sqlite3.h revision 342292
1/* 2** 2001-09-15 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_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since [version 3.6.18] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. If the source code has 119** been edited in any way since it was last checked in, then the last 120** four hexadecimal digits of the hash may be modified. 121** 122** See also: [sqlite3_libversion()], 123** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124** [sqlite_version()] and [sqlite_source_id()]. 125*/ 126#define SQLITE_VERSION "3.26.0" 127#define SQLITE_VERSION_NUMBER 3026000 128#define SQLITE_SOURCE_ID "2018-12-01 12:34:55 bf8c1b2b7a5960c282e543b9c293686dccff272512d08865f4600fb58238b4f9" 129 130/* 131** CAPI3REF: Run-Time Library Version Numbers 132** KEYWORDS: sqlite3_version sqlite3_sourceid 133** 134** These interfaces provide the same information as the [SQLITE_VERSION], 135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136** but are associated with the library instead of the header file. ^(Cautious 137** programmers might include assert() statements in their application to 138** verify that values returned by these interfaces match the macros in 139** the header, and thus ensure that the application is 140** compiled with matching library and header files. 141** 142** <blockquote><pre> 143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146** </pre></blockquote>)^ 147** 148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149** macro. ^The sqlite3_libversion() function returns a pointer to the 150** to the sqlite3_version[] string constant. The sqlite3_libversion() 151** function is provided for use in DLLs since DLL users usually do not have 152** direct access to string constants within the DLL. ^The 153** sqlite3_libversion_number() function returns an integer equal to 154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155** a pointer to a string constant whose value is the same as the 156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157** using an edited copy of [the amalgamation], then the last four characters 158** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159** 160** See also: [sqlite_version()] and [sqlite_source_id()]. 161*/ 162SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163SQLITE_API const char *sqlite3_libversion(void); 164SQLITE_API const char *sqlite3_sourceid(void); 165SQLITE_API int sqlite3_libversion_number(void); 166 167/* 168** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169** 170** ^The sqlite3_compileoption_used() function returns 0 or 1 171** indicating whether the specified option was defined at 172** compile time. ^The SQLITE_ prefix may be omitted from the 173** option name passed to sqlite3_compileoption_used(). 174** 175** ^The sqlite3_compileoption_get() function allows iterating 176** over the list of options that were defined at compile time by 177** returning the N-th compile time option string. ^If N is out of range, 178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179** prefix is omitted from any strings returned by 180** sqlite3_compileoption_get(). 181** 182** ^Support for the diagnostic functions sqlite3_compileoption_used() 183** and sqlite3_compileoption_get() may be omitted by specifying the 184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185** 186** See also: SQL functions [sqlite_compileoption_used()] and 187** [sqlite_compileoption_get()] and the [compile_options pragma]. 188*/ 189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191SQLITE_API const char *sqlite3_compileoption_get(int N); 192#endif 193 194/* 195** CAPI3REF: Test To See If The Library Is Threadsafe 196** 197** ^The sqlite3_threadsafe() function returns zero if and only if 198** SQLite was compiled with mutexing code omitted due to the 199** [SQLITE_THREADSAFE] compile-time option being set to 0. 200** 201** SQLite can be compiled with or without mutexes. When 202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203** are enabled and SQLite is threadsafe. When the 204** [SQLITE_THREADSAFE] macro is 0, 205** the mutexes are omitted. Without the mutexes, it is not safe 206** to use SQLite concurrently from more than one thread. 207** 208** Enabling mutexes incurs a measurable performance penalty. 209** So if speed is of utmost importance, it makes sense to disable 210** the mutexes. But for maximum safety, mutexes should be enabled. 211** ^The default behavior is for mutexes to be enabled. 212** 213** This interface can be used by an application to make sure that the 214** version of SQLite that it is linking against was compiled with 215** the desired setting of the [SQLITE_THREADSAFE] macro. 216** 217** This interface only reports on the compile-time mutex setting 218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220** can be fully or partially disabled using a call to [sqlite3_config()] 221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223** sqlite3_threadsafe() function shows only the compile-time setting of 224** thread safety, not any run-time changes to that setting made by 225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226** is unchanged by calls to sqlite3_config().)^ 227** 228** See the [threading mode] documentation for additional information. 229*/ 230SQLITE_API int sqlite3_threadsafe(void); 231 232/* 233** CAPI3REF: Database Connection Handle 234** KEYWORDS: {database connection} {database connections} 235** 236** Each open SQLite database is represented by a pointer to an instance of 237** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240** and [sqlite3_close_v2()] are its destructors. There are many other 241** interfaces (such as 242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243** [sqlite3_busy_timeout()] to name but three) that are methods on an 244** sqlite3 object. 245*/ 246typedef struct sqlite3 sqlite3; 247 248/* 249** CAPI3REF: 64-Bit Integer Types 250** KEYWORDS: sqlite_int64 sqlite_uint64 251** 252** Because there is no cross-platform way to specify 64-bit integer types 253** SQLite includes typedefs for 64-bit signed and unsigned integers. 254** 255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257** compatibility only. 258** 259** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261** sqlite3_uint64 and sqlite_uint64 types can store integer values 262** between 0 and +18446744073709551615 inclusive. 263*/ 264#ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266# ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268# else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270# endif 271#elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274#else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277#endif 278typedef sqlite_int64 sqlite3_int64; 279typedef sqlite_uint64 sqlite3_uint64; 280 281/* 282** If compiling for a processor that lacks floating point support, 283** substitute integer for floating-point. 284*/ 285#ifdef SQLITE_OMIT_FLOATING_POINT 286# define double sqlite3_int64 287#endif 288 289/* 290** CAPI3REF: Closing A Database Connection 291** DESTRUCTOR: sqlite3 292** 293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294** for the [sqlite3] object. 295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296** the [sqlite3] object is successfully destroyed and all associated 297** resources are deallocated. 298** 299** ^If the database connection is associated with unfinalized prepared 300** statements or unfinished sqlite3_backup objects then sqlite3_close() 301** will leave the database connection open and return [SQLITE_BUSY]. 302** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303** and/or unfinished sqlite3_backups, then the database connection becomes 304** an unusable "zombie" which will automatically be deallocated when the 305** last prepared statement is finalized or the last sqlite3_backup is 306** finished. The sqlite3_close_v2() interface is intended for use with 307** host languages that are garbage collected, and where the order in which 308** destructors are called is arbitrary. 309** 310** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311** [sqlite3_blob_close | close] all [BLOB handles], and 312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313** with the [sqlite3] object prior to attempting to close the object. ^If 314** sqlite3_close_v2() is called on a [database connection] that still has 315** outstanding [prepared statements], [BLOB handles], and/or 316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317** of resources is deferred until all [prepared statements], [BLOB handles], 318** and [sqlite3_backup] objects are also destroyed. 319** 320** ^If an [sqlite3] object is destroyed while a transaction is open, 321** the transaction is automatically rolled back. 322** 323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324** must be either a NULL 325** pointer or an [sqlite3] object pointer obtained 326** from [sqlite3_open()], [sqlite3_open16()], or 327** [sqlite3_open_v2()], and not previously closed. 328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329** argument is a harmless no-op. 330*/ 331SQLITE_API int sqlite3_close(sqlite3*); 332SQLITE_API int sqlite3_close_v2(sqlite3*); 333 334/* 335** The type for a callback function. 336** This is legacy and deprecated. It is included for historical 337** compatibility and is not documented. 