93** SQLite3) and Y is the minor version number and Z is the release number.)^ 94** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 95** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 96** numbers used in [SQLITE_VERSION].)^ 97** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 98** be larger than the release from which it is derived. Either Y will 99** be held constant and Z will be incremented or else Y will be incremented 100** and Z will be reset to zero. 101** 102** Since version 3.6.18, SQLite source code has been stored in the 103** <a href="http://www.fossil-scm.org/">Fossil configuration management 104** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 105** a string which identifies a particular check-in of SQLite 106** within its configuration management system. ^The SQLITE_SOURCE_ID 107** string contains the date and time of the check-in (UTC) and an SHA1 108** hash of the entire source tree. 109** 110** See also: [sqlite3_libversion()], 111** [sqlite3_libversion_number()], [sqlite3_sourceid()], 112** [sqlite_version()] and [sqlite_source_id()]. 113*/ 114#define SQLITE_VERSION "3.12.1" 115#define SQLITE_VERSION_NUMBER 3012001 116#define SQLITE_SOURCE_ID "2016-04-08 15:09:49 fe7d3b75fe1bde41511b323925af8ae1b910bc4d" 117 118/* 119** CAPI3REF: Run-Time Library Version Numbers 120** KEYWORDS: sqlite3_version, sqlite3_sourceid 121** 122** These interfaces provide the same information as the [SQLITE_VERSION], 123** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 124** but are associated with the library instead of the header file. ^(Cautious 125** programmers might include assert() statements in their application to 126** verify that values returned by these interfaces match the macros in 127** the header, and thus ensure that the application is 128** compiled with matching library and header files. 129** 130** <blockquote><pre> 131** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 132** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 133** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 134** </pre></blockquote>)^ 135** 136** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 137** macro. ^The sqlite3_libversion() function returns a pointer to the 138** to the sqlite3_version[] string constant. The sqlite3_libversion() 139** function is provided for use in DLLs since DLL users usually do not have 140** direct access to string constants within the DLL. ^The 141** sqlite3_libversion_number() function returns an integer equal to 142** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 143** a pointer to a string constant whose value is the same as the 144** [SQLITE_SOURCE_ID] C preprocessor macro. 145** 146** See also: [sqlite_version()] and [sqlite_source_id()]. 147*/ 148SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 149SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 150SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 151SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 152 153/* 154** CAPI3REF: Run-Time Library Compilation Options Diagnostics 155** 156** ^The sqlite3_compileoption_used() function returns 0 or 1 157** indicating whether the specified option was defined at 158** compile time. ^The SQLITE_ prefix may be omitted from the 159** option name passed to sqlite3_compileoption_used(). 160** 161** ^The sqlite3_compileoption_get() function allows iterating 162** over the list of options that were defined at compile time by 163** returning the N-th compile time option string. ^If N is out of range, 164** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 165** prefix is omitted from any strings returned by 166** sqlite3_compileoption_get(). 167** 168** ^Support for the diagnostic functions sqlite3_compileoption_used() 169** and sqlite3_compileoption_get() may be omitted by specifying the 170** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 171** 172** See also: SQL functions [sqlite_compileoption_used()] and 173** [sqlite_compileoption_get()] and the [compile_options pragma]. 174*/ 175#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 176SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 177SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 178#endif 179 180/* 181** CAPI3REF: Test To See If The Library Is Threadsafe 182** 183** ^The sqlite3_threadsafe() function returns zero if and only if 184** SQLite was compiled with mutexing code omitted due to the 185** [SQLITE_THREADSAFE] compile-time option being set to 0. 186** 187** SQLite can be compiled with or without mutexes. When 188** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 189** are enabled and SQLite is threadsafe. When the 190** [SQLITE_THREADSAFE] macro is 0, 191** the mutexes are omitted. Without the mutexes, it is not safe 192** to use SQLite concurrently from more than one thread. 193** 194** Enabling mutexes incurs a measurable performance penalty. 195** So if speed is of utmost importance, it makes sense to disable 196** the mutexes. But for maximum safety, mutexes should be enabled. 197** ^The default behavior is for mutexes to be enabled. 198** 199** This interface can be used by an application to make sure that the 200** version of SQLite that it is linking against was compiled with 201** the desired setting of the [SQLITE_THREADSAFE] macro. 202** 203** This interface only reports on the compile-time mutex setting 204** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 205** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 206** can be fully or partially disabled using a call to [sqlite3_config()] 207** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 208** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 209** sqlite3_threadsafe() function shows only the compile-time setting of 210** thread safety, not any run-time changes to that setting made by 211** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 212** is unchanged by calls to sqlite3_config().)^ 213** 214** See the [threading mode] documentation for additional information. 215*/ 216SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 217 218/* 219** CAPI3REF: Database Connection Handle 220** KEYWORDS: {database connection} {database connections} 221** 222** Each open SQLite database is represented by a pointer to an instance of 223** the opaque structure named "sqlite3". It is useful to think of an sqlite3 224** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 225** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 226** and [sqlite3_close_v2()] are its destructors. There are many other 227** interfaces (such as 228** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 229** [sqlite3_busy_timeout()] to name but three) that are methods on an 230** sqlite3 object. 231*/ 232typedef struct sqlite3 sqlite3; 233 234/* 235** CAPI3REF: 64-Bit Integer Types 236** KEYWORDS: sqlite_int64 sqlite_uint64 237** 238** Because there is no cross-platform way to specify 64-bit integer types 239** SQLite includes typedefs for 64-bit signed and unsigned integers. 240** 241** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 242** The sqlite_int64 and sqlite_uint64 types are supported for backwards 243** compatibility only. 244** 245** ^The sqlite3_int64 and sqlite_int64 types can store integer values 246** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 247** sqlite3_uint64 and sqlite_uint64 types can store integer values 248** between 0 and +18446744073709551615 inclusive. 249*/ 250#ifdef SQLITE_INT64_TYPE 251 typedef SQLITE_INT64_TYPE sqlite_int64; 252 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 253#elif defined(_MSC_VER) || defined(__BORLANDC__) 254 typedef __int64 sqlite_int64; 255 typedef unsigned __int64 sqlite_uint64; 256#else 257 typedef long long int sqlite_int64; 258 typedef unsigned long long int sqlite_uint64; 259#endif 260typedef sqlite_int64 sqlite3_int64; 261typedef sqlite_uint64 sqlite3_uint64; 262 263/* 264** If compiling for a processor that lacks floating point support, 265** substitute integer for floating-point. 266*/ 267#ifdef SQLITE_OMIT_FLOATING_POINT 268# define double sqlite3_int64 269#endif 270 271/* 272** CAPI3REF: Closing A Database Connection 273** DESTRUCTOR: sqlite3 274** 275** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 276** for the [sqlite3] object. 277** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 278** the [sqlite3] object is successfully destroyed and all associated 279** resources are deallocated. 280** 281** ^If the database connection is associated with unfinalized prepared 282** statements or unfinished sqlite3_backup objects then sqlite3_close() 283** will leave the database connection open and return [SQLITE_BUSY]. 284** ^If sqlite3_close_v2() is called with unfinalized prepared statements 285** and/or unfinished sqlite3_backups, then the database connection becomes 286** an unusable "zombie" which will automatically be deallocated when the 287** last prepared statement is finalized or the last sqlite3_backup is 288** finished. The sqlite3_close_v2() interface is intended for use with 289** host languages that are garbage collected, and where the order in which 290** destructors are called is arbitrary. 291** 292** Applications should [sqlite3_finalize | finalize] all [prepared statements], 293** [sqlite3_blob_close | close] all [BLOB handles], and 294** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 295** with the [sqlite3] object prior to attempting to close the object. ^If 296** sqlite3_close_v2() is called on a [database connection] that still has 297** outstanding [prepared statements], [BLOB handles], and/or 298** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 299** of resources is deferred until all [prepared statements], [BLOB handles], 300** and [sqlite3_backup] objects are also destroyed. 301** 302** ^If an [sqlite3] object is destroyed while a transaction is open, 303** the transaction is automatically rolled back. 304** 305** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 306** must be either a NULL 307** pointer or an [sqlite3] object pointer obtained 308** from [sqlite3_open()], [sqlite3_open16()], or 309** [sqlite3_open_v2()], and not previously closed. 310** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 311** argument is a harmless no-op. 312*/ 313SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 314SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 315 316/* 317** The type for a callback function. 318** This is legacy and deprecated. It is included for historical 319** compatibility and is not documented. 320*/ 321typedef int (*sqlite3_callback)(void*,int,char**, char**); 322 323/* 324** CAPI3REF: One-Step Query Execution Interface 325** METHOD: sqlite3 326** 327** The sqlite3_exec() interface is a convenience wrapper around 328** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 329** that allows an application to run multiple statements of SQL 330** without having to use a lot of C code. 331** 332** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 333** semicolon-separate SQL statements passed into its 2nd argument, 334** in the context of the [database connection] passed in as its 1st 335** argument. ^If the callback function of the 3rd argument to 336** sqlite3_exec() is not NULL, then it is invoked for each result row 337** coming out of the evaluated SQL statements. ^The 4th argument to 338** sqlite3_exec() is relayed through to the 1st argument of each 339** callback invocation. ^If the callback pointer to sqlite3_exec() 340** is NULL, then no callback is ever invoked and result rows are 341** ignored. 342** 343** ^If an error occurs while evaluating the SQL statements passed into 344** sqlite3_exec(), then execution of the current statement stops and 345** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 346** is not NULL then any error message is written into memory obtained 347** from [sqlite3_malloc()] and passed back through the 5th parameter. 348** To avoid memory leaks, the application should invoke [sqlite3_free()] 349** on error message strings returned through the 5th parameter of 350** sqlite3_exec() after the error message string is no longer needed. 351** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 352** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 353** NULL before returning. 354** 355** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 356** routine returns SQLITE_ABORT without invoking the callback again and 357** without running any subsequent SQL statements. 358** 359** ^The 2nd argument to the sqlite3_exec() callback function is the 360** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 361** callback is an array of pointers to strings obtained as if from 362** [sqlite3_column_text()], one for each column. ^If an element of a 363** result row is NULL then the corresponding string pointer for the 364** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 365** sqlite3_exec() callback is an array of pointers to strings where each 366** entry represents the name of corresponding result column as obtained 367** from [sqlite3_column_name()]. 368** 369** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 370** to an empty string, or a pointer that contains only whitespace and/or 371** SQL comments, then no SQL statements are evaluated and the database 372** is not changed. 373** 374** Restrictions: 375** 376** <ul> 377** <li> The application must ensure that the 1st parameter to sqlite3_exec() 378** is a valid and open [database connection]. 379** <li> The application must not close the [database connection] specified by 380** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 381** <li> The application must not modify the SQL statement text passed into 382** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 383** </ul> 384*/ 385SQLITE_API int SQLITE_STDCALL sqlite3_exec( 386 sqlite3*, /* An open database */ 387 const char *sql, /* SQL to be evaluated */ 388 int (*callback)(void*,int,char**,char**), /* Callback function */ 389 void *, /* 1st argument to callback */ 390 char **errmsg /* Error msg written here */ 391); 392 393/* 394** CAPI3REF: Result Codes 395** KEYWORDS: {result code definitions} 396** 397** Many SQLite functions return an integer result code from the set shown 398** here in order to indicate success or failure. 399** 400** New error codes may be added in future versions of SQLite. 401** 402** See also: [extended result code definitions] 403*/ 404#define SQLITE_OK 0 /* Successful result */ 405/* beginning-of-error-codes */ 406#define SQLITE_ERROR 1 /* SQL error or missing database */ 407#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 408#define SQLITE_PERM 3 /* Access permission denied */ 409#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 410#define SQLITE_BUSY 5 /* The database file is locked */ 411#define SQLITE_LOCKED 6 /* A table in the database is locked */ 412#define SQLITE_NOMEM 7 /* A malloc() failed */ 413#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 414#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 415#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 416#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 417#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 418#define SQLITE_FULL 13 /* Insertion failed because database is full */ 419#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 420#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 421#define SQLITE_EMPTY 16 /* Database is empty */ 422#define SQLITE_SCHEMA 17 /* The database schema changed */ 423#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 424#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 425#define SQLITE_MISMATCH 20 /* Data type mismatch */ 426#define SQLITE_MISUSE 21 /* Library used incorrectly */ 427#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 428#define SQLITE_AUTH 23 /* Authorization denied */ 429#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 430#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 431#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 432#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 433#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 434#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 435#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 436/* end-of-error-codes */ 437 438/* 439** CAPI3REF: Extended Result Codes 440** KEYWORDS: {extended result code definitions} 441** 442** In its default configuration, SQLite API routines return one of 30 integer 443** [result codes]. However, experience has shown that many of 444** these result codes are too coarse-grained. They do not provide as 445** much information about problems as programmers might like. In an effort to 446** address this, newer versions of SQLite (version 3.3.8 and later) include 447** support for additional result codes that provide more detailed information 448** about errors. These [extended result codes] are enabled or disabled 449** on a per database connection basis using the 450** [sqlite3_extended_result_codes()] API. Or, the extended code for 451** the most recent error can be obtained using 452** [sqlite3_extended_errcode()]. 453*/ 454#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 455#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 456#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 457#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 458#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 459#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 460#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 461#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 462#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 463#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 464#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 465#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 466#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 467#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 468#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 469#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 470#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 471#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 472#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 473#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 474#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 475#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 476#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 477#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 478#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 479#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 480#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 481#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 482#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 483#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 484#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 485#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 486#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 487#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 488#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 489#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 490#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 491#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 492#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 493#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 494#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 495#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 496#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 497#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 498#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 499#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 500#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 501#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 502#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 503#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 504#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 505#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 506#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 507#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 508#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 509 510/* 511** CAPI3REF: Flags For File Open Operations 512** 513** These bit values are intended for use in the 514** 3rd parameter to the [sqlite3_open_v2()] interface and 515** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 516*/ 517#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 518#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 519#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 520#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 521#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 522#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 523#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 524#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 525#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 526#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 527#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 528#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 529#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 530#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 531#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 532#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 533#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 534#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 535#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 536#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 537 538/* Reserved: 0x00F00000 */ 539 540/* 541** CAPI3REF: Device Characteristics 542** 543** The xDeviceCharacteristics method of the [sqlite3_io_methods] 544** object returns an integer which is a vector of these 545** bit values expressing I/O characteristics of the mass storage 546** device that holds the file that the [sqlite3_io_methods] 547** refers to. 548** 549** The SQLITE_IOCAP_ATOMIC property means that all writes of 550** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 551** mean that writes of blocks that are nnn bytes in size and 552** are aligned to an address which is an integer multiple of 553** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 554** that when data is appended to a file, the data is appended 555** first then the size of the file is extended, never the other 556** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 557** information is written to disk in the same order as calls 558** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 559** after reboot following a crash or power loss, the only bytes in a 560** file that were written at the application level might have changed 561** and that adjacent bytes, even bytes within the same sector are 562** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 563** flag indicate that a file cannot be deleted when open. The 564** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 565** read-only media and cannot be changed even by processes with 566** elevated privileges. 567*/ 568#define SQLITE_IOCAP_ATOMIC 0x00000001 569#define SQLITE_IOCAP_ATOMIC512 0x00000002 570#define SQLITE_IOCAP_ATOMIC1K 0x00000004 571#define SQLITE_IOCAP_ATOMIC2K 0x00000008 572#define SQLITE_IOCAP_ATOMIC4K 0x00000010 573#define SQLITE_IOCAP_ATOMIC8K 0x00000020 574#define SQLITE_IOCAP_ATOMIC16K 0x00000040 575#define SQLITE_IOCAP_ATOMIC32K 0x00000080 576#define SQLITE_IOCAP_ATOMIC64K 0x00000100 577#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 578#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 579#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 580#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 581#define SQLITE_IOCAP_IMMUTABLE 0x00002000 582 583/* 584** CAPI3REF: File Locking Levels 585** 586** SQLite uses one of these integer values as the second 587** argument to calls it makes to the xLock() and xUnlock() methods 588** of an [sqlite3_io_methods] object. 589*/ 590#define SQLITE_LOCK_NONE 0 591#define SQLITE_LOCK_SHARED 1 592#define SQLITE_LOCK_RESERVED 2 593#define SQLITE_LOCK_PENDING 3 594#define SQLITE_LOCK_EXCLUSIVE 4 595 596/* 597** CAPI3REF: Synchronization Type Flags 598** 599** When SQLite invokes the xSync() method of an 600** [sqlite3_io_methods] object it uses a combination of 601** these integer values as the second argument. 602** 603** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 604** sync operation only needs to flush data to mass storage. Inode 605** information need not be flushed. If the lower four bits of the flag 606** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 607** If the lower four bits equal SQLITE_SYNC_FULL, that means 608** to use Mac OS X style fullsync instead of fsync(). 609** 610** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 611** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 612** settings. The [synchronous pragma] determines when calls to the 613** xSync VFS method occur and applies uniformly across all platforms. 614** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 615** energetic or rigorous or forceful the sync operations are and 616** only make a difference on Mac OSX for the default SQLite code. 617** (Third-party VFS implementations might also make the distinction 618** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 619** operating systems natively supported by SQLite, only Mac OSX 620** cares about the difference.) 621*/ 622#define SQLITE_SYNC_NORMAL 0x00002 623#define SQLITE_SYNC_FULL 0x00003 624#define SQLITE_SYNC_DATAONLY 0x00010 625 626/* 627** CAPI3REF: OS Interface Open File Handle 628** 629** An [sqlite3_file] object represents an open file in the 630** [sqlite3_vfs | OS interface layer]. Individual OS interface 631** implementations will 632** want to subclass this object by appending additional fields 633** for their own use. The pMethods entry is a pointer to an 634** [sqlite3_io_methods] object that defines methods for performing 635** I/O operations on the open file. 636*/ 637typedef struct sqlite3_file sqlite3_file; 638struct sqlite3_file { 639 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 640}; 641 642/* 643** CAPI3REF: OS Interface File Virtual Methods Object 644** 645** Every file opened by the [sqlite3_vfs.xOpen] method populates an 646** [sqlite3_file] object (or, more commonly, a subclass of the 647** [sqlite3_file] object) with a pointer to an instance of this object. 648** This object defines the methods used to perform various operations 649** against the open file represented by the [sqlite3_file] object. 650** 651** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 652** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 653** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 654** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 655** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 656** to NULL. 657** 658** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 659** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 660** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 661** flag may be ORed in to indicate that only the data of the file 662** and not its inode needs to be synced. 663** 664** The integer values to xLock() and xUnlock() are one of 665** <ul> 666** <li> [SQLITE_LOCK_NONE], 667** <li> [SQLITE_LOCK_SHARED], 668** <li> [SQLITE_LOCK_RESERVED], 669** <li> [SQLITE_LOCK_PENDING], or 670** <li> [SQLITE_LOCK_EXCLUSIVE]. 671** </ul> 672** xLock() increases the lock. xUnlock() decreases the lock. 673** The xCheckReservedLock() method checks whether any database connection, 674** either in this process or in some other process, is holding a RESERVED, 675** PENDING, or EXCLUSIVE lock on the file. It returns true 676** if such a lock exists and false otherwise. 677** 678** The xFileControl() method is a generic interface that allows custom 679** VFS implementations to directly control an open file using the 680** [sqlite3_file_control()] interface. The second "op" argument is an 681** integer opcode. The third argument is a generic pointer intended to 682** point to a structure that may contain arguments or space in which to 683** write return values. Potential uses for xFileControl() might be 684** functions to enable blocking locks with timeouts, to change the 685** locking strategy (for example to use dot-file locks), to inquire 686** about the status of a lock, or to break stale locks. The SQLite 687** core reserves all opcodes less than 100 for its own use. 688** A [file control opcodes | list of opcodes] less than 100 is available. 689** Applications that define a custom xFileControl method should use opcodes 690** greater than 100 to avoid conflicts. VFS implementations should 691** return [SQLITE_NOTFOUND] for file control opcodes that they do not 692** recognize. 693** 694** The xSectorSize() method returns the sector size of the 695** device that underlies the file. The sector size is the 696** minimum write that can be performed without disturbing 697** other bytes in the file. The xDeviceCharacteristics() 698** method returns a bit vector describing behaviors of the 699** underlying device: 700** 701** <ul> 702** <li> [SQLITE_IOCAP_ATOMIC] 703** <li> [SQLITE_IOCAP_ATOMIC512] 704** <li> [SQLITE_IOCAP_ATOMIC1K] 705** <li> [SQLITE_IOCAP_ATOMIC2K] 706** <li> [SQLITE_IOCAP_ATOMIC4K] 707** <li> [SQLITE_IOCAP_ATOMIC8K] 708** <li> [SQLITE_IOCAP_ATOMIC16K] 709** <li> [SQLITE_IOCAP_ATOMIC32K] 710** <li> [SQLITE_IOCAP_ATOMIC64K] 711** <li> [SQLITE_IOCAP_SAFE_APPEND] 712** <li> [SQLITE_IOCAP_SEQUENTIAL] 713** </ul> 714** 715** The SQLITE_IOCAP_ATOMIC property means that all writes of 716** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 717** mean that writes of blocks that are nnn bytes in size and 718** are aligned to an address which is an integer multiple of 719** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 720** that when data is appended to a file, the data is appended 721** first then the size of the file is extended, never the other 722** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 723** information is written to disk in the same order as calls 724** to xWrite(). 725** 726** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 727** in the unread portions of the buffer with zeros. A VFS that 728** fails to zero-fill short reads might seem to work. However, 729** failure to zero-fill short reads will eventually lead to 730** database corruption. 731*/ 732typedef struct sqlite3_io_methods sqlite3_io_methods; 733struct sqlite3_io_methods { 734 int iVersion; 735 int (*xClose)(sqlite3_file*); 736 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 737 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 738 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 739 int (*xSync)(sqlite3_file*, int flags); 740 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 741 int (*xLock)(sqlite3_file*, int); 742 int (*xUnlock)(sqlite3_file*, int); 743 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 744 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 745 int (*xSectorSize)(sqlite3_file*); 746 int (*xDeviceCharacteristics)(sqlite3_file*); 747 /* Methods above are valid for version 1 */ 748 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 749 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 750 void (*xShmBarrier)(sqlite3_file*); 751 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 752 /* Methods above are valid for version 2 */ 753 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 754 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 755 /* Methods above are valid for version 3 */ 756 /* Additional methods may be added in future releases */ 757}; 758 759/* 760** CAPI3REF: Standard File Control Opcodes 761** KEYWORDS: {file control opcodes} {file control opcode} 762** 763** These integer constants are opcodes for the xFileControl method 764** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 765** interface. 766** 767** <ul> 768** <li>[[SQLITE_FCNTL_LOCKSTATE]] 769** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 770** opcode causes the xFileControl method to write the current state of 771** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 772** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 773** into an integer that the pArg argument points to. This capability 774** is used during testing and is only available when the SQLITE_TEST 775** compile-time option is used. 776** 777** <li>[[SQLITE_FCNTL_SIZE_HINT]] 778** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 779** layer a hint of how large the database file will grow to be during the 780** current transaction. This hint is not guaranteed to be accurate but it 781** is often close. The underlying VFS might choose to preallocate database 782** file space based on this hint in order to help writes to the database 783** file run faster. 784** 785** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 786** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 787** extends and truncates the database file in chunks of a size specified 788** by the user. The fourth argument to [sqlite3_file_control()] should 789** point to an integer (type int) containing the new chunk-size to use 790** for the nominated database. Allocating database file space in large 791** chunks (say 1MB at a time), may reduce file-system fragmentation and 792** improve performance on some systems. 793** 794** <li>[[SQLITE_FCNTL_FILE_POINTER]] 795** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 796** to the [sqlite3_file] object associated with a particular database 797** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 798** 799** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 800** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 801** to the [sqlite3_file] object associated with the journal file (either 802** the [rollback journal] or the [write-ahead log]) for a particular database 803** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 804** 805** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 806** No longer in use. 807** 808** <li>[[SQLITE_FCNTL_SYNC]] 809** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 810** sent to the VFS immediately before the xSync method is invoked on a 811** database file descriptor. Or, if the xSync method is not invoked 812** because the user has configured SQLite with 813** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 814** of the xSync method. In most cases, the pointer argument passed with 815** this file-control is NULL. However, if the database file is being synced 816** as part of a multi-database commit, the argument points to a nul-terminated 817** string containing the transactions master-journal file name. VFSes that 818** do not need this signal should silently ignore this opcode. Applications 819** should not call [sqlite3_file_control()] with this opcode as doing so may 820** disrupt the operation of the specialized VFSes that do require it. 821** 822** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 823** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 824** and sent to the VFS after a transaction has been committed immediately 825** but before the database is unlocked. VFSes that do not need this signal 826** should silently ignore this opcode. Applications should not call 827** [sqlite3_file_control()] with this opcode as doing so may disrupt the 828** operation of the specialized VFSes that do require it. 829** 830** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 831** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 832** retry counts and intervals for certain disk I/O operations for the 833** windows [VFS] in order to provide robustness in the presence of 834** anti-virus programs. By default, the windows VFS will retry file read, 835** file write, and file delete operations up to 10 times, with a delay 836** of 25 milliseconds before the first retry and with the delay increasing 837** by an additional 25 milliseconds with each subsequent retry. This 838** opcode allows these two values (10 retries and 25 milliseconds of delay) 839** to be adjusted. The values are changed for all database connections 840** within the same process. The argument is a pointer to an array of two 841** integers where the first integer i the new retry count and the second 842** integer is the delay. If either integer is negative, then the setting 843** is not changed but instead the prior value of that setting is written 844** into the array entry, allowing the current retry settings to be 845** interrogated. The zDbName parameter is ignored. 846** 847** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 848** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 849** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 850** write ahead log and shared memory files used for transaction control 851** are automatically deleted when the latest connection to the database 852** closes. Setting persistent WAL mode causes those files to persist after 853** close. Persisting the files is useful when other processes that do not 854** have write permission on the directory containing the database file want 855** to read the database file, as the WAL and shared memory files must exist 856** in order for the database to be readable. The fourth parameter to 857** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 858** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 859** WAL mode. If the integer is -1, then it is overwritten with the current 860** WAL persistence setting. 861** 862** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 863** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 864** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 865** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 866** xDeviceCharacteristics methods. The fourth parameter to 867** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 868** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 869** mode. If the integer is -1, then it is overwritten with the current 870** zero-damage mode setting. 871** 872** <li>[[SQLITE_FCNTL_OVERWRITE]] 873** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 874** a write transaction to indicate that, unless it is rolled back for some 875** reason, the entire database file will be overwritten by the current 876** transaction. This is used by VACUUM operations. 877** 878** <li>[[SQLITE_FCNTL_VFSNAME]] 879** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 880** all [VFSes] in the VFS stack. The names are of all VFS shims and the 881** final bottom-level VFS are written into memory obtained from 882** [sqlite3_malloc()] and the result is stored in the char* variable 883** that the fourth parameter of [sqlite3_file_control()] points to. 884** The caller is responsible for freeing the memory when done. As with 885** all file-control actions, there is no guarantee that this will actually 886** do anything. Callers should initialize the char* variable to a NULL 887** pointer in case this file-control is not implemented. This file-control 888** is intended for diagnostic use only. 889** 890** <li>[[SQLITE_FCNTL_VFS_POINTER]] 891** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 892** [VFSes] currently in use. ^(The argument X in 893** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 894** of type "[sqlite3_vfs] **". This opcodes will set *X 895** to a pointer to the top-level VFS.)^ 896** ^When there are multiple VFS shims in the stack, this opcode finds the 897** upper-most shim only. 898** 899** <li>[[SQLITE_FCNTL_PRAGMA]] 900** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 901** file control is sent to the open [sqlite3_file] object corresponding 902** to the database file to which the pragma statement refers. ^The argument 903** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 904** pointers to strings (char**) in which the second element of the array 905** is the name of the pragma and the third element is the argument to the 906** pragma or NULL if the pragma has no argument. ^The handler for an 907** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 908** of the char** argument point to a string obtained from [sqlite3_mprintf()] 909** or the equivalent and that string will become the result of the pragma or 910** the error message if the pragma fails. ^If the 911** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 912** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 913** file control returns [SQLITE_OK], then the parser assumes that the 914** VFS has handled the PRAGMA itself and the parser generates a no-op 915** prepared statement if result string is NULL, or that returns a copy 916** of the result string if the string is non-NULL. 917** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 918** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 919** that the VFS encountered an error while handling the [PRAGMA] and the 920** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 921** file control occurs at the beginning of pragma statement analysis and so 922** it is able to override built-in [PRAGMA] statements. 923** 924** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 925** ^The [SQLITE_FCNTL_BUSYHANDLER] 926** file-control may be invoked by SQLite on the database file handle 927** shortly after it is opened in order to provide a custom VFS with access 928** to the connections busy-handler callback. The argument is of type (void **) 929** - an array of two (void *) values. The first (void *) actually points 930** to a function of type (int (*)(void *)). In order to invoke the connections 931** busy-handler, this function should be invoked with the second (void *) in 932** the array as the only argument. If it returns non-zero, then the operation 933** should be retried. If it returns zero, the custom VFS should abandon the 934** current operation. 935** 936** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 937** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 938** to have SQLite generate a 939** temporary filename using the same algorithm that is followed to generate 940** temporary filenames for TEMP tables and other internal uses. The 941** argument should be a char** which will be filled with the filename 942** written into memory obtained from [sqlite3_malloc()]. The caller should 943** invoke [sqlite3_free()] on the result to avoid a memory leak. 944** 945** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 946** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 947** maximum number of bytes that will be used for memory-mapped I/O. 948** The argument is a pointer to a value of type sqlite3_int64 that 949** is an advisory maximum number of bytes in the file to memory map. The 950** pointer is overwritten with the old value. The limit is not changed if 951** the value originally pointed to is negative, and so the current limit 952** can be queried by passing in a pointer to a negative number. This 953** file-control is used internally to implement [PRAGMA mmap_size]. 954** 955** <li>[[SQLITE_FCNTL_TRACE]] 956** The [SQLITE_FCNTL_TRACE] file control provides advisory information 957** to the VFS about what the higher layers of the SQLite stack are doing. 958** This file control is used by some VFS activity tracing [shims]. 959** The argument is a zero-terminated string. Higher layers in the 960** SQLite stack may generate instances of this file control if 961** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 962** 963** <li>[[SQLITE_FCNTL_HAS_MOVED]] 964** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 965** pointer to an integer and it writes a boolean into that integer depending 966** on whether or not the file has been renamed, moved, or deleted since it 967** was first opened. 968** 969** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 970** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 971** opcode causes the xFileControl method to swap the file handle with the one 972** pointed to by the pArg argument. This capability is used during testing 973** and only needs to be supported when SQLITE_TEST is defined. 974** 975** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 976** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 977** be advantageous to block on the next WAL lock if the lock is not immediately 978** available. The WAL subsystem issues this signal during rare 979** circumstances in order to fix a problem with priority inversion. 980** Applications should <em>not</em> use this file-control. 981** 982** <li>[[SQLITE_FCNTL_ZIPVFS]] 983** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 984** VFS should return SQLITE_NOTFOUND for this opcode. 985** 986** <li>[[SQLITE_FCNTL_RBU]] 987** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 988** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 989** this opcode. 990** </ul> 991*/ 992#define SQLITE_FCNTL_LOCKSTATE 1 993#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 994#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 995#define SQLITE_FCNTL_LAST_ERRNO 4 996#define SQLITE_FCNTL_SIZE_HINT 5 997#define SQLITE_FCNTL_CHUNK_SIZE 6 998#define SQLITE_FCNTL_FILE_POINTER 7 999#define SQLITE_FCNTL_SYNC_OMITTED 8 1000#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1001#define SQLITE_FCNTL_PERSIST_WAL 10 1002#define SQLITE_FCNTL_OVERWRITE 11 1003#define SQLITE_FCNTL_VFSNAME 12 1004#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1005#define SQLITE_FCNTL_PRAGMA 14 1006#define SQLITE_FCNTL_BUSYHANDLER 15 1007#define SQLITE_FCNTL_TEMPFILENAME 16 1008#define SQLITE_FCNTL_MMAP_SIZE 18 1009#define SQLITE_FCNTL_TRACE 19 1010#define SQLITE_FCNTL_HAS_MOVED 20 1011#define SQLITE_FCNTL_SYNC 21 1012#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1013#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1014#define SQLITE_FCNTL_WAL_BLOCK 24 1015#define SQLITE_FCNTL_ZIPVFS 25 1016#define SQLITE_FCNTL_RBU 26 1017#define SQLITE_FCNTL_VFS_POINTER 27 1018#define SQLITE_FCNTL_JOURNAL_POINTER 28 1019 1020/* deprecated names */ 1021#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1022#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1023#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1024 1025 1026/* 1027** CAPI3REF: Mutex Handle 1028** 1029** The mutex module within SQLite defines [sqlite3_mutex] to be an 1030** abstract type for a mutex object. The SQLite core never looks 1031** at the internal representation of an [sqlite3_mutex]. It only 1032** deals with pointers to the [sqlite3_mutex] object. 1033** 1034** Mutexes are created using [sqlite3_mutex_alloc()]. 1035*/ 1036typedef struct sqlite3_mutex sqlite3_mutex; 1037 1038/* 1039** CAPI3REF: OS Interface Object 1040** 1041** An instance of the sqlite3_vfs object defines the interface between 1042** the SQLite core and the underlying operating system. The "vfs" 1043** in the name of the object stands for "virtual file system". See 1044** the [VFS | VFS documentation] for further information. 1045** 1046** The value of the iVersion field is initially 1 but may be larger in 1047** future versions of SQLite. Additional fields may be appended to this 1048** object when the iVersion value is increased. Note that the structure 1049** of the sqlite3_vfs object changes in the transaction between 1050** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1051** modified. 1052** 1053** The szOsFile field is the size of the subclassed [sqlite3_file] 1054** structure used by this VFS. mxPathname is the maximum length of 1055** a pathname in this VFS. 1056** 1057** Registered sqlite3_vfs objects are kept on a linked list formed by 1058** the pNext pointer. The [sqlite3_vfs_register()] 1059** and [sqlite3_vfs_unregister()] interfaces manage this list 1060** in a thread-safe way. The [sqlite3_vfs_find()] interface 1061** searches the list. Neither the application code nor the VFS 1062** implementation should use the pNext pointer. 1063** 1064** The pNext field is the only field in the sqlite3_vfs 1065** structure that SQLite will ever modify. SQLite will only access 1066** or modify this field while holding a particular static mutex. 1067** The application should never modify anything within the sqlite3_vfs 1068** object once the object has been registered. 1069** 1070** The zName field holds the name of the VFS module. The name must 1071** be unique across all VFS modules. 1072** 1073** [[sqlite3_vfs.xOpen]] 1074** ^SQLite guarantees that the zFilename parameter to xOpen 1075** is either a NULL pointer or string obtained 1076** from xFullPathname() with an optional suffix added. 1077** ^If a suffix is added to the zFilename parameter, it will 1078** consist of a single "-" character followed by no more than 1079** 11 alphanumeric and/or "-" characters. 1080** ^SQLite further guarantees that 1081** the string will be valid and unchanged until xClose() is 1082** called. Because of the previous sentence, 1083** the [sqlite3_file] can safely store a pointer to the 1084** filename if it needs to remember the filename for some reason. 1085** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1086** must invent its own temporary name for the file. ^Whenever the 1087** xFilename parameter is NULL it will also be the case that the 1088** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1089** 1090** The flags argument to xOpen() includes all bits set in 1091** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1092** or [sqlite3_open16()] is used, then flags includes at least 1093** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1094** If xOpen() opens a file read-only then it sets *pOutFlags to 1095** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1096** 1097** ^(SQLite will also add one of the following flags to the xOpen() 1098** call, depending on the object being opened: 1099** 1100** <ul> 1101** <li> [SQLITE_OPEN_MAIN_DB] 1102** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1103** <li> [SQLITE_OPEN_TEMP_DB] 1104** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1105** <li> [SQLITE_OPEN_TRANSIENT_DB] 1106** <li> [SQLITE_OPEN_SUBJOURNAL] 1107** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1108** <li> [SQLITE_OPEN_WAL] 1109** </ul>)^ 1110** 1111** The file I/O implementation can use the object type flags to 1112** change the way it deals with files. For example, an application 1113** that does not care about crash recovery or rollback might make 1114** the open of a journal file a no-op. Writes to this journal would 1115** also be no-ops, and any attempt to read the journal would return 1116** SQLITE_IOERR. Or the implementation might recognize that a database 1117** file will be doing page-aligned sector reads and writes in a random 1118** order and set up its I/O subsystem accordingly. 1119** 1120** SQLite might also add one of the following flags to the xOpen method: 1121** 1122** <ul> 1123** <li> [SQLITE_OPEN_DELETEONCLOSE] 1124** <li> [SQLITE_OPEN_EXCLUSIVE] 1125** </ul> 1126** 1127** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1128** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1129** will be set for TEMP databases and their journals, transient 1130** databases, and subjournals. 1131** 1132** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1133** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1134** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1135** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1136** SQLITE_OPEN_CREATE, is used to indicate that file should always 1137** be created, and that it is an error if it already exists. 1138** It is <i>not</i> used to indicate the file should be opened 1139** for exclusive access. 1140** 1141** ^At least szOsFile bytes of memory are allocated by SQLite 1142** to hold the [sqlite3_file] structure passed as the third 1143** argument to xOpen. The xOpen method does not have to 1144** allocate the structure; it should just fill it in. Note that 1145** the xOpen method must set the sqlite3_file.pMethods to either 1146** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1147** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1148** element will be valid after xOpen returns regardless of the success 1149** or failure of the xOpen call. 1150** 1151** [[sqlite3_vfs.xAccess]] 1152** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1153** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1154** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1155** to test whether a file is at least readable. The file can be a 1156** directory. 1157** 1158** ^SQLite will always allocate at least mxPathname+1 bytes for the 1159** output buffer xFullPathname. The exact size of the output buffer 1160** is also passed as a parameter to both methods. If the output buffer 1161** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1162** handled as a fatal error by SQLite, vfs implementations should endeavor 1163** to prevent this by setting mxPathname to a sufficiently large value. 1164** 1165** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1166** interfaces are not strictly a part of the filesystem, but they are 1167** included in the VFS structure for completeness. 1168** The xRandomness() function attempts to return nBytes bytes 1169** of good-quality randomness into zOut. The return value is 1170** the actual number of bytes of randomness obtained. 1171** The xSleep() method causes the calling thread to sleep for at 1172** least the number of microseconds given. ^The xCurrentTime() 1173** method returns a Julian Day Number for the current date and time as 1174** a floating point value. 1175** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1176** Day Number multiplied by 86400000 (the number of milliseconds in 1177** a 24-hour day). 1178** ^SQLite will use the xCurrentTimeInt64() method to get the current 1179** date and time if that method is available (if iVersion is 2 or 1180** greater and the function pointer is not NULL) and will fall back 1181** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1182** 1183** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1184** are not used by the SQLite core. These optional interfaces are provided 1185** by some VFSes to facilitate testing of the VFS code. By overriding 1186** system calls with functions under its control, a test program can 1187** simulate faults and error conditions that would otherwise be difficult 1188** or impossible to induce. The set of system calls that can be overridden 1189** varies from one VFS to another, and from one version of the same VFS to the 1190** next. Applications that use these interfaces must be prepared for any 1191** or all of these interfaces to be NULL or for their behavior to change 1192** from one release to the next. Applications must not attempt to access 1193** any of these methods if the iVersion of the VFS is less than 3. 1194*/ 1195typedef struct sqlite3_vfs sqlite3_vfs; 1196typedef void (*sqlite3_syscall_ptr)(void); 1197struct sqlite3_vfs { 1198 int iVersion; /* Structure version number (currently 3) */ 1199 int szOsFile; /* Size of subclassed sqlite3_file */ 1200 int mxPathname; /* Maximum file pathname length */ 1201 sqlite3_vfs *pNext; /* Next registered VFS */ 1202 const char *zName; /* Name of this virtual file system */ 1203 void *pAppData; /* Pointer to application-specific data */ 1204 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1205 int flags, int *pOutFlags); 1206 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1207 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1208 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1209 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1210 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1211 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1212 void (*xDlClose)(sqlite3_vfs*, void*); 1213 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1214 int (*xSleep)(sqlite3_vfs*, int microseconds); 1215 int (*xCurrentTime)(sqlite3_vfs*, double*); 1216 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1217 /* 1218 ** The methods above are in version 1 of the sqlite_vfs object 1219 ** definition. Those that follow are added in version 2 or later 1220 */ 1221 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1222 /* 1223 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1224 ** Those below are for version 3 and greater. 1225 */ 1226 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1227 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1228 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1229 /* 1230 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1231 ** New fields may be appended in future versions. The iVersion 1232 ** value will increment whenever this happens. 1233 */ 1234}; 1235 1236/* 1237** CAPI3REF: Flags for the xAccess VFS method 1238** 1239** These integer constants can be used as the third parameter to 1240** the xAccess method of an [sqlite3_vfs] object. They determine 1241** what kind of permissions the xAccess method is looking for. 1242** With SQLITE_ACCESS_EXISTS, the xAccess method 1243** simply checks whether the file exists. 1244** With SQLITE_ACCESS_READWRITE, the xAccess method 1245** checks whether the named directory is both readable and writable 1246** (in other words, if files can be added, removed, and renamed within 1247** the directory). 1248** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1249** [temp_store_directory pragma], though this could change in a future 1250** release of SQLite. 1251** With SQLITE_ACCESS_READ, the xAccess method 1252** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1253** currently unused, though it might be used in a future release of 1254** SQLite. 1255*/ 1256#define SQLITE_ACCESS_EXISTS 0 1257#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1258#define SQLITE_ACCESS_READ 2 /* Unused */ 1259 1260/* 1261** CAPI3REF: Flags for the xShmLock VFS method 1262** 1263** These integer constants define the various locking operations 1264** allowed by the xShmLock method of [sqlite3_io_methods]. The 1265** following are the only legal combinations of flags to the 1266** xShmLock method: 1267** 1268** <ul> 1269** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1270** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1271** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1272** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1273** </ul> 1274** 1275** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1276** was given on the corresponding lock. 1277** 1278** The xShmLock method can transition between unlocked and SHARED or 1279** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1280** and EXCLUSIVE. 1281*/ 1282#define SQLITE_SHM_UNLOCK 1 1283#define SQLITE_SHM_LOCK 2 1284#define SQLITE_SHM_SHARED 4 1285#define SQLITE_SHM_EXCLUSIVE 8 1286 1287/* 1288** CAPI3REF: Maximum xShmLock index 1289** 1290** The xShmLock method on [sqlite3_io_methods] may use values 1291** between 0 and this upper bound as its "offset" argument. 1292** The SQLite core will never attempt to acquire or release a 1293** lock outside of this range 1294*/ 1295#define SQLITE_SHM_NLOCK 8 1296 1297 1298/* 1299** CAPI3REF: Initialize The SQLite Library 1300** 1301** ^The sqlite3_initialize() routine initializes the 1302** SQLite library. ^The sqlite3_shutdown() routine 1303** deallocates any resources that were allocated by sqlite3_initialize(). 1304** These routines are designed to aid in process initialization and 1305** shutdown on embedded systems. Workstation applications using 1306** SQLite normally do not need to invoke either of these routines. 1307** 1308** A call to sqlite3_initialize() is an "effective" call if it is 1309** the first time sqlite3_initialize() is invoked during the lifetime of 1310** the process, or if it is the first time sqlite3_initialize() is invoked 1311** following a call to sqlite3_shutdown(). ^(Only an effective call 1312** of sqlite3_initialize() does any initialization. All other calls 1313** are harmless no-ops.)^ 1314** 1315** A call to sqlite3_shutdown() is an "effective" call if it is the first 1316** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1317** an effective call to sqlite3_shutdown() does any deinitialization. 1318** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1319** 1320** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1321** is not. The sqlite3_shutdown() interface must only be called from a 1322** single thread. All open [database connections] must be closed and all 1323** other SQLite resources must be deallocated prior to invoking 1324** sqlite3_shutdown(). 1325** 1326** Among other things, ^sqlite3_initialize() will invoke 1327** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1328** will invoke sqlite3_os_end(). 1329** 1330** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1331** ^If for some reason, sqlite3_initialize() is unable to initialize 1332** the library (perhaps it is unable to allocate a needed resource such 1333** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1334** 1335** ^The sqlite3_initialize() routine is called internally by many other 1336** SQLite interfaces so that an application usually does not need to 1337** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1338** calls sqlite3_initialize() so the SQLite library will be automatically 1339** initialized when [sqlite3_open()] is called if it has not be initialized 1340** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1341** compile-time option, then the automatic calls to sqlite3_initialize() 1342** are omitted and the application must call sqlite3_initialize() directly 1343** prior to using any other SQLite interface. For maximum portability, 1344** it is recommended that applications always invoke sqlite3_initialize() 1345** directly prior to using any other SQLite interface. Future releases 1346** of SQLite may require this. In other words, the behavior exhibited 1347** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1348** default behavior in some future release of SQLite. 1349** 1350** The sqlite3_os_init() routine does operating-system specific 1351** initialization of the SQLite library. The sqlite3_os_end() 1352** routine undoes the effect of sqlite3_os_init(). Typical tasks 1353** performed by these routines include allocation or deallocation 1354** of static resources, initialization of global variables, 1355** setting up a default [sqlite3_vfs] module, or setting up 1356** a default configuration using [sqlite3_config()]. 1357** 1358** The application should never invoke either sqlite3_os_init() 1359** or sqlite3_os_end() directly. The application should only invoke 1360** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1361** interface is called automatically by sqlite3_initialize() and 1362** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1363** implementations for sqlite3_os_init() and sqlite3_os_end() 1364** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1365** When [custom builds | built for other platforms] 1366** (using the [SQLITE_OS_OTHER=1] compile-time 1367** option) the application must supply a suitable implementation for 1368** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1369** implementation of sqlite3_os_init() or sqlite3_os_end() 1370** must return [SQLITE_OK] on success and some other [error code] upon 1371** failure. 1372*/ 1373SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1374SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1375SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1376SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1377 1378/* 1379** CAPI3REF: Configuring The SQLite Library 1380** 1381** The sqlite3_config() interface is used to make global configuration 1382** changes to SQLite in order to tune SQLite to the specific needs of 1383** the application. The default configuration is recommended for most 1384** applications and so this routine is usually not necessary. It is 1385** provided to support rare applications with unusual needs. 1386** 1387** <b>The sqlite3_config() interface is not threadsafe. The application 1388** must ensure that no other SQLite interfaces are invoked by other 1389** threads while sqlite3_config() is running.</b> 1390** 1391** The sqlite3_config() interface 1392** may only be invoked prior to library initialization using 1393** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1394** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1395** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1396** Note, however, that ^sqlite3_config() can be called as part of the 1397** implementation of an application-defined [sqlite3_os_init()]. 1398** 1399** The first argument to sqlite3_config() is an integer 1400** [configuration option] that determines 1401** what property of SQLite is to be configured. Subsequent arguments 1402** vary depending on the [configuration option] 1403** in the first argument. 1404** 1405** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1406** ^If the option is unknown or SQLite is unable to set the option 1407** then this routine returns a non-zero [error code]. 1408*/ 1409SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1410 1411/* 1412** CAPI3REF: Configure database connections 1413** METHOD: sqlite3 1414** 1415** The sqlite3_db_config() interface is used to make configuration 1416** changes to a [database connection]. The interface is similar to 1417** [sqlite3_config()] except that the changes apply to a single 1418** [database connection] (specified in the first argument). 1419** 1420** The second argument to sqlite3_db_config(D,V,...) is the 1421** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1422** that indicates what aspect of the [database connection] is being configured. 1423** Subsequent arguments vary depending on the configuration verb. 1424** 1425** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1426** the call is considered successful. 1427*/ 1428SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1429 1430/* 1431** CAPI3REF: Memory Allocation Routines 1432** 1433** An instance of this object defines the interface between SQLite 1434** and low-level memory allocation routines. 1435** 1436** This object is used in only one place in the SQLite interface. 1437** A pointer to an instance of this object is the argument to 1438** [sqlite3_config()] when the configuration option is 1439** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1440** By creating an instance of this object 1441** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1442** during configuration, an application can specify an alternative 1443** memory allocation subsystem for SQLite to use for all of its 1444** dynamic memory needs. 1445** 1446** Note that SQLite comes with several [built-in memory allocators] 1447** that are perfectly adequate for the overwhelming majority of applications 1448** and that this object is only useful to a tiny minority of applications 1449** with specialized memory allocation requirements. This object is 1450** also used during testing of SQLite in order to specify an alternative 1451** memory allocator that simulates memory out-of-memory conditions in 1452** order to verify that SQLite recovers gracefully from such 1453** conditions. 1454** 1455** The xMalloc, xRealloc, and xFree methods must work like the 1456** malloc(), realloc() and free() functions from the standard C library. 1457** ^SQLite guarantees that the second argument to 1458** xRealloc is always a value returned by a prior call to xRoundup. 1459** 1460** xSize should return the allocated size of a memory allocation 1461** previously obtained from xMalloc or xRealloc. The allocated size 1462** is always at least as big as the requested size but may be larger. 1463** 1464** The xRoundup method returns what would be the allocated size of 1465** a memory allocation given a particular requested size. Most memory 1466** allocators round up memory allocations at least to the next multiple 1467** of 8. Some allocators round up to a larger multiple or to a power of 2. 1468** Every memory allocation request coming in through [sqlite3_malloc()] 1469** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1470** that causes the corresponding memory allocation to fail. 1471** 1472** The xInit method initializes the memory allocator. For example, 1473** it might allocate any require mutexes or initialize internal data 1474** structures. The xShutdown method is invoked (indirectly) by 1475** [sqlite3_shutdown()] and should deallocate any resources acquired 1476** by xInit. The pAppData pointer is used as the only parameter to 1477** xInit and xShutdown. 1478** 1479** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1480** the xInit method, so the xInit method need not be threadsafe. The 1481** xShutdown method is only called from [sqlite3_shutdown()] so it does 1482** not need to be threadsafe either. For all other methods, SQLite 1483** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1484** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1485** it is by default) and so the methods are automatically serialized. 1486** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1487** methods must be threadsafe or else make their own arrangements for 1488** serialization. 1489** 1490** SQLite will never invoke xInit() more than once without an intervening 1491** call to xShutdown(). 1492*/ 1493typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1494struct sqlite3_mem_methods { 1495 void *(*xMalloc)(int); /* Memory allocation function */ 1496 void (*xFree)(void*); /* Free a prior allocation */ 1497 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1498 int (*xSize)(void*); /* Return the size of an allocation */ 1499 int (*xRoundup)(int); /* Round up request size to allocation size */ 1500 int (*xInit)(void*); /* Initialize the memory allocator */ 1501 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1502 void *pAppData; /* Argument to xInit() and xShutdown() */ 1503}; 1504 1505/* 1506** CAPI3REF: Configuration Options 1507** KEYWORDS: {configuration option} 1508** 1509** These constants are the available integer configuration options that 1510** can be passed as the first argument to the [sqlite3_config()] interface. 1511** 1512** New configuration options may be added in future releases of SQLite. 1513** Existing configuration options might be discontinued. Applications 1514** should check the return code from [sqlite3_config()] to make sure that 1515** the call worked. The [sqlite3_config()] interface will return a 1516** non-zero [error code] if a discontinued or unsupported configuration option 1517** is invoked. 1518** 1519** <dl> 1520** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1521** <dd>There are no arguments to this option. ^This option sets the 1522** [threading mode] to Single-thread. In other words, it disables 1523** all mutexing and puts SQLite into a mode where it can only be used 1524** by a single thread. ^If SQLite is compiled with 1525** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1526** it is not possible to change the [threading mode] from its default 1527** value of Single-thread and so [sqlite3_config()] will return 1528** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1529** configuration option.</dd> 1530** 1531** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1532** <dd>There are no arguments to this option. ^This option sets the 1533** [threading mode] to Multi-thread. In other words, it disables 1534** mutexing on [database connection] and [prepared statement] objects. 1535** The application is responsible for serializing access to 1536** [database connections] and [prepared statements]. But other mutexes 1537** are enabled so that SQLite will be safe to use in a multi-threaded 1538** environment as long as no two threads attempt to use the same 1539** [database connection] at the same time. ^If SQLite is compiled with 1540** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1541** it is not possible to set the Multi-thread [threading mode] and 1542** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1543** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1544** 1545** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1546** <dd>There are no arguments to this option. ^This option sets the 1547** [threading mode] to Serialized. In other words, this option enables 1548** all mutexes including the recursive 1549** mutexes on [database connection] and [prepared statement] objects. 1550** In this mode (which is the default when SQLite is compiled with 1551** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1552** to [database connections] and [prepared statements] so that the 1553** application is free to use the same [database connection] or the 1554** same [prepared statement] in different threads at the same time. 1555** ^If SQLite is compiled with 1556** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1557** it is not possible to set the Serialized [threading mode] and 1558** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1559** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1560** 1561** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1562** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1563** a pointer to an instance of the [sqlite3_mem_methods] structure. 1564** The argument specifies 1565** alternative low-level memory allocation routines to be used in place of 1566** the memory allocation routines built into SQLite.)^ ^SQLite makes 1567** its own private copy of the content of the [sqlite3_mem_methods] structure 1568** before the [sqlite3_config()] call returns.</dd> 1569** 1570** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1571** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1572** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1573** The [sqlite3_mem_methods] 1574** structure is filled with the currently defined memory allocation routines.)^ 1575** This option can be used to overload the default memory allocation 1576** routines with a wrapper that simulations memory allocation failure or 1577** tracks memory usage, for example. </dd> 1578** 1579** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1580** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1581** interpreted as a boolean, which enables or disables the collection of 1582** memory allocation statistics. ^(When memory allocation statistics are 1583** disabled, the following SQLite interfaces become non-operational: 1584** <ul> 1585** <li> [sqlite3_memory_used()] 1586** <li> [sqlite3_memory_highwater()] 1587** <li> [sqlite3_soft_heap_limit64()] 1588** <li> [sqlite3_status64()] 1589** </ul>)^ 1590** ^Memory allocation statistics are enabled by default unless SQLite is 1591** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1592** allocation statistics are disabled by default. 1593** </dd> 1594** 1595** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1596** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1597** that SQLite can use for scratch memory. ^(There are three arguments 1598** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1599** aligned memory buffer from which the scratch allocations will be 1600** drawn, the size of each scratch allocation (sz), 1601** and the maximum number of scratch allocations (N).)^ 1602** The first argument must be a pointer to an 8-byte aligned buffer 1603** of at least sz*N bytes of memory. 1604** ^SQLite will not use more than one scratch buffers per thread. 1605** ^SQLite will never request a scratch buffer that is more than 6 1606** times the database page size. 1607** ^If SQLite needs needs additional 1608** scratch memory beyond what is provided by this configuration option, then 1609** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1610** ^When the application provides any amount of scratch memory using 1611** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1612** [sqlite3_malloc|heap allocations]. 1613** This can help [Robson proof|prevent memory allocation failures] due to heap 1614** fragmentation in low-memory embedded systems. 1615** </dd> 1616** 1617** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1618** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1619** that SQLite can use for the database page cache with the default page 1620** cache implementation. 1621** This configuration option is a no-op if an application-define page 1622** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1623** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1624** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1625** and the number of cache lines (N). 1626** The sz argument should be the size of the largest database page 1627** (a power of two between 512 and 65536) plus some extra bytes for each 1628** page header. ^The number of extra bytes needed by the page header 1629** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1630** ^It is harmless, apart from the wasted memory, 1631** for the sz parameter to be larger than necessary. The pMem 1632** argument must be either a NULL pointer or a pointer to an 8-byte 1633** aligned block of memory of at least sz*N bytes, otherwise 1634** subsequent behavior is undefined. 1635** ^When pMem is not NULL, SQLite will strive to use the memory provided 1636** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1637** a page cache line is larger than sz bytes or if all of the pMem buffer 1638** is exhausted. 1639** ^If pMem is NULL and N is non-zero, then each database connection 1640** does an initial bulk allocation for page cache memory 1641** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1642** of -1024*N bytes if N is negative, . ^If additional 1643** page cache memory is needed beyond what is provided by the initial 1644** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1645** additional cache line. </dd> 1646** 1647** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1648** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1649** that SQLite will use for all of its dynamic memory allocation needs 1650** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1651** [SQLITE_CONFIG_PAGECACHE]. 1652** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1653** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1654** [SQLITE_ERROR] if invoked otherwise. 1655** ^There are three arguments to SQLITE_CONFIG_HEAP: 1656** An 8-byte aligned pointer to the memory, 1657** the number of bytes in the memory buffer, and the minimum allocation size. 1658** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1659** to using its default memory allocator (the system malloc() implementation), 1660** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1661** memory pointer is not NULL then the alternative memory 1662** allocator is engaged to handle all of SQLites memory allocation needs. 1663** The first pointer (the memory pointer) must be aligned to an 8-byte 1664** boundary or subsequent behavior of SQLite will be undefined. 1665** The minimum allocation size is capped at 2**12. Reasonable values 1666** for the minimum allocation size are 2**5 through 2**8.</dd> 1667** 1668** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1669** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1670** pointer to an instance of the [sqlite3_mutex_methods] structure. 1671** The argument specifies alternative low-level mutex routines to be used 1672** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1673** the content of the [sqlite3_mutex_methods] structure before the call to 1674** [sqlite3_config()] returns. ^If SQLite is compiled with 1675** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1676** the entire mutexing subsystem is omitted from the build and hence calls to 1677** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1678** return [SQLITE_ERROR].</dd> 1679** 1680** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1681** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1682** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1683** [sqlite3_mutex_methods] 1684** structure is filled with the currently defined mutex routines.)^ 1685** This option can be used to overload the default mutex allocation 1686** routines with a wrapper used to track mutex usage for performance 1687** profiling or testing, for example. ^If SQLite is compiled with 1688** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1689** the entire mutexing subsystem is omitted from the build and hence calls to 1690** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1691** return [SQLITE_ERROR].</dd> 1692** 1693** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1694** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1695** the default size of lookaside memory on each [database connection]. 1696** The first argument is the 1697** size of each lookaside buffer slot and the second is the number of 1698** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1699** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1700** option to [sqlite3_db_config()] can be used to change the lookaside 1701** configuration on individual connections.)^ </dd> 1702** 1703** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1704** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1705** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1706** the interface to a custom page cache implementation.)^ 1707** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1708** 1709** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1710** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1711** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1712** the current page cache implementation into that object.)^ </dd> 1713** 1714** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1715** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1716** global [error log]. 1717** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1718** function with a call signature of void(*)(void*,int,const char*), 1719** and a pointer to void. ^If the function pointer is not NULL, it is 1720** invoked by [sqlite3_log()] to process each logging event. ^If the 1721** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1722** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1723** passed through as the first parameter to the application-defined logger 1724** function whenever that function is invoked. ^The second parameter to 1725** the logger function is a copy of the first parameter to the corresponding 1726** [sqlite3_log()] call and is intended to be a [result code] or an 1727** [extended result code]. ^The third parameter passed to the logger is 1728** log message after formatting via [sqlite3_snprintf()]. 1729** The SQLite logging interface is not reentrant; the logger function 1730** supplied by the application must not invoke any SQLite interface. 1731** In a multi-threaded application, the application-defined logger 1732** function must be threadsafe. </dd> 1733** 1734** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1735** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1736** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1737** then URI handling is globally disabled.)^ ^If URI handling is globally 1738** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1739** [sqlite3_open16()] or 1740** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1741** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1742** connection is opened. ^If it is globally disabled, filenames are 1743** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1744** database connection is opened. ^(By default, URI handling is globally 1745** disabled. The default value may be changed by compiling with the 1746** [SQLITE_USE_URI] symbol defined.)^ 1747** 1748** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1749** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1750** argument which is interpreted as a boolean in order to enable or disable 1751** the use of covering indices for full table scans in the query optimizer. 1752** ^The default setting is determined 1753** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1754** if that compile-time option is omitted. 1755** The ability to disable the use of covering indices for full table scans 1756** is because some incorrectly coded legacy applications might malfunction 1757** when the optimization is enabled. Providing the ability to 1758** disable the optimization allows the older, buggy application code to work 1759** without change even with newer versions of SQLite. 1760** 1761** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1762** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1763** <dd> These options are obsolete and should not be used by new code. 1764** They are retained for backwards compatibility but are now no-ops. 1765** </dd> 1766** 1767** [[SQLITE_CONFIG_SQLLOG]] 1768** <dt>SQLITE_CONFIG_SQLLOG 1769** <dd>This option is only available if sqlite is compiled with the 1770** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1771** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1772** The second should be of type (void*). The callback is invoked by the library 1773** in three separate circumstances, identified by the value passed as the 1774** fourth parameter. If the fourth parameter is 0, then the database connection 1775** passed as the second argument has just been opened. The third argument 1776** points to a buffer containing the name of the main database file. If the 1777** fourth parameter is 1, then the SQL statement that the third parameter 1778** points to has just been executed. Or, if the fourth parameter is 2, then 1779** the connection being passed as the second parameter is being closed. The 1780** third parameter is passed NULL In this case. An example of using this 1781** configuration option can be seen in the "test_sqllog.c" source file in 1782** the canonical SQLite source tree.</dd> 1783** 1784** [[SQLITE_CONFIG_MMAP_SIZE]] 1785** <dt>SQLITE_CONFIG_MMAP_SIZE 1786** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1787** that are the default mmap size limit (the default setting for 1788** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1789** ^The default setting can be overridden by each database connection using 1790** either the [PRAGMA mmap_size] command, or by using the 1791** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1792** will be silently truncated if necessary so that it does not exceed the 1793** compile-time maximum mmap size set by the 1794** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1795** ^If either argument to this option is negative, then that argument is 1796** changed to its compile-time default. 1797** 1798** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1799** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1800** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1801** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1802** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1803** that specifies the maximum size of the created heap. 1804** 1805** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1806** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1807** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1808** is a pointer to an integer and writes into that integer the number of extra 1809** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1810** The amount of extra space required can change depending on the compiler, 1811** target platform, and SQLite version. 1812** 1813** [[SQLITE_CONFIG_PMASZ]] 1814** <dt>SQLITE_CONFIG_PMASZ 1815** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1816** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1817** sorter to that integer. The default minimum PMA Size is set by the 1818** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1819** to help with sort operations when multithreaded sorting 1820** is enabled (using the [PRAGMA threads] command) and the amount of content 1821** to be sorted exceeds the page size times the minimum of the 1822** [PRAGMA cache_size] setting and this value. 1823** 1824** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1825** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1826** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1827** becomes the [statement journal] spill-to-disk threshold. 1828** [Statement journals] are held in memory until their size (in bytes) 1829** exceeds this threshold, at which point they are written to disk. 1830** Or if the threshold is -1, statement journals are always held 1831** exclusively in memory. 1832** Since many statement journals never become large, setting the spill 1833** threshold to a value such as 64KiB can greatly reduce the amount of 1834** I/O required to support statement rollback. 1835** The default value for this setting is controlled by the 1836** [SQLITE_STMTJRNL_SPILL] compile-time option. 1837** </dl> 1838*/ 1839#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1840#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1841#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1842#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1843#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1844#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1845#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1846#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1847#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1848#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1849#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1850/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1851#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1852#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1853#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1854#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1855#define SQLITE_CONFIG_URI 17 /* int */ 1856#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1857#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1858#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1859#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1860#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1861#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1862#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1863#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1864#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1865 1866/* 1867** CAPI3REF: Database Connection Configuration Options 1868** 1869** These constants are the available integer configuration options that 1870** can be passed as the second argument to the [sqlite3_db_config()] interface. 1871** 1872** New configuration options may be added in future releases of SQLite. 1873** Existing configuration options might be discontinued. Applications 1874** should check the return code from [sqlite3_db_config()] to make sure that 1875** the call worked. ^The [sqlite3_db_config()] interface will return a 1876** non-zero [error code] if a discontinued or unsupported configuration option 1877** is invoked. 1878** 1879** <dl> 1880** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1881** <dd> ^This option takes three additional arguments that determine the 1882** [lookaside memory allocator] configuration for the [database connection]. 1883** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1884** pointer to a memory buffer to use for lookaside memory. 1885** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1886** may be NULL in which case SQLite will allocate the 1887** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1888** size of each lookaside buffer slot. ^The third argument is the number of 1889** slots. The size of the buffer in the first argument must be greater than 1890** or equal to the product of the second and third arguments. The buffer 1891** must be aligned to an 8-byte boundary. ^If the second argument to 1892** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1893** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1894** configuration for a database connection can only be changed when that 1895** connection is not currently using lookaside memory, or in other words 1896** when the "current value" returned by 1897** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1898** Any attempt to change the lookaside memory configuration when lookaside 1899** memory is in use leaves the configuration unchanged and returns 1900** [SQLITE_BUSY].)^</dd> 1901** 1902** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1903** <dd> ^This option is used to enable or disable the enforcement of 1904** [foreign key constraints]. There should be two additional arguments. 1905** The first argument is an integer which is 0 to disable FK enforcement, 1906** positive to enable FK enforcement or negative to leave FK enforcement 1907** unchanged. The second parameter is a pointer to an integer into which 1908** is written 0 or 1 to indicate whether FK enforcement is off or on 1909** following this call. The second parameter may be a NULL pointer, in 1910** which case the FK enforcement setting is not reported back. </dd> 1911** 1912** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1913** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1914** There should be two additional arguments. 1915** The first argument is an integer which is 0 to disable triggers, 1916** positive to enable triggers or negative to leave the setting unchanged. 1917** The second parameter is a pointer to an integer into which 1918** is written 0 or 1 to indicate whether triggers are disabled or enabled 1919** following this call. The second parameter may be a NULL pointer, in 1920** which case the trigger setting is not reported back. </dd> 1921** 1922** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1923** <dd> ^This option is used to enable or disable the two-argument 1924** version of the [fts3_tokenizer()] function which is part of the 1925** [FTS3] full-text search engine extension. 1926** There should be two additional arguments. 1927** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1928** positive to enable fts3_tokenizer() or negative to leave the setting 1929** unchanged. 1930** The second parameter is a pointer to an integer into which 1931** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1932** following this call. The second parameter may be a NULL pointer, in 1933** which case the new setting is not reported back. </dd> 1934** 1935** </dl> 1936*/ 1937#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1938#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1939#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1940#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 1941 1942 1943/* 1944** CAPI3REF: Enable Or Disable Extended Result Codes 1945** METHOD: sqlite3 1946** 1947** ^The sqlite3_extended_result_codes() routine enables or disables the 1948** [extended result codes] feature of SQLite. ^The extended result 1949** codes are disabled by default for historical compatibility. 1950*/ 1951SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1952 1953/* 1954** CAPI3REF: Last Insert Rowid 1955** METHOD: sqlite3 1956** 1957** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1958** has a unique 64-bit signed 1959** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1960** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1961** names are not also used by explicitly declared columns. ^If 1962** the table has a column of type [INTEGER PRIMARY KEY] then that column 1963** is another alias for the rowid. 1964** 1965** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1966** most recent successful [INSERT] into a rowid table or [virtual table] 1967** on database connection D. 1968** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1969** ^If no successful [INSERT]s into rowid tables 1970** have ever occurred on the database connection D, 1971** then sqlite3_last_insert_rowid(D) returns zero. 1972** 1973** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1974** method, then this routine will return the [rowid] of the inserted 1975** row as long as the trigger or virtual table method is running. 1976** But once the trigger or virtual table method ends, the value returned 1977** by this routine reverts to what it was before the trigger or virtual 1978** table method began.)^ 1979** 1980** ^An [INSERT] that fails due to a constraint violation is not a 1981** successful [INSERT] and does not change the value returned by this 1982** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1983** and INSERT OR ABORT make no changes to the return value of this 1984** routine when their insertion fails. ^(When INSERT OR REPLACE 1985** encounters a constraint violation, it does not fail. The 1986** INSERT continues to completion after deleting rows that caused 1987** the constraint problem so INSERT OR REPLACE will always change 1988** the return value of this interface.)^ 1989** 1990** ^For the purposes of this routine, an [INSERT] is considered to 1991** be successful even if it is subsequently rolled back. 1992** 1993** This function is accessible to SQL statements via the 1994** [last_insert_rowid() SQL function]. 1995** 1996** If a separate thread performs a new [INSERT] on the same 1997** database connection while the [sqlite3_last_insert_rowid()] 1998** function is running and thus changes the last insert [rowid], 1999** then the value returned by [sqlite3_last_insert_rowid()] is 2000** unpredictable and might not equal either the old or the new 2001** last insert [rowid]. 2002*/ 2003SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 2004 2005/* 2006** CAPI3REF: Count The Number Of Rows Modified 2007** METHOD: sqlite3 2008** 2009** ^This function returns the number of rows modified, inserted or 2010** deleted by the most recently completed INSERT, UPDATE or DELETE 2011** statement on the database connection specified by the only parameter. 2012** ^Executing any other type of SQL statement does not modify the value 2013** returned by this function. 2014** 2015** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2016** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2017** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2018** 2019** Changes to a view that are intercepted by 2020** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2021** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2022** DELETE statement run on a view is always zero. Only changes made to real 2023** tables are counted. 2024** 2025** Things are more complicated if the sqlite3_changes() function is 2026** executed while a trigger program is running. This may happen if the 2027** program uses the [changes() SQL function], or if some other callback 2028** function invokes sqlite3_changes() directly. Essentially: 2029** 2030** <ul> 2031** <li> ^(Before entering a trigger program the value returned by 2032** sqlite3_changes() function is saved. After the trigger program 2033** has finished, the original value is restored.)^ 2034** 2035** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2036** statement sets the value returned by sqlite3_changes() 2037** upon completion as normal. Of course, this value will not include 2038** any changes performed by sub-triggers, as the sqlite3_changes() 2039** value will be saved and restored after each sub-trigger has run.)^ 2040** </ul> 2041** 2042** ^This means that if the changes() SQL function (or similar) is used 2043** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2044** returns the value as set when the calling statement began executing. 2045** ^If it is used by the second or subsequent such statement within a trigger 2046** program, the value returned reflects the number of rows modified by the 2047** previous INSERT, UPDATE or DELETE statement within the same trigger. 2048** 2049** See also the [sqlite3_total_changes()] interface, the 2050** [count_changes pragma], and the [changes() SQL function]. 2051** 2052** If a separate thread makes changes on the same database connection 2053** while [sqlite3_changes()] is running then the value returned 2054** is unpredictable and not meaningful. 2055*/ 2056SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 2057 2058/* 2059** CAPI3REF: Total Number Of Rows Modified 2060** METHOD: sqlite3 2061** 2062** ^This function returns the total number of rows inserted, modified or 2063** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2064** since the database connection was opened, including those executed as 2065** part of trigger programs. ^Executing any other type of SQL statement 2066** does not affect the value returned by sqlite3_total_changes(). 2067** 2068** ^Changes made as part of [foreign key actions] are included in the 2069** count, but those made as part of REPLACE constraint resolution are 2070** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2071** are not counted. 2072** 2073** See also the [sqlite3_changes()] interface, the 2074** [count_changes pragma], and the [total_changes() SQL function]. 2075** 2076** If a separate thread makes changes on the same database connection 2077** while [sqlite3_total_changes()] is running then the value 2078** returned is unpredictable and not meaningful. 2079*/ 2080SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2081 2082/* 2083** CAPI3REF: Interrupt A Long-Running Query 2084** METHOD: sqlite3 2085** 2086** ^This function causes any pending database operation to abort and 2087** return at its earliest opportunity. This routine is typically 2088** called in response to a user action such as pressing "Cancel" 2089** or Ctrl-C where the user wants a long query operation to halt 2090** immediately. 2091** 2092** ^It is safe to call this routine from a thread different from the 2093** thread that is currently running the database operation. But it 2094** is not safe to call this routine with a [database connection] that 2095** is closed or might close before sqlite3_interrupt() returns. 2096** 2097** ^If an SQL operation is very nearly finished at the time when 2098** sqlite3_interrupt() is called, then it might not have an opportunity 2099** to be interrupted and might continue to completion. 2100** 2101** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2102** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2103** that is inside an explicit transaction, then the entire transaction 2104** will be rolled back automatically. 2105** 2106** ^The sqlite3_interrupt(D) call is in effect until all currently running 2107** SQL statements on [database connection] D complete. ^Any new SQL statements 2108** that are started after the sqlite3_interrupt() call and before the 2109** running statements reaches zero are interrupted as if they had been 2110** running prior to the sqlite3_interrupt() call. ^New SQL statements 2111** that are started after the running statement count reaches zero are 2112** not effected by the sqlite3_interrupt(). 2113** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2114** SQL statements is a no-op and has no effect on SQL statements 2115** that are started after the sqlite3_interrupt() call returns. 2116** 2117** If the database connection closes while [sqlite3_interrupt()] 2118** is running then bad things will likely happen. 2119*/ 2120SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2121 2122/* 2123** CAPI3REF: Determine If An SQL Statement Is Complete 2124** 2125** These routines are useful during command-line input to determine if the 2126** currently entered text seems to form a complete SQL statement or 2127** if additional input is needed before sending the text into 2128** SQLite for parsing. ^These routines return 1 if the input string 2129** appears to be a complete SQL statement. ^A statement is judged to be 2130** complete if it ends with a semicolon token and is not a prefix of a 2131** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2132** string literals or quoted identifier names or comments are not 2133** independent tokens (they are part of the token in which they are 2134** embedded) and thus do not count as a statement terminator. ^Whitespace 2135** and comments that follow the final semicolon are ignored. 