338*/ 339typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341/* 342** CAPI3REF: One-Step Query Execution Interface 343** METHOD: sqlite3 344** 345** The sqlite3_exec() interface is a convenience wrapper around 346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347** that allows an application to run multiple statements of SQL 348** without having to use a lot of C code. 349** 350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351** semicolon-separate SQL statements passed into its 2nd argument, 352** in the context of the [database connection] passed in as its 1st 353** argument. ^If the callback function of the 3rd argument to 354** sqlite3_exec() is not NULL, then it is invoked for each result row 355** coming out of the evaluated SQL statements. ^The 4th argument to 356** sqlite3_exec() is relayed through to the 1st argument of each 357** callback invocation. ^If the callback pointer to sqlite3_exec() 358** is NULL, then no callback is ever invoked and result rows are 359** ignored. 360** 361** ^If an error occurs while evaluating the SQL statements passed into 362** sqlite3_exec(), then execution of the current statement stops and 363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364** is not NULL then any error message is written into memory obtained 365** from [sqlite3_malloc()] and passed back through the 5th parameter. 366** To avoid memory leaks, the application should invoke [sqlite3_free()] 367** on error message strings returned through the 5th parameter of 368** sqlite3_exec() after the error message string is no longer needed. 369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371** NULL before returning. 372** 373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374** routine returns SQLITE_ABORT without invoking the callback again and 375** without running any subsequent SQL statements. 376** 377** ^The 2nd argument to the sqlite3_exec() callback function is the 378** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379** callback is an array of pointers to strings obtained as if from 380** [sqlite3_column_text()], one for each column. ^If an element of a 381** result row is NULL then the corresponding string pointer for the 382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383** sqlite3_exec() callback is an array of pointers to strings where each 384** entry represents the name of corresponding result column as obtained 385** from [sqlite3_column_name()]. 386** 387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388** to an empty string, or a pointer that contains only whitespace and/or 389** SQL comments, then no SQL statements are evaluated and the database 390** is not changed. 391** 392** Restrictions: 393** 394** <ul> 395** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396** is a valid and open [database connection]. 397** <li> The application must not close the [database connection] specified by 398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399** <li> The application must not modify the SQL statement text passed into 400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401** </ul> 402*/ 403SQLITE_API int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409); 410 411/* 412** CAPI3REF: Result Codes 413** KEYWORDS: {result code definitions} 414** 415** Many SQLite functions return an integer result code from the set shown 416** here in order to indicate success or failure. 417** 418** New error codes may be added in future versions of SQLite. 419** 420** See also: [extended result code definitions] 421*/ 422#define SQLITE_OK 0 /* Successful result */ 423/* beginning-of-error-codes */ 424#define SQLITE_ERROR 1 /* Generic error */ 425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426#define SQLITE_PERM 3 /* Access permission denied */ 427#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428#define SQLITE_BUSY 5 /* The database file is locked */ 429#define SQLITE_LOCKED 6 /* A table in the database is locked */ 430#define SQLITE_NOMEM 7 /* A malloc() failed */ 431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436#define SQLITE_FULL 13 /* Insertion failed because database is full */ 437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439#define SQLITE_EMPTY 16 /* Internal use only */ 440#define SQLITE_SCHEMA 17 /* The database schema changed */ 441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443#define SQLITE_MISMATCH 20 /* Data type mismatch */ 444#define SQLITE_MISUSE 21 /* Library used incorrectly */ 445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446#define SQLITE_AUTH 23 /* Authorization denied */ 447#define SQLITE_FORMAT 24 /* Not used */ 448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454/* end-of-error-codes */ 455 456/* 457** CAPI3REF: Extended Result Codes 458** KEYWORDS: {extended result code definitions} 459** 460** In its default configuration, SQLite API routines return one of 30 integer 461** [result codes]. However, experience has shown that many of 462** these result codes are too coarse-grained. They do not provide as 463** much information about problems as programmers might like. In an effort to 464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465** and later) include 466** support for additional result codes that provide more detailed information 467** about errors. These [extended result codes] are enabled or disabled 468** on a per database connection basis using the 469** [sqlite3_extended_result_codes()] API. Or, the extended code for 470** the most recent error can be obtained using 471** [sqlite3_extended_errcode()]. 472*/ 473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 476#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 477#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 478#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 479#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 480#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 481#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 482#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 483#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 484#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 485#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 486#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 487#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 488#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 489#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 490#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 491#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 492#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 493#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 494#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 495#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 496#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 497#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 498#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 499#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 500#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 501#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 502#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 503#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 504#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 505#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 506#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 507#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 508#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 509#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 510#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 511#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 512#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 513#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 514#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 515#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 516#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 517#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 518#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 519#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 520#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 521#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 522#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 523#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 524#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 525#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 526#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 527#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 528#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 529#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 530#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 531#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 532#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 533#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 534#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 535#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 536#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 537#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 538#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 539#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 540 541/* 542** CAPI3REF: Flags For File Open Operations 543** 544** These bit values are intended for use in the 545** 3rd parameter to the [sqlite3_open_v2()] interface and 546** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 547*/ 548#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 550#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 551#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 552#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 553#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 554#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 557#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 558#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 559#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 560#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 561#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 562#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 563#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 564#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 565#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 566#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 567#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 568 569/* Reserved: 0x00F00000 */ 570 571/* 572** CAPI3REF: Device Characteristics 573** 574** The xDeviceCharacteristics method of the [sqlite3_io_methods] 575** object returns an integer which is a vector of these 576** bit values expressing I/O characteristics of the mass storage 577** device that holds the file that the [sqlite3_io_methods] 578** refers to. 579** 580** The SQLITE_IOCAP_ATOMIC property means that all writes of 581** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 582** mean that writes of blocks that are nnn bytes in size and 583** are aligned to an address which is an integer multiple of 584** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 585** that when data is appended to a file, the data is appended 586** first then the size of the file is extended, never the other 587** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 588** information is written to disk in the same order as calls 589** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 590** after reboot following a crash or power loss, the only bytes in a 591** file that were written at the application level might have changed 592** and that adjacent bytes, even bytes within the same sector are 593** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 594** flag indicates that a file cannot be deleted when open. The 595** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 596** read-only media and cannot be changed even by processes with 597** elevated privileges. 598** 599** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 600** filesystem supports doing multiple write operations atomically when those 601** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 602** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 603*/ 604#define SQLITE_IOCAP_ATOMIC 0x00000001 605#define SQLITE_IOCAP_ATOMIC512 0x00000002 606#define SQLITE_IOCAP_ATOMIC1K 0x00000004 607#define SQLITE_IOCAP_ATOMIC2K 0x00000008 608#define SQLITE_IOCAP_ATOMIC4K 0x00000010 609#define SQLITE_IOCAP_ATOMIC8K 0x00000020 610#define SQLITE_IOCAP_ATOMIC16K 0x00000040 611#define SQLITE_IOCAP_ATOMIC32K 0x00000080 612#define SQLITE_IOCAP_ATOMIC64K 0x00000100 613#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 614#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 615#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 616#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 617#define SQLITE_IOCAP_IMMUTABLE 0x00002000 618#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 619 620/* 621** CAPI3REF: File Locking Levels 622** 623** SQLite uses one of these integer values as the second 624** argument to calls it makes to the xLock() and xUnlock() methods 625** of an [sqlite3_io_methods] object. 626*/ 627#define SQLITE_LOCK_NONE 0 628#define SQLITE_LOCK_SHARED 1 629#define SQLITE_LOCK_RESERVED 2 630#define SQLITE_LOCK_PENDING 3 631#define SQLITE_LOCK_EXCLUSIVE 4 632 633/* 634** CAPI3REF: Synchronization Type Flags 635** 636** When SQLite invokes the xSync() method of an 637** [sqlite3_io_methods] object it uses a combination of 638** these integer values as the second argument. 639** 640** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 641** sync operation only needs to flush data to mass storage. Inode 642** information need not be flushed. If the lower four bits of the flag 643** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 644** If the lower four bits equal SQLITE_SYNC_FULL, that means 645** to use Mac OS X style fullsync instead of fsync(). 646** 647** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 648** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 649** settings. The [synchronous pragma] determines when calls to the 650** xSync VFS method occur and applies uniformly across all platforms. 651** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 652** energetic or rigorous or forceful the sync operations are and 653** only make a difference on Mac OSX for the default SQLite code. 654** (Third-party VFS implementations might also make the distinction 655** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 656** operating systems natively supported by SQLite, only Mac OSX 657** cares about the difference.) 658*/ 659#define SQLITE_SYNC_NORMAL 0x00002 660#define SQLITE_SYNC_FULL 0x00003 661#define SQLITE_SYNC_DATAONLY 0x00010 662 663/* 664** CAPI3REF: OS Interface Open File Handle 665** 666** An [sqlite3_file] object represents an open file in the 667** [sqlite3_vfs | OS interface layer]. Individual OS interface 668** implementations will 669** want to subclass this object by appending additional fields 670** for their own use. The pMethods entry is a pointer to an 671** [sqlite3_io_methods] object that defines methods for performing 672** I/O operations on the open file. 673*/ 674typedef struct sqlite3_file sqlite3_file; 675struct sqlite3_file { 676 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 677}; 678 679/* 680** CAPI3REF: OS Interface File Virtual Methods Object 681** 682** Every file opened by the [sqlite3_vfs.xOpen] method populates an 683** [sqlite3_file] object (or, more commonly, a subclass of the 684** [sqlite3_file] object) with a pointer to an instance of this object. 685** This object defines the methods used to perform various operations 686** against the open file represented by the [sqlite3_file] object. 687** 688** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 689** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 690** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 691** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 692** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 693** to NULL. 694** 695** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 696** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 697** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 698** flag may be ORed in to indicate that only the data of the file 699** and not its inode needs to be synced. 700** 701** The integer values to xLock() and xUnlock() are one of 702** <ul> 703** <li> [SQLITE_LOCK_NONE], 704** <li> [SQLITE_LOCK_SHARED], 705** <li> [SQLITE_LOCK_RESERVED], 706** <li> [SQLITE_LOCK_PENDING], or 707** <li> [SQLITE_LOCK_EXCLUSIVE]. 708** </ul> 709** xLock() increases the lock. xUnlock() decreases the lock. 710** The xCheckReservedLock() method checks whether any database connection, 711** either in this process or in some other process, is holding a RESERVED, 712** PENDING, or EXCLUSIVE lock on the file. It returns true 713** if such a lock exists and false otherwise. 714** 715** The xFileControl() method is a generic interface that allows custom 716** VFS implementations to directly control an open file using the 717** [sqlite3_file_control()] interface. The second "op" argument is an 718** integer opcode. The third argument is a generic pointer intended to 719** point to a structure that may contain arguments or space in which to 720** write return values. Potential uses for xFileControl() might be 721** functions to enable blocking locks with timeouts, to change the 722** locking strategy (for example to use dot-file locks), to inquire 723** about the status of a lock, or to break stale locks. The SQLite 724** core reserves all opcodes less than 100 for its own use. 725** A [file control opcodes | list of opcodes] less than 100 is available. 726** Applications that define a custom xFileControl method should use opcodes 727** greater than 100 to avoid conflicts. VFS implementations should 728** return [SQLITE_NOTFOUND] for file control opcodes that they do not 729** recognize. 730** 731** The xSectorSize() method returns the sector size of the 732** device that underlies the file. The sector size is the 733** minimum write that can be performed without disturbing 734** other bytes in the file. The xDeviceCharacteristics() 735** method returns a bit vector describing behaviors of the 736** underlying device: 737** 738** <ul> 739** <li> [SQLITE_IOCAP_ATOMIC] 740** <li> [SQLITE_IOCAP_ATOMIC512] 741** <li> [SQLITE_IOCAP_ATOMIC1K] 742** <li> [SQLITE_IOCAP_ATOMIC2K] 743** <li> [SQLITE_IOCAP_ATOMIC4K] 744** <li> [SQLITE_IOCAP_ATOMIC8K] 745** <li> [SQLITE_IOCAP_ATOMIC16K] 746** <li> [SQLITE_IOCAP_ATOMIC32K] 747** <li> [SQLITE_IOCAP_ATOMIC64K] 748** <li> [SQLITE_IOCAP_SAFE_APPEND] 749** <li> [SQLITE_IOCAP_SEQUENTIAL] 750** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 751** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 752** <li> [SQLITE_IOCAP_IMMUTABLE] 753** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 754** </ul> 755** 756** The SQLITE_IOCAP_ATOMIC property means that all writes of 757** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 758** mean that writes of blocks that are nnn bytes in size and 759** are aligned to an address which is an integer multiple of 760** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 761** that when data is appended to a file, the data is appended 762** first then the size of the file is extended, never the other 763** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 764** information is written to disk in the same order as calls 765** to xWrite(). 