2136** 2137** ^These routines return 0 if the statement is incomplete. ^If a 2138** memory allocation fails, then SQLITE_NOMEM is returned. 2139** 2140** ^These routines do not parse the SQL statements thus 2141** will not detect syntactically incorrect SQL. 2142** 2143** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2144** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2145** automatically by sqlite3_complete16(). If that initialization fails, 2146** then the return value from sqlite3_complete16() will be non-zero 2147** regardless of whether or not the input SQL is complete.)^ 2148** 2149** The input to [sqlite3_complete()] must be a zero-terminated 2150** UTF-8 string. 2151** 2152** The input to [sqlite3_complete16()] must be a zero-terminated 2153** UTF-16 string in native byte order. 2154*/ 2155SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2156SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2157 2158/* 2159** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2160** KEYWORDS: {busy-handler callback} {busy handler} 2161** METHOD: sqlite3 2162** 2163** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2164** that might be invoked with argument P whenever 2165** an attempt is made to access a database table associated with 2166** [database connection] D when another thread 2167** or process has the table locked. 2168** The sqlite3_busy_handler() interface is used to implement 2169** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2170** 2171** ^If the busy callback is NULL, then [SQLITE_BUSY] 2172** is returned immediately upon encountering the lock. ^If the busy callback 2173** is not NULL, then the callback might be invoked with two arguments. 2174** 2175** ^The first argument to the busy handler is a copy of the void* pointer which 2176** is the third argument to sqlite3_busy_handler(). ^The second argument to 2177** the busy handler callback is the number of times that the busy handler has 2178** been invoked previously for the same locking event. ^If the 2179** busy callback returns 0, then no additional attempts are made to 2180** access the database and [SQLITE_BUSY] is returned 2181** to the application. 2182** ^If the callback returns non-zero, then another attempt 2183** is made to access the database and the cycle repeats. 2184** 2185** The presence of a busy handler does not guarantee that it will be invoked 2186** when there is lock contention. ^If SQLite determines that invoking the busy 2187** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2188** to the application instead of invoking the 2189** busy handler. 2190** Consider a scenario where one process is holding a read lock that 2191** it is trying to promote to a reserved lock and 2192** a second process is holding a reserved lock that it is trying 2193** to promote to an exclusive lock. The first process cannot proceed 2194** because it is blocked by the second and the second process cannot 2195** proceed because it is blocked by the first. If both processes 2196** invoke the busy handlers, neither will make any progress. Therefore, 2197** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2198** will induce the first process to release its read lock and allow 2199** the second process to proceed. 2200** 2201** ^The default busy callback is NULL. 2202** 2203** ^(There can only be a single busy handler defined for each 2204** [database connection]. Setting a new busy handler clears any 2205** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2206** or evaluating [PRAGMA busy_timeout=N] will change the 2207** busy handler and thus clear any previously set busy handler. 2208** 2209** The busy callback should not take any actions which modify the 2210** database connection that invoked the busy handler. In other words, 2211** the busy handler is not reentrant. Any such actions 2212** result in undefined behavior. 2213** 2214** A busy handler must not close the database connection 2215** or [prepared statement] that invoked the busy handler. 2216*/ 2217SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2218 2219/* 2220** CAPI3REF: Set A Busy Timeout 2221** METHOD: sqlite3 2222** 2223** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2224** for a specified amount of time when a table is locked. ^The handler 2225** will sleep multiple times until at least "ms" milliseconds of sleeping 2226** have accumulated. ^After at least "ms" milliseconds of sleeping, 2227** the handler returns 0 which causes [sqlite3_step()] to return 2228** [SQLITE_BUSY]. 2229** 2230** ^Calling this routine with an argument less than or equal to zero 2231** turns off all busy handlers. 2232** 2233** ^(There can only be a single busy handler for a particular 2234** [database connection] at any given moment. If another busy handler 2235** was defined (using [sqlite3_busy_handler()]) prior to calling 2236** this routine, that other busy handler is cleared.)^ 2237** 2238** See also: [PRAGMA busy_timeout] 2239*/ 2240SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2241 2242/* 2243** CAPI3REF: Convenience Routines For Running Queries 2244** METHOD: sqlite3 2245** 2246** This is a legacy interface that is preserved for backwards compatibility. 2247** Use of this interface is not recommended. 2248** 2249** Definition: A <b>result table</b> is memory data structure created by the 2250** [sqlite3_get_table()] interface. A result table records the 2251** complete query results from one or more queries. 2252** 2253** The table conceptually has a number of rows and columns. But 2254** these numbers are not part of the result table itself. These 2255** numbers are obtained separately. Let N be the number of rows 2256** and M be the number of columns. 2257** 2258** A result table is an array of pointers to zero-terminated UTF-8 strings. 2259** There are (N+1)*M elements in the array. The first M pointers point 2260** to zero-terminated strings that contain the names of the columns. 2261** The remaining entries all point to query results. NULL values result 2262** in NULL pointers. All other values are in their UTF-8 zero-terminated 2263** string representation as returned by [sqlite3_column_text()]. 2264** 2265** A result table might consist of one or more memory allocations. 2266** It is not safe to pass a result table directly to [sqlite3_free()]. 2267** A result table should be deallocated using [sqlite3_free_table()]. 2268** 2269** ^(As an example of the result table format, suppose a query result 2270** is as follows: 2271** 2272** <blockquote><pre> 2273** Name | Age 2274** ----------------------- 2275** Alice | 43 2276** Bob | 28 2277** Cindy | 21 2278** </pre></blockquote> 2279** 2280** There are two column (M==2) and three rows (N==3). Thus the 2281** result table has 8 entries. Suppose the result table is stored 2282** in an array names azResult. Then azResult holds this content: 2283** 2284** <blockquote><pre> 2285** azResult[0] = "Name"; 2286** azResult[1] = "Age"; 2287** azResult[2] = "Alice"; 2288** azResult[3] = "43"; 2289** azResult[4] = "Bob"; 2290** azResult[5] = "28"; 2291** azResult[6] = "Cindy"; 2292** azResult[7] = "21"; 2293** </pre></blockquote>)^ 2294** 2295** ^The sqlite3_get_table() function evaluates one or more 2296** semicolon-separated SQL statements in the zero-terminated UTF-8 2297** string of its 2nd parameter and returns a result table to the 2298** pointer given in its 3rd parameter. 2299** 2300** After the application has finished with the result from sqlite3_get_table(), 2301** it must pass the result table pointer to sqlite3_free_table() in order to 2302** release the memory that was malloced. Because of the way the 2303** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2304** function must not try to call [sqlite3_free()] directly. Only 2305** [sqlite3_free_table()] is able to release the memory properly and safely. 2306** 2307** The sqlite3_get_table() interface is implemented as a wrapper around 2308** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2309** to any internal data structures of SQLite. It uses only the public 2310** interface defined here. As a consequence, errors that occur in the 2311** wrapper layer outside of the internal [sqlite3_exec()] call are not 2312** reflected in subsequent calls to [sqlite3_errcode()] or 2313** [sqlite3_errmsg()]. 2314*/ 2315SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2316 sqlite3 *db, /* An open database */ 2317 const char *zSql, /* SQL to be evaluated */ 2318 char ***pazResult, /* Results of the query */ 2319 int *pnRow, /* Number of result rows written here */ 2320 int *pnColumn, /* Number of result columns written here */ 2321 char **pzErrmsg /* Error msg written here */ 2322); 2323SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2324 2325/* 2326** CAPI3REF: Formatted String Printing Functions 2327** 2328** These routines are work-alikes of the "printf()" family of functions 2329** from the standard C library. 2330** These routines understand most of the common K&R formatting options, 2331** plus some additional non-standard formats, detailed below. 2332** Note that some of the more obscure formatting options from recent 2333** C-library standards are omitted from this implementation. 2334** 2335** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2336** results into memory obtained from [sqlite3_malloc()]. 2337** The strings returned by these two routines should be 2338** released by [sqlite3_free()]. ^Both routines return a 2339** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2340** memory to hold the resulting string. 2341** 2342** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2343** the standard C library. The result is written into the 2344** buffer supplied as the second parameter whose size is given by 2345** the first parameter. Note that the order of the 2346** first two parameters is reversed from snprintf().)^ This is an 2347** historical accident that cannot be fixed without breaking 2348** backwards compatibility. ^(Note also that sqlite3_snprintf() 2349** returns a pointer to its buffer instead of the number of 2350** characters actually written into the buffer.)^ We admit that 2351** the number of characters written would be a more useful return 2352** value but we cannot change the implementation of sqlite3_snprintf() 2353** now without breaking compatibility. 2354** 2355** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2356** guarantees that the buffer is always zero-terminated. ^The first 2357** parameter "n" is the total size of the buffer, including space for 2358** the zero terminator. So the longest string that can be completely 2359** written will be n-1 characters. 2360** 2361** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2362** 2363** These routines all implement some additional formatting 2364** options that are useful for constructing SQL statements. 2365** All of the usual printf() formatting options apply. In addition, there 2366** is are "%q", "%Q", "%w" and "%z" options. 2367** 2368** ^(The %q option works like %s in that it substitutes a nul-terminated 2369** string from the argument list. But %q also doubles every '\'' character. 2370** %q is designed for use inside a string literal.)^ By doubling each '\'' 2371** character it escapes that character and allows it to be inserted into 2372** the string. 2373** 2374** For example, assume the string variable zText contains text as follows: 2375** 2376** <blockquote><pre> 2377** char *zText = "It's a happy day!"; 2378** </pre></blockquote> 2379** 2380** One can use this text in an SQL statement as follows: 2381** 2382** <blockquote><pre> 2383** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2384** sqlite3_exec(db, zSQL, 0, 0, 0); 2385** sqlite3_free(zSQL); 2386** </pre></blockquote> 2387** 2388** Because the %q format string is used, the '\'' character in zText 2389** is escaped and the SQL generated is as follows: 2390** 2391** <blockquote><pre> 2392** INSERT INTO table1 VALUES('It''s a happy day!') 2393** </pre></blockquote> 2394** 2395** This is correct. Had we used %s instead of %q, the generated SQL 2396** would have looked like this: 2397** 2398** <blockquote><pre> 2399** INSERT INTO table1 VALUES('It's a happy day!'); 2400** </pre></blockquote> 2401** 2402** This second example is an SQL syntax error. As a general rule you should 2403** always use %q instead of %s when inserting text into a string literal. 2404** 2405** ^(The %Q option works like %q except it also adds single quotes around 2406** the outside of the total string. Additionally, if the parameter in the 2407** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2408** single quotes).)^ So, for example, one could say: 2409** 2410** <blockquote><pre> 2411** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2412** sqlite3_exec(db, zSQL, 0, 0, 0); 2413** sqlite3_free(zSQL); 2414** </pre></blockquote> 2415** 2416** The code above will render a correct SQL statement in the zSQL 2417** variable even if the zText variable is a NULL pointer. 2418** 2419** ^(The "%w" formatting option is like "%q" except that it expects to 2420** be contained within double-quotes instead of single quotes, and it 2421** escapes the double-quote character instead of the single-quote 2422** character.)^ The "%w" formatting option is intended for safely inserting 2423** table and column names into a constructed SQL statement. 2424** 2425** ^(The "%z" formatting option works like "%s" but with the 2426** addition that after the string has been read and copied into 2427** the result, [sqlite3_free()] is called on the input string.)^ 2428*/ 2429SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2430SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2431SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2432SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2433 2434/* 2435** CAPI3REF: Memory Allocation Subsystem 2436** 2437** The SQLite core uses these three routines for all of its own 2438** internal memory allocation needs. "Core" in the previous sentence 2439** does not include operating-system specific VFS implementation. The 2440** Windows VFS uses native malloc() and free() for some operations. 2441** 2442** ^The sqlite3_malloc() routine returns a pointer to a block 2443** of memory at least N bytes in length, where N is the parameter. 2444** ^If sqlite3_malloc() is unable to obtain sufficient free 2445** memory, it returns a NULL pointer. ^If the parameter N to 2446** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2447** a NULL pointer. 2448** 2449** ^The sqlite3_malloc64(N) routine works just like 2450** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2451** of a signed 32-bit integer. 2452** 2453** ^Calling sqlite3_free() with a pointer previously returned 2454** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2455** that it might be reused. ^The sqlite3_free() routine is 2456** a no-op if is called with a NULL pointer. Passing a NULL pointer 2457** to sqlite3_free() is harmless. After being freed, memory 2458** should neither be read nor written. Even reading previously freed 2459** memory might result in a segmentation fault or other severe error. 2460** Memory corruption, a segmentation fault, or other severe error 2461** might result if sqlite3_free() is called with a non-NULL pointer that 2462** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2463** 2464** ^The sqlite3_realloc(X,N) interface attempts to resize a 2465** prior memory allocation X to be at least N bytes. 2466** ^If the X parameter to sqlite3_realloc(X,N) 2467** is a NULL pointer then its behavior is identical to calling 2468** sqlite3_malloc(N). 2469** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2470** negative then the behavior is exactly the same as calling 2471** sqlite3_free(X). 2472** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2473** of at least N bytes in size or NULL if insufficient memory is available. 2474** ^If M is the size of the prior allocation, then min(N,M) bytes 2475** of the prior allocation are copied into the beginning of buffer returned 2476** by sqlite3_realloc(X,N) and the prior allocation is freed. 2477** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2478** prior allocation is not freed. 2479** 2480** ^The sqlite3_realloc64(X,N) interfaces works the same as 2481** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2482** of a 32-bit signed integer. 2483** 2484** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2485** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2486** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2487** ^The value returned by sqlite3_msize(X) might be larger than the number 2488** of bytes requested when X was allocated. ^If X is a NULL pointer then 2489** sqlite3_msize(X) returns zero. If X points to something that is not 2490** the beginning of memory allocation, or if it points to a formerly 2491** valid memory allocation that has now been freed, then the behavior 2492** of sqlite3_msize(X) is undefined and possibly harmful. 2493** 2494** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2495** sqlite3_malloc64(), and sqlite3_realloc64() 2496** is always aligned to at least an 8 byte boundary, or to a 2497** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2498** option is used. 2499** 2500** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2501** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2502** implementation of these routines to be omitted. That capability 2503** is no longer provided. Only built-in memory allocators can be used. 2504** 2505** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2506** the system malloc() and free() directly when converting 2507** filenames between the UTF-8 encoding used by SQLite 2508** and whatever filename encoding is used by the particular Windows 2509** installation. Memory allocation errors were detected, but 2510** they were reported back as [SQLITE_CANTOPEN] or 2511** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2512** 2513** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2514** must be either NULL or else pointers obtained from a prior 2515** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2516** not yet been released. 2517** 2518** The application must not read or write any part of 2519** a block of memory after it has been released using 2520** [sqlite3_free()] or [sqlite3_realloc()]. 2521*/ 2522SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2523SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2524SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2525SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2526SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2527SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2528 2529/* 2530** CAPI3REF: Memory Allocator Statistics 2531** 2532** SQLite provides these two interfaces for reporting on the status 2533** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2534** routines, which form the built-in memory allocation subsystem. 2535** 2536** ^The [sqlite3_memory_used()] routine returns the number of bytes 2537** of memory currently outstanding (malloced but not freed). 2538** ^The [sqlite3_memory_highwater()] routine returns the maximum 2539** value of [sqlite3_memory_used()] since the high-water mark 2540** was last reset. ^The values returned by [sqlite3_memory_used()] and 2541** [sqlite3_memory_highwater()] include any overhead 2542** added by SQLite in its implementation of [sqlite3_malloc()], 2543** but not overhead added by the any underlying system library 2544** routines that [sqlite3_malloc()] may call. 2545** 2546** ^The memory high-water mark is reset to the current value of 2547** [sqlite3_memory_used()] if and only if the parameter to 2548** [sqlite3_memory_highwater()] is true. ^The value returned 2549** by [sqlite3_memory_highwater(1)] is the high-water mark 2550** prior to the reset. 2551*/ 2552SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2553SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2554 2555/* 2556** CAPI3REF: Pseudo-Random Number Generator 2557** 2558** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2559** select random [ROWID | ROWIDs] when inserting new records into a table that 2560** already uses the largest possible [ROWID]. The PRNG is also used for 2561** the build-in random() and randomblob() SQL functions. This interface allows 2562** applications to access the same PRNG for other purposes. 2563** 2564** ^A call to this routine stores N bytes of randomness into buffer P. 2565** ^The P parameter can be a NULL pointer. 2566** 2567** ^If this routine has not been previously called or if the previous 2568** call had N less than one or a NULL pointer for P, then the PRNG is 2569** seeded using randomness obtained from the xRandomness method of 2570** the default [sqlite3_vfs] object. 2571** ^If the previous call to this routine had an N of 1 or more and a 2572** non-NULL P then the pseudo-randomness is generated 2573** internally and without recourse to the [sqlite3_vfs] xRandomness 2574** method. 2575*/ 2576SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2577 2578/* 2579** CAPI3REF: Compile-Time Authorization Callbacks 2580** METHOD: sqlite3 2581** 2582** ^This routine registers an authorizer callback with a particular 2583** [database connection], supplied in the first argument. 2584** ^The authorizer callback is invoked as SQL statements are being compiled 2585** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2586** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2587** points during the compilation process, as logic is being created 2588** to perform various actions, the authorizer callback is invoked to 2589** see if those actions are allowed. ^The authorizer callback should 2590** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2591** specific action but allow the SQL statement to continue to be 2592** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2593** rejected with an error. ^If the authorizer callback returns 2594** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2595** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2596** the authorizer will fail with an error message. 2597** 2598** When the callback returns [SQLITE_OK], that means the operation 2599** requested is ok. ^When the callback returns [SQLITE_DENY], the 2600** [sqlite3_prepare_v2()] or equivalent call that triggered the 2601** authorizer will fail with an error message explaining that 2602** access is denied. 2603** 2604** ^The first parameter to the authorizer callback is a copy of the third 2605** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2606** to the callback is an integer [SQLITE_COPY | action code] that specifies 2607** the particular action to be authorized. ^The third through sixth parameters 2608** to the callback are zero-terminated strings that contain additional 2609** details about the action to be authorized. 2610** 2611** ^If the action code is [SQLITE_READ] 2612** and the callback returns [SQLITE_IGNORE] then the 2613** [prepared statement] statement is constructed to substitute 2614** a NULL value in place of the table column that would have 2615** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2616** return can be used to deny an untrusted user access to individual 2617** columns of a table. 2618** ^If the action code is [SQLITE_DELETE] and the callback returns 2619** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2620** [truncate optimization] is disabled and all rows are deleted individually. 2621** 2622** An authorizer is used when [sqlite3_prepare | preparing] 2623** SQL statements from an untrusted source, to ensure that the SQL statements 2624** do not try to access data they are not allowed to see, or that they do not 2625** try to execute malicious statements that damage the database. For 2626** example, an application may allow a user to enter arbitrary 2627** SQL queries for evaluation by a database. But the application does 2628** not want the user to be able to make arbitrary changes to the 2629** database. An authorizer could then be put in place while the 2630** user-entered SQL is being [sqlite3_prepare | prepared] that 2631** disallows everything except [SELECT] statements. 2632** 2633** Applications that need to process SQL from untrusted sources 2634** might also consider lowering resource limits using [sqlite3_limit()] 2635** and limiting database size using the [max_page_count] [PRAGMA] 2636** in addition to using an authorizer. 2637** 2638** ^(Only a single authorizer can be in place on a database connection 2639** at a time. Each call to sqlite3_set_authorizer overrides the 2640** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2641** The authorizer is disabled by default. 2642** 2643** The authorizer callback must not do anything that will modify 2644** the database connection that invoked the authorizer callback. 2645** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2646** database connections for the meaning of "modify" in this paragraph. 2647** 2648** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2649** statement might be re-prepared during [sqlite3_step()] due to a 2650** schema change. Hence, the application should ensure that the 2651** correct authorizer callback remains in place during the [sqlite3_step()]. 2652** 2653** ^Note that the authorizer callback is invoked only during 2654** [sqlite3_prepare()] or its variants. Authorization is not 2655** performed during statement evaluation in [sqlite3_step()], unless 2656** as stated in the previous paragraph, sqlite3_step() invokes 2657** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2658*/ 2659SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2660 sqlite3*, 2661 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2662 void *pUserData 2663); 2664 2665/* 2666** CAPI3REF: Authorizer Return Codes 2667** 2668** The [sqlite3_set_authorizer | authorizer callback function] must 2669** return either [SQLITE_OK] or one of these two constants in order 2670** to signal SQLite whether or not the action is permitted. See the 2671** [sqlite3_set_authorizer | authorizer documentation] for additional 2672** information. 2673** 2674** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2675** returned from the [sqlite3_vtab_on_conflict()] interface. 2676*/ 2677#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2678#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2679 2680/* 2681** CAPI3REF: Authorizer Action Codes 2682** 2683** The [sqlite3_set_authorizer()] interface registers a callback function 2684** that is invoked to authorize certain SQL statement actions. The 2685** second parameter to the callback is an integer code that specifies 2686** what action is being authorized. These are the integer action codes that 2687** the authorizer callback may be passed. 2688** 2689** These action code values signify what kind of operation is to be 2690** authorized. The 3rd and 4th parameters to the authorization 2691** callback function will be parameters or NULL depending on which of these 2692** codes is used as the second parameter. ^(The 5th parameter to the 2693** authorizer callback is the name of the database ("main", "temp", 2694** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2695** is the name of the inner-most trigger or view that is responsible for 2696** the access attempt or NULL if this access attempt is directly from 2697** top-level SQL code. 2698*/ 2699/******************************************* 3rd ************ 4th ***********/ 2700#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2701#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2702#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2703#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2704#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2705#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2706#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2707#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2708#define SQLITE_DELETE 9 /* Table Name NULL */ 2709#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2710#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2711#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2712#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2713#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2714#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2715#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2716#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2717#define SQLITE_INSERT 18 /* Table Name NULL */ 2718#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2719#define SQLITE_READ 20 /* Table Name Column Name */ 2720#define SQLITE_SELECT 21 /* NULL NULL */ 2721#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2722#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2723#define SQLITE_ATTACH 24 /* Filename NULL */ 2724#define SQLITE_DETACH 25 /* Database Name NULL */ 2725#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2726#define SQLITE_REINDEX 27 /* Index Name NULL */ 2727#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2728#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2729#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2730#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2731#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2732#define SQLITE_COPY 0 /* No longer used */ 2733#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2734 2735/* 2736** CAPI3REF: Tracing And Profiling Functions 2737** METHOD: sqlite3 2738** 2739** These routines register callback functions that can be used for 2740** tracing and profiling the execution of SQL statements. 2741** 2742** ^The callback function registered by sqlite3_trace() is invoked at 2743** various times when an SQL statement is being run by [sqlite3_step()]. 2744** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2745** SQL statement text as the statement first begins executing. 2746** ^(Additional sqlite3_trace() callbacks might occur 2747** as each triggered subprogram is entered. The callbacks for triggers 2748** contain a UTF-8 SQL comment that identifies the trigger.)^ 2749** 2750** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2751** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2752** 2753** ^The callback function registered by sqlite3_profile() is invoked 2754** as each SQL statement finishes. ^The profile callback contains 2755** the original statement text and an estimate of wall-clock time 2756** of how long that statement took to run. ^The profile callback 2757** time is in units of nanoseconds, however the current implementation 2758** is only capable of millisecond resolution so the six least significant 2759** digits in the time are meaningless. Future versions of SQLite 2760** might provide greater resolution on the profiler callback. The 2761** sqlite3_profile() function is considered experimental and is 2762** subject to change in future versions of SQLite. 2763*/ 2764SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2765SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2766 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2767 2768/* 2769** CAPI3REF: Query Progress Callbacks 2770** METHOD: sqlite3 2771** 2772** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2773** function X to be invoked periodically during long running calls to 2774** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2775** database connection D. An example use for this 2776** interface is to keep a GUI updated during a large query. 2777** 2778** ^The parameter P is passed through as the only parameter to the 2779** callback function X. ^The parameter N is the approximate number of 2780** [virtual machine instructions] that are evaluated between successive 2781** invocations of the callback X. ^If N is less than one then the progress 2782** handler is disabled. 2783** 2784** ^Only a single progress handler may be defined at one time per 2785** [database connection]; setting a new progress handler cancels the 2786** old one. ^Setting parameter X to NULL disables the progress handler. 2787** ^The progress handler is also disabled by setting N to a value less 2788** than 1. 2789** 2790** ^If the progress callback returns non-zero, the operation is 2791** interrupted. This feature can be used to implement a 2792** "Cancel" button on a GUI progress dialog box. 2793** 2794** The progress handler callback must not do anything that will modify 2795** the database connection that invoked the progress handler. 2796** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2797** database connections for the meaning of "modify" in this paragraph. 2798** 2799*/ 2800SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2801 2802/* 2803** CAPI3REF: Opening A New Database Connection 2804** CONSTRUCTOR: sqlite3 2805** 2806** ^These routines open an SQLite database file as specified by the 2807** filename argument. ^The filename argument is interpreted as UTF-8 for 2808** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2809** order for sqlite3_open16(). ^(A [database connection] handle is usually 2810** returned in *ppDb, even if an error occurs. The only exception is that 2811** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2812** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2813** object.)^ ^(If the database is opened (and/or created) successfully, then 2814** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2815** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2816** an English language description of the error following a failure of any 2817** of the sqlite3_open() routines. 2818** 2819** ^The default encoding will be UTF-8 for databases created using 2820** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2821** created using sqlite3_open16() will be UTF-16 in the native byte order. 2822** 2823** Whether or not an error occurs when it is opened, resources 2824** associated with the [database connection] handle should be released by 2825** passing it to [sqlite3_close()] when it is no longer required. 2826** 2827** The sqlite3_open_v2() interface works like sqlite3_open() 2828** except that it accepts two additional parameters for additional control 2829** over the new database connection. ^(The flags parameter to 2830** sqlite3_open_v2() can take one of 2831** the following three values, optionally combined with the 2832** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2833** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2834** 2835** <dl> 2836** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2837** <dd>The database is opened in read-only mode. If the database does not 2838** already exist, an error is returned.</dd>)^ 2839** 2840** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2841** <dd>The database is opened for reading and writing if possible, or reading 2842** only if the file is write protected by the operating system. In either 2843** case the database must already exist, otherwise an error is returned.</dd>)^ 2844** 2845** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2846** <dd>The database is opened for reading and writing, and is created if 2847** it does not already exist. This is the behavior that is always used for 2848** sqlite3_open() and sqlite3_open16().</dd>)^ 2849** </dl> 2850** 2851** If the 3rd parameter to sqlite3_open_v2() is not one of the 2852** combinations shown above optionally combined with other 2853** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2854** then the behavior is undefined. 2855** 2856** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2857** opens in the multi-thread [threading mode] as long as the single-thread 2858** mode has not been set at compile-time or start-time. ^If the 2859** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2860** in the serialized [threading mode] unless single-thread was 2861** previously selected at compile-time or start-time. 2862** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2863** eligible to use [shared cache mode], regardless of whether or not shared 2864** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2865** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2866** participate in [shared cache mode] even if it is enabled. 2867** 2868** ^The fourth parameter to sqlite3_open_v2() is the name of the 2869** [sqlite3_vfs] object that defines the operating system interface that 2870** the new database connection should use. ^If the fourth parameter is 2871** a NULL pointer then the default [sqlite3_vfs] object is used. 2872** 2873** ^If the filename is ":memory:", then a private, temporary in-memory database 2874** is created for the connection. ^This in-memory database will vanish when 2875** the database connection is closed. Future versions of SQLite might 2876** make use of additional special filenames that begin with the ":" character. 2877** It is recommended that when a database filename actually does begin with 2878** a ":" character you should prefix the filename with a pathname such as 2879** "./" to avoid ambiguity. 2880** 2881** ^If the filename is an empty string, then a private, temporary 2882** on-disk database will be created. ^This private database will be 2883** automatically deleted as soon as the database connection is closed. 2884** 2885** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2886** 2887** ^If [URI filename] interpretation is enabled, and the filename argument 2888** begins with "file:", then the filename is interpreted as a URI. ^URI 2889** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2890** set in the fourth argument to sqlite3_open_v2(), or if it has 2891** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2892** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2893** As of SQLite version 3.7.7, URI filename interpretation is turned off 2894** by default, but future releases of SQLite might enable URI filename 2895** interpretation by default. See "[URI filenames]" for additional 2896** information. 2897** 2898** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2899** authority, then it must be either an empty string or the string 2900** "localhost". ^If the authority is not an empty string or "localhost", an 2901** error is returned to the caller. ^The fragment component of a URI, if 2902** present, is ignored. 2903** 2904** ^SQLite uses the path component of the URI as the name of the disk file 2905** which contains the database. ^If the path begins with a '/' character, 2906** then it is interpreted as an absolute path. ^If the path does not begin 2907** with a '/' (meaning that the authority section is omitted from the URI) 2908** then the path is interpreted as a relative path. 2909** ^(On windows, the first component of an absolute path 2910** is a drive specification (e.g. "C:").)^ 2911** 2912** [[core URI query parameters]] 2913** The query component of a URI may contain parameters that are interpreted 2914** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2915** SQLite and its built-in [VFSes] interpret the 2916** following query parameters: 2917** 2918** <ul> 2919** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2920** a VFS object that provides the operating system interface that should 2921** be used to access the database file on disk. ^If this option is set to 2922** an empty string the default VFS object is used. ^Specifying an unknown 2923** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2924** present, then the VFS specified by the option takes precedence over 2925** the value passed as the fourth parameter to sqlite3_open_v2(). 2926** 2927** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2928** "rwc", or "memory". Attempting to set it to any other value is 2929** an error)^. 2930** ^If "ro" is specified, then the database is opened for read-only 2931** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2932** third argument to sqlite3_open_v2(). ^If the mode option is set to 2933** "rw", then the database is opened for read-write (but not create) 2934** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2935** been set. ^Value "rwc" is equivalent to setting both 2936** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2937** set to "memory" then a pure [in-memory database] that never reads 2938** or writes from disk is used. ^It is an error to specify a value for 2939** the mode parameter that is less restrictive than that specified by 2940** the flags passed in the third parameter to sqlite3_open_v2(). 2941** 2942** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2943** "private". ^Setting it to "shared" is equivalent to setting the 2944** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2945** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2946** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2947** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2948** a URI filename, its value overrides any behavior requested by setting 2949** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2950** 2951** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2952** [powersafe overwrite] property does or does not apply to the 2953** storage media on which the database file resides. 2954** 2955** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2956** which if set disables file locking in rollback journal modes. This 2957** is useful for accessing a database on a filesystem that does not 2958** support locking. Caution: Database corruption might result if two 2959** or more processes write to the same database and any one of those 2960** processes uses nolock=1. 2961** 2962** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2963** parameter that indicates that the database file is stored on 2964** read-only media. ^When immutable is set, SQLite assumes that the 2965** database file cannot be changed, even by a process with higher 2966** privilege, and so the database is opened read-only and all locking 2967** and change detection is disabled. Caution: Setting the immutable 2968** property on a database file that does in fact change can result 2969** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2970** See also: [SQLITE_IOCAP_IMMUTABLE]. 2971** 2972** </ul> 2973** 2974** ^Specifying an unknown parameter in the query component of a URI is not an 2975** error. Future versions of SQLite might understand additional query 2976** parameters. See "[query parameters with special meaning to SQLite]" for 2977** additional information. 2978** 2979** [[URI filename examples]] <h3>URI filename examples</h3> 2980** 2981** <table border="1" align=center cellpadding=5> 2982** <tr><th> URI filenames <th> Results 2983** <tr><td> file:data.db <td> 2984** Open the file "data.db" in the current directory. 2985** <tr><td> file:/home/fred/data.db<br> 2986** file:///home/fred/data.db <br> 2987** file://localhost/home/fred/data.db <br> <td> 2988** Open the database file "/home/fred/data.db". 2989** <tr><td> file://darkstar/home/fred/data.db <td> 2990** An error. "darkstar" is not a recognized authority. 2991** <tr><td style="white-space:nowrap"> 2992** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2993** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2994** C:. Note that the %20 escaping in this example is not strictly 2995** necessary - space characters can be used literally 2996** in URI filenames. 2997** <tr><td> file:data.db?mode=ro&cache=private <td> 2998** Open file "data.db" in the current directory for read-only access. 2999** Regardless of whether or not shared-cache mode is enabled by 3000** default, use a private cache. 3001** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3002** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3003** that uses dot-files in place of posix advisory locking. 3004** <tr><td> file:data.db?mode=readonly <td> 3005** An error. "readonly" is not a valid option for the "mode" parameter. 3006** </table> 3007** 3008** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3009** query components of a URI. A hexadecimal escape sequence consists of a 3010** percent sign - "%" - followed by exactly two hexadecimal digits 3011** specifying an octet value. ^Before the path or query components of a 3012** URI filename are interpreted, they are encoded using UTF-8 and all 3013** hexadecimal escape sequences replaced by a single byte containing the 3014** corresponding octet. If this process generates an invalid UTF-8 encoding, 3015** the results are undefined. 3016** 3017** <b>Note to Windows users:</b> The encoding used for the filename argument 3018** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3019** codepage is currently defined. Filenames containing international 3020** characters must be converted to UTF-8 prior to passing them into 3021** sqlite3_open() or sqlite3_open_v2(). 3022** 3023** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3024** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3025** features that require the use of temporary files may fail. 3026** 3027** See also: [sqlite3_temp_directory] 3028*/ 3029SQLITE_API int SQLITE_STDCALL sqlite3_open( 3030 const char *filename, /* Database filename (UTF-8) */ 3031 sqlite3 **ppDb /* OUT: SQLite db handle */ 3032); 3033SQLITE_API int SQLITE_STDCALL sqlite3_open16( 3034 const void *filename, /* Database filename (UTF-16) */ 3035 sqlite3 **ppDb /* OUT: SQLite db handle */ 3036); 3037SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 3038 const char *filename, /* Database filename (UTF-8) */ 3039 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3040 int flags, /* Flags */ 3041 const char *zVfs /* Name of VFS module to use */ 3042); 3043 3044/* 3045** CAPI3REF: Obtain Values For URI Parameters 3046** 3047** These are utility routines, useful to VFS implementations, that check 3048** to see if a database file was a URI that contained a specific query 3049** parameter, and if so obtains the value of that query parameter. 3050** 3051** If F is the database filename pointer passed into the xOpen() method of 3052** a VFS implementation when the flags parameter to xOpen() has one or 3053** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3054** P is the name of the query parameter, then 3055** sqlite3_uri_parameter(F,P) returns the value of the P 3056** parameter if it exists or a NULL pointer if P does not appear as a 3057** query parameter on F. If P is a query parameter of F 3058** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3059** a pointer to an empty string. 3060** 3061** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3062** parameter and returns true (1) or false (0) according to the value 3063** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3064** value of query parameter P is one of "yes", "true", or "on" in any 3065** case or if the value begins with a non-zero number. The 3066** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3067** query parameter P is one of "no", "false", or "off" in any case or 3068** if the value begins with a numeric zero. If P is not a query 3069** parameter on F or if the value of P is does not match any of the 3070** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3071** 3072** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3073** 64-bit signed integer and returns that integer, or D if P does not 3074** exist. If the value of P is something other than an integer, then 3075** zero is returned. 3076** 3077** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3078** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3079** is not a database file pathname pointer that SQLite passed into the xOpen 3080** VFS method, then the behavior of this routine is undefined and probably 3081** undesirable. 3082*/ 3083SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3084SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3085SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3086 3087 3088/* 3089** CAPI3REF: Error Codes And Messages 3090** METHOD: sqlite3 3091** 3092** ^If the most recent sqlite3_* API call associated with 3093** [database connection] D failed, then the sqlite3_errcode(D) interface 3094** returns the numeric [result code] or [extended result code] for that 3095** API call. 3096** If the most recent API call was successful, 3097** then the return value from sqlite3_errcode() is undefined. 3098** ^The sqlite3_extended_errcode() 3099** interface is the same except that it always returns the 3100** [extended result code] even when extended result codes are 3101** disabled. 3102** 3103** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3104** text that describes the error, as either UTF-8 or UTF-16 respectively. 3105** ^(Memory to hold the error message string is managed internally. 3106** The application does not need to worry about freeing the result. 3107** However, the error string might be overwritten or deallocated by 3108** subsequent calls to other SQLite interface functions.)^ 3109** 3110** ^The sqlite3_errstr() interface returns the English-language text 3111** that describes the [result code], as UTF-8. 3112** ^(Memory to hold the error message string is managed internally 3113** and must not be freed by the application)^. 3114** 3115** When the serialized [threading mode] is in use, it might be the 3116** case that a second error occurs on a separate thread in between 3117** the time of the first error and the call to these interfaces. 3118** When that happens, the second error will be reported since these 3119** interfaces always report the most recent result. To avoid 3120** this, each thread can obtain exclusive use of the [database connection] D 3121** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3122** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3123** all calls to the interfaces listed here are completed. 3124** 3125** If an interface fails with SQLITE_MISUSE, that means the interface 3126** was invoked incorrectly by the application. In that case, the 3127** error code and message may or may not be set. 3128*/ 3129SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3130SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3131SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3132SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3133SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3134 3135/* 3136** CAPI3REF: Prepared Statement Object 3137** KEYWORDS: {prepared statement} {prepared statements} 3138** 3139** An instance of this object represents a single SQL statement that 3140** has been compiled into binary form and is ready to be evaluated. 3141** 3142** Think of each SQL statement as a separate computer program. The 3143** original SQL text is source code. A prepared statement object 3144** is the compiled object code. All SQL must be converted into a 3145** prepared statement before it can be run. 3146** 3147** The life-cycle of a prepared statement object usually goes like this: 3148** 3149** <ol> 3150** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3151** <li> Bind values to [parameters] using the sqlite3_bind_*() 3152** interfaces. 3153** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3154** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3155** to step 2. Do this zero or more times. 3156** <li> Destroy the object using [sqlite3_finalize()]. 3157** </ol> 3158*/ 3159typedef struct sqlite3_stmt sqlite3_stmt; 3160 3161/* 3162** CAPI3REF: Run-time Limits 3163** METHOD: sqlite3 3164** 3165** ^(This interface allows the size of various constructs to be limited 3166** on a connection by connection basis. The first parameter is the 3167** [database connection] whose limit is to be set or queried. The 3168** second parameter is one of the [limit categories] that define a 3169** class of constructs to be size limited. The third parameter is the 3170** new limit for that construct.)^ 3171** 3172** ^If the new limit is a negative number, the limit is unchanged. 3173** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3174** [limits | hard upper bound] 3175** set at compile-time by a C preprocessor macro called 3176** [limits | SQLITE_MAX_<i>NAME</i>]. 