766** 767** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 768** in the unread portions of the buffer with zeros. A VFS that 769** fails to zero-fill short reads might seem to work. However, 770** failure to zero-fill short reads will eventually lead to 771** database corruption. 772*/ 773typedef struct sqlite3_io_methods sqlite3_io_methods; 774struct sqlite3_io_methods { 775 int iVersion; 776 int (*xClose)(sqlite3_file*); 777 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 778 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 779 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 780 int (*xSync)(sqlite3_file*, int flags); 781 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 782 int (*xLock)(sqlite3_file*, int); 783 int (*xUnlock)(sqlite3_file*, int); 784 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 785 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 786 int (*xSectorSize)(sqlite3_file*); 787 int (*xDeviceCharacteristics)(sqlite3_file*); 788 /* Methods above are valid for version 1 */ 789 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 790 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 791 void (*xShmBarrier)(sqlite3_file*); 792 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 793 /* Methods above are valid for version 2 */ 794 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 795 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 796 /* Methods above are valid for version 3 */ 797 /* Additional methods may be added in future releases */ 798}; 799 800/* 801** CAPI3REF: Standard File Control Opcodes 802** KEYWORDS: {file control opcodes} {file control opcode} 803** 804** These integer constants are opcodes for the xFileControl method 805** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 806** interface. 807** 808** <ul> 809** <li>[[SQLITE_FCNTL_LOCKSTATE]] 810** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 811** opcode causes the xFileControl method to write the current state of 812** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 813** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 814** into an integer that the pArg argument points to. This capability 815** is used during testing and is only available when the SQLITE_TEST 816** compile-time option is used. 817** 818** <li>[[SQLITE_FCNTL_SIZE_HINT]] 819** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 820** layer a hint of how large the database file will grow to be during the 821** current transaction. This hint is not guaranteed to be accurate but it 822** is often close. The underlying VFS might choose to preallocate database 823** file space based on this hint in order to help writes to the database 824** file run faster. 825** 826** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 827** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 828** extends and truncates the database file in chunks of a size specified 829** by the user. The fourth argument to [sqlite3_file_control()] should 830** point to an integer (type int) containing the new chunk-size to use 831** for the nominated database. Allocating database file space in large 832** chunks (say 1MB at a time), may reduce file-system fragmentation and 833** improve performance on some systems. 834** 835** <li>[[SQLITE_FCNTL_FILE_POINTER]] 836** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 837** to the [sqlite3_file] object associated with a particular database 838** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 839** 840** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 841** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 842** to the [sqlite3_file] object associated with the journal file (either 843** the [rollback journal] or the [write-ahead log]) for a particular database 844** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 845** 846** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 847** No longer in use. 848** 849** <li>[[SQLITE_FCNTL_SYNC]] 850** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 851** sent to the VFS immediately before the xSync method is invoked on a 852** database file descriptor. Or, if the xSync method is not invoked 853** because the user has configured SQLite with 854** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 855** of the xSync method. In most cases, the pointer argument passed with 856** this file-control is NULL. However, if the database file is being synced 857** as part of a multi-database commit, the argument points to a nul-terminated 858** string containing the transactions master-journal file name. VFSes that 859** do not need this signal should silently ignore this opcode. Applications 860** should not call [sqlite3_file_control()] with this opcode as doing so may 861** disrupt the operation of the specialized VFSes that do require it. 862** 863** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 864** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 865** and sent to the VFS after a transaction has been committed immediately 866** but before the database is unlocked. VFSes that do not need this signal 867** should silently ignore this opcode. Applications should not call 868** [sqlite3_file_control()] with this opcode as doing so may disrupt the 869** operation of the specialized VFSes that do require it. 870** 871** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 872** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 873** retry counts and intervals for certain disk I/O operations for the 874** windows [VFS] in order to provide robustness in the presence of 875** anti-virus programs. By default, the windows VFS will retry file read, 876** file write, and file delete operations up to 10 times, with a delay 877** of 25 milliseconds before the first retry and with the delay increasing 878** by an additional 25 milliseconds with each subsequent retry. This 879** opcode allows these two values (10 retries and 25 milliseconds of delay) 880** to be adjusted. The values are changed for all database connections 881** within the same process. The argument is a pointer to an array of two 882** integers where the first integer is the new retry count and the second 883** integer is the delay. If either integer is negative, then the setting 884** is not changed but instead the prior value of that setting is written 885** into the array entry, allowing the current retry settings to be 886** interrogated. The zDbName parameter is ignored. 887** 888** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 889** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 890** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 891** write ahead log ([WAL file]) and shared memory 892** files used for transaction control 893** are automatically deleted when the latest connection to the database 894** closes. Setting persistent WAL mode causes those files to persist after 895** close. Persisting the files is useful when other processes that do not 896** have write permission on the directory containing the database file want 897** to read the database file, as the WAL and shared memory files must exist 898** in order for the database to be readable. The fourth parameter to 899** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 900** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 901** WAL mode. If the integer is -1, then it is overwritten with the current 902** WAL persistence setting. 903** 904** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 905** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 906** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 907** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 908** xDeviceCharacteristics methods. The fourth parameter to 909** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 910** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 911** mode. If the integer is -1, then it is overwritten with the current 912** zero-damage mode setting. 913** 914** <li>[[SQLITE_FCNTL_OVERWRITE]] 915** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 916** a write transaction to indicate that, unless it is rolled back for some 917** reason, the entire database file will be overwritten by the current 918** transaction. This is used by VACUUM operations. 919** 920** <li>[[SQLITE_FCNTL_VFSNAME]] 921** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 922** all [VFSes] in the VFS stack. The names are of all VFS shims and the 923** final bottom-level VFS are written into memory obtained from 924** [sqlite3_malloc()] and the result is stored in the char* variable 925** that the fourth parameter of [sqlite3_file_control()] points to. 926** The caller is responsible for freeing the memory when done. As with 927** all file-control actions, there is no guarantee that this will actually 928** do anything. Callers should initialize the char* variable to a NULL 929** pointer in case this file-control is not implemented. This file-control 930** is intended for diagnostic use only. 931** 932** <li>[[SQLITE_FCNTL_VFS_POINTER]] 933** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 934** [VFSes] currently in use. ^(The argument X in 935** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 936** of type "[sqlite3_vfs] **". This opcodes will set *X 937** to a pointer to the top-level VFS.)^ 938** ^When there are multiple VFS shims in the stack, this opcode finds the 939** upper-most shim only. 940** 941** <li>[[SQLITE_FCNTL_PRAGMA]] 942** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 943** file control is sent to the open [sqlite3_file] object corresponding 944** to the database file to which the pragma statement refers. ^The argument 945** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 946** pointers to strings (char**) in which the second element of the array 947** is the name of the pragma and the third element is the argument to the 948** pragma or NULL if the pragma has no argument. ^The handler for an 949** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 950** of the char** argument point to a string obtained from [sqlite3_mprintf()] 951** or the equivalent and that string will become the result of the pragma or 952** the error message if the pragma fails. ^If the 953** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 954** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 955** file control returns [SQLITE_OK], then the parser assumes that the 956** VFS has handled the PRAGMA itself and the parser generates a no-op 957** prepared statement if result string is NULL, or that returns a copy 958** of the result string if the string is non-NULL. 959** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 960** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 961** that the VFS encountered an error while handling the [PRAGMA] and the 962** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 963** file control occurs at the beginning of pragma statement analysis and so 964** it is able to override built-in [PRAGMA] statements. 965** 966** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 967** ^The [SQLITE_FCNTL_BUSYHANDLER] 968** file-control may be invoked by SQLite on the database file handle 969** shortly after it is opened in order to provide a custom VFS with access 970** to the connections busy-handler callback. The argument is of type (void **) 971** - an array of two (void *) values. The first (void *) actually points 972** to a function of type (int (*)(void *)). In order to invoke the connections 973** busy-handler, this function should be invoked with the second (void *) in 974** the array as the only argument. If it returns non-zero, then the operation 975** should be retried. If it returns zero, the custom VFS should abandon the 976** current operation. 977** 978** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 979** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 980** to have SQLite generate a 981** temporary filename using the same algorithm that is followed to generate 982** temporary filenames for TEMP tables and other internal uses. The 983** argument should be a char** which will be filled with the filename 984** written into memory obtained from [sqlite3_malloc()]. The caller should 985** invoke [sqlite3_free()] on the result to avoid a memory leak. 986** 987** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 988** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 989** maximum number of bytes that will be used for memory-mapped I/O. 990** The argument is a pointer to a value of type sqlite3_int64 that 991** is an advisory maximum number of bytes in the file to memory map. The 992** pointer is overwritten with the old value. The limit is not changed if 993** the value originally pointed to is negative, and so the current limit 994** can be queried by passing in a pointer to a negative number. This 995** file-control is used internally to implement [PRAGMA mmap_size]. 996** 997** <li>[[SQLITE_FCNTL_TRACE]] 998** The [SQLITE_FCNTL_TRACE] file control provides advisory information 999** to the VFS about what the higher layers of the SQLite stack are doing. 1000** This file control is used by some VFS activity tracing [shims]. 1001** The argument is a zero-terminated string. Higher layers in the 1002** SQLite stack may generate instances of this file control if 1003** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1004** 1005** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1006** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1007** pointer to an integer and it writes a boolean into that integer depending 1008** on whether or not the file has been renamed, moved, or deleted since it 1009** was first opened. 1010** 1011** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1012** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1013** underlying native file handle associated with a file handle. This file 1014** control interprets its argument as a pointer to a native file handle and 1015** writes the resulting value there. 1016** 1017** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1018** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1019** opcode causes the xFileControl method to swap the file handle with the one 1020** pointed to by the pArg argument. This capability is used during testing 1021** and only needs to be supported when SQLITE_TEST is defined. 1022** 1023** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1024** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1025** be advantageous to block on the next WAL lock if the lock is not immediately 1026** available. The WAL subsystem issues this signal during rare 1027** circumstances in order to fix a problem with priority inversion. 1028** Applications should <em>not</em> use this file-control. 1029** 1030** <li>[[SQLITE_FCNTL_ZIPVFS]] 1031** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1032** VFS should return SQLITE_NOTFOUND for this opcode. 1033** 1034** <li>[[SQLITE_FCNTL_RBU]] 1035** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1036** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1037** this opcode. 1038** 1039** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1040** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1041** the file descriptor is placed in "batch write mode", which 1042** means all subsequent write operations will be deferred and done 1043** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1044** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1045** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1046** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1047** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1048** no VFS interface calls on the same [sqlite3_file] file descriptor 1049** except for calls to the xWrite method and the xFileControl method 1050** with [SQLITE_FCNTL_SIZE_HINT]. 1051** 1052** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1053** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1054** operations since the previous successful call to 1055** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1056** This file control returns [SQLITE_OK] if and only if the writes were 1057** all performed successfully and have been committed to persistent storage. 1058** ^Regardless of whether or not it is successful, this file control takes 1059** the file descriptor out of batch write mode so that all subsequent 1060** write operations are independent. 1061** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1062** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1063** 1064** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1065** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1066** operations since the previous successful call to 1067** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1068** ^This file control takes the file descriptor out of batch write mode 1069** so that all subsequent write operations are independent. 1070** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1071** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1072** 1073** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1074** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1075** a file lock using the xLock or xShmLock methods of the VFS to wait 1076** for up to M milliseconds before failing, where M is the single 1077** unsigned integer parameter. 1078** 1079** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1080** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1081** a database file. The argument is a pointer to a 32-bit unsigned integer. 1082** The "data version" for the pager is written into the pointer. The 1083** "data version" changes whenever any change occurs to the corresponding 1084** database file, either through SQL statements on the same database 1085** connection or through transactions committed by separate database 1086** connections possibly in other processes. The [sqlite3_total_changes()] 1087** interface can be used to find if any database on the connection has changed, 1088** but that interface responds to changes on TEMP as well as MAIN and does 1089** not provide a mechanism to detect changes to MAIN only. Also, the 1090** [sqlite3_total_changes()] interface responds to internal changes only and 1091** omits changes made by other database connections. The 1092** [PRAGMA data_version] command provide a mechanism to detect changes to 1093** a single attached database that occur due to other database connections, 1094** but omits changes implemented by the database connection on which it is 1095** called. This file control is the only mechanism to detect changes that 1096** happen either internally or externally and that are associated with 1097** a particular attached database. 