3177** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3178** ^Attempts to increase a limit above its hard upper bound are 3179** silently truncated to the hard upper bound. 3180** 3181** ^Regardless of whether or not the limit was changed, the 3182** [sqlite3_limit()] interface returns the prior value of the limit. 3183** ^Hence, to find the current value of a limit without changing it, 3184** simply invoke this interface with the third parameter set to -1. 3185** 3186** Run-time limits are intended for use in applications that manage 3187** both their own internal database and also databases that are controlled 3188** by untrusted external sources. An example application might be a 3189** web browser that has its own databases for storing history and 3190** separate databases controlled by JavaScript applications downloaded 3191** off the Internet. The internal databases can be given the 3192** large, default limits. Databases managed by external sources can 3193** be given much smaller limits designed to prevent a denial of service 3194** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3195** interface to further control untrusted SQL. The size of the database 3196** created by an untrusted script can be contained using the 3197** [max_page_count] [PRAGMA]. 3198** 3199** New run-time limit categories may be added in future releases. 3200*/ 3201SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3202 3203/* 3204** CAPI3REF: Run-Time Limit Categories 3205** KEYWORDS: {limit category} {*limit categories} 3206** 3207** These constants define various performance limits 3208** that can be lowered at run-time using [sqlite3_limit()]. 3209** The synopsis of the meanings of the various limits is shown below. 3210** Additional information is available at [limits | Limits in SQLite]. 3211** 3212** <dl> 3213** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3214** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3215** 3216** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3217** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3218** 3219** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3220** <dd>The maximum number of columns in a table definition or in the 3221** result set of a [SELECT] or the maximum number of columns in an index 3222** or in an ORDER BY or GROUP BY clause.</dd>)^ 3223** 3224** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3225** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3226** 3227** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3228** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3229** 3230** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3231** <dd>The maximum number of instructions in a virtual machine program 3232** used to implement an SQL statement. This limit is not currently 3233** enforced, though that might be added in some future release of 3234** SQLite.</dd>)^ 3235** 3236** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3237** <dd>The maximum number of arguments on a function.</dd>)^ 3238** 3239** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3240** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3241** 3242** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3243** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3244** <dd>The maximum length of the pattern argument to the [LIKE] or 3245** [GLOB] operators.</dd>)^ 3246** 3247** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3248** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3249** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3250** 3251** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3252** <dd>The maximum depth of recursion for triggers.</dd>)^ 3253** 3254** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3255** <dd>The maximum number of auxiliary worker threads that a single 3256** [prepared statement] may start.</dd>)^ 3257** </dl> 3258*/ 3259#define SQLITE_LIMIT_LENGTH 0 3260#define SQLITE_LIMIT_SQL_LENGTH 1 3261#define SQLITE_LIMIT_COLUMN 2 3262#define SQLITE_LIMIT_EXPR_DEPTH 3 3263#define SQLITE_LIMIT_COMPOUND_SELECT 4 3264#define SQLITE_LIMIT_VDBE_OP 5 3265#define SQLITE_LIMIT_FUNCTION_ARG 6 3266#define SQLITE_LIMIT_ATTACHED 7 3267#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3268#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3269#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3270#define SQLITE_LIMIT_WORKER_THREADS 11 3271 3272/* 3273** CAPI3REF: Compiling An SQL Statement 3274** KEYWORDS: {SQL statement compiler} 3275** METHOD: sqlite3 3276** CONSTRUCTOR: sqlite3_stmt 3277** 3278** To execute an SQL query, it must first be compiled into a byte-code 3279** program using one of these routines. 3280** 3281** The first argument, "db", is a [database connection] obtained from a 3282** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3283** [sqlite3_open16()]. The database connection must not have been closed. 3284** 3285** The second argument, "zSql", is the statement to be compiled, encoded 3286** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3287** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3288** use UTF-16. 3289** 3290** ^If the nByte argument is negative, then zSql is read up to the 3291** first zero terminator. ^If nByte is positive, then it is the 3292** number of bytes read from zSql. ^If nByte is zero, then no prepared 3293** statement is generated. 3294** If the caller knows that the supplied string is nul-terminated, then 3295** there is a small performance advantage to passing an nByte parameter that 3296** is the number of bytes in the input string <i>including</i> 3297** the nul-terminator. 3298** 3299** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3300** past the end of the first SQL statement in zSql. These routines only 3301** compile the first statement in zSql, so *pzTail is left pointing to 3302** what remains uncompiled. 3303** 3304** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3305** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3306** to NULL. ^If the input text contains no SQL (if the input is an empty 3307** string or a comment) then *ppStmt is set to NULL. 3308** The calling procedure is responsible for deleting the compiled 3309** SQL statement using [sqlite3_finalize()] after it has finished with it. 3310** ppStmt may not be NULL. 3311** 3312** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3313** otherwise an [error code] is returned. 3314** 3315** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3316** recommended for all new programs. The two older interfaces are retained 3317** for backwards compatibility, but their use is discouraged. 3318** ^In the "v2" interfaces, the prepared statement 3319** that is returned (the [sqlite3_stmt] object) contains a copy of the 3320** original SQL text. This causes the [sqlite3_step()] interface to 3321** behave differently in three ways: 3322** 3323** <ol> 3324** <li> 3325** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3326** always used to do, [sqlite3_step()] will automatically recompile the SQL 3327** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3328** retries will occur before sqlite3_step() gives up and returns an error. 3329** </li> 3330** 3331** <li> 3332** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3333** [error codes] or [extended error codes]. ^The legacy behavior was that 3334** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3335** and the application would have to make a second call to [sqlite3_reset()] 3336** in order to find the underlying cause of the problem. With the "v2" prepare 3337** interfaces, the underlying reason for the error is returned immediately. 3338** </li> 3339** 3340** <li> 3341** ^If the specific value bound to [parameter | host parameter] in the 3342** WHERE clause might influence the choice of query plan for a statement, 3343** then the statement will be automatically recompiled, as if there had been 3344** a schema change, on the first [sqlite3_step()] call following any change 3345** to the [sqlite3_bind_text | bindings] of that [parameter]. 3346** ^The specific value of WHERE-clause [parameter] might influence the 3347** choice of query plan if the parameter is the left-hand side of a [LIKE] 3348** or [GLOB] operator or if the parameter is compared to an indexed column 3349** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3350** </li> 3351** </ol> 3352*/ 3353SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3354 sqlite3 *db, /* Database handle */ 3355 const char *zSql, /* SQL statement, UTF-8 encoded */ 3356 int nByte, /* Maximum length of zSql in bytes. */ 3357 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3358 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3359); 3360SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3361 sqlite3 *db, /* Database handle */ 3362 const char *zSql, /* SQL statement, UTF-8 encoded */ 3363 int nByte, /* Maximum length of zSql in bytes. */ 3364 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3365 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3366); 3367SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3368 sqlite3 *db, /* Database handle */ 3369 const void *zSql, /* SQL statement, UTF-16 encoded */ 3370 int nByte, /* Maximum length of zSql in bytes. */ 3371 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3372 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3373); 3374SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3375 sqlite3 *db, /* Database handle */ 3376 const void *zSql, /* SQL statement, UTF-16 encoded */ 3377 int nByte, /* Maximum length of zSql in bytes. */ 3378 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3379 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3380); 3381 3382/* 3383** CAPI3REF: Retrieving Statement SQL 3384** METHOD: sqlite3_stmt 3385** 3386** ^This interface can be used to retrieve a saved copy of the original 3387** SQL text used to create a [prepared statement] if that statement was 3388** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3389*/ 3390SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3391 3392/* 3393** CAPI3REF: Determine If An SQL Statement Writes The Database 3394** METHOD: sqlite3_stmt 3395** 3396** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3397** and only if the [prepared statement] X makes no direct changes to 3398** the content of the database file. 3399** 3400** Note that [application-defined SQL functions] or 3401** [virtual tables] might change the database indirectly as a side effect. 3402** ^(For example, if an application defines a function "eval()" that 3403** calls [sqlite3_exec()], then the following SQL statement would 3404** change the database file through side-effects: 3405** 3406** <blockquote><pre> 3407** SELECT eval('DELETE FROM t1') FROM t2; 3408** </pre></blockquote> 3409** 3410** But because the [SELECT] statement does not change the database file 3411** directly, sqlite3_stmt_readonly() would still return true.)^ 3412** 3413** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3414** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3415** since the statements themselves do not actually modify the database but 3416** rather they control the timing of when other statements modify the 3417** database. ^The [ATTACH] and [DETACH] statements also cause 3418** sqlite3_stmt_readonly() to return true since, while those statements 3419** change the configuration of a database connection, they do not make 3420** changes to the content of the database files on disk. 3421*/ 3422SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3423 3424/* 3425** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3426** METHOD: sqlite3_stmt 3427** 3428** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3429** [prepared statement] S has been stepped at least once using 3430** [sqlite3_step(S)] but has neither run to completion (returned 3431** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3432** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3433** interface returns false if S is a NULL pointer. If S is not a 3434** NULL pointer and is not a pointer to a valid [prepared statement] 3435** object, then the behavior is undefined and probably undesirable. 3436** 3437** This interface can be used in combination [sqlite3_next_stmt()] 3438** to locate all prepared statements associated with a database 3439** connection that are in need of being reset. This can be used, 3440** for example, in diagnostic routines to search for prepared 3441** statements that are holding a transaction open. 3442*/ 3443SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3444 3445/* 3446** CAPI3REF: Dynamically Typed Value Object 3447** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3448** 3449** SQLite uses the sqlite3_value object to represent all values 3450** that can be stored in a database table. SQLite uses dynamic typing 3451** for the values it stores. ^Values stored in sqlite3_value objects 3452** can be integers, floating point values, strings, BLOBs, or NULL. 3453** 3454** An sqlite3_value object may be either "protected" or "unprotected". 3455** Some interfaces require a protected sqlite3_value. Other interfaces 3456** will accept either a protected or an unprotected sqlite3_value. 3457** Every interface that accepts sqlite3_value arguments specifies 3458** whether or not it requires a protected sqlite3_value. The 3459** [sqlite3_value_dup()] interface can be used to construct a new 3460** protected sqlite3_value from an unprotected sqlite3_value. 3461** 3462** The terms "protected" and "unprotected" refer to whether or not 3463** a mutex is held. An internal mutex is held for a protected 3464** sqlite3_value object but no mutex is held for an unprotected 3465** sqlite3_value object. If SQLite is compiled to be single-threaded 3466** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3467** or if SQLite is run in one of reduced mutex modes 3468** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3469** then there is no distinction between protected and unprotected 3470** sqlite3_value objects and they can be used interchangeably. However, 3471** for maximum code portability it is recommended that applications 3472** still make the distinction between protected and unprotected 3473** sqlite3_value objects even when not strictly required. 3474** 3475** ^The sqlite3_value objects that are passed as parameters into the 3476** implementation of [application-defined SQL functions] are protected. 3477** ^The sqlite3_value object returned by 3478** [sqlite3_column_value()] is unprotected. 3479** Unprotected sqlite3_value objects may only be used with 3480** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3481** The [sqlite3_value_blob | sqlite3_value_type()] family of 3482** interfaces require protected sqlite3_value objects. 3483*/ 3484typedef struct Mem sqlite3_value; 3485 3486/* 3487** CAPI3REF: SQL Function Context Object 3488** 3489** The context in which an SQL function executes is stored in an 3490** sqlite3_context object. ^A pointer to an sqlite3_context object 3491** is always first parameter to [application-defined SQL functions]. 3492** The application-defined SQL function implementation will pass this 3493** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3494** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3495** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3496** and/or [sqlite3_set_auxdata()]. 3497*/ 3498typedef struct sqlite3_context sqlite3_context; 3499 3500/* 3501** CAPI3REF: Binding Values To Prepared Statements 3502** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3503** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3504** METHOD: sqlite3_stmt 3505** 3506** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3507** literals may be replaced by a [parameter] that matches one of following 3508** templates: 3509** 3510** <ul> 3511** <li> ? 3512** <li> ?NNN 3513** <li> :VVV 3514** <li> @VVV 3515** <li> $VVV 3516** </ul> 3517** 3518** In the templates above, NNN represents an integer literal, 3519** and VVV represents an alphanumeric identifier.)^ ^The values of these 3520** parameters (also called "host parameter names" or "SQL parameters") 3521** can be set using the sqlite3_bind_*() routines defined here. 3522** 3523** ^The first argument to the sqlite3_bind_*() routines is always 3524** a pointer to the [sqlite3_stmt] object returned from 3525** [sqlite3_prepare_v2()] or its variants. 3526** 3527** ^The second argument is the index of the SQL parameter to be set. 3528** ^The leftmost SQL parameter has an index of 1. ^When the same named 3529** SQL parameter is used more than once, second and subsequent 3530** occurrences have the same index as the first occurrence. 3531** ^The index for named parameters can be looked up using the 3532** [sqlite3_bind_parameter_index()] API if desired. ^The index 3533** for "?NNN" parameters is the value of NNN. 3534** ^The NNN value must be between 1 and the [sqlite3_limit()] 3535** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3536** 3537** ^The third argument is the value to bind to the parameter. 3538** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3539** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3540** is ignored and the end result is the same as sqlite3_bind_null(). 3541** 3542** ^(In those routines that have a fourth argument, its value is the 3543** number of bytes in the parameter. To be clear: the value is the 3544** number of <u>bytes</u> in the value, not the number of characters.)^ 3545** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3546** is negative, then the length of the string is 3547** the number of bytes up to the first zero terminator. 3548** If the fourth parameter to sqlite3_bind_blob() is negative, then 3549** the behavior is undefined. 3550** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3551** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3552** that parameter must be the byte offset 3553** where the NUL terminator would occur assuming the string were NUL 3554** terminated. If any NUL characters occur at byte offsets less than 3555** the value of the fourth parameter then the resulting string value will 3556** contain embedded NULs. The result of expressions involving strings 3557** with embedded NULs is undefined. 3558** 3559** ^The fifth argument to the BLOB and string binding interfaces 3560** is a destructor used to dispose of the BLOB or 3561** string after SQLite has finished with it. ^The destructor is called 3562** to dispose of the BLOB or string even if the call to bind API fails. 3563** ^If the fifth argument is 3564** the special value [SQLITE_STATIC], then SQLite assumes that the 3565** information is in static, unmanaged space and does not need to be freed. 3566** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3567** SQLite makes its own private copy of the data immediately, before 3568** the sqlite3_bind_*() routine returns. 3569** 3570** ^The sixth argument to sqlite3_bind_text64() must be one of 3571** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3572** to specify the encoding of the text in the third parameter. If 3573** the sixth argument to sqlite3_bind_text64() is not one of the 3574** allowed values shown above, or if the text encoding is different 3575** from the encoding specified by the sixth parameter, then the behavior 3576** is undefined. 3577** 3578** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3579** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3580** (just an integer to hold its size) while it is being processed. 3581** Zeroblobs are intended to serve as placeholders for BLOBs whose 3582** content is later written using 3583** [sqlite3_blob_open | incremental BLOB I/O] routines. 3584** ^A negative value for the zeroblob results in a zero-length BLOB. 3585** 3586** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3587** for the [prepared statement] or with a prepared statement for which 3588** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3589** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3590** routine is passed a [prepared statement] that has been finalized, the 3591** result is undefined and probably harmful. 3592** 3593** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3594** ^Unbound parameters are interpreted as NULL. 3595** 3596** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3597** [error code] if anything goes wrong. 3598** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3599** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3600** [SQLITE_MAX_LENGTH]. 3601** ^[SQLITE_RANGE] is returned if the parameter 3602** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3603** 3604** See also: [sqlite3_bind_parameter_count()], 3605** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3606*/ 3607SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3608SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3609 void(*)(void*)); 3610SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3611SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3612SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3613SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3614SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3615SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3616SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3617 void(*)(void*), unsigned char encoding); 3618SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3619SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3620SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3621 3622/* 3623** CAPI3REF: Number Of SQL Parameters 3624** METHOD: sqlite3_stmt 3625** 3626** ^This routine can be used to find the number of [SQL parameters] 3627** in a [prepared statement]. SQL parameters are tokens of the 3628** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3629** placeholders for values that are [sqlite3_bind_blob | bound] 3630** to the parameters at a later time. 3631** 3632** ^(This routine actually returns the index of the largest (rightmost) 3633** parameter. For all forms except ?NNN, this will correspond to the 3634** number of unique parameters. If parameters of the ?NNN form are used, 3635** there may be gaps in the list.)^ 3636** 3637** See also: [sqlite3_bind_blob|sqlite3_bind()], 3638** [sqlite3_bind_parameter_name()], and 3639** [sqlite3_bind_parameter_index()]. 3640*/ 3641SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3642 3643/* 3644** CAPI3REF: Name Of A Host Parameter 3645** METHOD: sqlite3_stmt 3646** 3647** ^The sqlite3_bind_parameter_name(P,N) interface returns 3648** the name of the N-th [SQL parameter] in the [prepared statement] P. 3649** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3650** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3651** respectively. 3652** In other words, the initial ":" or "$" or "@" or "?" 3653** is included as part of the name.)^ 3654** ^Parameters of the form "?" without a following integer have no name 3655** and are referred to as "nameless" or "anonymous parameters". 3656** 3657** ^The first host parameter has an index of 1, not 0. 3658** 3659** ^If the value N is out of range or if the N-th parameter is 3660** nameless, then NULL is returned. ^The returned string is 3661** always in UTF-8 encoding even if the named parameter was 3662** originally specified as UTF-16 in [sqlite3_prepare16()] or 3663** [sqlite3_prepare16_v2()]. 3664** 3665** See also: [sqlite3_bind_blob|sqlite3_bind()], 3666** [sqlite3_bind_parameter_count()], and 3667** [sqlite3_bind_parameter_index()]. 3668*/ 3669SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3670 3671/* 3672** CAPI3REF: Index Of A Parameter With A Given Name 3673** METHOD: sqlite3_stmt 3674** 3675** ^Return the index of an SQL parameter given its name. ^The 3676** index value returned is suitable for use as the second 3677** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3678** is returned if no matching parameter is found. ^The parameter 3679** name must be given in UTF-8 even if the original statement 3680** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3681** 3682** See also: [sqlite3_bind_blob|sqlite3_bind()], 3683** [sqlite3_bind_parameter_count()], and 3684** [sqlite3_bind_parameter_name()]. 3685*/ 3686SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3687 3688/* 3689** CAPI3REF: Reset All Bindings On A Prepared Statement 3690** METHOD: sqlite3_stmt 3691** 3692** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3693** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3694** ^Use this routine to reset all host parameters to NULL. 3695*/ 3696SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3697 3698/* 3699** CAPI3REF: Number Of Columns In A Result Set 3700** METHOD: sqlite3_stmt 3701** 3702** ^Return the number of columns in the result set returned by the 3703** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3704** statement that does not return data (for example an [UPDATE]). 3705** 3706** See also: [sqlite3_data_count()] 3707*/ 3708SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3709 3710/* 3711** CAPI3REF: Column Names In A Result Set 3712** METHOD: sqlite3_stmt 3713** 3714** ^These routines return the name assigned to a particular column 3715** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3716** interface returns a pointer to a zero-terminated UTF-8 string 3717** and sqlite3_column_name16() returns a pointer to a zero-terminated 3718** UTF-16 string. ^The first parameter is the [prepared statement] 3719** that implements the [SELECT] statement. ^The second parameter is the 3720** column number. ^The leftmost column is number 0. 3721** 3722** ^The returned string pointer is valid until either the [prepared statement] 3723** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3724** reprepared by the first call to [sqlite3_step()] for a particular run 3725** or until the next call to 3726** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3727** 3728** ^If sqlite3_malloc() fails during the processing of either routine 3729** (for example during a conversion from UTF-8 to UTF-16) then a 3730** NULL pointer is returned. 3731** 3732** ^The name of a result column is the value of the "AS" clause for 3733** that column, if there is an AS clause. If there is no AS clause 3734** then the name of the column is unspecified and may change from 3735** one release of SQLite to the next. 3736*/ 3737SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3738SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3739 3740/* 3741** CAPI3REF: Source Of Data In A Query Result 3742** METHOD: sqlite3_stmt 3743** 3744** ^These routines provide a means to determine the database, table, and 3745** table column that is the origin of a particular result column in 3746** [SELECT] statement. 3747** ^The name of the database or table or column can be returned as 3748** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3749** the database name, the _table_ routines return the table name, and 3750** the origin_ routines return the column name. 3751** ^The returned string is valid until the [prepared statement] is destroyed 3752** using [sqlite3_finalize()] or until the statement is automatically 3753** reprepared by the first call to [sqlite3_step()] for a particular run 3754** or until the same information is requested 3755** again in a different encoding. 3756** 3757** ^The names returned are the original un-aliased names of the 3758** database, table, and column. 3759** 3760** ^The first argument to these interfaces is a [prepared statement]. 3761** ^These functions return information about the Nth result column returned by 3762** the statement, where N is the second function argument. 3763** ^The left-most column is column 0 for these routines. 3764** 3765** ^If the Nth column returned by the statement is an expression or 3766** subquery and is not a column value, then all of these functions return 3767** NULL. ^These routine might also return NULL if a memory allocation error 3768** occurs. ^Otherwise, they return the name of the attached database, table, 3769** or column that query result column was extracted from. 3770** 3771** ^As with all other SQLite APIs, those whose names end with "16" return 3772** UTF-16 encoded strings and the other functions return UTF-8. 3773** 3774** ^These APIs are only available if the library was compiled with the 3775** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3776** 3777** If two or more threads call one or more of these routines against the same 3778** prepared statement and column at the same time then the results are 3779** undefined. 3780** 3781** If two or more threads call one or more 3782** [sqlite3_column_database_name | column metadata interfaces] 3783** for the same [prepared statement] and result column 3784** at the same time then the results are undefined. 3785*/ 3786SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3787SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3788SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3789SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3790SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3791SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3792 3793/* 3794** CAPI3REF: Declared Datatype Of A Query Result 3795** METHOD: sqlite3_stmt 3796** 3797** ^(The first parameter is a [prepared statement]. 3798** If this statement is a [SELECT] statement and the Nth column of the 3799** returned result set of that [SELECT] is a table column (not an 3800** expression or subquery) then the declared type of the table 3801** column is returned.)^ ^If the Nth column of the result set is an 3802** expression or subquery, then a NULL pointer is returned. 3803** ^The returned string is always UTF-8 encoded. 3804** 3805** ^(For example, given the database schema: 3806** 3807** CREATE TABLE t1(c1 VARIANT); 3808** 3809** and the following statement to be compiled: 3810** 3811** SELECT c1 + 1, c1 FROM t1; 3812** 3813** this routine would return the string "VARIANT" for the second result 3814** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3815** 3816** ^SQLite uses dynamic run-time typing. ^So just because a column 3817** is declared to contain a particular type does not mean that the 3818** data stored in that column is of the declared type. SQLite is 3819** strongly typed, but the typing is dynamic not static. ^Type 3820** is associated with individual values, not with the containers 3821** used to hold those values. 3822*/ 3823SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3824SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3825 3826/* 3827** CAPI3REF: Evaluate An SQL Statement 3828** METHOD: sqlite3_stmt 3829** 3830** After a [prepared statement] has been prepared using either 3831** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3832** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3833** must be called one or more times to evaluate the statement. 3834** 3835** The details of the behavior of the sqlite3_step() interface depend 3836** on whether the statement was prepared using the newer "v2" interface 3837** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3838** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3839** new "v2" interface is recommended for new applications but the legacy 3840** interface will continue to be supported. 3841** 3842** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3843** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3844** ^With the "v2" interface, any of the other [result codes] or 3845** [extended result codes] might be returned as well. 3846** 3847** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3848** database locks it needs to do its job. ^If the statement is a [COMMIT] 3849** or occurs outside of an explicit transaction, then you can retry the 3850** statement. If the statement is not a [COMMIT] and occurs within an 3851** explicit transaction then you should rollback the transaction before 3852** continuing. 3853** 3854** ^[SQLITE_DONE] means that the statement has finished executing 3855** successfully. sqlite3_step() should not be called again on this virtual 3856** machine without first calling [sqlite3_reset()] to reset the virtual 3857** machine back to its initial state. 3858** 3859** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3860** is returned each time a new row of data is ready for processing by the 3861** caller. The values may be accessed using the [column access functions]. 3862** sqlite3_step() is called again to retrieve the next row of data. 3863** 3864** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3865** violation) has occurred. sqlite3_step() should not be called again on 3866** the VM. More information may be found by calling [sqlite3_errmsg()]. 3867** ^With the legacy interface, a more specific error code (for example, 3868** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3869** can be obtained by calling [sqlite3_reset()] on the 3870** [prepared statement]. ^In the "v2" interface, 3871** the more specific error code is returned directly by sqlite3_step(). 3872** 3873** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3874** Perhaps it was called on a [prepared statement] that has 3875** already been [sqlite3_finalize | finalized] or on one that had 3876** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3877** be the case that the same database connection is being used by two or 3878** more threads at the same moment in time. 3879** 3880** For all versions of SQLite up to and including 3.6.23.1, a call to 3881** [sqlite3_reset()] was required after sqlite3_step() returned anything 3882** other than [SQLITE_ROW] before any subsequent invocation of 3883** sqlite3_step(). Failure to reset the prepared statement using 3884** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3885** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3886** calling [sqlite3_reset()] automatically in this circumstance rather 3887** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3888** break because any application that ever receives an SQLITE_MISUSE error 3889** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3890** can be used to restore the legacy behavior. 3891** 3892** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3893** API always returns a generic error code, [SQLITE_ERROR], following any 3894** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3895** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3896** specific [error codes] that better describes the error. 3897** We admit that this is a goofy design. The problem has been fixed 3898** with the "v2" interface. If you prepare all of your SQL statements 3899** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3900** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3901** then the more specific [error codes] are returned directly 3902** by sqlite3_step(). The use of the "v2" interface is recommended. 3903*/ 3904SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 3905 3906/* 3907** CAPI3REF: Number of columns in a result set 3908** METHOD: sqlite3_stmt 3909** 3910** ^The sqlite3_data_count(P) interface returns the number of columns in the 3911** current row of the result set of [prepared statement] P. 3912** ^If prepared statement P does not have results ready to return 3913** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3914** interfaces) then sqlite3_data_count(P) returns 0. 3915** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3916** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3917** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3918** will return non-zero if previous call to [sqlite3_step](P) returned 3919** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3920** where it always returns zero since each step of that multi-step 3921** pragma returns 0 columns of data. 3922** 3923** See also: [sqlite3_column_count()] 3924*/ 3925SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 3926 3927/* 3928** CAPI3REF: Fundamental Datatypes 3929** KEYWORDS: SQLITE_TEXT 3930** 3931** ^(Every value in SQLite has one of five fundamental datatypes: 3932** 3933** <ul> 3934** <li> 64-bit signed integer 3935** <li> 64-bit IEEE floating point number 3936** <li> string 3937** <li> BLOB 3938** <li> NULL 3939** </ul>)^ 3940** 3941** These constants are codes for each of those types. 3942** 3943** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3944** for a completely different meaning. Software that links against both 3945** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3946** SQLITE_TEXT. 3947*/ 3948#define SQLITE_INTEGER 1 3949#define SQLITE_FLOAT 2 3950#define SQLITE_BLOB 4 3951#define SQLITE_NULL 5 3952#ifdef SQLITE_TEXT 3953# undef SQLITE_TEXT 3954#else 3955# define SQLITE_TEXT 3 3956#endif 3957#define SQLITE3_TEXT 3 3958 3959/* 3960** CAPI3REF: Result Values From A Query 3961** KEYWORDS: {column access functions} 3962** METHOD: sqlite3_stmt 3963** 3964** ^These routines return information about a single column of the current 3965** result row of a query. ^In every case the first argument is a pointer 3966** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3967** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3968** and the second argument is the index of the column for which information 3969** should be returned. ^The leftmost column of the result set has the index 0. 3970** ^The number of columns in the result can be determined using 3971** [sqlite3_column_count()]. 3972** 3973** If the SQL statement does not currently point to a valid row, or if the 3974** column index is out of range, the result is undefined. 3975** These routines may only be called when the most recent call to 3976** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3977** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3978** If any of these routines are called after [sqlite3_reset()] or 3979** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3980** something other than [SQLITE_ROW], the results are undefined. 3981** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3982** are called from a different thread while any of these routines 3983** are pending, then the results are undefined. 3984** 3985** ^The sqlite3_column_type() routine returns the 3986** [SQLITE_INTEGER | datatype code] for the initial data type 3987** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3988** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3989** returned by sqlite3_column_type() is only meaningful if no type 3990** conversions have occurred as described below. After a type conversion, 3991** the value returned by sqlite3_column_type() is undefined. Future 3992** versions of SQLite may change the behavior of sqlite3_column_type() 3993** following a type conversion. 3994** 3995** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3996** routine returns the number of bytes in that BLOB or string. 3997** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3998** the string to UTF-8 and then returns the number of bytes. 3999** ^If the result is a numeric value then sqlite3_column_bytes() uses 4000** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4001** the number of bytes in that string. 4002** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4003** 4004** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4005** routine returns the number of bytes in that BLOB or string. 4006** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4007** the string to UTF-16 and then returns the number of bytes. 4008** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4009** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4010** the number of bytes in that string. 4011** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4012** 4013** ^The values returned by [sqlite3_column_bytes()] and 4014** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4015** of the string. ^For clarity: the values returned by 4016** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4017** bytes in the string, not the number of characters. 4018** 4019** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4020** even empty strings, are always zero-terminated. ^The return 4021** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4022** 4023** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4024** [unprotected sqlite3_value] object. In a multithreaded environment, 4025** an unprotected sqlite3_value object may only be used safely with 4026** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4027** If the [unprotected sqlite3_value] object returned by 4028** [sqlite3_column_value()] is used in any other way, including calls 4029** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4030** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4031** 4032** These routines attempt to convert the value where appropriate. ^For 4033** example, if the internal representation is FLOAT and a text result 4034** is requested, [sqlite3_snprintf()] is used internally to perform the 4035** conversion automatically. ^(The following table details the conversions 4036** that are applied: 4037** 4038** <blockquote> 4039** <table border="1"> 4040** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4041** 4042** <tr><td> NULL <td> INTEGER <td> Result is 0 4043** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4044** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4045** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4046** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4047** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4048** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4049** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4050** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4051** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4052** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4053** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4054** <tr><td> TEXT <td> BLOB <td> No change 4055** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4056** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4057** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4058** </table> 4059** </blockquote>)^ 4060** 4061** Note that when type conversions occur, pointers returned by prior 4062** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4063** sqlite3_column_text16() may be invalidated. 4064** Type conversions and pointer invalidations might occur 4065** in the following cases: 4066** 4067** <ul> 4068** <li> The initial content is a BLOB and sqlite3_column_text() or 4069** sqlite3_column_text16() is called. A zero-terminator might 4070** need to be added to the string.</li> 4071** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4072** sqlite3_column_text16() is called. The content must be converted 4073** to UTF-16.</li> 4074** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4075** sqlite3_column_text() is called. The content must be converted 4076** to UTF-8.</li> 4077** </ul> 4078** 4079** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4080** not invalidate a prior pointer, though of course the content of the buffer 4081** that the prior pointer references will have been modified. Other kinds 4082** of conversion are done in place when it is possible, but sometimes they 4083** are not possible and in those cases prior pointers are invalidated. 4084** 4085** The safest policy is to invoke these routines 4086** in one of the following ways: 4087** 4088** <ul> 4089** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4090** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4091** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4092** </ul> 4093** 4094** In other words, you should call sqlite3_column_text(), 4095** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4096** into the desired format, then invoke sqlite3_column_bytes() or 4097** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4098** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4099** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4100** with calls to sqlite3_column_bytes(). 4101** 4102** ^The pointers returned are valid until a type conversion occurs as 4103** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4104** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4105** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4106** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4107** [sqlite3_free()]. 4108** 4109** ^(If a memory allocation error occurs during the evaluation of any 4110** of these routines, a default value is returned. The default value 4111** is either the integer 0, the floating point number 0.0, or a NULL 4112** pointer. Subsequent calls to [sqlite3_errcode()] will return 4113** [SQLITE_NOMEM].)^ 4114*/ 4115SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4116SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4117SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4118SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4119SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4120SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4121SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4122SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4123SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4124SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4125 4126/* 4127** CAPI3REF: Destroy A Prepared Statement Object 4128** DESTRUCTOR: sqlite3_stmt 4129** 4130** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4131** ^If the most recent evaluation of the statement encountered no errors 4132** or if the statement is never been evaluated, then sqlite3_finalize() returns 4133** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4134** sqlite3_finalize(S) returns the appropriate [error code] or 4135** [extended error code]. 4136** 4137** ^The sqlite3_finalize(S) routine can be called at any point during 4138** the life cycle of [prepared statement] S: 4139** before statement S is ever evaluated, after 4140** one or more calls to [sqlite3_reset()], or after any call 4141** to [sqlite3_step()] regardless of whether or not the statement has 4142** completed execution. 4143** 4144** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4145** 4146** The application must finalize every [prepared statement] in order to avoid 4147** resource leaks. It is a grievous error for the application to try to use 4148** a prepared statement after it has been finalized. Any use of a prepared 4149** statement after it has been finalized can result in undefined and 4150** undesirable behavior such as segfaults and heap corruption. 4151*/ 4152SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4153 4154/* 4155** CAPI3REF: Reset A Prepared Statement Object 4156** METHOD: sqlite3_stmt 4157** 4158** The sqlite3_reset() function is called to reset a [prepared statement] 4159** object back to its initial state, ready to be re-executed. 4160** ^Any SQL statement variables that had values bound to them using 4161** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4162** Use [sqlite3_clear_bindings()] to reset the bindings. 4163** 4164** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4165** back to the beginning of its program. 4166** 4167** ^If the most recent call to [sqlite3_step(S)] for the 4168** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4169** or if [sqlite3_step(S)] has never before been called on S, 4170** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4171** 4172** ^If the most recent call to [sqlite3_step(S)] for the 4173** [prepared statement] S indicated an error, then 4174** [sqlite3_reset(S)] returns an appropriate [error code]. 4175** 4176** ^The [sqlite3_reset(S)] interface does not change the values 4177** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4178*/ 4179SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4180 4181/* 4182** CAPI3REF: Create Or Redefine SQL Functions 4183** KEYWORDS: {function creation routines} 4184** KEYWORDS: {application-defined SQL function} 4185** KEYWORDS: {application-defined SQL functions} 4186** METHOD: sqlite3 4187** 4188** ^These functions (collectively known as "function creation routines") 4189** are used to add SQL functions or aggregates or to redefine the behavior 4190** of existing SQL functions or aggregates. The only differences between 4191** these routines are the text encoding expected for 4192** the second parameter (the name of the function being created) 4193** and the presence or absence of a destructor callback for 4194** the application data pointer. 4195** 4196** ^The first parameter is the [database connection] to which the SQL 4197** function is to be added. ^If an application uses more than one database 4198** connection then application-defined SQL functions must be added 4199** to each database connection separately. 4200** 4201** ^The second parameter is the name of the SQL function to be created or 4202** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4203** representation, exclusive of the zero-terminator. ^Note that the name 4204** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4205** ^Any attempt to create a function with a longer name 4206** will result in [SQLITE_MISUSE] being returned. 4207** 4208** ^The third parameter (nArg) 4209** is the number of arguments that the SQL function or 4210** aggregate takes. ^If this parameter is -1, then the SQL function or 4211** aggregate may take any number of arguments between 0 and the limit 4212** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4213** parameter is less than -1 or greater than 127 then the behavior is 4214** undefined. 4215** 4216** ^The fourth parameter, eTextRep, specifies what 4217** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4218** its parameters. The application should set this parameter to 4219** [SQLITE_UTF16LE] if the function implementation invokes 4220** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4221** implementation invokes [sqlite3_value_text16be()] on an input, or 4222** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4223** otherwise. ^The same SQL function may be registered multiple times using 4224** different preferred text encodings, with different implementations for 4225** each encoding. 4226** ^When multiple implementations of the same function are available, SQLite 4227** will pick the one that involves the least amount of data conversion. 4228** 4229** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4230** to signal that the function will always return the same result given 4231** the same inputs within a single SQL statement. Most SQL functions are 4232** deterministic. The built-in [random()] SQL function is an example of a 4233** function that is not deterministic. The SQLite query planner is able to 4234** perform additional optimizations on deterministic functions, so use 4235** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4236** 4237** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4238** function can gain access to this pointer using [sqlite3_user_data()].)^ 4239** 4240** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4241** pointers to C-language functions that implement the SQL function or 4242** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4243** callback only; NULL pointers must be passed as the xStep and xFinal 4244** parameters. ^An aggregate SQL function requires an implementation of xStep 4245** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4246** SQL function or aggregate, pass NULL pointers for all three function 4247** callbacks. 4248** 4249** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4250** then it is destructor for the application data pointer. 4251** The destructor is invoked when the function is deleted, either by being 4252** overloaded or when the database connection closes.)^ 4253** ^The destructor is also invoked if the call to 4254** sqlite3_create_function_v2() fails. 4255** ^When the destructor callback of the tenth parameter is invoked, it 4256** is passed a single argument which is a copy of the application data 4257** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4258** 4259** ^It is permitted to register multiple implementations of the same 4260** functions with the same name but with either differing numbers of 4261** arguments or differing preferred text encodings. ^SQLite will use 4262** the implementation that most closely matches the way in which the 4263** SQL function is used. ^A function implementation with a non-negative 4264** nArg parameter is a better match than a function implementation with 4265** a negative nArg. ^A function where the preferred text encoding 4266** matches the database encoding is a better 4267** match than a function where the encoding is different. 4268** ^A function where the encoding difference is between UTF16le and UTF16be 4269** is a closer match than a function where the encoding difference is 4270** between UTF8 and UTF16. 4271** 4272** ^Built-in functions may be overloaded by new application-defined functions. 4273** 4274** ^An application-defined function is permitted to call other 4275** SQLite interfaces. However, such calls must not 4276** close the database connection nor finalize or reset the prepared 4277** statement in which the function is running. 4278*/ 4279SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4280 sqlite3 *db, 4281 const char *zFunctionName, 4282 int nArg, 4283 int eTextRep, 4284 void *pApp, 4285 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4286 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4287 void (*xFinal)(sqlite3_context*) 4288); 4289SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4290 sqlite3 *db, 4291 const void *zFunctionName, 4292 int nArg, 4293 int eTextRep, 4294 void *pApp, 4295 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4296 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4297 void (*xFinal)(sqlite3_context*) 4298); 4299SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4300 sqlite3 *db, 4301 const char *zFunctionName, 4302 int nArg, 4303 int eTextRep, 4304 void *pApp, 4305 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4306 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4307 void (*xFinal)(sqlite3_context*), 4308 void(*xDestroy)(void*) 4309); 4310 4311/* 4312** CAPI3REF: Text Encodings 4313** 4314** These constant define integer codes that represent the various 4315** text encodings supported by SQLite. 4316*/ 4317#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4318#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4319#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4320#define SQLITE_UTF16 4 /* Use native byte order */ 4321#define SQLITE_ANY 5 /* Deprecated */ 4322#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4323 4324/* 4325** CAPI3REF: Function Flags 4326** 4327** These constants may be ORed together with the 4328** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4329** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4330** [sqlite3_create_function_v2()]. 4331*/ 4332#define SQLITE_DETERMINISTIC 0x800 4333 4334/* 4335** CAPI3REF: Deprecated Functions 4336** DEPRECATED 4337** 4338** These functions are [deprecated]. In order to maintain 4339** backwards compatibility with older code, these functions continue 4340** to be supported. However, new applications should avoid 4341** the use of these functions. To encourage programmers to avoid 4342** these functions, we will not explain what they do. 4343*/ 4344#ifndef SQLITE_OMIT_DEPRECATED 4345SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4346SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4347SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4348SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4349SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4350SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4351 void*,sqlite3_int64); 4352#endif 4353 4354/* 4355** CAPI3REF: Obtaining SQL Values 4356** METHOD: sqlite3_value 4357** 4358** The C-language implementation of SQL functions and aggregates uses 4359** this set of interface routines to access the parameter values on 4360** the function or aggregate. 4361** 4362** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4363** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4364** define callbacks that implement the SQL functions and aggregates. 4365** The 3rd parameter to these callbacks is an array of pointers to 4366** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4367** each parameter to the SQL function. These routines are used to 4368** extract values from the [sqlite3_value] objects. 4369** 4370** These routines work only with [protected sqlite3_value] objects. 4371** Any attempt to use these routines on an [unprotected sqlite3_value] 4372** object results in undefined behavior. 4373** 4374** ^These routines work just like the corresponding [column access functions] 4375** except that these routines take a single [protected sqlite3_value] object 4376** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4377** 4378** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4379** in the native byte-order of the host machine. ^The 4380** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4381** extract UTF-16 strings as big-endian and little-endian respectively. 4382** 4383** ^(The sqlite3_value_numeric_type() interface attempts to apply 4384** numeric affinity to the value. This means that an attempt is 4385** made to convert the value to an integer or floating point. If 4386** such a conversion is possible without loss of information (in other 4387** words, if the value is a string that looks like a number) 4388** then the conversion is performed. Otherwise no conversion occurs. 4389** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4390** 4391** Please pay particular attention to the fact that the pointer returned 4392** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4393** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4394** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4395** or [sqlite3_value_text16()]. 4396** 4397** These routines must be called from the same thread as 4398** the SQL function that supplied the [sqlite3_value*] parameters. 4399*/ 4400SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4401SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4402SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4403SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4404SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4405SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4406SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4407SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4408SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4409SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4410SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4411SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4412 4413/* 4414** CAPI3REF: Finding The Subtype Of SQL Values 4415** METHOD: sqlite3_value 4416** 4417** The sqlite3_value_subtype(V) function returns the subtype for 4418** an [application-defined SQL function] argument V. The subtype 4419** information can be used to pass a limited amount of context from 4420** one SQL function to another. Use the [sqlite3_result_subtype()] 4421** routine to set the subtype for the return value of an SQL function. 4422** 4423** SQLite makes no use of subtype itself. It merely passes the subtype 4424** from the result of one [application-defined SQL function] into the 4425** input of another. 4426*/ 4427SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*); 4428 4429/* 4430** CAPI3REF: Copy And Free SQL Values 4431** METHOD: sqlite3_value 4432** 4433** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4434** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4435** is a [protected sqlite3_value] object even if the input is not. 4436** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4437** memory allocation fails. 4438** 4439** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4440** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4441** then sqlite3_value_free(V) is a harmless no-op. 4442*/ 4443SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*); 4444SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*); 4445 4446/* 4447** CAPI3REF: Obtain Aggregate Function Context 4448** METHOD: sqlite3_context 4449** 4450** Implementations of aggregate SQL functions use this 4451** routine to allocate memory for storing their state. 4452** 4453** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4454** for a particular aggregate function, SQLite 4455** allocates N of memory, zeroes out that memory, and returns a pointer 4456** to the new memory. ^On second and subsequent calls to 4457** sqlite3_aggregate_context() for the same aggregate function instance, 4458** the same buffer is returned. Sqlite3_aggregate_context() is normally 4459** called once for each invocation of the xStep callback and then one 4460** last time when the xFinal callback is invoked. ^(When no rows match 4461** an aggregate query, the xStep() callback of the aggregate function 4462** implementation is never called and xFinal() is called exactly once. 4463** In those cases, sqlite3_aggregate_context() might be called for the 4464** first time from within xFinal().)^ 4465** 4466** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4467** when first called if N is less than or equal to zero or if a memory 4468** allocate error occurs. 4469** 4470** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4471** determined by the N parameter on first successful call. Changing the 4472** value of N in subsequent call to sqlite3_aggregate_context() within 4473** the same aggregate function instance will not resize the memory 4474** allocation.)^ Within the xFinal callback, it is customary to set 4475** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4476** pointless memory allocations occur. 4477** 4478** ^SQLite automatically frees the memory allocated by 4479** sqlite3_aggregate_context() when the aggregate query concludes. 4480** 4481** The first parameter must be a copy of the 4482** [sqlite3_context | SQL function context] that is the first parameter 4483** to the xStep or xFinal callback routine that implements the aggregate 4484** function. 4485** 4486** This routine must be called from the same thread in which 4487** the aggregate SQL function is running. 4488*/ 4489SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4490 4491/* 4492** CAPI3REF: User Data For Functions 4493** METHOD: sqlite3_context 4494** 4495** ^The sqlite3_user_data() interface returns a copy of 4496** the pointer that was the pUserData parameter (the 5th parameter) 4497** of the [sqlite3_create_function()] 4498** and [sqlite3_create_function16()] routines that originally 4499** registered the application defined function. 4500** 4501** This routine must be called from the same thread in which 4502** the application-defined function is running. 4503*/ 4504SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4505 4506/* 4507** CAPI3REF: Database Connection For Functions 4508** METHOD: sqlite3_context 4509** 4510** ^The sqlite3_context_db_handle() interface returns a copy of 4511** the pointer to the [database connection] (the 1st parameter) 4512** of the [sqlite3_create_function()] 4513** and [sqlite3_create_function16()] routines that originally 4514** registered the application defined function. 4515*/ 4516SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4517 4518/* 4519** CAPI3REF: Function Auxiliary Data 4520** METHOD: sqlite3_context 4521** 4522** These functions may be used by (non-aggregate) SQL functions to 4523** associate metadata with argument values. If the same value is passed to 4524** multiple invocations of the same SQL function during query execution, under 4525** some circumstances the associated metadata may be preserved. An example 4526** of where this might be useful is in a regular-expression matching 4527** function. The compiled version of the regular expression can be stored as 4528** metadata associated with the pattern string. 4529** Then as long as the pattern string remains the same, 4530** the compiled regular expression can be reused on multiple 4531** invocations of the same function. 4532** 4533** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4534** associated by the sqlite3_set_auxdata() function with the Nth argument 4535** value to the application-defined function. ^If there is no metadata 4536** associated with the function argument, this sqlite3_get_auxdata() interface 4537** returns a NULL pointer. 4538** 4539** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4540** argument of the application-defined function. ^Subsequent 4541** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4542** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4543** NULL if the metadata has been discarded. 4544** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4545** SQLite will invoke the destructor function X with parameter P exactly 4546** once, when the metadata is discarded. 4547** SQLite is free to discard the metadata at any time, including: <ul> 4548** <li> when the corresponding function parameter changes, or 4549** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4550** SQL statement, or 4551** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4552** <li> during the original sqlite3_set_auxdata() call when a memory 4553** allocation error occurs. </ul>)^ 4554** 4555** Note the last bullet in particular. The destructor X in 4556** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4557** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4558** should be called near the end of the function implementation and the 4559** function implementation should not make any use of P after 4560** sqlite3_set_auxdata() has been called. 4561** 4562** ^(In practice, metadata is preserved between function calls for 4563** function parameters that are compile-time constants, including literal 4564** values and [parameters] and expressions composed from the same.)^ 4565** 4566** These routines must be called from the same thread in which 4567** the SQL function is running. 4568*/ 4569SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4570SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4571 4572 4573/* 4574** CAPI3REF: Constants Defining Special Destructor Behavior 4575** 4576** These are special values for the destructor that is passed in as the 4577** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4578** argument is SQLITE_STATIC, it means that the content pointer is constant 4579** and will never change. It does not need to be destroyed. ^The 4580** SQLITE_TRANSIENT value means that the content will likely change in 4581** the near future and that SQLite should make its own private copy of 4582** the content before returning. 4583** 4584** The typedef is necessary to work around problems in certain 4585** C++ compilers. 4586*/ 4587typedef void (*sqlite3_destructor_type)(void*); 4588#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4589#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4590 4591/* 4592** CAPI3REF: Setting The Result Of An SQL Function 4593** METHOD: sqlite3_context 4594** 4595** These routines are used by the xFunc or xFinal callbacks that 4596** implement SQL functions and aggregates. See 4597** [sqlite3_create_function()] and [sqlite3_create_function16()] 4598** for additional information. 4599** 4600** These functions work very much like the [parameter binding] family of 4601** functions used to bind values to host parameters in prepared statements. 4602** Refer to the [SQL parameter] documentation for additional information. 4603** 4604** ^The sqlite3_result_blob() interface sets the result from 4605** an application-defined function to be the BLOB whose content is pointed 4606** to by the second parameter and which is N bytes long where N is the 4607** third parameter. 4608** 4609** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4610** interfaces set the result of the application-defined function to be 4611** a BLOB containing all zero bytes and N bytes in size. 4612** 4613** ^The sqlite3_result_double() interface sets the result from 4614** an application-defined function to be a floating point value specified 4615** by its 2nd argument. 4616** 4617** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4618** cause the implemented SQL function to throw an exception. 4619** ^SQLite uses the string pointed to by the 4620** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4621** as the text of an error message. ^SQLite interprets the error 4622** message string from sqlite3_result_error() as UTF-8. ^SQLite 4623** interprets the string from sqlite3_result_error16() as UTF-16 in native 4624** byte order. ^If the third parameter to sqlite3_result_error() 4625** or sqlite3_result_error16() is negative then SQLite takes as the error 4626** message all text up through the first zero character. 4627** ^If the third parameter to sqlite3_result_error() or 4628** sqlite3_result_error16() is non-negative then SQLite takes that many 4629** bytes (not characters) from the 2nd parameter as the error message. 4630** ^The sqlite3_result_error() and sqlite3_result_error16() 4631** routines make a private copy of the error message text before 4632** they return. Hence, the calling function can deallocate or 4633** modify the text after they return without harm. 4634** ^The sqlite3_result_error_code() function changes the error code 4635** returned by SQLite as a result of an error in a function. ^By default, 4636** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4637** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4638** 4639** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4640** error indicating that a string or BLOB is too long to represent. 4641** 4642** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4643** error indicating that a memory allocation failed. 4644** 4645** ^The sqlite3_result_int() interface sets the return value 4646** of the application-defined function to be the 32-bit signed integer 4647** value given in the 2nd argument. 4648** ^The sqlite3_result_int64() interface sets the return value 4649** of the application-defined function to be the 64-bit signed integer 4650** value given in the 2nd argument. 4651** 4652** ^The sqlite3_result_null() interface sets the return value 4653** of the application-defined function to be NULL. 4654** 4655** ^The sqlite3_result_text(), sqlite3_result_text16(), 4656** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4657** set the return value of the application-defined function to be 4658** a text string which is represented as UTF-8, UTF-16 native byte order, 4659** UTF-16 little endian, or UTF-16 big endian, respectively. 4660** ^The sqlite3_result_text64() interface sets the return value of an 4661** application-defined function to be a text string in an encoding 4662** specified by the fifth (and last) parameter, which must be one 4663** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4664** ^SQLite takes the text result from the application from 4665** the 2nd parameter of the sqlite3_result_text* interfaces. 4666** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4667** is negative, then SQLite takes result text from the 2nd parameter 4668** through the first zero character. 4669** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4670** is non-negative, then as many bytes (not characters) of the text 4671** pointed to by the 2nd parameter are taken as the application-defined 4672** function result. If the 3rd parameter is non-negative, then it 4673** must be the byte offset into the string where the NUL terminator would 4674** appear if the string where NUL terminated. If any NUL characters occur 4675** in the string at a byte offset that is less than the value of the 3rd 4676** parameter, then the resulting string will contain embedded NULs and the 4677** result of expressions operating on strings with embedded NULs is undefined. 4678** ^If the 4th parameter to the sqlite3_result_text* interfaces 4679** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4680** function as the destructor on the text or BLOB result when it has 4681** finished using that result. 4682** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4683** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4684** assumes that the text or BLOB result is in constant space and does not 4685** copy the content of the parameter nor call a destructor on the content 4686** when it has finished using that result. 4687** ^If the 4th parameter to the sqlite3_result_text* interfaces 4688** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4689** then SQLite makes a copy of the result into space obtained from 4690** from [sqlite3_malloc()] before it returns. 4691** 4692** ^The sqlite3_result_value() interface sets the result of 4693** the application-defined function to be a copy of the 4694** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4695** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4696** so that the [sqlite3_value] specified in the parameter may change or 4697** be deallocated after sqlite3_result_value() returns without harm. 4698** ^A [protected sqlite3_value] object may always be used where an 4699** [unprotected sqlite3_value] object is required, so either 4700** kind of [sqlite3_value] object can be used with this interface. 4701** 4702** If these routines are called from within the different thread 4703** than the one containing the application-defined function that received 4704** the [sqlite3_context] pointer, the results are undefined. 4705*/ 4706SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4707SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4708 sqlite3_uint64,void(*)(void*)); 4709SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4710SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4711SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4712SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4713SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4714SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4715SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4716SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4717SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4718SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4719SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4720 void(*)(void*), unsigned char encoding); 4721SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4722SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4723SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4724SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4725SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4726SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4727 4728 4729/* 4730** CAPI3REF: Setting The Subtype Of An SQL Function 4731** METHOD: sqlite3_context 4732** 4733** The sqlite3_result_subtype(C,T) function causes the subtype of 4734** the result from the [application-defined SQL function] with 4735** [sqlite3_context] C to be the value T. Only the lower 8 bits 4736** of the subtype T are preserved in current versions of SQLite; 4737** higher order bits are discarded. 4738** The number of subtype bytes preserved by SQLite might increase 4739** in future releases of SQLite. 4740*/ 4741SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int); 4742 4743/* 4744** CAPI3REF: Define New Collating Sequences 4745** METHOD: sqlite3 4746** 4747** ^These functions add, remove, or modify a [collation] associated 4748** with the [database connection] specified as the first argument. 4749** 4750** ^The name of the collation is a UTF-8 string 4751** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4752** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4753** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4754** considered to be the same name. 4755** 4756** ^(The third argument (eTextRep) must be one of the constants: 4757** <ul> 4758** <li> [SQLITE_UTF8], 4759** <li> [SQLITE_UTF16LE], 4760** <li> [SQLITE_UTF16BE], 4761** <li> [SQLITE_UTF16], or 4762** <li> [SQLITE_UTF16_ALIGNED]. 4763** </ul>)^ 4764** ^The eTextRep argument determines the encoding of strings passed 4765** to the collating function callback, xCallback. 4766** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4767** force strings to be UTF16 with native byte order. 4768** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4769** on an even byte address. 4770** 4771** ^The fourth argument, pArg, is an application data pointer that is passed 4772** through as the first argument to the collating function callback. 4773** 4774** ^The fifth argument, xCallback, is a pointer to the collating function. 4775** ^Multiple collating functions can be registered using the same name but 4776** with different eTextRep parameters and SQLite will use whichever 4777** function requires the least amount of data transformation. 4778** ^If the xCallback argument is NULL then the collating function is 4779** deleted. ^When all collating functions having the same name are deleted, 4780** that collation is no longer usable. 4781** 4782** ^The collating function callback is invoked with a copy of the pArg 4783** application data pointer and with two strings in the encoding specified 4784** by the eTextRep argument. The collating function must return an 4785** integer that is negative, zero, or positive 4786** if the first string is less than, equal to, or greater than the second, 4787** respectively. A collating function must always return the same answer 4788** given the same inputs. If two or more collating functions are registered 4789** to the same collation name (using different eTextRep values) then all 4790** must give an equivalent answer when invoked with equivalent strings. 4791** The collating function must obey the following properties for all 4792** strings A, B, and C: 4793** 4794** <ol> 4795** <li> If A==B then B==A. 4796** <li> If A==B and B==C then A==C. 4797** <li> If A<B THEN B>A. 4798** <li> If A<B and B<C then A<C. 4799** </ol> 4800** 4801** If a collating function fails any of the above constraints and that 4802** collating function is registered and used, then the behavior of SQLite 4803** is undefined. 4804** 4805** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4806** with the addition that the xDestroy callback is invoked on pArg when 4807** the collating function is deleted. 4808** ^Collating functions are deleted when they are overridden by later 4809** calls to the collation creation functions or when the 4810** [database connection] is closed using [sqlite3_close()]. 4811** 4812** ^The xDestroy callback is <u>not</u> called if the 4813** sqlite3_create_collation_v2() function fails. Applications that invoke 4814** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4815** check the return code and dispose of the application data pointer 4816** themselves rather than expecting SQLite to deal with it for them. 4817** This is different from every other SQLite interface. The inconsistency 4818** is unfortunate but cannot be changed without breaking backwards 4819** compatibility. 4820** 4821** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4822*/ 4823SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4824 sqlite3*, 4825 const char *zName, 4826 int eTextRep, 4827 void *pArg, 4828 int(*xCompare)(void*,int,const void*,int,const void*) 4829); 4830SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4831 sqlite3*, 4832 const char *zName, 4833 int eTextRep, 4834 void *pArg, 4835 int(*xCompare)(void*,int,const void*,int,const void*), 4836 void(*xDestroy)(void*) 4837); 4838SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4839 sqlite3*, 4840 const void *zName, 4841 int eTextRep, 4842 void *pArg, 4843 int(*xCompare)(void*,int,const void*,int,const void*) 4844); 4845 4846/* 4847** CAPI3REF: Collation Needed Callbacks 4848** METHOD: sqlite3 4849** 4850** ^To avoid having to register all collation sequences before a database 4851** can be used, a single callback function may be registered with the 4852** [database connection] to be invoked whenever an undefined collation 4853** sequence is required. 4854** 4855** ^If the function is registered using the sqlite3_collation_needed() API, 4856** then it is passed the names of undefined collation sequences as strings 4857** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4858** the names are passed as UTF-16 in machine native byte order. 4859** ^A call to either function replaces the existing collation-needed callback. 4860** 4861** ^(When the callback is invoked, the first argument passed is a copy 4862** of the second argument to sqlite3_collation_needed() or 4863** sqlite3_collation_needed16(). The second argument is the database 4864** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4865** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4866** sequence function required. The fourth parameter is the name of the 4867** required collation sequence.)^ 4868** 4869** The callback function should register the desired collation using 4870** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4871** [sqlite3_create_collation_v2()]. 4872*/ 4873SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 4874 sqlite3*, 4875 void*, 4876 void(*)(void*,sqlite3*,int eTextRep,const char*) 4877); 4878SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 4879 sqlite3*, 4880 void*, 4881 void(*)(void*,sqlite3*,int eTextRep,const void*) 4882); 4883 4884#ifdef SQLITE_HAS_CODEC 4885/* 4886** Specify the key for an encrypted database. This routine should be 4887** called right after sqlite3_open(). 4888** 4889** The code to implement this API is not available in the public release 4890** of SQLite. 4891*/ 4892SQLITE_API int SQLITE_STDCALL sqlite3_key( 4893 sqlite3 *db, /* Database to be rekeyed */ 4894 const void *pKey, int nKey /* The key */ 4895); 4896SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 4897 sqlite3 *db, /* Database to be rekeyed */ 4898 const char *zDbName, /* Name of the database */ 4899 const void *pKey, int nKey /* The key */ 4900); 4901 4902/* 4903** Change the key on an open database. If the current database is not 4904** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4905** database is decrypted. 4906** 4907** The code to implement this API is not available in the public release 4908** of SQLite. 4909*/ 4910SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 4911 sqlite3 *db, /* Database to be rekeyed */ 4912 const void *pKey, int nKey /* The new key */ 4913); 4914SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 4915 sqlite3 *db, /* Database to be rekeyed */ 4916 const char *zDbName, /* Name of the database */ 4917 const void *pKey, int nKey /* The new key */ 4918); 4919 4920/* 4921** Specify the activation key for a SEE database. Unless 4922** activated, none of the SEE routines will work. 4923*/ 4924SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 4925 const char *zPassPhrase /* Activation phrase */ 4926); 4927#endif 4928 4929#ifdef SQLITE_ENABLE_CEROD 4930/* 4931** Specify the activation key for a CEROD database. Unless 4932** activated, none of the CEROD routines will work. 4933*/ 4934SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 4935 const char *zPassPhrase /* Activation phrase */ 4936); 4937#endif 4938 4939/* 4940** CAPI3REF: Suspend Execution For A Short Time 4941** 4942** The sqlite3_sleep() function causes the current thread to suspend execution 4943** for at least a number of milliseconds specified in its parameter. 4944** 4945** If the operating system does not support sleep requests with 4946** millisecond time resolution, then the time will be rounded up to 4947** the nearest second. The number of milliseconds of sleep actually 4948** requested from the operating system is returned. 4949** 4950** ^SQLite implements this interface by calling the xSleep() 4951** method of the default [sqlite3_vfs] object. If the xSleep() method 4952** of the default VFS is not implemented correctly, or not implemented at 4953** all, then the behavior of sqlite3_sleep() may deviate from the description 4954** in the previous paragraphs. 4955*/ 4956SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 4957 4958/* 4959** CAPI3REF: Name Of The Folder Holding Temporary Files 4960** 4961** ^(If this global variable is made to point to a string which is 4962** the name of a folder (a.k.a. directory), then all temporary files 4963** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4964** will be placed in that directory.)^ ^If this variable 4965** is a NULL pointer, then SQLite performs a search for an appropriate 4966** temporary file directory. 4967** 4968** Applications are strongly discouraged from using this global variable. 4969** It is required to set a temporary folder on Windows Runtime (WinRT). 4970** But for all other platforms, it is highly recommended that applications 4971** neither read nor write this variable. This global variable is a relic 4972** that exists for backwards compatibility of legacy applications and should 4973** be avoided in new projects. 4974** 4975** It is not safe to read or modify this variable in more than one 4976** thread at a time. It is not safe to read or modify this variable 4977** if a [database connection] is being used at the same time in a separate 4978** thread. 4979** It is intended that this variable be set once 4980** as part of process initialization and before any SQLite interface 4981** routines have been called and that this variable remain unchanged 4982** thereafter. 4983** 4984** ^The [temp_store_directory pragma] may modify this variable and cause 4985** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4986** the [temp_store_directory pragma] always assumes that any string 4987** that this variable points to is held in memory obtained from 4988** [sqlite3_malloc] and the pragma may attempt to free that memory 4989** using [sqlite3_free]. 4990** Hence, if this variable is modified directly, either it should be 4991** made NULL or made to point to memory obtained from [sqlite3_malloc] 4992** or else the use of the [temp_store_directory pragma] should be avoided. 4993** Except when requested by the [temp_store_directory pragma], SQLite 4994** does not free the memory that sqlite3_temp_directory points to. If 4995** the application wants that memory to be freed, it must do 4996** so itself, taking care to only do so after all [database connection] 4997** objects have been destroyed. 4998** 4999** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5000** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5001** features that require the use of temporary files may fail. Here is an 5002** example of how to do this using C++ with the Windows Runtime: 5003** 5004** <blockquote><pre> 5005** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5006** TemporaryFolder->Path->Data(); 5007** char zPathBuf[MAX_PATH + 1]; 5008** memset(zPathBuf, 0, sizeof(zPathBuf)); 5009** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5010** NULL, NULL); 5011** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5012** </pre></blockquote> 5013*/ 5014SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5015 5016/* 5017** CAPI3REF: Name Of The Folder Holding Database Files 5018** 5019** ^(If this global variable is made to point to a string which is 5020** the name of a folder (a.k.a. directory), then all database files 5021** specified with a relative pathname and created or accessed by 5022** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5023** to be relative to that directory.)^ ^If this variable is a NULL 5024** pointer, then SQLite assumes that all database files specified 5025** with a relative pathname are relative to the current directory 5026** for the process. Only the windows VFS makes use of this global 5027** variable; it is ignored by the unix VFS. 5028** 5029** Changing the value of this variable while a database connection is 5030** open can result in a corrupt database. 5031** 5032** It is not safe to read or modify this variable in more than one 5033** thread at a time. It is not safe to read or modify this variable 5034** if a [database connection] is being used at the same time in a separate 5035** thread. 5036** It is intended that this variable be set once 5037** as part of process initialization and before any SQLite interface 5038** routines have been called and that this variable remain unchanged 5039** thereafter. 5040** 5041** ^The [data_store_directory pragma] may modify this variable and cause 5042** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5043** the [data_store_directory pragma] always assumes that any string 5044** that this variable points to is held in memory obtained from 5045** [sqlite3_malloc] and the pragma may attempt to free that memory 5046** using [sqlite3_free]. 5047** Hence, if this variable is modified directly, either it should be 5048** made NULL or made to point to memory obtained from [sqlite3_malloc] 5049** or else the use of the [data_store_directory pragma] should be avoided. 5050*/ 5051SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5052 5053/* 5054** CAPI3REF: Test For Auto-Commit Mode 5055** KEYWORDS: {autocommit mode} 5056** METHOD: sqlite3 5057** 5058** ^The sqlite3_get_autocommit() interface returns non-zero or 5059** zero if the given database connection is or is not in autocommit mode, 5060** respectively. ^Autocommit mode is on by default. 5061** ^Autocommit mode is disabled by a [BEGIN] statement. 5062** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5063** 5064** If certain kinds of errors occur on a statement within a multi-statement 5065** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5066** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5067** transaction might be rolled back automatically. The only way to 5068** find out whether SQLite automatically rolled back the transaction after 5069** an error is to use this function. 5070** 5071** If another thread changes the autocommit status of the database 5072** connection while this routine is running, then the return value 5073** is undefined. 5074*/ 5075SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 5076 5077/* 5078** CAPI3REF: Find The Database Handle Of A Prepared Statement 5079** METHOD: sqlite3_stmt 5080** 5081** ^The sqlite3_db_handle interface returns the [database connection] handle 5082** to which a [prepared statement] belongs. ^The [database connection] 5083** returned by sqlite3_db_handle is the same [database connection] 5084** that was the first argument 5085** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5086** create the statement in the first place. 5087*/ 5088SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 5089 5090/* 5091** CAPI3REF: Return The Filename For A Database Connection 5092** METHOD: sqlite3 5093** 5094** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5095** associated with database N of connection D. ^The main database file 5096** has the name "main". If there is no attached database N on the database 5097** connection D, or if database N is a temporary or in-memory database, then 5098** a NULL pointer is returned. 5099** 5100** ^The filename returned by this function is the output of the 5101** xFullPathname method of the [VFS]. ^In other words, the filename 5102** will be an absolute pathname, even if the filename used 5103** to open the database originally was a URI or relative pathname. 5104*/ 5105SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5106 5107/* 5108** CAPI3REF: Determine if a database is read-only 5109** METHOD: sqlite3 5110** 5111** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5112** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5113** the name of a database on connection D. 5114*/ 5115SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5116 5117/* 5118** CAPI3REF: Find the next prepared statement 5119** METHOD: sqlite3 5120** 5121** ^This interface returns a pointer to the next [prepared statement] after 5122** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5123** then this interface returns a pointer to the first prepared statement 5124** associated with the database connection pDb. ^If no prepared statement 5125** satisfies the conditions of this routine, it returns NULL. 5126** 5127** The [database connection] pointer D in a call to 5128** [sqlite3_next_stmt(D,S)] must refer to an open database 5129** connection and in particular must not be a NULL pointer. 5130*/ 5131SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5132 5133/* 5134** CAPI3REF: Commit And Rollback Notification Callbacks 5135** METHOD: sqlite3 5136** 5137** ^The sqlite3_commit_hook() interface registers a callback 5138** function to be invoked whenever a transaction is [COMMIT | committed]. 5139** ^Any callback set by a previous call to sqlite3_commit_hook() 5140** for the same database connection is overridden. 5141** ^The sqlite3_rollback_hook() interface registers a callback 5142** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5143** ^Any callback set by a previous call to sqlite3_rollback_hook() 5144** for the same database connection is overridden. 5145** ^The pArg argument is passed through to the callback. 5146** ^If the callback on a commit hook function returns non-zero, 5147** then the commit is converted into a rollback. 5148** 5149** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5150** return the P argument from the previous call of the same function 5151** on the same [database connection] D, or NULL for 5152** the first call for each function on D. 5153** 5154** The commit and rollback hook callbacks are not reentrant. 5155** The callback implementation must not do anything that will modify 5156** the database connection that invoked the callback. Any actions 5157** to modify the database connection must be deferred until after the 5158** completion of the [sqlite3_step()] call that triggered the commit 5159** or rollback hook in the first place. 5160** Note that running any other SQL statements, including SELECT statements, 5161** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5162** the database connections for the meaning of "modify" in this paragraph. 5163** 5164** ^Registering a NULL function disables the callback. 5165** 5166** ^When the commit hook callback routine returns zero, the [COMMIT] 5167** operation is allowed to continue normally. ^If the commit hook 5168** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5169** ^The rollback hook is invoked on a rollback that results from a commit 5170** hook returning non-zero, just as it would be with any other rollback. 5171** 5172** ^For the purposes of this API, a transaction is said to have been 5173** rolled back if an explicit "ROLLBACK" statement is executed, or 5174** an error or constraint causes an implicit rollback to occur. 5175** ^The rollback callback is not invoked if a transaction is 5176** automatically rolled back because the database connection is closed. 5177** 5178** See also the [sqlite3_update_hook()] interface. 5179*/ 5180SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5181SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5182 5183/* 5184** CAPI3REF: Data Change Notification Callbacks 5185** METHOD: sqlite3 5186** 5187** ^The sqlite3_update_hook() interface registers a callback function 5188** with the [database connection] identified by the first argument 5189** to be invoked whenever a row is updated, inserted or deleted in 5190** a rowid table. 5191** ^Any callback set by a previous call to this function 5192** for the same database connection is overridden. 5193** 5194** ^The second argument is a pointer to the function to invoke when a 5195** row is updated, inserted or deleted in a rowid table. 5196** ^The first argument to the callback is a copy of the third argument 5197** to sqlite3_update_hook(). 5198** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5199** or [SQLITE_UPDATE], depending on the operation that caused the callback 5200** to be invoked. 5201** ^The third and fourth arguments to the callback contain pointers to the 5202** database and table name containing the affected row. 5203** ^The final callback parameter is the [rowid] of the row. 5204** ^In the case of an update, this is the [rowid] after the update takes place. 5205** 5206** ^(The update hook is not invoked when internal system tables are 5207** modified (i.e. sqlite_master and sqlite_sequence).)^ 5208** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5209** 5210** ^In the current implementation, the update hook 5211** is not invoked when duplication rows are deleted because of an 5212** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5213** invoked when rows are deleted using the [truncate optimization]. 5214** The exceptions defined in this paragraph might change in a future 5215** release of SQLite. 5216** 5217** The update hook implementation must not do anything that will modify 5218** the database connection that invoked the update hook. Any actions 5219** to modify the database connection must be deferred until after the 5220** completion of the [sqlite3_step()] call that triggered the update hook. 5221** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5222** database connections for the meaning of "modify" in this paragraph. 5223** 5224** ^The sqlite3_update_hook(D,C,P) function 5225** returns the P argument from the previous call 5226** on the same [database connection] D, or NULL for 5227** the first call on D. 5228** 5229** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5230** interfaces. 5231*/ 5232SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5233 sqlite3*, 5234 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5235 void* 5236); 5237 5238/* 5239** CAPI3REF: Enable Or Disable Shared Pager Cache 5240** 5241** ^(This routine enables or disables the sharing of the database cache 5242** and schema data structures between [database connection | connections] 5243** to the same database. Sharing is enabled if the argument is true 5244** and disabled if the argument is false.)^ 5245** 5246** ^Cache sharing is enabled and disabled for an entire process. 5247** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5248** sharing was enabled or disabled for each thread separately. 5249** 5250** ^(The cache sharing mode set by this interface effects all subsequent 5251** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5252** Existing database connections continue use the sharing mode 5253** that was in effect at the time they were opened.)^ 5254** 5255** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5256** successfully. An [error code] is returned otherwise.)^ 5257** 5258** ^Shared cache is disabled by default. But this might change in 5259** future releases of SQLite. Applications that care about shared 5260** cache setting should set it explicitly. 5261** 5262** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5263** and will always return SQLITE_MISUSE. On those systems, 5264** shared cache mode should be enabled per-database connection via 5265** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5266** 5267** This interface is threadsafe on processors where writing a 5268** 32-bit integer is atomic. 5269** 5270** See Also: [SQLite Shared-Cache Mode] 5271*/ 5272SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5273 5274/* 5275** CAPI3REF: Attempt To Free Heap Memory 5276** 5277** ^The sqlite3_release_memory() interface attempts to free N bytes 5278** of heap memory by deallocating non-essential memory allocations 5279** held by the database library. Memory used to cache database 5280** pages to improve performance is an example of non-essential memory. 5281** ^sqlite3_release_memory() returns the number of bytes actually freed, 5282** which might be more or less than the amount requested. 5283** ^The sqlite3_release_memory() routine is a no-op returning zero 5284** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5285** 5286** See also: [sqlite3_db_release_memory()] 5287*/ 5288SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5289 5290/* 5291** CAPI3REF: Free Memory Used By A Database Connection 5292** METHOD: sqlite3 5293** 5294** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5295** memory as possible from database connection D. Unlike the 5296** [sqlite3_release_memory()] interface, this interface is in effect even 5297** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5298** omitted. 5299** 5300** See also: [sqlite3_release_memory()] 5301*/ 5302SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5303 5304/* 5305** CAPI3REF: Impose A Limit On Heap Size 5306** 5307** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5308** soft limit on the amount of heap memory that may be allocated by SQLite. 5309** ^SQLite strives to keep heap memory utilization below the soft heap 5310** limit by reducing the number of pages held in the page cache 5311** as heap memory usages approaches the limit. 5312** ^The soft heap limit is "soft" because even though SQLite strives to stay 5313** below the limit, it will exceed the limit rather than generate 5314** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5315** is advisory only. 5316** 5317** ^The return value from sqlite3_soft_heap_limit64() is the size of 5318** the soft heap limit prior to the call, or negative in the case of an 5319** error. ^If the argument N is negative 5320** then no change is made to the soft heap limit. Hence, the current 5321** size of the soft heap limit can be determined by invoking 5322** sqlite3_soft_heap_limit64() with a negative argument. 5323** 5324** ^If the argument N is zero then the soft heap limit is disabled. 5325** 5326** ^(The soft heap limit is not enforced in the current implementation 5327** if one or more of following conditions are true: 5328** 5329** <ul> 5330** <li> The soft heap limit is set to zero. 5331** <li> Memory accounting is disabled using a combination of the 5332** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5333** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5334** <li> An alternative page cache implementation is specified using 5335** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5336** <li> The page cache allocates from its own memory pool supplied 5337** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5338** from the heap. 5339** </ul>)^ 5340** 5341** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5342** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5343** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5344** the soft heap limit is enforced on every memory allocation. Without 5345** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5346** when memory is allocated by the page cache. Testing suggests that because 5347** the page cache is the predominate memory user in SQLite, most 5348** applications will achieve adequate soft heap limit enforcement without 5349** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5350** 5351** The circumstances under which SQLite will enforce the soft heap limit may 5352** changes in future releases of SQLite. 5353*/ 5354SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5355 5356/* 5357** CAPI3REF: Deprecated Soft Heap Limit Interface 5358** DEPRECATED 5359** 5360** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5361** interface. This routine is provided for historical compatibility 5362** only. All new applications should use the 5363** [sqlite3_soft_heap_limit64()] interface rather than this one. 5364*/ 5365SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5366 5367 5368/* 5369** CAPI3REF: Extract Metadata About A Column Of A Table 5370** METHOD: sqlite3 5371** 5372** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5373** information about column C of table T in database D 5374** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5375** interface returns SQLITE_OK and fills in the non-NULL pointers in 5376** the final five arguments with appropriate values if the specified 5377** column exists. ^The sqlite3_table_column_metadata() interface returns 5378** SQLITE_ERROR and if the specified column does not exist. 