1098** </ul> 1099*/ 1100#define SQLITE_FCNTL_LOCKSTATE 1 1101#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1102#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1103#define SQLITE_FCNTL_LAST_ERRNO 4 1104#define SQLITE_FCNTL_SIZE_HINT 5 1105#define SQLITE_FCNTL_CHUNK_SIZE 6 1106#define SQLITE_FCNTL_FILE_POINTER 7 1107#define SQLITE_FCNTL_SYNC_OMITTED 8 1108#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1109#define SQLITE_FCNTL_PERSIST_WAL 10 1110#define SQLITE_FCNTL_OVERWRITE 11 1111#define SQLITE_FCNTL_VFSNAME 12 1112#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1113#define SQLITE_FCNTL_PRAGMA 14 1114#define SQLITE_FCNTL_BUSYHANDLER 15 1115#define SQLITE_FCNTL_TEMPFILENAME 16 1116#define SQLITE_FCNTL_MMAP_SIZE 18 1117#define SQLITE_FCNTL_TRACE 19 1118#define SQLITE_FCNTL_HAS_MOVED 20 1119#define SQLITE_FCNTL_SYNC 21 1120#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1121#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1122#define SQLITE_FCNTL_WAL_BLOCK 24 1123#define SQLITE_FCNTL_ZIPVFS 25 1124#define SQLITE_FCNTL_RBU 26 1125#define SQLITE_FCNTL_VFS_POINTER 27 1126#define SQLITE_FCNTL_JOURNAL_POINTER 28 1127#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1128#define SQLITE_FCNTL_PDB 30 1129#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1130#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1131#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1132#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1133#define SQLITE_FCNTL_DATA_VERSION 35 1134 1135/* deprecated names */ 1136#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1137#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1138#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1139 1140 1141/* 1142** CAPI3REF: Mutex Handle 1143** 1144** The mutex module within SQLite defines [sqlite3_mutex] to be an 1145** abstract type for a mutex object. The SQLite core never looks 1146** at the internal representation of an [sqlite3_mutex]. It only 1147** deals with pointers to the [sqlite3_mutex] object. 1148** 1149** Mutexes are created using [sqlite3_mutex_alloc()]. 1150*/ 1151typedef struct sqlite3_mutex sqlite3_mutex; 1152 1153/* 1154** CAPI3REF: Loadable Extension Thunk 1155** 1156** A pointer to the opaque sqlite3_api_routines structure is passed as 1157** the third parameter to entry points of [loadable extensions]. This 1158** structure must be typedefed in order to work around compiler warnings 1159** on some platforms. 1160*/ 1161typedef struct sqlite3_api_routines sqlite3_api_routines; 1162 1163/* 1164** CAPI3REF: OS Interface Object 1165** 1166** An instance of the sqlite3_vfs object defines the interface between 1167** the SQLite core and the underlying operating system. The "vfs" 1168** in the name of the object stands for "virtual file system". See 1169** the [VFS | VFS documentation] for further information. 1170** 1171** The VFS interface is sometimes extended by adding new methods onto 1172** the end. Each time such an extension occurs, the iVersion field 1173** is incremented. The iVersion value started out as 1 in 1174** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1175** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1176** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1177** may be appended to the sqlite3_vfs object and the iVersion value 1178** may increase again in future versions of SQLite. 1179** Note that the structure 1180** of the sqlite3_vfs object changes in the transition from 1181** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1182** and yet the iVersion field was not modified. 1183** 1184** The szOsFile field is the size of the subclassed [sqlite3_file] 1185** structure used by this VFS. mxPathname is the maximum length of 1186** a pathname in this VFS. 1187** 1188** Registered sqlite3_vfs objects are kept on a linked list formed by 1189** the pNext pointer. The [sqlite3_vfs_register()] 1190** and [sqlite3_vfs_unregister()] interfaces manage this list 1191** in a thread-safe way. The [sqlite3_vfs_find()] interface 1192** searches the list. Neither the application code nor the VFS 1193** implementation should use the pNext pointer. 1194** 1195** The pNext field is the only field in the sqlite3_vfs 1196** structure that SQLite will ever modify. SQLite will only access 1197** or modify this field while holding a particular static mutex. 1198** The application should never modify anything within the sqlite3_vfs 1199** object once the object has been registered. 1200** 1201** The zName field holds the name of the VFS module. The name must 1202** be unique across all VFS modules. 1203** 1204** [[sqlite3_vfs.xOpen]] 1205** ^SQLite guarantees that the zFilename parameter to xOpen 1206** is either a NULL pointer or string obtained 1207** from xFullPathname() with an optional suffix added. 1208** ^If a suffix is added to the zFilename parameter, it will 1209** consist of a single "-" character followed by no more than 1210** 11 alphanumeric and/or "-" characters. 1211** ^SQLite further guarantees that 1212** the string will be valid and unchanged until xClose() is 1213** called. Because of the previous sentence, 1214** the [sqlite3_file] can safely store a pointer to the 1215** filename if it needs to remember the filename for some reason. 1216** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1217** must invent its own temporary name for the file. ^Whenever the 1218** xFilename parameter is NULL it will also be the case that the 1219** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1220** 1221** The flags argument to xOpen() includes all bits set in 1222** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1223** or [sqlite3_open16()] is used, then flags includes at least 1224** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1225** If xOpen() opens a file read-only then it sets *pOutFlags to 1226** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1227** 1228** ^(SQLite will also add one of the following flags to the xOpen() 1229** call, depending on the object being opened: 1230** 1231** <ul> 1232** <li> [SQLITE_OPEN_MAIN_DB] 1233** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1234** <li> [SQLITE_OPEN_TEMP_DB] 1235** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1236** <li> [SQLITE_OPEN_TRANSIENT_DB] 1237** <li> [SQLITE_OPEN_SUBJOURNAL] 1238** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1239** <li> [SQLITE_OPEN_WAL] 1240** </ul>)^ 1241** 1242** The file I/O implementation can use the object type flags to 1243** change the way it deals with files. For example, an application 1244** that does not care about crash recovery or rollback might make 1245** the open of a journal file a no-op. Writes to this journal would 1246** also be no-ops, and any attempt to read the journal would return 1247** SQLITE_IOERR. Or the implementation might recognize that a database 1248** file will be doing page-aligned sector reads and writes in a random 1249** order and set up its I/O subsystem accordingly. 1250** 1251** SQLite might also add one of the following flags to the xOpen method: 1252** 1253** <ul> 1254** <li> [SQLITE_OPEN_DELETEONCLOSE] 1255** <li> [SQLITE_OPEN_EXCLUSIVE] 1256** </ul> 1257** 1258** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1259** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1260** will be set for TEMP databases and their journals, transient 1261** databases, and subjournals. 1262** 1263** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1264** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1265** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1266** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1267** SQLITE_OPEN_CREATE, is used to indicate that file should always 1268** be created, and that it is an error if it already exists. 1269** It is <i>not</i> used to indicate the file should be opened 1270** for exclusive access. 1271** 1272** ^At least szOsFile bytes of memory are allocated by SQLite 1273** to hold the [sqlite3_file] structure passed as the third 1274** argument to xOpen. The xOpen method does not have to 1275** allocate the structure; it should just fill it in. Note that 1276** the xOpen method must set the sqlite3_file.pMethods to either 1277** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1278** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1279** element will be valid after xOpen returns regardless of the success 1280** or failure of the xOpen call. 1281** 1282** [[sqlite3_vfs.xAccess]] 1283** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1284** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1285** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1286** to test whether a file is at least readable. The file can be a 1287** directory. 1288** 1289** ^SQLite will always allocate at least mxPathname+1 bytes for the 1290** output buffer xFullPathname. The exact size of the output buffer 1291** is also passed as a parameter to both methods. If the output buffer 1292** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1293** handled as a fatal error by SQLite, vfs implementations should endeavor 1294** to prevent this by setting mxPathname to a sufficiently large value. 1295** 1296** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1297** interfaces are not strictly a part of the filesystem, but they are 1298** included in the VFS structure for completeness. 1299** The xRandomness() function attempts to return nBytes bytes 1300** of good-quality randomness into zOut. The return value is 1301** the actual number of bytes of randomness obtained. 1302** The xSleep() method causes the calling thread to sleep for at 1303** least the number of microseconds given. ^The xCurrentTime() 1304** method returns a Julian Day Number for the current date and time as 1305** a floating point value. 1306** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1307** Day Number multiplied by 86400000 (the number of milliseconds in 1308** a 24-hour day). 1309** ^SQLite will use the xCurrentTimeInt64() method to get the current 1310** date and time if that method is available (if iVersion is 2 or 1311** greater and the function pointer is not NULL) and will fall back 1312** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1313** 1314** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1315** are not used by the SQLite core. These optional interfaces are provided 1316** by some VFSes to facilitate testing of the VFS code. By overriding 1317** system calls with functions under its control, a test program can 1318** simulate faults and error conditions that would otherwise be difficult 1319** or impossible to induce. The set of system calls that can be overridden 1320** varies from one VFS to another, and from one version of the same VFS to the 1321** next. Applications that use these interfaces must be prepared for any 1322** or all of these interfaces to be NULL or for their behavior to change 1323** from one release to the next. Applications must not attempt to access 1324** any of these methods if the iVersion of the VFS is less than 3. 1325*/ 1326typedef struct sqlite3_vfs sqlite3_vfs; 1327typedef void (*sqlite3_syscall_ptr)(void); 1328struct sqlite3_vfs { 1329 int iVersion; /* Structure version number (currently 3) */ 1330 int szOsFile; /* Size of subclassed sqlite3_file */ 1331 int mxPathname; /* Maximum file pathname length */ 1332 sqlite3_vfs *pNext; /* Next registered VFS */ 1333 const char *zName; /* Name of this virtual file system */ 1334 void *pAppData; /* Pointer to application-specific data */ 1335 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1336 int flags, int *pOutFlags); 1337 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1338 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1339 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1340 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1341 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1342 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1343 void (*xDlClose)(sqlite3_vfs*, void*); 1344 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1345 int (*xSleep)(sqlite3_vfs*, int microseconds); 1346 int (*xCurrentTime)(sqlite3_vfs*, double*); 1347 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1348 /* 1349 ** The methods above are in version 1 of the sqlite_vfs object 1350 ** definition. Those that follow are added in version 2 or later 1351 */ 1352 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1353 /* 1354 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1355 ** Those below are for version 3 and greater. 1356 */ 1357 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1358 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1359 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1360 /* 1361 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1362 ** New fields may be appended in future versions. The iVersion 1363 ** value will increment whenever this happens. 1364 */ 1365}; 1366 1367/* 1368** CAPI3REF: Flags for the xAccess VFS method 1369** 1370** These integer constants can be used as the third parameter to 1371** the xAccess method of an [sqlite3_vfs] object. They determine 1372** what kind of permissions the xAccess method is looking for. 1373** With SQLITE_ACCESS_EXISTS, the xAccess method 1374** simply checks whether the file exists. 1375** With SQLITE_ACCESS_READWRITE, the xAccess method 1376** checks whether the named directory is both readable and writable 1377** (in other words, if files can be added, removed, and renamed within 1378** the directory). 1379** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1380** [temp_store_directory pragma], though this could change in a future 1381** release of SQLite. 1382** With SQLITE_ACCESS_READ, the xAccess method 1383** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1384** currently unused, though it might be used in a future release of 1385** SQLite. 1386*/ 1387#define SQLITE_ACCESS_EXISTS 0 1388#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1389#define SQLITE_ACCESS_READ 2 /* Unused */ 1390 1391/* 1392** CAPI3REF: Flags for the xShmLock VFS method 1393** 1394** These integer constants define the various locking operations 1395** allowed by the xShmLock method of [sqlite3_io_methods]. The 1396** following are the only legal combinations of flags to the 1397** xShmLock method: 1398** 1399** <ul> 1400** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1401** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1402** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1403** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1404** </ul> 1405** 1406** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1407** was given on the corresponding lock. 1408** 1409** The xShmLock method can transition between unlocked and SHARED or 1410** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1411** and EXCLUSIVE. 1412*/ 1413#define SQLITE_SHM_UNLOCK 1 1414#define SQLITE_SHM_LOCK 2 1415#define SQLITE_SHM_SHARED 4 1416#define SQLITE_SHM_EXCLUSIVE 8 1417 1418/* 1419** CAPI3REF: Maximum xShmLock index 1420** 1421** The xShmLock method on [sqlite3_io_methods] may use values 1422** between 0 and this upper bound as its "offset" argument. 1423** The SQLite core will never attempt to acquire or release a 1424** lock outside of this range 1425*/ 1426#define SQLITE_SHM_NLOCK 8 1427 1428 1429/* 1430** CAPI3REF: Initialize The SQLite Library 1431** 1432** ^The sqlite3_initialize() routine initializes the 1433** SQLite library. ^The sqlite3_shutdown() routine 1434** deallocates any resources that were allocated by sqlite3_initialize(). 1435** These routines are designed to aid in process initialization and 1436** shutdown on embedded systems. Workstation applications using 1437** SQLite normally do not need to invoke either of these routines. 1438** 1439** A call to sqlite3_initialize() is an "effective" call if it is 1440** the first time sqlite3_initialize() is invoked during the lifetime of 1441** the process, or if it is the first time sqlite3_initialize() is invoked 1442** following a call to sqlite3_shutdown(). ^(Only an effective call 1443** of sqlite3_initialize() does any initialization. All other calls 1444** are harmless no-ops.)^ 1445** 1446** A call to sqlite3_shutdown() is an "effective" call if it is the first 1447** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1448** an effective call to sqlite3_shutdown() does any deinitialization. 1449** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1450** 1451** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1452** is not. The sqlite3_shutdown() interface must only be called from a 1453** single thread. All open [database connections] must be closed and all 1454** other SQLite resources must be deallocated prior to invoking 1455** sqlite3_shutdown(). 1456** 1457** Among other things, ^sqlite3_initialize() will invoke 1458** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1459** will invoke sqlite3_os_end(). 1460** 1461** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1462** ^If for some reason, sqlite3_initialize() is unable to initialize 1463** the library (perhaps it is unable to allocate a needed resource such 1464** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1465** 1466** ^The sqlite3_initialize() routine is called internally by many other 1467** SQLite interfaces so that an application usually does not need to 1468** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1469** calls sqlite3_initialize() so the SQLite library will be automatically 1470** initialized when [sqlite3_open()] is called if it has not be initialized 1471** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1472** compile-time option, then the automatic calls to sqlite3_initialize() 1473** are omitted and the application must call sqlite3_initialize() directly 1474** prior to using any other SQLite interface. For maximum portability, 1475** it is recommended that applications always invoke sqlite3_initialize() 1476** directly prior to using any other SQLite interface. Future releases 1477** of SQLite may require this. In other words, the behavior exhibited 1478** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1479** default behavior in some future release of SQLite. 