5379** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5380** NULL pointer, then this routine simply checks for the existance of the 5381** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5382** does not. 5383** 5384** ^The column is identified by the second, third and fourth parameters to 5385** this function. ^(The second parameter is either the name of the database 5386** (i.e. "main", "temp", or an attached database) containing the specified 5387** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5388** for the table using the same algorithm used by the database engine to 5389** resolve unqualified table references. 5390** 5391** ^The third and fourth parameters to this function are the table and column 5392** name of the desired column, respectively. 5393** 5394** ^Metadata is returned by writing to the memory locations passed as the 5th 5395** and subsequent parameters to this function. ^Any of these arguments may be 5396** NULL, in which case the corresponding element of metadata is omitted. 5397** 5398** ^(<blockquote> 5399** <table border="1"> 5400** <tr><th> Parameter <th> Output<br>Type <th> Description 5401** 5402** <tr><td> 5th <td> const char* <td> Data type 5403** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5404** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5405** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5406** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5407** </table> 5408** </blockquote>)^ 5409** 5410** ^The memory pointed to by the character pointers returned for the 5411** declaration type and collation sequence is valid until the next 5412** call to any SQLite API function. 5413** 5414** ^If the specified table is actually a view, an [error code] is returned. 5415** 5416** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5417** is not a [WITHOUT ROWID] table and an 5418** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5419** parameters are set for the explicitly declared column. ^(If there is no 5420** [INTEGER PRIMARY KEY] column, then the outputs 5421** for the [rowid] are set as follows: 5422** 5423** <pre> 5424** data type: "INTEGER" 5425** collation sequence: "BINARY" 5426** not null: 0 5427** primary key: 1 5428** auto increment: 0 5429** </pre>)^ 5430** 5431** ^This function causes all database schemas to be read from disk and 5432** parsed, if that has not already been done, and returns an error if 5433** any errors are encountered while loading the schema. 5434*/ 5435SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5436 sqlite3 *db, /* Connection handle */ 5437 const char *zDbName, /* Database name or NULL */ 5438 const char *zTableName, /* Table name */ 5439 const char *zColumnName, /* Column name */ 5440 char const **pzDataType, /* OUTPUT: Declared data type */ 5441 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5442 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5443 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5444 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5445); 5446 5447/* 5448** CAPI3REF: Load An Extension 5449** METHOD: sqlite3 5450** 5451** ^This interface loads an SQLite extension library from the named file. 5452** 5453** ^The sqlite3_load_extension() interface attempts to load an 5454** [SQLite extension] library contained in the file zFile. If 5455** the file cannot be loaded directly, attempts are made to load 5456** with various operating-system specific extensions added. 5457** So for example, if "samplelib" cannot be loaded, then names like 5458** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5459** be tried also. 5460** 5461** ^The entry point is zProc. 5462** ^(zProc may be 0, in which case SQLite will try to come up with an 5463** entry point name on its own. It first tries "sqlite3_extension_init". 5464** If that does not work, it constructs a name "sqlite3_X_init" where the 5465** X is consists of the lower-case equivalent of all ASCII alphabetic 5466** characters in the filename from the last "/" to the first following 5467** "." and omitting any initial "lib".)^ 5468** ^The sqlite3_load_extension() interface returns 5469** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5470** ^If an error occurs and pzErrMsg is not 0, then the 5471** [sqlite3_load_extension()] interface shall attempt to 5472** fill *pzErrMsg with error message text stored in memory 5473** obtained from [sqlite3_malloc()]. The calling function 5474** should free this memory by calling [sqlite3_free()]. 5475** 5476** ^Extension loading must be enabled using 5477** [sqlite3_enable_load_extension()] prior to calling this API, 5478** otherwise an error will be returned. 5479** 5480** See also the [load_extension() SQL function]. 5481*/ 5482SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5483 sqlite3 *db, /* Load the extension into this database connection */ 5484 const char *zFile, /* Name of the shared library containing extension */ 5485 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5486 char **pzErrMsg /* Put error message here if not 0 */ 5487); 5488 5489/* 5490** CAPI3REF: Enable Or Disable Extension Loading 5491** METHOD: sqlite3 5492** 5493** ^So as not to open security holes in older applications that are 5494** unprepared to deal with [extension loading], and as a means of disabling 5495** [extension loading] while evaluating user-entered SQL, the following API 5496** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5497** 5498** ^Extension loading is off by default. 5499** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5500** to turn extension loading on and call it with onoff==0 to turn 5501** it back off again. 5502*/ 5503SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5504 5505/* 5506** CAPI3REF: Automatically Load Statically Linked Extensions 5507** 5508** ^This interface causes the xEntryPoint() function to be invoked for 5509** each new [database connection] that is created. The idea here is that 5510** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5511** that is to be automatically loaded into all new database connections. 5512** 5513** ^(Even though the function prototype shows that xEntryPoint() takes 5514** no arguments and returns void, SQLite invokes xEntryPoint() with three 5515** arguments and expects and integer result as if the signature of the 5516** entry point where as follows: 5517** 5518** <blockquote><pre> 5519** int xEntryPoint( 5520** sqlite3 *db, 5521** const char **pzErrMsg, 5522** const struct sqlite3_api_routines *pThunk 5523** ); 5524** </pre></blockquote>)^ 5525** 5526** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5527** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5528** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5529** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5530** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5531** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5532** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5533** 5534** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5535** on the list of automatic extensions is a harmless no-op. ^No entry point 5536** will be called more than once for each database connection that is opened. 5537** 5538** See also: [sqlite3_reset_auto_extension()] 5539** and [sqlite3_cancel_auto_extension()] 5540*/ 5541SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); 5542 5543/* 5544** CAPI3REF: Cancel Automatic Extension Loading 5545** 5546** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5547** initialization routine X that was registered using a prior call to 5548** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5549** routine returns 1 if initialization routine X was successfully 5550** unregistered and it returns 0 if X was not on the list of initialization 5551** routines. 5552*/ 5553SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5554 5555/* 5556** CAPI3REF: Reset Automatic Extension Loading 5557** 5558** ^This interface disables all automatic extensions previously 5559** registered using [sqlite3_auto_extension()]. 5560*/ 5561SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5562 5563/* 5564** The interface to the virtual-table mechanism is currently considered 5565** to be experimental. The interface might change in incompatible ways. 5566** If this is a problem for you, do not use the interface at this time. 5567** 5568** When the virtual-table mechanism stabilizes, we will declare the 5569** interface fixed, support it indefinitely, and remove this comment. 5570*/ 5571 5572/* 5573** Structures used by the virtual table interface 5574*/ 5575typedef struct sqlite3_vtab sqlite3_vtab; 5576typedef struct sqlite3_index_info sqlite3_index_info; 5577typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5578typedef struct sqlite3_module sqlite3_module; 5579 5580/* 5581** CAPI3REF: Virtual Table Object 5582** KEYWORDS: sqlite3_module {virtual table module} 5583** 5584** This structure, sometimes called a "virtual table module", 5585** defines the implementation of a [virtual tables]. 5586** This structure consists mostly of methods for the module. 5587** 5588** ^A virtual table module is created by filling in a persistent 5589** instance of this structure and passing a pointer to that instance 5590** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5591** ^The registration remains valid until it is replaced by a different 5592** module or until the [database connection] closes. The content 5593** of this structure must not change while it is registered with 5594** any database connection. 5595*/ 5596struct sqlite3_module { 5597 int iVersion; 5598 int (*xCreate)(sqlite3*, void *pAux, 5599 int argc, const char *const*argv, 5600 sqlite3_vtab **ppVTab, char**); 5601 int (*xConnect)(sqlite3*, void *pAux, 5602 int argc, const char *const*argv, 5603 sqlite3_vtab **ppVTab, char**); 5604 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5605 int (*xDisconnect)(sqlite3_vtab *pVTab); 5606 int (*xDestroy)(sqlite3_vtab *pVTab); 5607 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5608 int (*xClose)(sqlite3_vtab_cursor*); 5609 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5610 int argc, sqlite3_value **argv); 5611 int (*xNext)(sqlite3_vtab_cursor*); 5612 int (*xEof)(sqlite3_vtab_cursor*); 5613 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5614 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5615 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5616 int (*xBegin)(sqlite3_vtab *pVTab); 5617 int (*xSync)(sqlite3_vtab *pVTab); 5618 int (*xCommit)(sqlite3_vtab *pVTab); 5619 int (*xRollback)(sqlite3_vtab *pVTab); 5620 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5621 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5622 void **ppArg); 5623 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5624 /* The methods above are in version 1 of the sqlite_module object. Those 5625 ** below are for version 2 and greater. */ 5626 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5627 int (*xRelease)(sqlite3_vtab *pVTab, int); 5628 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5629}; 5630 5631/* 5632** CAPI3REF: Virtual Table Indexing Information 5633** KEYWORDS: sqlite3_index_info 5634** 5635** The sqlite3_index_info structure and its substructures is used as part 5636** of the [virtual table] interface to 5637** pass information into and receive the reply from the [xBestIndex] 5638** method of a [virtual table module]. The fields under **Inputs** are the 5639** inputs to xBestIndex and are read-only. xBestIndex inserts its 5640** results into the **Outputs** fields. 5641** 5642** ^(The aConstraint[] array records WHERE clause constraints of the form: 5643** 5644** <blockquote>column OP expr</blockquote> 5645** 5646** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5647** stored in aConstraint[].op using one of the 5648** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5649** ^(The index of the column is stored in 5650** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5651** expr on the right-hand side can be evaluated (and thus the constraint 5652** is usable) and false if it cannot.)^ 5653** 5654** ^The optimizer automatically inverts terms of the form "expr OP column" 5655** and makes other simplifications to the WHERE clause in an attempt to 5656** get as many WHERE clause terms into the form shown above as possible. 5657** ^The aConstraint[] array only reports WHERE clause terms that are 5658** relevant to the particular virtual table being queried. 5659** 5660** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5661** ^Each term of aOrderBy records a column of the ORDER BY clause. 5662** 5663** The colUsed field indicates which columns of the virtual table may be 5664** required by the current scan. Virtual table columns are numbered from 5665** zero in the order in which they appear within the CREATE TABLE statement 5666** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5667** the corresponding bit is set within the colUsed mask if the column may be 5668** required by SQLite. If the table has at least 64 columns and any column 5669** to the right of the first 63 is required, then bit 63 of colUsed is also 5670** set. In other words, column iCol may be required if the expression 5671** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5672** non-zero. 5673** 5674** The [xBestIndex] method must fill aConstraintUsage[] with information 5675** about what parameters to pass to xFilter. ^If argvIndex>0 then 5676** the right-hand side of the corresponding aConstraint[] is evaluated 5677** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5678** is true, then the constraint is assumed to be fully handled by the 5679** virtual table and is not checked again by SQLite.)^ 5680** 5681** ^The idxNum and idxPtr values are recorded and passed into the 5682** [xFilter] method. 5683** ^[sqlite3_free()] is used to free idxPtr if and only if 5684** needToFreeIdxPtr is true. 5685** 5686** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5687** the correct order to satisfy the ORDER BY clause so that no separate 5688** sorting step is required. 5689** 5690** ^The estimatedCost value is an estimate of the cost of a particular 5691** strategy. A cost of N indicates that the cost of the strategy is similar 5692** to a linear scan of an SQLite table with N rows. A cost of log(N) 5693** indicates that the expense of the operation is similar to that of a 5694** binary search on a unique indexed field of an SQLite table with N rows. 5695** 5696** ^The estimatedRows value is an estimate of the number of rows that 5697** will be returned by the strategy. 5698** 5699** The xBestIndex method may optionally populate the idxFlags field with a 5700** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5701** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5702** assumes that the strategy may visit at most one row. 5703** 5704** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5705** SQLite also assumes that if a call to the xUpdate() method is made as 5706** part of the same statement to delete or update a virtual table row and the 5707** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5708** any database changes. In other words, if the xUpdate() returns 5709** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5710** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5711** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5712** the xUpdate method are automatically rolled back by SQLite. 5713** 5714** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5715** structure for SQLite version 3.8.2. If a virtual table extension is 5716** used with an SQLite version earlier than 3.8.2, the results of attempting 5717** to read or write the estimatedRows field are undefined (but are likely 5718** to included crashing the application). The estimatedRows field should 5719** therefore only be used if [sqlite3_libversion_number()] returns a 5720** value greater than or equal to 3008002. Similarly, the idxFlags field 5721** was added for version 3.9.0. It may therefore only be used if 5722** sqlite3_libversion_number() returns a value greater than or equal to 5723** 3009000. 5724*/ 5725struct sqlite3_index_info { 5726 /* Inputs */ 5727 int nConstraint; /* Number of entries in aConstraint */ 5728 struct sqlite3_index_constraint { 5729 int iColumn; /* Column constrained. -1 for ROWID */ 5730 unsigned char op; /* Constraint operator */ 5731 unsigned char usable; /* True if this constraint is usable */ 5732 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5733 } *aConstraint; /* Table of WHERE clause constraints */ 5734 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5735 struct sqlite3_index_orderby { 5736 int iColumn; /* Column number */ 5737 unsigned char desc; /* True for DESC. False for ASC. */ 5738 } *aOrderBy; /* The ORDER BY clause */ 5739 /* Outputs */ 5740 struct sqlite3_index_constraint_usage { 5741 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5742 unsigned char omit; /* Do not code a test for this constraint */ 5743 } *aConstraintUsage; 5744 int idxNum; /* Number used to identify the index */ 5745 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5746 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5747 int orderByConsumed; /* True if output is already ordered */ 5748 double estimatedCost; /* Estimated cost of using this index */ 5749 /* Fields below are only available in SQLite 3.8.2 and later */ 5750 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5751 /* Fields below are only available in SQLite 3.9.0 and later */ 5752 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5753 /* Fields below are only available in SQLite 3.10.0 and later */ 5754 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5755}; 5756 5757/* 5758** CAPI3REF: Virtual Table Scan Flags 5759*/ 5760#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5761 5762/* 5763** CAPI3REF: Virtual Table Constraint Operator Codes 5764** 5765** These macros defined the allowed values for the 5766** [sqlite3_index_info].aConstraint[].op field. Each value represents 5767** an operator that is part of a constraint term in the wHERE clause of 5768** a query that uses a [virtual table]. 5769*/ 5770#define SQLITE_INDEX_CONSTRAINT_EQ 2 5771#define SQLITE_INDEX_CONSTRAINT_GT 4 5772#define SQLITE_INDEX_CONSTRAINT_LE 8 5773#define SQLITE_INDEX_CONSTRAINT_LT 16 5774#define SQLITE_INDEX_CONSTRAINT_GE 32 5775#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5776#define SQLITE_INDEX_CONSTRAINT_LIKE 65 5777#define SQLITE_INDEX_CONSTRAINT_GLOB 66 5778#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5779 5780/* 5781** CAPI3REF: Register A Virtual Table Implementation 5782** METHOD: sqlite3 5783** 5784** ^These routines are used to register a new [virtual table module] name. 5785** ^Module names must be registered before 5786** creating a new [virtual table] using the module and before using a 5787** preexisting [virtual table] for the module. 5788** 5789** ^The module name is registered on the [database connection] specified 5790** by the first parameter. ^The name of the module is given by the 5791** second parameter. ^The third parameter is a pointer to 5792** the implementation of the [virtual table module]. ^The fourth 5793** parameter is an arbitrary client data pointer that is passed through 5794** into the [xCreate] and [xConnect] methods of the virtual table module 5795** when a new virtual table is be being created or reinitialized. 5796** 5797** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5798** is a pointer to a destructor for the pClientData. ^SQLite will 5799** invoke the destructor function (if it is not NULL) when SQLite 5800** no longer needs the pClientData pointer. ^The destructor will also 5801** be invoked if the call to sqlite3_create_module_v2() fails. 5802** ^The sqlite3_create_module() 5803** interface is equivalent to sqlite3_create_module_v2() with a NULL 5804** destructor. 5805*/ 5806SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5807 sqlite3 *db, /* SQLite connection to register module with */ 5808 const char *zName, /* Name of the module */ 5809 const sqlite3_module *p, /* Methods for the module */ 5810 void *pClientData /* Client data for xCreate/xConnect */ 5811); 5812SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5813 sqlite3 *db, /* SQLite connection to register module with */ 5814 const char *zName, /* Name of the module */ 5815 const sqlite3_module *p, /* Methods for the module */ 5816 void *pClientData, /* Client data for xCreate/xConnect */ 5817 void(*xDestroy)(void*) /* Module destructor function */ 5818); 5819 5820/* 5821** CAPI3REF: Virtual Table Instance Object 5822** KEYWORDS: sqlite3_vtab 5823** 5824** Every [virtual table module] implementation uses a subclass 5825** of this object to describe a particular instance 5826** of the [virtual table]. Each subclass will 5827** be tailored to the specific needs of the module implementation. 5828** The purpose of this superclass is to define certain fields that are 5829** common to all module implementations. 5830** 5831** ^Virtual tables methods can set an error message by assigning a 5832** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5833** take care that any prior string is freed by a call to [sqlite3_free()] 5834** prior to assigning a new string to zErrMsg. ^After the error message 5835** is delivered up to the client application, the string will be automatically 5836** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5837*/ 5838struct sqlite3_vtab { 5839 const sqlite3_module *pModule; /* The module for this virtual table */ 5840 int nRef; /* Number of open cursors */ 5841 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5842 /* Virtual table implementations will typically add additional fields */ 5843}; 5844 5845/* 5846** CAPI3REF: Virtual Table Cursor Object 5847** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5848** 5849** Every [virtual table module] implementation uses a subclass of the 5850** following structure to describe cursors that point into the 5851** [virtual table] and are used 5852** to loop through the virtual table. Cursors are created using the 5853** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5854** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5855** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5856** of the module. Each module implementation will define 5857** the content of a cursor structure to suit its own needs. 5858** 5859** This superclass exists in order to define fields of the cursor that 5860** are common to all implementations. 5861*/ 5862struct sqlite3_vtab_cursor { 5863 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5864 /* Virtual table implementations will typically add additional fields */ 5865}; 5866 5867/* 5868** CAPI3REF: Declare The Schema Of A Virtual Table 5869** 5870** ^The [xCreate] and [xConnect] methods of a 5871** [virtual table module] call this interface 5872** to declare the format (the names and datatypes of the columns) of 5873** the virtual tables they implement. 5874*/ 5875SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5876 5877/* 5878** CAPI3REF: Overload A Function For A Virtual Table 5879** METHOD: sqlite3 5880** 5881** ^(Virtual tables can provide alternative implementations of functions 5882** using the [xFindFunction] method of the [virtual table module]. 5883** But global versions of those functions 5884** must exist in order to be overloaded.)^ 5885** 5886** ^(This API makes sure a global version of a function with a particular 5887** name and number of parameters exists. If no such function exists 5888** before this API is called, a new function is created.)^ ^The implementation 5889** of the new function always causes an exception to be thrown. So 5890** the new function is not good for anything by itself. Its only 5891** purpose is to be a placeholder function that can be overloaded 5892** by a [virtual table]. 5893*/ 5894SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5895 5896/* 5897** The interface to the virtual-table mechanism defined above (back up 5898** to a comment remarkably similar to this one) is currently considered 5899** to be experimental. The interface might change in incompatible ways. 5900** If this is a problem for you, do not use the interface at this time. 5901** 5902** When the virtual-table mechanism stabilizes, we will declare the 5903** interface fixed, support it indefinitely, and remove this comment. 5904*/ 5905 5906/* 5907** CAPI3REF: A Handle To An Open BLOB 5908** KEYWORDS: {BLOB handle} {BLOB handles} 5909** 5910** An instance of this object represents an open BLOB on which 5911** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5912** ^Objects of this type are created by [sqlite3_blob_open()] 5913** and destroyed by [sqlite3_blob_close()]. 5914** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5915** can be used to read or write small subsections of the BLOB. 5916** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5917*/ 5918typedef struct sqlite3_blob sqlite3_blob; 5919 5920/* 5921** CAPI3REF: Open A BLOB For Incremental I/O 5922** METHOD: sqlite3 5923** CONSTRUCTOR: sqlite3_blob 5924** 5925** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5926** in row iRow, column zColumn, table zTable in database zDb; 5927** in other words, the same BLOB that would be selected by: 5928** 5929** <pre> 5930** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5931** </pre>)^ 5932** 5933** ^(Parameter zDb is not the filename that contains the database, but 5934** rather the symbolic name of the database. For attached databases, this is 5935** the name that appears after the AS keyword in the [ATTACH] statement. 5936** For the main database file, the database name is "main". For TEMP 5937** tables, the database name is "temp".)^ 5938** 5939** ^If the flags parameter is non-zero, then the BLOB is opened for read 5940** and write access. ^If the flags parameter is zero, the BLOB is opened for 5941** read-only access. 5942** 5943** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5944** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5945** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5946** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5947** on *ppBlob after this function it returns. 5948** 5949** This function fails with SQLITE_ERROR if any of the following are true: 5950** <ul> 5951** <li> ^(Database zDb does not exist)^, 5952** <li> ^(Table zTable does not exist within database zDb)^, 5953** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5954** <li> ^(Column zColumn does not exist)^, 5955** <li> ^(Row iRow is not present in the table)^, 5956** <li> ^(The specified column of row iRow contains a value that is not 5957** a TEXT or BLOB value)^, 5958** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5959** constraint and the blob is being opened for read/write access)^, 5960** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5961** column zColumn is part of a [child key] definition and the blob is 5962** being opened for read/write access)^. 5963** </ul> 5964** 5965** ^Unless it returns SQLITE_MISUSE, this function sets the 5966** [database connection] error code and message accessible via 5967** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5968** 5969** 5970** ^(If the row that a BLOB handle points to is modified by an 5971** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5972** then the BLOB handle is marked as "expired". 5973** This is true if any column of the row is changed, even a column 5974** other than the one the BLOB handle is open on.)^ 5975** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5976** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5977** ^(Changes written into a BLOB prior to the BLOB expiring are not 5978** rolled back by the expiration of the BLOB. Such changes will eventually 5979** commit if the transaction continues to completion.)^ 5980** 5981** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5982** the opened blob. ^The size of a blob may not be changed by this 5983** interface. Use the [UPDATE] SQL command to change the size of a 5984** blob. 5985** 5986** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5987** and the built-in [zeroblob] SQL function may be used to create a 5988** zero-filled blob to read or write using the incremental-blob interface. 5989** 5990** To avoid a resource leak, every open [BLOB handle] should eventually 5991** be released by a call to [sqlite3_blob_close()]. 5992*/ 5993SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 5994 sqlite3*, 5995 const char *zDb, 5996 const char *zTable, 5997 const char *zColumn, 5998 sqlite3_int64 iRow, 5999 int flags, 6000 sqlite3_blob **ppBlob 6001); 6002 6003/* 6004** CAPI3REF: Move a BLOB Handle to a New Row 6005** METHOD: sqlite3_blob 6006** 6007** ^This function is used to move an existing blob handle so that it points 6008** to a different row of the same database table. ^The new row is identified 6009** by the rowid value passed as the second argument. Only the row can be 6010** changed. ^The database, table and column on which the blob handle is open 6011** remain the same. Moving an existing blob handle to a new row can be 6012** faster than closing the existing handle and opening a new one. 6013** 6014** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6015** it must exist and there must be either a blob or text value stored in 6016** the nominated column.)^ ^If the new row is not present in the table, or if 6017** it does not contain a blob or text value, or if another error occurs, an 6018** SQLite error code is returned and the blob handle is considered aborted. 6019** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6020** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6021** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6022** always returns zero. 6023** 6024** ^This function sets the database handle error code and message. 6025*/ 6026SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6027 6028/* 6029** CAPI3REF: Close A BLOB Handle 6030** DESTRUCTOR: sqlite3_blob 6031** 6032** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6033** unconditionally. Even if this routine returns an error code, the 6034** handle is still closed.)^ 6035** 6036** ^If the blob handle being closed was opened for read-write access, and if 6037** the database is in auto-commit mode and there are no other open read-write 6038** blob handles or active write statements, the current transaction is 6039** committed. ^If an error occurs while committing the transaction, an error 6040** code is returned and the transaction rolled back. 6041** 6042** Calling this function with an argument that is not a NULL pointer or an 6043** open blob handle results in undefined behaviour. ^Calling this routine 6044** with a null pointer (such as would be returned by a failed call to 6045** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6046** is passed a valid open blob handle, the values returned by the 6047** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6048*/ 6049SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 6050 6051/* 6052** CAPI3REF: Return The Size Of An Open BLOB 6053** METHOD: sqlite3_blob 6054** 6055** ^Returns the size in bytes of the BLOB accessible via the 6056** successfully opened [BLOB handle] in its only argument. ^The 6057** incremental blob I/O routines can only read or overwriting existing 6058** blob content; they cannot change the size of a blob. 6059** 6060** This routine only works on a [BLOB handle] which has been created 6061** by a prior successful call to [sqlite3_blob_open()] and which has not 6062** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6063** to this routine results in undefined and probably undesirable behavior. 6064*/ 6065SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 6066 6067/* 6068** CAPI3REF: Read Data From A BLOB Incrementally 6069** METHOD: sqlite3_blob 6070** 6071** ^(This function is used to read data from an open [BLOB handle] into a 6072** caller-supplied buffer. N bytes of data are copied into buffer Z 6073** from the open BLOB, starting at offset iOffset.)^ 6074** 6075** ^If offset iOffset is less than N bytes from the end of the BLOB, 6076** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6077** less than zero, [SQLITE_ERROR] is returned and no data is read. 6078** ^The size of the blob (and hence the maximum value of N+iOffset) 6079** can be determined using the [sqlite3_blob_bytes()] interface. 6080** 6081** ^An attempt to read from an expired [BLOB handle] fails with an 6082** error code of [SQLITE_ABORT]. 6083** 6084** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6085** Otherwise, an [error code] or an [extended error code] is returned.)^ 6086** 6087** This routine only works on a [BLOB handle] which has been created 6088** by a prior successful call to [sqlite3_blob_open()] and which has not 6089** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6090** to this routine results in undefined and probably undesirable behavior. 6091** 6092** See also: [sqlite3_blob_write()]. 6093*/ 6094SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6095 6096/* 6097** CAPI3REF: Write Data Into A BLOB Incrementally 6098** METHOD: sqlite3_blob 6099** 6100** ^(This function is used to write data into an open [BLOB handle] from a 6101** caller-supplied buffer. N bytes of data are copied from the buffer Z 6102** into the open BLOB, starting at offset iOffset.)^ 6103** 6104** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6105** Otherwise, an [error code] or an [extended error code] is returned.)^ 6106** ^Unless SQLITE_MISUSE is returned, this function sets the 6107** [database connection] error code and message accessible via 6108** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6109** 6110** ^If the [BLOB handle] passed as the first argument was not opened for 6111** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6112** this function returns [SQLITE_READONLY]. 6113** 6114** This function may only modify the contents of the BLOB; it is 6115** not possible to increase the size of a BLOB using this API. 6116** ^If offset iOffset is less than N bytes from the end of the BLOB, 6117** [SQLITE_ERROR] is returned and no data is written. The size of the 6118** BLOB (and hence the maximum value of N+iOffset) can be determined 6119** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6120** than zero [SQLITE_ERROR] is returned and no data is written. 6121** 6122** ^An attempt to write to an expired [BLOB handle] fails with an 6123** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6124** before the [BLOB handle] expired are not rolled back by the 6125** expiration of the handle, though of course those changes might 6126** have been overwritten by the statement that expired the BLOB handle 6127** or by other independent statements. 6128** 6129** This routine only works on a [BLOB handle] which has been created 6130** by a prior successful call to [sqlite3_blob_open()] and which has not 6131** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6132** to this routine results in undefined and probably undesirable behavior. 6133** 6134** See also: [sqlite3_blob_read()]. 6135*/ 6136SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6137 6138/* 6139** CAPI3REF: Virtual File System Objects 6140** 6141** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6142** that SQLite uses to interact 6143** with the underlying operating system. Most SQLite builds come with a 6144** single default VFS that is appropriate for the host computer. 6145** New VFSes can be registered and existing VFSes can be unregistered. 6146** The following interfaces are provided. 6147** 6148** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6149** ^Names are case sensitive. 6150** ^Names are zero-terminated UTF-8 strings. 6151** ^If there is no match, a NULL pointer is returned. 6152** ^If zVfsName is NULL then the default VFS is returned. 6153** 6154** ^New VFSes are registered with sqlite3_vfs_register(). 6155** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6156** ^The same VFS can be registered multiple times without injury. 6157** ^To make an existing VFS into the default VFS, register it again 6158** with the makeDflt flag set. If two different VFSes with the 6159** same name are registered, the behavior is undefined. If a 6160** VFS is registered with a name that is NULL or an empty string, 6161** then the behavior is undefined. 6162** 6163** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6164** ^(If the default VFS is unregistered, another VFS is chosen as 6165** the default. The choice for the new VFS is arbitrary.)^ 6166*/ 6167SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6168SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6169SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6170 6171/* 6172** CAPI3REF: Mutexes 6173** 6174** The SQLite core uses these routines for thread 6175** synchronization. Though they are intended for internal 6176** use by SQLite, code that links against SQLite is 6177** permitted to use any of these routines. 6178** 6179** The SQLite source code contains multiple implementations 6180** of these mutex routines. An appropriate implementation 6181** is selected automatically at compile-time. The following 6182** implementations are available in the SQLite core: 6183** 6184** <ul> 6185** <li> SQLITE_MUTEX_PTHREADS 6186** <li> SQLITE_MUTEX_W32 6187** <li> SQLITE_MUTEX_NOOP 6188** </ul> 6189** 6190** The SQLITE_MUTEX_NOOP implementation is a set of routines 6191** that does no real locking and is appropriate for use in 6192** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6193** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6194** and Windows. 6195** 6196** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6197** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6198** implementation is included with the library. In this case the 6199** application must supply a custom mutex implementation using the 6200** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6201** before calling sqlite3_initialize() or any other public sqlite3_ 6202** function that calls sqlite3_initialize(). 6203** 6204** ^The sqlite3_mutex_alloc() routine allocates a new 6205** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6206** routine returns NULL if it is unable to allocate the requested 6207** mutex. The argument to sqlite3_mutex_alloc() must one of these 6208** integer constants: 6209** 6210** <ul> 6211** <li> SQLITE_MUTEX_FAST 6212** <li> SQLITE_MUTEX_RECURSIVE 6213** <li> SQLITE_MUTEX_STATIC_MASTER 6214** <li> SQLITE_MUTEX_STATIC_MEM 6215** <li> SQLITE_MUTEX_STATIC_OPEN 6216** <li> SQLITE_MUTEX_STATIC_PRNG 6217** <li> SQLITE_MUTEX_STATIC_LRU 6218** <li> SQLITE_MUTEX_STATIC_PMEM 6219** <li> SQLITE_MUTEX_STATIC_APP1 6220** <li> SQLITE_MUTEX_STATIC_APP2 6221** <li> SQLITE_MUTEX_STATIC_APP3 6222** <li> SQLITE_MUTEX_STATIC_VFS1 6223** <li> SQLITE_MUTEX_STATIC_VFS2 6224** <li> SQLITE_MUTEX_STATIC_VFS3 6225** </ul> 6226** 6227** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6228** cause sqlite3_mutex_alloc() to create 6229** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6230** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6231** The mutex implementation does not need to make a distinction 6232** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6233** not want to. SQLite will only request a recursive mutex in 6234** cases where it really needs one. If a faster non-recursive mutex 6235** implementation is available on the host platform, the mutex subsystem 6236** might return such a mutex in response to SQLITE_MUTEX_FAST. 6237** 6238** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6239** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6240** a pointer to a static preexisting mutex. ^Nine static mutexes are 6241** used by the current version of SQLite. Future versions of SQLite 6242** may add additional static mutexes. Static mutexes are for internal 6243** use by SQLite only. Applications that use SQLite mutexes should 6244** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6245** SQLITE_MUTEX_RECURSIVE. 6246** 6247** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6248** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6249** returns a different mutex on every call. ^For the static 6250** mutex types, the same mutex is returned on every call that has 6251** the same type number. 6252** 6253** ^The sqlite3_mutex_free() routine deallocates a previously 6254** allocated dynamic mutex. Attempting to deallocate a static 6255** mutex results in undefined behavior. 6256** 6257** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6258** to enter a mutex. ^If another thread is already within the mutex, 6259** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6260** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6261** upon successful entry. ^(Mutexes created using 6262** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6263** In such cases, the 6264** mutex must be exited an equal number of times before another thread 6265** can enter.)^ If the same thread tries to enter any mutex other 6266** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6267** 6268** ^(Some systems (for example, Windows 95) do not support the operation 6269** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6270** will always return SQLITE_BUSY. The SQLite core only ever uses 6271** sqlite3_mutex_try() as an optimization so this is acceptable 6272** behavior.)^ 6273** 6274** ^The sqlite3_mutex_leave() routine exits a mutex that was 6275** previously entered by the same thread. The behavior 6276** is undefined if the mutex is not currently entered by the 6277** calling thread or is not currently allocated. 6278** 6279** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6280** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6281** behave as no-ops. 6282** 6283** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6284*/ 6285SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6286SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6287SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6288SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6289SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6290 6291/* 6292** CAPI3REF: Mutex Methods Object 6293** 6294** An instance of this structure defines the low-level routines 6295** used to allocate and use mutexes. 6296** 6297** Usually, the default mutex implementations provided by SQLite are 6298** sufficient, however the application has the option of substituting a custom 6299** implementation for specialized deployments or systems for which SQLite 6300** does not provide a suitable implementation. In this case, the application 6301** creates and populates an instance of this structure to pass 6302** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6303** Additionally, an instance of this structure can be used as an 6304** output variable when querying the system for the current mutex 6305** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6306** 6307** ^The xMutexInit method defined by this structure is invoked as 6308** part of system initialization by the sqlite3_initialize() function. 6309** ^The xMutexInit routine is called by SQLite exactly once for each 6310** effective call to [sqlite3_initialize()]. 6311** 6312** ^The xMutexEnd method defined by this structure is invoked as 6313** part of system shutdown by the sqlite3_shutdown() function. The 6314** implementation of this method is expected to release all outstanding 6315** resources obtained by the mutex methods implementation, especially 6316** those obtained by the xMutexInit method. ^The xMutexEnd() 6317** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6318** 6319** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6320** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6321** xMutexNotheld) implement the following interfaces (respectively): 6322** 6323** <ul> 6324** <li> [sqlite3_mutex_alloc()] </li> 6325** <li> [sqlite3_mutex_free()] </li> 6326** <li> [sqlite3_mutex_enter()] </li> 6327** <li> [sqlite3_mutex_try()] </li> 6328** <li> [sqlite3_mutex_leave()] </li> 6329** <li> [sqlite3_mutex_held()] </li> 6330** <li> [sqlite3_mutex_notheld()] </li> 6331** </ul>)^ 6332** 6333** The only difference is that the public sqlite3_XXX functions enumerated 6334** above silently ignore any invocations that pass a NULL pointer instead 6335** of a valid mutex handle. The implementations of the methods defined 6336** by this structure are not required to handle this case, the results 6337** of passing a NULL pointer instead of a valid mutex handle are undefined 6338** (i.e. it is acceptable to provide an implementation that segfaults if 6339** it is passed a NULL pointer). 6340** 6341** The xMutexInit() method must be threadsafe. It must be harmless to 6342** invoke xMutexInit() multiple times within the same process and without 6343** intervening calls to xMutexEnd(). Second and subsequent calls to 6344** xMutexInit() must be no-ops. 6345** 6346** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6347** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6348** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6349** memory allocation for a fast or recursive mutex. 6350** 6351** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6352** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6353** If xMutexInit fails in any way, it is expected to clean up after itself 6354** prior to returning. 6355*/ 6356typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6357struct sqlite3_mutex_methods { 6358 int (*xMutexInit)(void); 6359 int (*xMutexEnd)(void); 6360 sqlite3_mutex *(*xMutexAlloc)(int); 6361 void (*xMutexFree)(sqlite3_mutex *); 6362 void (*xMutexEnter)(sqlite3_mutex *); 6363 int (*xMutexTry)(sqlite3_mutex *); 6364 void (*xMutexLeave)(sqlite3_mutex *); 6365 int (*xMutexHeld)(sqlite3_mutex *); 6366 int (*xMutexNotheld)(sqlite3_mutex *); 6367}; 6368 6369/* 6370** CAPI3REF: Mutex Verification Routines 6371** 6372** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6373** are intended for use inside assert() statements. The SQLite core 6374** never uses these routines except inside an assert() and applications 6375** are advised to follow the lead of the core. The SQLite core only 6376** provides implementations for these routines when it is compiled 6377** with the SQLITE_DEBUG flag. External mutex implementations 6378** are only required to provide these routines if SQLITE_DEBUG is 6379** defined and if NDEBUG is not defined. 6380** 6381** These routines should return true if the mutex in their argument 6382** is held or not held, respectively, by the calling thread. 6383** 6384** The implementation is not required to provide versions of these 6385** routines that actually work. If the implementation does not provide working 6386** versions of these routines, it should at least provide stubs that always 6387** return true so that one does not get spurious assertion failures. 6388** 6389** If the argument to sqlite3_mutex_held() is a NULL pointer then 6390** the routine should return 1. This seems counter-intuitive since 6391** clearly the mutex cannot be held if it does not exist. But 6392** the reason the mutex does not exist is because the build is not 6393** using mutexes. And we do not want the assert() containing the 6394** call to sqlite3_mutex_held() to fail, so a non-zero return is 6395** the appropriate thing to do. The sqlite3_mutex_notheld() 6396** interface should also return 1 when given a NULL pointer. 6397*/ 6398#ifndef NDEBUG 6399SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6400SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6401#endif 6402 6403/* 6404** CAPI3REF: Mutex Types 6405** 6406** The [sqlite3_mutex_alloc()] interface takes a single argument 6407** which is one of these integer constants. 6408** 6409** The set of static mutexes may change from one SQLite release to the 6410** next. Applications that override the built-in mutex logic must be 6411** prepared to accommodate additional static mutexes. 6412*/ 6413#define SQLITE_MUTEX_FAST 0 6414#define SQLITE_MUTEX_RECURSIVE 1 6415#define SQLITE_MUTEX_STATIC_MASTER 2 6416#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6417#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6418#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6419#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6420#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6421#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6422#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6423#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6424#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6425#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6426#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6427#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6428#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6429 6430/* 6431** CAPI3REF: Retrieve the mutex for a database connection 6432** METHOD: sqlite3 6433** 6434** ^This interface returns a pointer the [sqlite3_mutex] object that 6435** serializes access to the [database connection] given in the argument 6436** when the [threading mode] is Serialized. 6437** ^If the [threading mode] is Single-thread or Multi-thread then this 6438** routine returns a NULL pointer. 6439*/ 6440SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6441 6442/* 6443** CAPI3REF: Low-Level Control Of Database Files 6444** METHOD: sqlite3 6445** 6446** ^The [sqlite3_file_control()] interface makes a direct call to the 6447** xFileControl method for the [sqlite3_io_methods] object associated 6448** with a particular database identified by the second argument. ^The 6449** name of the database is "main" for the main database or "temp" for the 6450** TEMP database, or the name that appears after the AS keyword for 6451** databases that are added using the [ATTACH] SQL command. 6452** ^A NULL pointer can be used in place of "main" to refer to the 6453** main database file. 6454** ^The third and fourth parameters to this routine 6455** are passed directly through to the second and third parameters of 6456** the xFileControl method. ^The return value of the xFileControl 6457** method becomes the return value of this routine. 6458** 6459** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6460** a pointer to the underlying [sqlite3_file] object to be written into 6461** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6462** case is a short-circuit path which does not actually invoke the 6463** underlying sqlite3_io_methods.xFileControl method. 6464** 6465** ^If the second parameter (zDbName) does not match the name of any 6466** open database file, then SQLITE_ERROR is returned. ^This error 6467** code is not remembered and will not be recalled by [sqlite3_errcode()] 6468** or [sqlite3_errmsg()]. The underlying xFileControl method might 6469** also return SQLITE_ERROR. There is no way to distinguish between 6470** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6471** xFileControl method. 6472** 6473** See also: [SQLITE_FCNTL_LOCKSTATE] 6474*/ 6475SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6476 6477/* 6478** CAPI3REF: Testing Interface 6479** 6480** ^The sqlite3_test_control() interface is used to read out internal 6481** state of SQLite and to inject faults into SQLite for testing 6482** purposes. ^The first parameter is an operation code that determines 6483** the number, meaning, and operation of all subsequent parameters. 6484** 6485** This interface is not for use by applications. It exists solely 6486** for verifying the correct operation of the SQLite library. Depending 6487** on how the SQLite library is compiled, this interface might not exist. 6488** 6489** The details of the operation codes, their meanings, the parameters 6490** they take, and what they do are all subject to change without notice. 6491** Unlike most of the SQLite API, this function is not guaranteed to 6492** operate consistently from one release to the next. 6493*/ 6494SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6495 6496/* 6497** CAPI3REF: Testing Interface Operation Codes 6498** 6499** These constants are the valid operation code parameters used 6500** as the first argument to [sqlite3_test_control()]. 6501** 6502** These parameters and their meanings are subject to change 6503** without notice. These values are for testing purposes only. 6504** Applications should not use any of these parameters or the 6505** [sqlite3_test_control()] interface. 6506*/ 6507#define SQLITE_TESTCTRL_FIRST 5 6508#define SQLITE_TESTCTRL_PRNG_SAVE 5 6509#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6510#define SQLITE_TESTCTRL_PRNG_RESET 7 6511#define SQLITE_TESTCTRL_BITVEC_TEST 8 6512#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6513#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6514#define SQLITE_TESTCTRL_PENDING_BYTE 11 6515#define SQLITE_TESTCTRL_ASSERT 12 6516#define SQLITE_TESTCTRL_ALWAYS 13 6517#define SQLITE_TESTCTRL_RESERVE 14 6518#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6519#define SQLITE_TESTCTRL_ISKEYWORD 16 6520#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6521#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6522#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6523#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6524#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6525#define SQLITE_TESTCTRL_BYTEORDER 22 6526#define SQLITE_TESTCTRL_ISINIT 23 6527#define SQLITE_TESTCTRL_SORTER_MMAP 24 6528#define SQLITE_TESTCTRL_IMPOSTER 25 6529#define SQLITE_TESTCTRL_LAST 25 6530 6531/* 6532** CAPI3REF: SQLite Runtime Status 6533** 6534** ^These interfaces are used to retrieve runtime status information 6535** about the performance of SQLite, and optionally to reset various 6536** highwater marks. ^The first argument is an integer code for 6537** the specific parameter to measure. ^(Recognized integer codes 6538** are of the form [status parameters | SQLITE_STATUS_...].)^ 6539** ^The current value of the parameter is returned into *pCurrent. 6540** ^The highest recorded value is returned in *pHighwater. ^If the 6541** resetFlag is true, then the highest record value is reset after 6542** *pHighwater is written. ^(Some parameters do not record the highest 6543** value. For those parameters 6544** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6545** ^(Other parameters record only the highwater mark and not the current 6546** value. For these latter parameters nothing is written into *pCurrent.)^ 6547** 6548** ^The sqlite3_status() and sqlite3_status64() routines return 6549** SQLITE_OK on success and a non-zero [error code] on failure. 6550** 6551** If either the current value or the highwater mark is too large to 6552** be represented by a 32-bit integer, then the values returned by 6553** sqlite3_status() are undefined. 6554** 6555** See also: [sqlite3_db_status()] 6556*/ 6557SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6558SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6559 int op, 6560 sqlite3_int64 *pCurrent, 6561 sqlite3_int64 *pHighwater, 6562 int resetFlag 6563); 6564 6565 6566/* 6567** CAPI3REF: Status Parameters 6568** KEYWORDS: {status parameters} 6569** 6570** These integer constants designate various run-time status parameters 6571** that can be returned by [sqlite3_status()]. 6572** 6573** <dl> 6574** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6575** <dd>This parameter is the current amount of memory checked out 6576** using [sqlite3_malloc()], either directly or indirectly. The 6577** figure includes calls made to [sqlite3_malloc()] by the application 6578** and internal memory usage by the SQLite library. Scratch memory 6579** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6580** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6581** this parameter. The amount returned is the sum of the allocation 6582** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6583** 6584** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6585** <dd>This parameter records the largest memory allocation request 6586** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6587** internal equivalents). Only the value returned in the 6588** *pHighwater parameter to [sqlite3_status()] is of interest. 6589** The value written into the *pCurrent parameter is undefined.</dd>)^ 6590** 6591** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6592** <dd>This parameter records the number of separate memory allocations 6593** currently checked out.</dd>)^ 6594** 6595** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6596** <dd>This parameter returns the number of pages used out of the 6597** [pagecache memory allocator] that was configured using 6598** [SQLITE_CONFIG_PAGECACHE]. The 6599** value returned is in pages, not in bytes.</dd>)^ 6600** 6601** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6602** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6603** <dd>This parameter returns the number of bytes of page cache 6604** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6605** buffer and where forced to overflow to [sqlite3_malloc()]. The 6606** returned value includes allocations that overflowed because they 6607** where too large (they were larger than the "sz" parameter to 6608** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6609** no space was left in the page cache.</dd>)^ 6610** 6611** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6612** <dd>This parameter records the largest memory allocation request 6613** handed to [pagecache memory allocator]. Only the value returned in the 6614** *pHighwater parameter to [sqlite3_status()] is of interest. 6615** The value written into the *pCurrent parameter is undefined.</dd>)^ 6616** 6617** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6618** <dd>This parameter returns the number of allocations used out of the 6619** [scratch memory allocator] configured using 6620** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6621** in bytes. Since a single thread may only have one scratch allocation 6622** outstanding at time, this parameter also reports the number of threads 6623** using scratch memory at the same time.</dd>)^ 6624** 6625** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6626** <dd>This parameter returns the number of bytes of scratch memory 6627** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6628** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6629** returned include overflows because the requested allocation was too 6630** larger (that is, because the requested allocation was larger than the 6631** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6632** slots were available. 6633** </dd>)^ 6634** 6635** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6636** <dd>This parameter records the largest memory allocation request 6637** handed to [scratch memory allocator]. Only the value returned in the 6638** *pHighwater parameter to [sqlite3_status()] is of interest. 6639** The value written into the *pCurrent parameter is undefined.</dd>)^ 6640** 6641** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6642** <dd>The *pHighwater parameter records the deepest parser stack. 6643** The *pCurrent value is undefined. The *pHighwater value is only 6644** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6645** </dl> 6646** 6647** New status parameters may be added from time to time. 6648*/ 6649#define SQLITE_STATUS_MEMORY_USED 0 6650#define SQLITE_STATUS_PAGECACHE_USED 1 6651#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6652#define SQLITE_STATUS_SCRATCH_USED 3 6653#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6654#define SQLITE_STATUS_MALLOC_SIZE 5 6655#define SQLITE_STATUS_PARSER_STACK 6 6656#define SQLITE_STATUS_PAGECACHE_SIZE 7 6657#define SQLITE_STATUS_SCRATCH_SIZE 8 6658#define SQLITE_STATUS_MALLOC_COUNT 9 6659 6660/* 6661** CAPI3REF: Database Connection Status 6662** METHOD: sqlite3 6663** 6664** ^This interface is used to retrieve runtime status information 6665** about a single [database connection]. ^The first argument is the 6666** database connection object to be interrogated. ^The second argument 6667** is an integer constant, taken from the set of 6668** [SQLITE_DBSTATUS options], that 6669** determines the parameter to interrogate. The set of 6670** [SQLITE_DBSTATUS options] is likely 6671** to grow in future releases of SQLite. 6672** 6673** ^The current value of the requested parameter is written into *pCur 6674** and the highest instantaneous value is written into *pHiwtr. ^If 6675** the resetFlg is true, then the highest instantaneous value is 6676** reset back down to the current value. 6677** 6678** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6679** non-zero [error code] on failure. 6680** 6681** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6682*/ 6683SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6684 6685/* 6686** CAPI3REF: Status Parameters for database connections 6687** KEYWORDS: {SQLITE_DBSTATUS options} 6688** 6689** These constants are the available integer "verbs" that can be passed as 6690** the second argument to the [sqlite3_db_status()] interface. 6691** 6692** New verbs may be added in future releases of SQLite. Existing verbs 6693** might be discontinued. Applications should check the return code from 6694** [sqlite3_db_status()] to make sure that the call worked. 6695** The [sqlite3_db_status()] interface will return a non-zero error code 6696** if a discontinued or unsupported verb is invoked. 6697** 6698** <dl> 6699** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6700** <dd>This parameter returns the number of lookaside memory slots currently 6701** checked out.</dd>)^ 6702** 6703** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6704** <dd>This parameter returns the number malloc attempts that were 6705** satisfied using lookaside memory. Only the high-water value is meaningful; 6706** the current value is always zero.)^ 6707** 6708** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6709** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6710** <dd>This parameter returns the number malloc attempts that might have 6711** been satisfied using lookaside memory but failed due to the amount of 6712** memory requested being larger than the lookaside slot size. 6713** Only the high-water value is meaningful; 6714** the current value is always zero.)^ 6715** 6716** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6717** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6718** <dd>This parameter returns the number malloc attempts that might have 6719** been satisfied using lookaside memory but failed due to all lookaside 6720** memory already being in use. 6721** Only the high-water value is meaningful; 6722** the current value is always zero.)^ 6723** 6724** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6725** <dd>This parameter returns the approximate number of bytes of heap 6726** memory used by all pager caches associated with the database connection.)^ 6727** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6728** 6729** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6730** <dd>This parameter returns the approximate number of bytes of heap 6731** memory used to store the schema for all databases associated 6732** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6733** ^The full amount of memory used by the schemas is reported, even if the 6734** schema memory is shared with other database connections due to 6735** [shared cache mode] being enabled. 6736** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6737** 6738** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6739** <dd>This parameter returns the approximate number of bytes of heap 6740** and lookaside memory used by all prepared statements associated with 6741** the database connection.)^ 6742** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6743** </dd> 6744** 6745** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6746** <dd>This parameter returns the number of pager cache hits that have 6747** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6748** is always 0. 6749** </dd> 6750** 6751** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6752** <dd>This parameter returns the number of pager cache misses that have 6753** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6754** is always 0. 6755** </dd> 6756** 6757** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6758** <dd>This parameter returns the number of dirty cache entries that have 6759** been written to disk. Specifically, the number of pages written to the 6760** wal file in wal mode databases, or the number of pages written to the 6761** database file in rollback mode databases. Any pages written as part of 6762** transaction rollback or database recovery operations are not included. 6763** If an IO or other error occurs while writing a page to disk, the effect 6764** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6765** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6766** </dd> 6767** 6768** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6769** <dd>This parameter returns zero for the current value if and only if 6770** all foreign key constraints (deferred or immediate) have been 6771** resolved.)^ ^The highwater mark is always 0. 6772** </dd> 6773** </dl> 6774*/ 6775#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6776#define SQLITE_DBSTATUS_CACHE_USED 1 6777#define SQLITE_DBSTATUS_SCHEMA_USED 2 6778#define SQLITE_DBSTATUS_STMT_USED 3 6779#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6780#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6781#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6782#define SQLITE_DBSTATUS_CACHE_HIT 7 6783#define SQLITE_DBSTATUS_CACHE_MISS 8 6784#define SQLITE_DBSTATUS_CACHE_WRITE 9 6785#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6786#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6787 6788 6789/* 6790** CAPI3REF: Prepared Statement Status 6791** METHOD: sqlite3_stmt 6792** 6793** ^(Each prepared statement maintains various 6794** [SQLITE_STMTSTATUS counters] that measure the number 6795** of times it has performed specific operations.)^ These counters can 6796** be used to monitor the performance characteristics of the prepared 6797** statements. For example, if the number of table steps greatly exceeds 6798** the number of table searches or result rows, that would tend to indicate 6799** that the prepared statement is using a full table scan rather than 6800** an index. 6801** 6802** ^(This interface is used to retrieve and reset counter values from 6803** a [prepared statement]. The first argument is the prepared statement 6804** object to be interrogated. The second argument 6805** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6806** to be interrogated.)^ 6807** ^The current value of the requested counter is returned. 6808** ^If the resetFlg is true, then the counter is reset to zero after this 6809** interface call returns. 6810** 6811** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6812*/ 6813SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6814 6815/* 6816** CAPI3REF: Status Parameters for prepared statements 6817** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6818** 6819** These preprocessor macros define integer codes that name counter 6820** values associated with the [sqlite3_stmt_status()] interface. 6821** The meanings of the various counters are as follows: 6822** 6823** <dl> 6824** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6825** <dd>^This is the number of times that SQLite has stepped forward in 6826** a table as part of a full table scan. Large numbers for this counter 6827** may indicate opportunities for performance improvement through 6828** careful use of indices.</dd> 6829** 6830** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6831** <dd>^This is the number of sort operations that have occurred. 6832** A non-zero value in this counter may indicate an opportunity to 6833** improvement performance through careful use of indices.</dd> 6834** 6835** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6836** <dd>^This is the number of rows inserted into transient indices that 6837** were created automatically in order to help joins run faster. 6838** A non-zero value in this counter may indicate an opportunity to 6839** improvement performance by adding permanent indices that do not 6840** need to be reinitialized each time the statement is run.</dd> 6841** 6842** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6843** <dd>^This is the number of virtual machine operations executed 6844** by the prepared statement if that number is less than or equal 6845** to 2147483647. The number of virtual machine operations can be 6846** used as a proxy for the total work done by the prepared statement. 6847** If the number of virtual machine operations exceeds 2147483647 6848** then the value returned by this statement status code is undefined. 6849** </dd> 6850** </dl> 6851*/ 6852#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6853#define SQLITE_STMTSTATUS_SORT 2 6854#define SQLITE_STMTSTATUS_AUTOINDEX 3 6855#define SQLITE_STMTSTATUS_VM_STEP 4 6856 6857/* 6858** CAPI3REF: Custom Page Cache Object 6859** 6860** The sqlite3_pcache type is opaque. It is implemented by 6861** the pluggable module. The SQLite core has no knowledge of 6862** its size or internal structure and never deals with the 6863** sqlite3_pcache object except by holding and passing pointers 6864** to the object. 6865** 6866** See [sqlite3_pcache_methods2] for additional information. 6867*/ 6868typedef struct sqlite3_pcache sqlite3_pcache; 6869 6870/* 6871** CAPI3REF: Custom Page Cache Object 6872** 6873** The sqlite3_pcache_page object represents a single page in the 6874** page cache. The page cache will allocate instances of this 6875** object. Various methods of the page cache use pointers to instances 6876** of this object as parameters or as their return value. 6877** 6878** See [sqlite3_pcache_methods2] for additional information. 6879*/ 6880typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6881struct sqlite3_pcache_page { 6882 void *pBuf; /* The content of the page */ 6883 void *pExtra; /* Extra information associated with the page */ 6884}; 6885 6886/* 6887** CAPI3REF: Application Defined Page Cache. 6888** KEYWORDS: {page cache} 6889** 6890** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6891** register an alternative page cache implementation by passing in an 6892** instance of the sqlite3_pcache_methods2 structure.)^ 6893** In many applications, most of the heap memory allocated by 6894** SQLite is used for the page cache. 6895** By implementing a 6896** custom page cache using this API, an application can better control 6897** the amount of memory consumed by SQLite, the way in which 6898** that memory is allocated and released, and the policies used to 6899** determine exactly which parts of a database file are cached and for 6900** how long. 6901** 6902** The alternative page cache mechanism is an 6903** extreme measure that is only needed by the most demanding applications. 6904** The built-in page cache is recommended for most uses. 6905** 6906** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6907** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6908** the application may discard the parameter after the call to 6909** [sqlite3_config()] returns.)^ 6910** 6911** [[the xInit() page cache method]] 6912** ^(The xInit() method is called once for each effective 6913** call to [sqlite3_initialize()])^ 6914** (usually only once during the lifetime of the process). ^(The xInit() 6915** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6916** The intent of the xInit() method is to set up global data structures 6917** required by the custom page cache implementation. 6918** ^(If the xInit() method is NULL, then the 6919** built-in default page cache is used instead of the application defined 6920** page cache.)^ 6921** 6922** [[the xShutdown() page cache method]] 6923** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6924** It can be used to clean up 6925** any outstanding resources before process shutdown, if required. 6926** ^The xShutdown() method may be NULL. 6927** 6928** ^SQLite automatically serializes calls to the xInit method, 6929** so the xInit method need not be threadsafe. ^The 6930** xShutdown method is only called from [sqlite3_shutdown()] so it does 6931** not need to be threadsafe either. All other methods must be threadsafe 6932** in multithreaded applications. 6933** 6934** ^SQLite will never invoke xInit() more than once without an intervening 6935** call to xShutdown(). 6936** 6937** [[the xCreate() page cache methods]] 6938** ^SQLite invokes the xCreate() method to construct a new cache instance. 6939** SQLite will typically create one cache instance for each open database file, 6940** though this is not guaranteed. ^The 6941** first parameter, szPage, is the size in bytes of the pages that must 6942** be allocated by the cache. ^szPage will always a power of two. ^The 6943** second parameter szExtra is a number of bytes of extra storage 6944** associated with each page cache entry. ^The szExtra parameter will 6945** a number less than 250. SQLite will use the 6946** extra szExtra bytes on each page to store metadata about the underlying 6947** database page on disk. The value passed into szExtra depends 6948** on the SQLite version, the target platform, and how SQLite was compiled. 6949** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6950** created will be used to cache database pages of a file stored on disk, or 6951** false if it is used for an in-memory database. The cache implementation 6952** does not have to do anything special based with the value of bPurgeable; 6953** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6954** never invoke xUnpin() except to deliberately delete a page. 6955** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6956** false will always have the "discard" flag set to true. 6957** ^Hence, a cache created with bPurgeable false will 6958** never contain any unpinned pages. 6959** 6960** [[the xCachesize() page cache method]] 6961** ^(The xCachesize() method may be called at any time by SQLite to set the 6962** suggested maximum cache-size (number of pages stored by) the cache 6963** instance passed as the first argument. This is the value configured using 6964** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6965** parameter, the implementation is not required to do anything with this 6966** value; it is advisory only. 6967** 6968** [[the xPagecount() page cache methods]] 6969** The xPagecount() method must return the number of pages currently 6970** stored in the cache, both pinned and unpinned. 6971** 6972** [[the xFetch() page cache methods]] 6973** The xFetch() method locates a page in the cache and returns a pointer to 6974** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6975** The pBuf element of the returned sqlite3_pcache_page object will be a 6976** pointer to a buffer of szPage bytes used to store the content of a 6977** single database page. The pExtra element of sqlite3_pcache_page will be 6978** a pointer to the szExtra bytes of extra storage that SQLite has requested 6979** for each entry in the page cache. 6980** 6981** The page to be fetched is determined by the key. ^The minimum key value 6982** is 1. After it has been retrieved using xFetch, the page is considered 6983** to be "pinned". 6984** 6985** If the requested page is already in the page cache, then the page cache 6986** implementation must return a pointer to the page buffer with its content 6987** intact. If the requested page is not already in the cache, then the 6988** cache implementation should use the value of the createFlag 6989** parameter to help it determined what action to take: 6990** 6991** <table border=1 width=85% align=center> 6992** <tr><th> createFlag <th> Behavior when page is not already in cache 6993** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6994** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6995** Otherwise return NULL. 6996** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6997** NULL if allocating a new page is effectively impossible. 6998** </table> 6999** 7000** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7001** will only use a createFlag of 2 after a prior call with a createFlag of 1 7002** failed.)^ In between the to xFetch() calls, SQLite may 7003** attempt to unpin one or more cache pages by spilling the content of 7004** pinned pages to disk and synching the operating system disk cache. 7005** 7006** [[the xUnpin() page cache method]] 7007** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7008** as its second argument. If the third parameter, discard, is non-zero, 7009** then the page must be evicted from the cache. 7010** ^If the discard parameter is 7011** zero, then the page may be discarded or retained at the discretion of 7012** page cache implementation. ^The page cache implementation 7013** may choose to evict unpinned pages at any time. 7014** 7015** The cache must not perform any reference counting. A single 7016** call to xUnpin() unpins the page regardless of the number of prior calls 7017** to xFetch(). 7018** 7019** [[the xRekey() page cache methods]] 7020** The xRekey() method is used to change the key value associated with the 7021** page passed as the second argument. If the cache 7022** previously contains an entry associated with newKey, it must be 7023** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7024** to be pinned. 7025** 7026** When SQLite calls the xTruncate() method, the cache must discard all 7027** existing cache entries with page numbers (keys) greater than or equal 7028** to the value of the iLimit parameter passed to xTruncate(). If any 7029** of these pages are pinned, they are implicitly unpinned, meaning that 7030** they can be safely discarded. 7031** 7032** [[the xDestroy() page cache method]] 7033** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7034** All resources associated with the specified cache should be freed. ^After 7035** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7036** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7037** functions. 7038** 7039** [[the xShrink() page cache method]] 7040** ^SQLite invokes the xShrink() method when it wants the page cache to 7041** free up as much of heap memory as possible. The page cache implementation 7042** is not obligated to free any memory, but well-behaved implementations should 7043** do their best. 7044*/ 7045typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7046struct sqlite3_pcache_methods2 { 7047 int iVersion; 7048 void *pArg; 7049 int (*xInit)(void*); 7050 void (*xShutdown)(void*); 7051 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7052 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7053 int (*xPagecount)(sqlite3_pcache*); 7054 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7055 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7056 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7057 unsigned oldKey, unsigned newKey); 7058 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7059 void (*xDestroy)(sqlite3_pcache*); 7060 void (*xShrink)(sqlite3_pcache*); 7061}; 7062 7063/* 7064** This is the obsolete pcache_methods object that has now been replaced 7065** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7066** retained in the header file for backwards compatibility only. 7067*/ 7068typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7069struct sqlite3_pcache_methods { 7070 void *pArg; 7071 int (*xInit)(void*); 7072 void (*xShutdown)(void*); 7073 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7074 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7075 int (*xPagecount)(sqlite3_pcache*); 7076 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7077 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7078 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7079 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7080 void (*xDestroy)(sqlite3_pcache*); 7081}; 7082 7083 7084/* 7085** CAPI3REF: Online Backup Object 7086** 7087** The sqlite3_backup object records state information about an ongoing 7088** online backup operation. ^The sqlite3_backup object is created by 7089** a call to [sqlite3_backup_init()] and is destroyed by a call to 7090** [sqlite3_backup_finish()]. 7091** 7092** See Also: [Using the SQLite Online Backup API] 7093*/ 7094typedef struct sqlite3_backup sqlite3_backup; 7095 7096/* 7097** CAPI3REF: Online Backup API. 7098** 7099** The backup API copies the content of one database into another. 7100** It is useful either for creating backups of databases or 7101** for copying in-memory databases to or from persistent files. 7102** 7103** See Also: [Using the SQLite Online Backup API] 7104** 7105** ^SQLite holds a write transaction open on the destination database file 7106** for the duration of the backup operation. 7107** ^The source database is read-locked only while it is being read; 7108** it is not locked continuously for the entire backup operation. 7109** ^Thus, the backup may be performed on a live source database without 7110** preventing other database connections from 7111** reading or writing to the source database while the backup is underway. 7112** 7113** ^(To perform a backup operation: 7114** <ol> 7115** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7116** backup, 7117** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7118** the data between the two databases, and finally 7119** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7120** associated with the backup operation. 7121** </ol>)^ 7122** There should be exactly one call to sqlite3_backup_finish() for each 7123** successful call to sqlite3_backup_init(). 7124** 7125** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7126** 7127** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7128** [database connection] associated with the destination database 7129** and the database name, respectively. 7130** ^The database name is "main" for the main database, "temp" for the 7131** temporary database, or the name specified after the AS keyword in 7132** an [ATTACH] statement for an attached database. 7133** ^The S and M arguments passed to 7134** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7135** and database name of the source database, respectively. 7136** ^The source and destination [database connections] (parameters S and D) 7137** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7138** an error. 7139** 7140** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 7141** there is already a read or read-write transaction open on the 7142** destination database. 7143** 7144** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7145** returned and an error code and error message are stored in the 7146** destination [database connection] D. 7147** ^The error code and message for the failed call to sqlite3_backup_init() 7148** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7149** [sqlite3_errmsg16()] functions. 7150** ^A successful call to sqlite3_backup_init() returns a pointer to an 7151** [sqlite3_backup] object. 7152** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7153** sqlite3_backup_finish() functions to perform the specified backup 7154** operation. 7155** 7156** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7157** 7158** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7159** the source and destination databases specified by [sqlite3_backup] object B. 7160** ^If N is negative, all remaining source pages are copied. 7161** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7162** are still more pages to be copied, then the function returns [SQLITE_OK]. 7163** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7164** from source to destination, then it returns [SQLITE_DONE]. 7165** ^If an error occurs while running sqlite3_backup_step(B,N), 7166** then an [error code] is returned. ^As well as [SQLITE_OK] and 7167** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7168** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7169** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7170** 7171** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7172** <ol> 7173** <li> the destination database was opened read-only, or 7174** <li> the destination database is using write-ahead-log journaling 7175** and the destination and source page sizes differ, or 7176** <li> the destination database is an in-memory database and the 7177** destination and source page sizes differ. 7178** </ol>)^ 7179** 7180** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7181** the [sqlite3_busy_handler | busy-handler function] 7182** is invoked (if one is specified). ^If the 7183** busy-handler returns non-zero before the lock is available, then 7184** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7185** sqlite3_backup_step() can be retried later. ^If the source 7186** [database connection] 7187** is being used to write to the source database when sqlite3_backup_step() 7188** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7189** case the call to sqlite3_backup_step() can be retried later on. ^(If 7190** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7191** [SQLITE_READONLY] is returned, then 7192** there is no point in retrying the call to sqlite3_backup_step(). These 7193** errors are considered fatal.)^ The application must accept 7194** that the backup operation has failed and pass the backup operation handle 7195** to the sqlite3_backup_finish() to release associated resources. 7196** 7197** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7198** on the destination file. ^The exclusive lock is not released until either 7199** sqlite3_backup_finish() is called or the backup operation is complete 7200** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7201** sqlite3_backup_step() obtains a [shared lock] on the source database that 7202** lasts for the duration of the sqlite3_backup_step() call. 7203** ^Because the source database is not locked between calls to 7204** sqlite3_backup_step(), the source database may be modified mid-way 7205** through the backup process. ^If the source database is modified by an 7206** external process or via a database connection other than the one being 7207** used by the backup operation, then the backup will be automatically 7208** restarted by the next call to sqlite3_backup_step(). ^If the source 7209** database is modified by the using the same database connection as is used 7210** by the backup operation, then the backup database is automatically 7211** updated at the same time. 7212** 7213** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7214** 7215** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7216** application wishes to abandon the backup operation, the application 7217** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7218** ^The sqlite3_backup_finish() interfaces releases all 7219** resources associated with the [sqlite3_backup] object. 7220** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7221** active write-transaction on the destination database is rolled back. 7222** The [sqlite3_backup] object is invalid 7223** and may not be used following a call to sqlite3_backup_finish(). 7224** 7225** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7226** sqlite3_backup_step() errors occurred, regardless or whether or not 7227** sqlite3_backup_step() completed. 7228** ^If an out-of-memory condition or IO error occurred during any prior 7229** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7230** sqlite3_backup_finish() returns the corresponding [error code]. 7231** 7232** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7233** is not a permanent error and does not affect the return value of 7234** sqlite3_backup_finish(). 7235** 7236** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7237** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7238** 7239** ^The sqlite3_backup_remaining() routine returns the number of pages still 7240** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7241** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7242** in the source database at the conclusion of the most recent 7243** sqlite3_backup_step(). 7244** ^(The values returned by these functions are only updated by 7245** sqlite3_backup_step(). If the source database is modified in a way that 7246** changes the size of the source database or the number of pages remaining, 7247** those changes are not reflected in the output of sqlite3_backup_pagecount() 7248** and sqlite3_backup_remaining() until after the next 7249** sqlite3_backup_step().)^ 7250** 7251** <b>Concurrent Usage of Database Handles</b> 7252** 7253** ^The source [database connection] may be used by the application for other 7254** purposes while a backup operation is underway or being initialized. 7255** ^If SQLite is compiled and configured to support threadsafe database 7256** connections, then the source database connection may be used concurrently 7257** from within other threads. 7258** 7259** However, the application must guarantee that the destination 7260** [database connection] is not passed to any other API (by any thread) after 7261** sqlite3_backup_init() is called and before the corresponding call to 7262** sqlite3_backup_finish(). SQLite does not currently check to see 7263** if the application incorrectly accesses the destination [database connection] 7264** and so no error code is reported, but the operations may malfunction 7265** nevertheless. Use of the destination database connection while a 7266** backup is in progress might also also cause a mutex deadlock. 7267** 7268** If running in [shared cache mode], the application must 7269** guarantee that the shared cache used by the destination database 7270** is not accessed while the backup is running. In practice this means 7271** that the application must guarantee that the disk file being 7272** backed up to is not accessed by any connection within the process, 7273** not just the specific connection that was passed to sqlite3_backup_init(). 7274** 7275** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7276** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7277** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7278** APIs are not strictly speaking threadsafe. If they are invoked at the 7279** same time as another thread is invoking sqlite3_backup_step() it is 7280** possible that they return invalid values. 7281*/ 7282SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7283 sqlite3 *pDest, /* Destination database handle */ 7284 const char *zDestName, /* Destination database name */ 7285 sqlite3 *pSource, /* Source database handle */ 7286 const char *zSourceName /* Source database name */ 7287); 7288SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7289SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7290SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7291SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7292 7293/* 7294** CAPI3REF: Unlock Notification 7295** METHOD: sqlite3 7296** 7297** ^When running in shared-cache mode, a database operation may fail with 7298** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7299** individual tables within the shared-cache cannot be obtained. See 7300** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7301** ^This API may be used to register a callback that SQLite will invoke 7302** when the connection currently holding the required lock relinquishes it. 7303** ^This API is only available if the library was compiled with the 7304** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7305** 7306** See Also: [Using the SQLite Unlock Notification Feature]. 7307** 7308** ^Shared-cache locks are released when a database connection concludes 7309** its current transaction, either by committing it or rolling it back. 7310** 7311** ^When a connection (known as the blocked connection) fails to obtain a 7312** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7313** identity of the database connection (the blocking connection) that 7314** has locked the required resource is stored internally. ^After an 7315** application receives an SQLITE_LOCKED error, it may call the 7316** sqlite3_unlock_notify() method with the blocked connection handle as 7317** the first argument to register for a callback that will be invoked 7318** when the blocking connections current transaction is concluded. ^The 7319** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7320** call that concludes the blocking connections transaction. 7321** 7322** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7323** there is a chance that the blocking connection will have already 7324** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7325** If this happens, then the specified callback is invoked immediately, 7326** from within the call to sqlite3_unlock_notify().)^ 7327** 7328** ^If the blocked connection is attempting to obtain a write-lock on a 7329** shared-cache table, and more than one other connection currently holds 7330** a read-lock on the same table, then SQLite arbitrarily selects one of 7331** the other connections to use as the blocking connection. 7332** 7333** ^(There may be at most one unlock-notify callback registered by a 7334** blocked connection. If sqlite3_unlock_notify() is called when the 7335** blocked connection already has a registered unlock-notify callback, 7336** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7337** called with a NULL pointer as its second argument, then any existing 7338** unlock-notify callback is canceled. ^The blocked connections 7339** unlock-notify callback may also be canceled by closing the blocked 7340** connection using [sqlite3_close()]. 7341** 7342** The unlock-notify callback is not reentrant. If an application invokes 7343** any sqlite3_xxx API functions from within an unlock-notify callback, a 7344** crash or deadlock may be the result. 7345** 7346** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7347** returns SQLITE_OK. 7348** 7349** <b>Callback Invocation Details</b> 7350** 7351** When an unlock-notify callback is registered, the application provides a 7352** single void* pointer that is passed to the callback when it is invoked. 7353** However, the signature of the callback function allows SQLite to pass 7354** it an array of void* context pointers. The first argument passed to 7355** an unlock-notify callback is a pointer to an array of void* pointers, 7356** and the second is the number of entries in the array. 7357** 7358** When a blocking connections transaction is concluded, there may be 7359** more than one blocked connection that has registered for an unlock-notify 7360** callback. ^If two or more such blocked connections have specified the 7361** same callback function, then instead of invoking the callback function 7362** multiple times, it is invoked once with the set of void* context pointers 7363** specified by the blocked connections bundled together into an array. 7364** This gives the application an opportunity to prioritize any actions 7365** related to the set of unblocked database connections. 7366** 7367** <b>Deadlock Detection</b> 7368** 7369** Assuming that after registering for an unlock-notify callback a 7370** database waits for the callback to be issued before taking any further 7371** action (a reasonable assumption), then using this API may cause the 7372** application to deadlock. For example, if connection X is waiting for 7373** connection Y's transaction to be concluded, and similarly connection 7374** Y is waiting on connection X's transaction, then neither connection 7375** will proceed and the system may remain deadlocked indefinitely. 7376** 7377** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7378** detection. ^If a given call to sqlite3_unlock_notify() would put the 7379** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7380** unlock-notify callback is registered. The system is said to be in 7381** a deadlocked state if connection A has registered for an unlock-notify 7382** callback on the conclusion of connection B's transaction, and connection 7383** B has itself registered for an unlock-notify callback when connection 7384** A's transaction is concluded. ^Indirect deadlock is also detected, so 7385** the system is also considered to be deadlocked if connection B has 7386** registered for an unlock-notify callback on the conclusion of connection 7387** C's transaction, where connection C is waiting on connection A. ^Any 7388** number of levels of indirection are allowed. 7389** 7390** <b>The "DROP TABLE" Exception</b> 7391** 7392** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7393** always appropriate to call sqlite3_unlock_notify(). There is however, 7394** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7395** SQLite checks if there are any currently executing SELECT statements 7396** that belong to the same connection. If there are, SQLITE_LOCKED is 7397** returned. In this case there is no "blocking connection", so invoking 7398** sqlite3_unlock_notify() results in the unlock-notify callback being 7399** invoked immediately. If the application then re-attempts the "DROP TABLE" 7400** or "DROP INDEX" query, an infinite loop might be the result. 7401** 7402** One way around this problem is to check the extended error code returned 7403** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7404** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7405** the special "DROP TABLE/INDEX" case, the extended error code is just 7406** SQLITE_LOCKED.)^ 7407*/ 7408SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7409 sqlite3 *pBlocked, /* Waiting connection */ 7410 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7411 void *pNotifyArg /* Argument to pass to xNotify */ 7412); 7413 7414 7415/* 7416** CAPI3REF: String Comparison 7417** 7418** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7419** and extensions to compare the contents of two buffers containing UTF-8 7420** strings in a case-independent fashion, using the same definition of "case 7421** independence" that SQLite uses internally when comparing identifiers. 7422*/ 7423SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7424SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7425 7426/* 7427** CAPI3REF: String Globbing 7428* 7429** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7430** string X matches the [GLOB] pattern P. 7431** ^The definition of [GLOB] pattern matching used in 7432** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7433** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7434** is case sensitive. 7435** 7436** Note that this routine returns zero on a match and non-zero if the strings 7437** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7438** 7439** See also: [sqlite3_strlike()]. 7440*/ 7441SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7442 7443/* 7444** CAPI3REF: String LIKE Matching 7445* 7446** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7447** string X matches the [LIKE] pattern P with escape character E. 7448** ^The definition of [LIKE] pattern matching used in 7449** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7450** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7451** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7452** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7453** insensitive - equivalent upper and lower case ASCII characters match 7454** one another. 7455** 7456** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7457** only ASCII characters are case folded. 7458** 7459** Note that this routine returns zero on a match and non-zero if the strings 7460** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7461** 7462** See also: [sqlite3_strglob()]. 7463*/ 7464SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7465 7466/* 7467** CAPI3REF: Error Logging Interface 7468** 7469** ^The [sqlite3_log()] interface writes a message into the [error log] 7470** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7471** ^If logging is enabled, the zFormat string and subsequent arguments are 7472** used with [sqlite3_snprintf()] to generate the final output string. 7473** 7474** The sqlite3_log() interface is intended for use by extensions such as 7475** virtual tables, collating functions, and SQL functions. While there is 7476** nothing to prevent an application from calling sqlite3_log(), doing so 7477** is considered bad form. 7478** 7479** The zFormat string must not be NULL. 7480** 7481** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7482** will not use dynamically allocated memory. The log message is stored in 7483** a fixed-length buffer on the stack. If the log message is longer than 7484** a few hundred characters, it will be truncated to the length of the 7485** buffer. 7486*/ 7487SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7488 7489/* 7490** CAPI3REF: Write-Ahead Log Commit Hook 7491** METHOD: sqlite3 7492** 7493** ^The [sqlite3_wal_hook()] function is used to register a callback that 7494** is invoked each time data is committed to a database in wal mode. 7495** 7496** ^(The callback is invoked by SQLite after the commit has taken place and 7497** the associated write-lock on the database released)^, so the implementation 7498** may read, write or [checkpoint] the database as required. 7499** 7500** ^The first parameter passed to the callback function when it is invoked 7501** is a copy of the third parameter passed to sqlite3_wal_hook() when 7502** registering the callback. ^The second is a copy of the database handle. 7503** ^The third parameter is the name of the database that was written to - 7504** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7505** is the number of pages currently in the write-ahead log file, 7506** including those that were just committed. 7507** 7508** The callback function should normally return [SQLITE_OK]. ^If an error 7509** code is returned, that error will propagate back up through the 7510** SQLite code base to cause the statement that provoked the callback 7511** to report an error, though the commit will have still occurred. If the 7512** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7513** that does not correspond to any valid SQLite error code, the results 7514** are undefined. 7515** 7516** A single database handle may have at most a single write-ahead log callback 7517** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7518** previously registered write-ahead log callback. ^Note that the 7519** [sqlite3_wal_autocheckpoint()] interface and the 7520** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7521** overwrite any prior [sqlite3_wal_hook()] settings. 7522*/ 7523SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7524 sqlite3*, 7525 int(*)(void *,sqlite3*,const char*,int), 7526 void* 7527); 7528 7529/* 7530** CAPI3REF: Configure an auto-checkpoint 7531** METHOD: sqlite3 7532** 7533** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7534** [sqlite3_wal_hook()] that causes any database on [database connection] D 7535** to automatically [checkpoint] 7536** after committing a transaction if there are N or 7537** more frames in the [write-ahead log] file. ^Passing zero or 7538** a negative value as the nFrame parameter disables automatic 7539** checkpoints entirely. 7540** 7541** ^The callback registered by this function replaces any existing callback 7542** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7543** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7544** configured by this function. 7545** 7546** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7547** from SQL. 7548** 7549** ^Checkpoints initiated by this mechanism are 7550** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7551** 7552** ^Every new [database connection] defaults to having the auto-checkpoint 7553** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7554** pages. The use of this interface 7555** is only necessary if the default setting is found to be suboptimal 7556** for a particular application. 7557*/ 7558SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7559 7560/* 7561** CAPI3REF: Checkpoint a database 7562** METHOD: sqlite3 7563** 7564** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7565** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7566** 7567** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7568** [write-ahead log] for database X on [database connection] D to be 7569** transferred into the database file and for the write-ahead log to 7570** be reset. See the [checkpointing] documentation for addition 7571** information. 7572** 7573** This interface used to be the only way to cause a checkpoint to 7574** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7575** interface was added. This interface is retained for backwards 7576** compatibility and as a convenience for applications that need to manually 7577** start a callback but which do not need the full power (and corresponding 7578** complication) of [sqlite3_wal_checkpoint_v2()]. 7579*/ 7580SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7581 7582/* 7583** CAPI3REF: Checkpoint a database 7584** METHOD: sqlite3 7585** 7586** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7587** operation on database X of [database connection] D in mode M. Status 7588** information is written back into integers pointed to by L and C.)^ 7589** ^(The M parameter must be a valid [checkpoint mode]:)^ 7590** 7591** <dl> 7592** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7593** ^Checkpoint as many frames as possible without waiting for any database 7594** readers or writers to finish, then sync the database file if all frames 7595** in the log were checkpointed. ^The [busy-handler callback] 7596** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7597** ^On the other hand, passive mode might leave the checkpoint unfinished 7598** if there are concurrent readers or writers. 7599** 7600** <dt>SQLITE_CHECKPOINT_FULL<dd> 7601** ^This mode blocks (it invokes the 7602** [sqlite3_busy_handler|busy-handler callback]) until there is no 7603** database writer and all readers are reading from the most recent database 7604** snapshot. ^It then checkpoints all frames in the log file and syncs the 7605** database file. ^This mode blocks new database writers while it is pending, 7606** but new database readers are allowed to continue unimpeded. 7607** 7608** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7609** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7610** that after checkpointing the log file it blocks (calls the 7611** [busy-handler callback]) 7612** until all readers are reading from the database file only. ^This ensures 7613** that the next writer will restart the log file from the beginning. 7614** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7615** database writer attempts while it is pending, but does not impede readers. 7616** 7617** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7618** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7619** addition that it also truncates the log file to zero bytes just prior 7620** to a successful return. 7621** </dl> 7622** 7623** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7624** the log file or to -1 if the checkpoint could not run because 7625** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7626** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7627** log file (including any that were already checkpointed before the function 7628** was called) or to -1 if the checkpoint could not run due to an error or 7629** because the database is not in WAL mode. ^Note that upon successful 7630** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7631** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7632** 7633** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7634** any other process is running a checkpoint operation at the same time, the 7635** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7636** busy-handler configured, it will not be invoked in this case. 7637** 7638** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7639** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7640** obtained immediately, and a busy-handler is configured, it is invoked and 7641** the writer lock retried until either the busy-handler returns 0 or the lock 7642** is successfully obtained. ^The busy-handler is also invoked while waiting for 7643** database readers as described above. ^If the busy-handler returns 0 before 7644** the writer lock is obtained or while waiting for database readers, the 7645** checkpoint operation proceeds from that point in the same way as 7646** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7647** without blocking any further. ^SQLITE_BUSY is returned in this case. 7648** 7649** ^If parameter zDb is NULL or points to a zero length string, then the 7650** specified operation is attempted on all WAL databases [attached] to 7651** [database connection] db. In this case the 7652** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7653** an SQLITE_BUSY error is encountered when processing one or more of the 7654** attached WAL databases, the operation is still attempted on any remaining 7655** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7656** error occurs while processing an attached database, processing is abandoned 7657** and the error code is returned to the caller immediately. ^If no error 7658** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7659** databases, SQLITE_OK is returned. 7660** 7661** ^If database zDb is the name of an attached database that is not in WAL 7662** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7663** zDb is not NULL (or a zero length string) and is not the name of any 7664** attached database, SQLITE_ERROR is returned to the caller. 7665** 7666** ^Unless it returns SQLITE_MISUSE, 7667** the sqlite3_wal_checkpoint_v2() interface 7668** sets the error information that is queried by 7669** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7670** 7671** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7672** from SQL. 7673*/ 7674SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7675 sqlite3 *db, /* Database handle */ 7676 const char *zDb, /* Name of attached database (or NULL) */ 7677 int eMode, /* SQLITE_CHECKPOINT_* value */ 7678 int *pnLog, /* OUT: Size of WAL log in frames */ 7679 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7680); 7681 7682/* 7683** CAPI3REF: Checkpoint Mode Values 7684** KEYWORDS: {checkpoint mode} 7685** 7686** These constants define all valid values for the "checkpoint mode" passed 7687** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7688** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7689** meaning of each of these checkpoint modes. 7690*/ 7691#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7692#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7693#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7694#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7695 7696/* 7697** CAPI3REF: Virtual Table Interface Configuration 7698** 7699** This function may be called by either the [xConnect] or [xCreate] method 7700** of a [virtual table] implementation to configure 7701** various facets of the virtual table interface. 7702** 7703** If this interface is invoked outside the context of an xConnect or 7704** xCreate virtual table method then the behavior is undefined. 7705** 7706** At present, there is only one option that may be configured using 7707** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7708** may be added in the future. 7709*/ 7710SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7711 7712/* 7713** CAPI3REF: Virtual Table Configuration Options 7714** 7715** These macros define the various options to the 7716** [sqlite3_vtab_config()] interface that [virtual table] implementations 7717** can use to customize and optimize their behavior. 7718** 7719** <dl> 7720** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7721** <dd>Calls of the form 7722** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7723** where X is an integer. If X is zero, then the [virtual table] whose 7724** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7725** support constraints. In this configuration (which is the default) if 7726** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7727** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7728** specified as part of the users SQL statement, regardless of the actual 7729** ON CONFLICT mode specified. 7730** 7731** If X is non-zero, then the virtual table implementation guarantees 7732** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7733** any modifications to internal or persistent data structures have been made. 7734** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7735** is able to roll back a statement or database transaction, and abandon 7736** or continue processing the current SQL statement as appropriate. 7737** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7738** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7739** had been ABORT. 7740** 7741** Virtual table implementations that are required to handle OR REPLACE 7742** must do so within the [xUpdate] method. If a call to the 7743** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7744** CONFLICT policy is REPLACE, the virtual table implementation should 7745** silently replace the appropriate rows within the xUpdate callback and 7746** return SQLITE_OK. Or, if this is not possible, it may return 7747** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7748** constraint handling. 7749** </dl> 7750*/ 7751#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7752 7753/* 7754** CAPI3REF: Determine The Virtual Table Conflict Policy 7755** 7756** This function may only be called from within a call to the [xUpdate] method 7757** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7758** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7759** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7760** of the SQL statement that triggered the call to the [xUpdate] method of the 7761** [virtual table]. 7762*/ 7763SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7764 7765/* 7766** CAPI3REF: Conflict resolution modes 7767** KEYWORDS: {conflict resolution mode} 7768** 7769** These constants are returned by [sqlite3_vtab_on_conflict()] to 7770** inform a [virtual table] implementation what the [ON CONFLICT] mode 7771** is for the SQL statement being evaluated. 7772** 7773** Note that the [SQLITE_IGNORE] constant is also used as a potential 7774** return value from the [sqlite3_set_authorizer()] callback and that 7775** [SQLITE_ABORT] is also a [result code]. 7776*/ 7777#define SQLITE_ROLLBACK 1 7778/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7779#define SQLITE_FAIL 3 7780/* #define SQLITE_ABORT 4 // Also an error code */ 7781#define SQLITE_REPLACE 5 7782 7783/* 7784** CAPI3REF: Prepared Statement Scan Status Opcodes 7785** KEYWORDS: {scanstatus options} 7786** 7787** The following constants can be used for the T parameter to the 7788** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7789** different metric for sqlite3_stmt_scanstatus() to return. 7790** 7791** When the value returned to V is a string, space to hold that string is 7792** managed by the prepared statement S and will be automatically freed when 7793** S is finalized. 7794** 7795** <dl> 7796** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7797** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7798** set to the total number of times that the X-th loop has run.</dd> 7799** 7800** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7801** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7802** to the total number of rows examined by all iterations of the X-th loop.</dd> 7803** 7804** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7805** <dd>^The "double" variable pointed to by the T parameter will be set to the 7806** query planner's estimate for the average number of rows output from each 7807** iteration of the X-th loop. If the query planner's estimates was accurate, 7808** then this value will approximate the quotient NVISIT/NLOOP and the 7809** product of this value for all prior loops with the same SELECTID will 7810** be the NLOOP value for the current loop. 7811** 7812** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7813** <dd>^The "const char *" variable pointed to by the T parameter will be set 7814** to a zero-terminated UTF-8 string containing the name of the index or table 7815** used for the X-th loop. 7816** 7817** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7818** <dd>^The "const char *" variable pointed to by the T parameter will be set 7819** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7820** description for the X-th loop. 7821** 7822** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7823** <dd>^The "int" variable pointed to by the T parameter will be set to the 7824** "select-id" for the X-th loop. The select-id identifies which query or 7825** subquery the loop is part of. The main query has a select-id of zero. 7826** The select-id is the same value as is output in the first column 7827** of an [EXPLAIN QUERY PLAN] query. 7828** </dl> 7829*/ 7830#define SQLITE_SCANSTAT_NLOOP 0 7831#define SQLITE_SCANSTAT_NVISIT 1 7832#define SQLITE_SCANSTAT_EST 2 7833#define SQLITE_SCANSTAT_NAME 3 7834#define SQLITE_SCANSTAT_EXPLAIN 4 7835#define SQLITE_SCANSTAT_SELECTID 5 7836 7837/* 7838** CAPI3REF: Prepared Statement Scan Status 7839** METHOD: sqlite3_stmt 7840** 7841** This interface returns information about the predicted and measured 7842** performance for pStmt. Advanced applications can use this 7843** interface to compare the predicted and the measured performance and 7844** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7845** 7846** Since this interface is expected to be rarely used, it is only 7847** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7848** compile-time option. 7849** 7850** The "iScanStatusOp" parameter determines which status information to return. 7851** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7852** of this interface is undefined. 7853** ^The requested measurement is written into a variable pointed to by 7854** the "pOut" parameter. 7855** Parameter "idx" identifies the specific loop to retrieve statistics for. 7856** Loops are numbered starting from zero. ^If idx is out of range - less than 7857** zero or greater than or equal to the total number of loops used to implement 7858** the statement - a non-zero value is returned and the variable that pOut 7859** points to is unchanged. 7860** 7861** ^Statistics might not be available for all loops in all statements. ^In cases 7862** where there exist loops with no available statistics, this function behaves 7863** as if the loop did not exist - it returns non-zero and leave the variable 7864** that pOut points to unchanged. 7865** 7866** See also: [sqlite3_stmt_scanstatus_reset()] 7867*/ 7868SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus( 7869 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7870 int idx, /* Index of loop to report on */ 7871 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7872 void *pOut /* Result written here */ 7873); 7874 7875/* 7876** CAPI3REF: Zero Scan-Status Counters 7877** METHOD: sqlite3_stmt 7878** 7879** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7880** 7881** This API is only available if the library is built with pre-processor 7882** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7883*/ 7884SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7885 7886/* 7887** CAPI3REF: Flush caches to disk mid-transaction 7888** 7889** ^If a write-transaction is open on [database connection] D when the 7890** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 7891** pages in the pager-cache that are not currently in use are written out 7892** to disk. A dirty page may be in use if a database cursor created by an 7893** active SQL statement is reading from it, or if it is page 1 of a database 7894** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 7895** interface flushes caches for all schemas - "main", "temp", and 7896** any [attached] databases. 7897** 7898** ^If this function needs to obtain extra database locks before dirty pages 7899** can be flushed to disk, it does so. ^If those locks cannot be obtained 7900** immediately and there is a busy-handler callback configured, it is invoked 7901** in the usual manner. ^If the required lock still cannot be obtained, then 7902** the database is skipped and an attempt made to flush any dirty pages 7903** belonging to the next (if any) database. ^If any databases are skipped 7904** because locks cannot be obtained, but no other error occurs, this 7905** function returns SQLITE_BUSY. 7906** 7907** ^If any other error occurs while flushing dirty pages to disk (for 7908** example an IO error or out-of-memory condition), then processing is 7909** abandoned and an SQLite [error code] is returned to the caller immediately. 7910** 7911** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 7912** 7913** ^This function does not set the database handle error code or message 7914** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 7915*/ 7916SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*); 7917 7918/* 7919** CAPI3REF: Low-level system error code 7920** 7921** ^Attempt to return the underlying operating system error code or error 7922** number that caused the most reason I/O error or failure to open a file. 7923** The return value is OS-dependent. For example, on unix systems, after 7924** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 7925** called to get back the underlying "errno" that caused the problem, such 7926** as ENOSPC, EAUTH, EISDIR, and so forth. 7927*/ 7928SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*); 7929 7930/* 7931** CAPI3REF: Database Snapshot 7932** KEYWORDS: {snapshot} 7933** EXPERIMENTAL 7934** 7935** An instance of the snapshot object records the state of a [WAL mode] 7936** database for some specific point in history. 7937** 7938** In [WAL mode], multiple [database connections] that are open on the 7939** same database file can each be reading a different historical version 7940** of the database file. When a [database connection] begins a read 7941** transaction, that connection sees an unchanging copy of the database 7942** as it existed for the point in time when the transaction first started. 7943** Subsequent changes to the database from other connections are not seen 7944** by the reader until a new read transaction is started. 7945** 7946** The sqlite3_snapshot object records state information about an historical 7947** version of the database file so that it is possible to later open a new read 7948** transaction that sees that historical version of the database rather than 7949** the most recent version. 7950** 7951** The constructor for this object is [sqlite3_snapshot_get()]. The 7952** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 7953** to an historical snapshot (if possible). The destructor for 7954** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 7955*/ 7956typedef struct sqlite3_snapshot sqlite3_snapshot; 7957 7958/* 7959** CAPI3REF: Record A Database Snapshot 7960** EXPERIMENTAL 7961** 7962** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 7963** new [sqlite3_snapshot] object that records the current state of 7964** schema S in database connection D. ^On success, the 7965** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 7966** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 7967** ^If schema S of [database connection] D is not a [WAL mode] database 7968** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 7969** leaves the *P value unchanged and returns an appropriate [error code]. 7970** 7971** The [sqlite3_snapshot] object returned from a successful call to 7972** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 7973** to avoid a memory leak. 7974** 7975** The [sqlite3_snapshot_get()] interface is only available when the 7976** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 7977*/ 7978SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get( 7979 sqlite3 *db, 7980 const char *zSchema, 7981 sqlite3_snapshot **ppSnapshot 7982); 7983 7984/* 7985** CAPI3REF: Start a read transaction on an historical snapshot 7986** EXPERIMENTAL 7987** 7988** ^The [sqlite3_snapshot_open(D,S,P)] interface attempts to move the 7989** read transaction that is currently open on schema S of 7990** [database connection] D so that it refers to historical [snapshot] P. 7991** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 7992** or an appropriate [error code] if it fails. 7993** 7994** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 7995** the first operation, apart from other sqlite3_snapshot_open() calls, 7996** following the [BEGIN] that starts a new read transaction. 7997** ^A [snapshot] will fail to open if it has been overwritten by a 7998** [checkpoint]. 7999** ^A [snapshot] will fail to open if the database connection D has not 8000** previously completed at least one read operation against the database 8001** file. (Hint: Run "[PRAGMA application_id]" against a newly opened 8002** database connection in order to make it ready to use snapshots.) 8003** 8004** The [sqlite3_snapshot_open()] interface is only available when the 8005** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8006*/ 8007SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open( 8008 sqlite3 *db, 8009 const char *zSchema, 8010 sqlite3_snapshot *pSnapshot 8011); 8012 8013/* 8014** CAPI3REF: Destroy a snapshot 8015** EXPERIMENTAL 8016** 8017** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8018** The application must eventually free every [sqlite3_snapshot] object 8019** using this routine to avoid a memory leak. 8020** 8021** The [sqlite3_snapshot_free()] interface is only available when the 8022** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8023*/ 8024SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*); 8025 8026/* 8027** Undo the hack that converts floating point types to integer for 8028** builds on processors without floating point support. 8029*/ 8030#ifdef SQLITE_OMIT_FLOATING_POINT 8031# undef double 8032#endif 8033 8034#ifdef __cplusplus 8035} /* End of the 'extern "C"' block */ 8036#endif 8037#endif /* _SQLITE3_H_ */ 8038 8039/* 8040** 2010 August 30 8041** 8042** The author disclaims copyright to this source code. In place of 8043** a legal notice, here is a blessing: 8044** 8045** May you do good and not evil. 8046** May you find forgiveness for yourself and forgive others. 8047** May you share freely, never taking more than you give. 8048** 8049************************************************************************* 8050*/ 8051 8052#ifndef _SQLITE3RTREE_H_ 8053#define _SQLITE3RTREE_H_ 8054 8055 8056#ifdef __cplusplus 8057extern "C" { 8058#endif 8059 8060typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8061typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8062 8063/* The double-precision datatype used by RTree depends on the 8064** SQLITE_RTREE_INT_ONLY compile-time option. 8065*/ 8066#ifdef SQLITE_RTREE_INT_ONLY 8067 typedef sqlite3_int64 sqlite3_rtree_dbl; 8068#else 8069 typedef double sqlite3_rtree_dbl; 8070#endif 8071 8072/* 8073** Register a geometry callback named zGeom that can be used as part of an 8074** R-Tree geometry query as follows: 8075** 8076** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8077*/ 8078SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 8079 sqlite3 *db, 8080 const char *zGeom, 8081 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8082 void *pContext 8083); 8084 8085 8086/* 8087** A pointer to a structure of the following type is passed as the first 8088** argument to callbacks registered using rtree_geometry_callback(). 8089*/ 8090struct sqlite3_rtree_geometry { 8091 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8092 int nParam; /* Size of array aParam[] */ 8093 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8094 void *pUser; /* Callback implementation user data */ 8095 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8096}; 8097 8098/* 8099** Register a 2nd-generation geometry callback named zScore that can be 8100** used as part of an R-Tree geometry query as follows: 8101** 8102** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8103*/ 8104SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 8105 sqlite3 *db, 8106 const char *zQueryFunc, 8107 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8108 void *pContext, 8109 void (*xDestructor)(void*) 8110); 8111 8112 8113/* 8114** A pointer to a structure of the following type is passed as the 8115** argument to scored geometry callback registered using 8116** sqlite3_rtree_query_callback(). 8117** 8118** Note that the first 5 fields of this structure are identical to 8119** sqlite3_rtree_geometry. This structure is a subclass of 8120** sqlite3_rtree_geometry. 8121*/ 8122struct sqlite3_rtree_query_info { 8123 void *pContext; /* pContext from when function registered */ 8124 int nParam; /* Number of function parameters */ 8125 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8126 void *pUser; /* callback can use this, if desired */ 8127 void (*xDelUser)(void*); /* function to free pUser */ 8128 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8129 unsigned int *anQueue; /* Number of pending entries in the queue */ 8130 int nCoord; /* Number of coordinates */ 8131 int iLevel; /* Level of current node or entry */ 8132 int mxLevel; /* The largest iLevel value in the tree */ 8133 sqlite3_int64 iRowid; /* Rowid for current entry */ 8134 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8135 int eParentWithin; /* Visibility of parent node */ 8136 int eWithin; /* OUT: Visiblity */ 8137 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8138 /* The following fields are only available in 3.8.11 and later */ 8139 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8140}; 8141 8142/* 8143** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8144*/ 8145#define NOT_WITHIN 0 /* Object completely outside of query region */ 8146#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8147#define FULLY_WITHIN 2 /* Object fully contained within query region */ 8148 8149 8150#ifdef __cplusplus 8151} /* end of the 'extern "C"' block */ 8152#endif 8153 8154#endif /* ifndef _SQLITE3RTREE_H_ */ 8155 8156/* 8157** 2014 May 31 8158** 8159** The author disclaims copyright to this source code. In place of 8160** a legal notice, here is a blessing: 8161** 8162** May you do good and not evil. 8163** May you find forgiveness for yourself and forgive others. 8164** May you share freely, never taking more than you give. 8165** 8166****************************************************************************** 8167** 8168** Interfaces to extend FTS5. Using the interfaces defined in this file, 8169** FTS5 may be extended with: 8170** 8171** * custom tokenizers, and 8172** * custom auxiliary functions. 8173*/ 8174 8175 8176#ifndef _FTS5_H 8177#define _FTS5_H 8178 8179 8180#ifdef __cplusplus 8181extern "C" { 8182#endif 8183 8184/************************************************************************* 8185** CUSTOM AUXILIARY FUNCTIONS 8186** 8187** Virtual table implementations may overload SQL functions by implementing 8188** the sqlite3_module.xFindFunction() method. 8189*/ 8190 8191typedef struct Fts5ExtensionApi Fts5ExtensionApi; 8192typedef struct Fts5Context Fts5Context; 8193typedef struct Fts5PhraseIter Fts5PhraseIter; 8194 8195typedef void (*fts5_extension_function)( 8196 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 8197 Fts5Context *pFts, /* First arg to pass to pApi functions */ 8198 sqlite3_context *pCtx, /* Context for returning result/error */ 8199 int nVal, /* Number of values in apVal[] array */ 8200 sqlite3_value **apVal /* Array of trailing arguments */ 8201); 8202 8203struct Fts5PhraseIter { 8204 const unsigned char *a; 8205 const unsigned char *b; 8206}; 8207 8208/* 8209** EXTENSION API FUNCTIONS 8210** 8211** xUserData(pFts): 8212** Return a copy of the context pointer the extension function was 8213** registered with. 8214** 8215** xColumnTotalSize(pFts, iCol, pnToken): 8216** If parameter iCol is less than zero, set output variable *pnToken 8217** to the total number of tokens in the FTS5 table. Or, if iCol is 8218** non-negative but less than the number of columns in the table, return 8219** the total number of tokens in column iCol, considering all rows in 8220** the FTS5 table. 8221** 8222** If parameter iCol is greater than or equal to the number of columns 8223** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 8224** an OOM condition or IO error), an appropriate SQLite error code is 8225** returned. 8226** 8227** xColumnCount(pFts): 8228** Return the number of columns in the table. 8229** 8230** xColumnSize(pFts, iCol, pnToken): 8231** If parameter iCol is less than zero, set output variable *pnToken 8232** to the total number of tokens in the current row. Or, if iCol is 8233** non-negative but less than the number of columns in the table, set 8234** *pnToken to the number of tokens in column iCol of the current row. 8235** 8236** If parameter iCol is greater than or equal to the number of columns 8237** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 8238** an OOM condition or IO error), an appropriate SQLite error code is 8239** returned. 8240** 8241** This function may be quite inefficient if used with an FTS5 table 8242** created with the "columnsize=0" option. 8243** 8244** xColumnText: 8245** This function attempts to retrieve the text of column iCol of the 8246** current document. If successful, (*pz) is set to point to a buffer 8247** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 8248** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 8249** if an error occurs, an SQLite error code is returned and the final values 8250** of (*pz) and (*pn) are undefined. 8251** 8252** xPhraseCount: 8253** Returns the number of phrases in the current query expression. 8254** 8255** xPhraseSize: 8256** Returns the number of tokens in phrase iPhrase of the query. Phrases 8257** are numbered starting from zero. 8258** 8259** xInstCount: 8260** Set *pnInst to the total number of occurrences of all phrases within 8261** the query within the current row. Return SQLITE_OK if successful, or 8262** an error code (i.e. SQLITE_NOMEM) if an error occurs. 8263** 8264** This API can be quite slow if used with an FTS5 table created with the 8265** "detail=none" or "detail=column" option. If the FTS5 table is created 8266** with either "detail=none" or "detail=column" and "content=" option 8267** (i.e. if it is a contentless table), then this API always returns 0. 8268** 8269** xInst: 8270** Query for the details of phrase match iIdx within the current row. 8271** Phrase matches are numbered starting from zero, so the iIdx argument 8272** should be greater than or equal to zero and smaller than the value 8273** output by xInstCount(). 8274** 8275** Usually, output parameter *piPhrase is set to the phrase number, *piCol 8276** to the column in which it occurs and *piOff the token offset of the 8277** first token of the phrase. The exception is if the table was created 8278** with the offsets=0 option specified. In this case *piOff is always 8279** set to -1. 8280** 8281** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 8282** if an error occurs. 8283** 8284** This API can be quite slow if used with an FTS5 table created with the 8285** "detail=none" or "detail=column" option. 8286** 8287** xRowid: 8288** Returns the rowid of the current row. 8289** 8290** xTokenize: 8291** Tokenize text using the tokenizer belonging to the FTS5 table. 8292** 8293** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 8294** This API function is used to query the FTS table for phrase iPhrase 8295** of the current query. Specifically, a query equivalent to: 8296** 8297** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 8298** 8299** with $p set to a phrase equivalent to the phrase iPhrase of the 8300** current query is executed. For each row visited, the callback function 8301** passed as the fourth argument is invoked. The context and API objects 8302** passed to the callback function may be used to access the properties of 8303** each matched row. Invoking Api.xUserData() returns a copy of the pointer 8304** passed as the third argument to pUserData. 8305** 8306** If the callback function returns any value other than SQLITE_OK, the 8307** query is abandoned and the xQueryPhrase function returns immediately. 8308** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 8309** Otherwise, the error code is propagated upwards. 8310** 8311** If the query runs to completion without incident, SQLITE_OK is returned. 8312** Or, if some error occurs before the query completes or is aborted by 8313** the callback, an SQLite error code is returned. 8314** 8315** 8316** xSetAuxdata(pFts5, pAux, xDelete) 8317** 8318** Save the pointer passed as the second argument as the extension functions 8319** "auxiliary data". The pointer may then be retrieved by the current or any 8320** future invocation of the same fts5 extension function made as part of 8321** of the same MATCH query using the xGetAuxdata() API. 8322** 8323** Each extension function is allocated a single auxiliary data slot for 8324** each FTS query (MATCH expression). If the extension function is invoked 8325** more than once for a single FTS query, then all invocations share a 8326** single auxiliary data context. 8327** 8328** If there is already an auxiliary data pointer when this function is 8329** invoked, then it is replaced by the new pointer. If an xDelete callback 8330** was specified along with the original pointer, it is invoked at this 8331** point. 8332** 8333** The xDelete callback, if one is specified, is also invoked on the 8334** auxiliary data pointer after the FTS5 query has finished. 8335** 8336** If an error (e.g. an OOM condition) occurs within this function, an 8337** the auxiliary data is set to NULL and an error code returned. If the 8338** xDelete parameter was not NULL, it is invoked on the auxiliary data 8339** pointer before returning. 8340** 8341** 8342** xGetAuxdata(pFts5, bClear) 8343** 8344** Returns the current auxiliary data pointer for the fts5 extension 8345** function. See the xSetAuxdata() method for details. 8346** 8347** If the bClear argument is non-zero, then the auxiliary data is cleared 8348** (set to NULL) before this function returns. In this case the xDelete, 8349** if any, is not invoked. 8350** 8351** 8352** xRowCount(pFts5, pnRow) 8353** 8354** This function is used to retrieve the total number of rows in the table. 8355** In other words, the same value that would be returned by: 8356** 8357** SELECT count(*) FROM ftstable; 8358** 8359** xPhraseFirst() 8360** This function is used, along with type Fts5PhraseIter and the xPhraseNext 8361** method, to iterate through all instances of a single query phrase within 8362** the current row. This is the same information as is accessible via the 8363** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 8364** to use, this API may be faster under some circumstances. To iterate 8365** through instances of phrase iPhrase, use the following code: 8366** 8367** Fts5PhraseIter iter; 8368** int iCol, iOff; 8369** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 8370** iCol>=0; 8371** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 8372** ){ 8373** // An instance of phrase iPhrase at offset iOff of column iCol 8374** } 8375** 8376** The Fts5PhraseIter structure is defined above. Applications should not 8377** modify this structure directly - it should only be used as shown above 8378** with the xPhraseFirst() and xPhraseNext() API methods (and by 8379** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 8380** 8381** This API can be quite slow if used with an FTS5 table created with the 8382** "detail=none" or "detail=column" option. If the FTS5 table is created 8383** with either "detail=none" or "detail=column" and "content=" option 8384** (i.e. if it is a contentless table), then this API always iterates 8385** through an empty set (all calls to xPhraseFirst() set iCol to -1). 8386** 8387** xPhraseNext() 8388** See xPhraseFirst above. 8389** 8390** xPhraseFirstColumn() 8391** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 8392** and xPhraseNext() APIs described above. The difference is that instead 8393** of iterating through all instances of a phrase in the current row, these 8394** APIs are used to iterate through the set of columns in the current row 8395** that contain one or more instances of a specified phrase. For example: 8396** 8397** Fts5PhraseIter iter; 8398** int iCol; 8399** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 8400** iCol>=0; 8401** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 8402** ){ 8403** // Column iCol contains at least one instance of phrase iPhrase 8404** } 8405** 8406** This API can be quite slow if used with an FTS5 table created with the 8407** "detail=none" option. If the FTS5 table is created with either 8408** "detail=none" "content=" option (i.e. if it is a contentless table), 8409** then this API always iterates through an empty set (all calls to 8410** xPhraseFirstColumn() set iCol to -1). 8411** 8412** The information accessed using this API and its companion 8413** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 8414** (or xInst/xInstCount). The chief advantage of this API is that it is 8415** significantly more efficient than those alternatives when used with 8416** "detail=column" tables. 8417** 8418** xPhraseNextColumn() 8419** See xPhraseFirstColumn above. 8420*/ 8421struct Fts5ExtensionApi { 8422 int iVersion; /* Currently always set to 3 */ 8423 8424 void *(*xUserData)(Fts5Context*); 8425 8426 int (*xColumnCount)(Fts5Context*); 8427 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 8428 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 8429 8430 int (*xTokenize)(Fts5Context*, 8431 const char *pText, int nText, /* Text to tokenize */ 8432 void *pCtx, /* Context passed to xToken() */ 8433 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 8434 ); 8435 8436 int (*xPhraseCount)(Fts5Context*); 8437 int (*xPhraseSize)(Fts5Context*, int iPhrase); 8438 8439 int (*xInstCount)(Fts5Context*, int *pnInst); 8440 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 8441 8442 sqlite3_int64 (*xRowid)(Fts5Context*); 8443 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 8444 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 8445 8446 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 8447 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 8448 ); 8449 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 8450 void *(*xGetAuxdata)(Fts5Context*, int bClear); 8451 8452 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 8453 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 8454 8455 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 8456 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 8457}; 8458 8459/* 8460** CUSTOM AUXILIARY FUNCTIONS 8461*************************************************************************/ 8462 8463/************************************************************************* 8464** CUSTOM TOKENIZERS 8465** 8466** Applications may also register custom tokenizer types. A tokenizer 8467** is registered by providing fts5 with a populated instance of the 8468** following structure. All structure methods must be defined, setting 8469** any member of the fts5_tokenizer struct to NULL leads to undefined 8470** behaviour. The structure methods are expected to function as follows: 8471** 8472** xCreate: 8473** This function is used to allocate and inititalize a tokenizer instance. 8474** A tokenizer instance is required to actually tokenize text. 8475** 8476** The first argument passed to this function is a copy of the (void*) 8477** pointer provided by the application when the fts5_tokenizer object 8478** was registered with FTS5 (the third argument to xCreateTokenizer()). 8479** The second and third arguments are an array of nul-terminated strings 8480** containing the tokenizer arguments, if any, specified following the 8481** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 8482** to create the FTS5 table. 8483** 8484** The final argument is an output variable. If successful, (*ppOut) 8485** should be set to point to the new tokenizer handle and SQLITE_OK 8486** returned. If an error occurs, some value other than SQLITE_OK should 8487** be returned. In this case, fts5 assumes that the final value of *ppOut 8488** is undefined. 8489** 8490** xDelete: 8491** This function is invoked to delete a tokenizer handle previously 8492** allocated using xCreate(). Fts5 guarantees that this function will 8493** be invoked exactly once for each successful call to xCreate(). 8494** 8495** xTokenize: 8496** This function is expected to tokenize the nText byte string indicated 8497** by argument pText. pText may or may not be nul-terminated. The first 8498** argument passed to this function is a pointer to an Fts5Tokenizer object 8499** returned by an earlier call to xCreate(). 8500** 8501** The second argument indicates the reason that FTS5 is requesting 8502** tokenization of the supplied text. This is always one of the following 8503** four values: 8504** 8505** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 8506** or removed from the FTS table. The tokenizer is being invoked to 8507** determine the set of tokens to add to (or delete from) the 8508** FTS index. 8509** 8510** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 8511** against the FTS index. The tokenizer is being called to tokenize 8512** a bareword or quoted string specified as part of the query. 8513** 8514** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 8515** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 8516** followed by a "*" character, indicating that the last token 8517** returned by the tokenizer will be treated as a token prefix. 8518** 8519** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 8520** satisfy an fts5_api.xTokenize() request made by an auxiliary 8521** function. Or an fts5_api.xColumnSize() request made by the same 8522** on a columnsize=0 database. 8523** </ul> 8524** 8525** For each token in the input string, the supplied callback xToken() must 8526** be invoked. The first argument to it should be a copy of the pointer 8527** passed as the second argument to xTokenize(). The third and fourth 8528** arguments are a pointer to a buffer containing the token text, and the 8529** size of the token in bytes. The 4th and 5th arguments are the byte offsets 8530** of the first byte of and first byte immediately following the text from 8531** which the token is derived within the input. 8532** 8533** The second argument passed to the xToken() callback ("tflags") should 8534** normally be set to 0. The exception is if the tokenizer supports 8535** synonyms. In this case see the discussion below for details. 8536** 8537** FTS5 assumes the xToken() callback is invoked for each token in the 8538** order that they occur within the input text. 8539** 8540** If an xToken() callback returns any value other than SQLITE_OK, then 8541** the tokenization should be abandoned and the xTokenize() method should 8542** immediately return a copy of the xToken() return value. Or, if the 8543** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 8544** if an error occurs with the xTokenize() implementation itself, it 8545** may abandon the tokenization and return any error code other than 8546** SQLITE_OK or SQLITE_DONE. 8547** 8548** SYNONYM SUPPORT 8549** 8550** Custom tokenizers may also support synonyms. Consider a case in which a 8551** user wishes to query for a phrase such as "first place". Using the 8552** built-in tokenizers, the FTS5 query 'first + place' will match instances 8553** of "first place" within the document set, but not alternative forms 8554** such as "1st place". In some applications, it would be better to match 8555** all instances of "first place" or "1st place" regardless of which form 8556** the user specified in the MATCH query text. 8557** 8558** There are several ways to approach this in FTS5: 8559** 8560** <ol><li> By mapping all synonyms to a single token. In this case, the 8561** In the above example, this means that the tokenizer returns the 8562** same token for inputs "first" and "1st". Say that token is in 8563** fact "first", so that when the user inserts the document "I won 8564** 1st place" entries are added to the index for tokens "i", "won", 8565** "first" and "place". If the user then queries for '1st + place', 8566** the tokenizer substitutes "first" for "1st" and the query works 8567** as expected. 8568** 8569** <li> By adding multiple synonyms for a single term to the FTS index. 8570** In this case, when tokenizing query text, the tokenizer may 8571** provide multiple synonyms for a single term within the document. 8572** FTS5 then queries the index for each synonym individually. For 8573** example, faced with the query: 8574** 8575** <codeblock> 8576** ... MATCH 'first place'</codeblock> 8577** 8578** the tokenizer offers both "1st" and "first" as synonyms for the 8579** first token in the MATCH query and FTS5 effectively runs a query 8580** similar to: 8581** 8582** <codeblock> 8583** ... MATCH '(first OR 1st) place'</codeblock> 8584** 8585** except that, for the purposes of auxiliary functions, the query 8586** still appears to contain just two phrases - "(first OR 1st)" 8587** being treated as a single phrase. 8588** 8589** <li> By adding multiple synonyms for a single term to the FTS index. 8590** Using this method, when tokenizing document text, the tokenizer 8591** provides multiple synonyms for each token. So that when a 8592** document such as "I won first place" is tokenized, entries are 8593** added to the FTS index for "i", "won", "first", "1st" and 8594** "place". 8595** 8596** This way, even if the tokenizer does not provide synonyms 8597** when tokenizing query text (it should not - to do would be 8598** inefficient), it doesn't matter if the user queries for 8599** 'first + place' or '1st + place', as there are entires in the 8600** FTS index corresponding to both forms of the first token. 8601** </ol> 8602** 8603** Whether it is parsing document or query text, any call to xToken that 8604** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 8605** is considered to supply a synonym for the previous token. For example, 8606** when parsing the document "I won first place", a tokenizer that supports 8607** synonyms would call xToken() 5 times, as follows: 8608** 8609** <codeblock> 8610** xToken(pCtx, 0, "i", 1, 0, 1); 8611** xToken(pCtx, 0, "won", 3, 2, 5); 8612** xToken(pCtx, 0, "first", 5, 6, 11); 8613** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 8614** xToken(pCtx, 0, "place", 5, 12, 17); 8615**</codeblock> 8616** 8617** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 8618** xToken() is called. Multiple synonyms may be specified for a single token 8619** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 8620** There is no limit to the number of synonyms that may be provided for a 8621** single token. 8622** 8623** In many cases, method (1) above is the best approach. It does not add 8624** extra data to the FTS index or require FTS5 to query for multiple terms, 8625** so it is efficient in terms of disk space and query speed. However, it 8626** does not support prefix queries very well. If, as suggested above, the 8627** token "first" is subsituted for "1st" by the tokenizer, then the query: 8628** 8629** <codeblock> 8630** ... MATCH '1s*'</codeblock> 8631** 8632** will not match documents that contain the token "1st" (as the tokenizer 8633** will probably not map "1s" to any prefix of "first"). 8634** 8635** For full prefix support, method (3) may be preferred. In this case, 8636** because the index contains entries for both "first" and "1st", prefix 8637** queries such as 'fi*' or '1s*' will match correctly. However, because 8638** extra entries are added to the FTS index, this method uses more space 8639** within the database. 8640** 8641** Method (2) offers a midpoint between (1) and (3). Using this method, 8642** a query such as '1s*' will match documents that contain the literal 8643** token "1st", but not "first" (assuming the tokenizer is not able to 8644** provide synonyms for prefixes). However, a non-prefix query like '1st' 8645** will match against "1st" and "first". This method does not require 8646** extra disk space, as no extra entries are added to the FTS index. 8647** On the other hand, it may require more CPU cycles to run MATCH queries, 8648** as separate queries of the FTS index are required for each synonym. 8649** 8650** When using methods (2) or (3), it is important that the tokenizer only 8651** provide synonyms when tokenizing document text (method (2)) or query 8652** text (method (3)), not both. Doing so will not cause any errors, but is 8653** inefficient. 8654*/ 8655typedef struct Fts5Tokenizer Fts5Tokenizer; 8656typedef struct fts5_tokenizer fts5_tokenizer; 8657struct fts5_tokenizer { 8658 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 8659 void (*xDelete)(Fts5Tokenizer*); 8660 int (*xTokenize)(Fts5Tokenizer*, 8661 void *pCtx, 8662 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 8663 const char *pText, int nText, 8664 int (*xToken)( 8665 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 8666 int tflags, /* Mask of FTS5_TOKEN_* flags */ 8667 const char *pToken, /* Pointer to buffer containing token */ 8668 int nToken, /* Size of token in bytes */ 8669 int iStart, /* Byte offset of token within input text */ 8670 int iEnd /* Byte offset of end of token within input text */ 8671 ) 8672 ); 8673}; 8674 8675/* Flags that may be passed as the third argument to xTokenize() */ 8676#define FTS5_TOKENIZE_QUERY 0x0001 8677#define FTS5_TOKENIZE_PREFIX 0x0002 8678#define FTS5_TOKENIZE_DOCUMENT 0x0004 8679#define FTS5_TOKENIZE_AUX 0x0008 8680 8681/* Flags that may be passed by the tokenizer implementation back to FTS5 8682** as the third argument to the supplied xToken callback. */ 8683#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 8684 8685/* 8686** END OF CUSTOM TOKENIZERS 8687*************************************************************************/ 8688 8689/************************************************************************* 8690** FTS5 EXTENSION REGISTRATION API 8691*/ 8692typedef struct fts5_api fts5_api; 8693struct fts5_api { 8694 int iVersion; /* Currently always set to 2 */ 8695 8696 /* Create a new tokenizer */ 8697 int (*xCreateTokenizer)( 8698 fts5_api *pApi, 8699 const char *zName, 8700 void *pContext, 8701 fts5_tokenizer *pTokenizer, 8702 void (*xDestroy)(void*) 8703 ); 8704 8705 /* Find an existing tokenizer */ 8706 int (*xFindTokenizer)( 8707 fts5_api *pApi, 8708 const char *zName, 8709 void **ppContext, 8710 fts5_tokenizer *pTokenizer 8711 ); 8712 8713 /* Create a new auxiliary function */ 8714 int (*xCreateFunction)( 8715 fts5_api *pApi, 8716 const char *zName, 8717 void *pContext, 8718 fts5_extension_function xFunction, 8719 void (*xDestroy)(void*) 8720 ); 8721}; 8722 8723/* 8724** END OF REGISTRATION API 8725*************************************************************************/ 8726 8727#ifdef __cplusplus 8728} /* end of the 'extern "C"' block */ 8729#endif 8730 8731#endif /* _FTS5_H */ 8732 8733 8734