1480** 1481** The sqlite3_os_init() routine does operating-system specific 1482** initialization of the SQLite library. The sqlite3_os_end() 1483** routine undoes the effect of sqlite3_os_init(). Typical tasks 1484** performed by these routines include allocation or deallocation 1485** of static resources, initialization of global variables, 1486** setting up a default [sqlite3_vfs] module, or setting up 1487** a default configuration using [sqlite3_config()]. 1488** 1489** The application should never invoke either sqlite3_os_init() 1490** or sqlite3_os_end() directly. The application should only invoke 1491** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1492** interface is called automatically by sqlite3_initialize() and 1493** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1494** implementations for sqlite3_os_init() and sqlite3_os_end() 1495** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1496** When [custom builds | built for other platforms] 1497** (using the [SQLITE_OS_OTHER=1] compile-time 1498** option) the application must supply a suitable implementation for 1499** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1500** implementation of sqlite3_os_init() or sqlite3_os_end() 1501** must return [SQLITE_OK] on success and some other [error code] upon 1502** failure. 1503*/ 1504SQLITE_API int sqlite3_initialize(void); 1505SQLITE_API int sqlite3_shutdown(void); 1506SQLITE_API int sqlite3_os_init(void); 1507SQLITE_API int sqlite3_os_end(void); 1508 1509/* 1510** CAPI3REF: Configuring The SQLite Library 1511** 1512** The sqlite3_config() interface is used to make global configuration 1513** changes to SQLite in order to tune SQLite to the specific needs of 1514** the application. The default configuration is recommended for most 1515** applications and so this routine is usually not necessary. It is 1516** provided to support rare applications with unusual needs. 1517** 1518** <b>The sqlite3_config() interface is not threadsafe. The application 1519** must ensure that no other SQLite interfaces are invoked by other 1520** threads while sqlite3_config() is running.</b> 1521** 1522** The sqlite3_config() interface 1523** may only be invoked prior to library initialization using 1524** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1525** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1526** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1527** Note, however, that ^sqlite3_config() can be called as part of the 1528** implementation of an application-defined [sqlite3_os_init()]. 1529** 1530** The first argument to sqlite3_config() is an integer 1531** [configuration option] that determines 1532** what property of SQLite is to be configured. Subsequent arguments 1533** vary depending on the [configuration option] 1534** in the first argument. 1535** 1536** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1537** ^If the option is unknown or SQLite is unable to set the option 1538** then this routine returns a non-zero [error code]. 1539*/ 1540SQLITE_API int sqlite3_config(int, ...); 1541 1542/* 1543** CAPI3REF: Configure database connections 1544** METHOD: sqlite3 1545** 1546** The sqlite3_db_config() interface is used to make configuration 1547** changes to a [database connection]. The interface is similar to 1548** [sqlite3_config()] except that the changes apply to a single 1549** [database connection] (specified in the first argument). 1550** 1551** The second argument to sqlite3_db_config(D,V,...) is the 1552** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1553** that indicates what aspect of the [database connection] is being configured. 1554** Subsequent arguments vary depending on the configuration verb. 1555** 1556** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1557** the call is considered successful. 1558*/ 1559SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1560 1561/* 1562** CAPI3REF: Memory Allocation Routines 1563** 1564** An instance of this object defines the interface between SQLite 1565** and low-level memory allocation routines. 1566** 1567** This object is used in only one place in the SQLite interface. 1568** A pointer to an instance of this object is the argument to 1569** [sqlite3_config()] when the configuration option is 1570** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1571** By creating an instance of this object 1572** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1573** during configuration, an application can specify an alternative 1574** memory allocation subsystem for SQLite to use for all of its 1575** dynamic memory needs. 1576** 1577** Note that SQLite comes with several [built-in memory allocators] 1578** that are perfectly adequate for the overwhelming majority of applications 1579** and that this object is only useful to a tiny minority of applications 1580** with specialized memory allocation requirements. This object is 1581** also used during testing of SQLite in order to specify an alternative 1582** memory allocator that simulates memory out-of-memory conditions in 1583** order to verify that SQLite recovers gracefully from such 1584** conditions. 1585** 1586** The xMalloc, xRealloc, and xFree methods must work like the 1587** malloc(), realloc() and free() functions from the standard C library. 1588** ^SQLite guarantees that the second argument to 1589** xRealloc is always a value returned by a prior call to xRoundup. 1590** 1591** xSize should return the allocated size of a memory allocation 1592** previously obtained from xMalloc or xRealloc. The allocated size 1593** is always at least as big as the requested size but may be larger. 1594** 1595** The xRoundup method returns what would be the allocated size of 1596** a memory allocation given a particular requested size. Most memory 1597** allocators round up memory allocations at least to the next multiple 1598** of 8. Some allocators round up to a larger multiple or to a power of 2. 1599** Every memory allocation request coming in through [sqlite3_malloc()] 1600** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1601** that causes the corresponding memory allocation to fail. 1602** 1603** The xInit method initializes the memory allocator. For example, 1604** it might allocate any require mutexes or initialize internal data 1605** structures. The xShutdown method is invoked (indirectly) by 1606** [sqlite3_shutdown()] and should deallocate any resources acquired 1607** by xInit. The pAppData pointer is used as the only parameter to 1608** xInit and xShutdown. 1609** 1610** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1611** the xInit method, so the xInit method need not be threadsafe. The 1612** xShutdown method is only called from [sqlite3_shutdown()] so it does 1613** not need to be threadsafe either. For all other methods, SQLite 1614** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1615** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1616** it is by default) and so the methods are automatically serialized. 1617** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1618** methods must be threadsafe or else make their own arrangements for 1619** serialization. 1620** 1621** SQLite will never invoke xInit() more than once without an intervening 1622** call to xShutdown(). 1623*/ 1624typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1625struct sqlite3_mem_methods { 1626 void *(*xMalloc)(int); /* Memory allocation function */ 1627 void (*xFree)(void*); /* Free a prior allocation */ 1628 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1629 int (*xSize)(void*); /* Return the size of an allocation */ 1630 int (*xRoundup)(int); /* Round up request size to allocation size */ 1631 int (*xInit)(void*); /* Initialize the memory allocator */ 1632 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1633 void *pAppData; /* Argument to xInit() and xShutdown() */ 1634}; 1635 1636/* 1637** CAPI3REF: Configuration Options 1638** KEYWORDS: {configuration option} 1639** 1640** These constants are the available integer configuration options that 1641** can be passed as the first argument to the [sqlite3_config()] interface. 1642** 1643** New configuration options may be added in future releases of SQLite. 1644** Existing configuration options might be discontinued. Applications 1645** should check the return code from [sqlite3_config()] to make sure that 1646** the call worked. The [sqlite3_config()] interface will return a 1647** non-zero [error code] if a discontinued or unsupported configuration option 1648** is invoked. 1649** 1650** <dl> 1651** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1652** <dd>There are no arguments to this option. ^This option sets the 1653** [threading mode] to Single-thread. In other words, it disables 1654** all mutexing and puts SQLite into a mode where it can only be used 1655** by a single thread. ^If SQLite is compiled with 1656** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1657** it is not possible to change the [threading mode] from its default 1658** value of Single-thread and so [sqlite3_config()] will return 1659** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1660** configuration option.</dd> 1661** 1662** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1663** <dd>There are no arguments to this option. ^This option sets the 1664** [threading mode] to Multi-thread. In other words, it disables 1665** mutexing on [database connection] and [prepared statement] objects. 1666** The application is responsible for serializing access to 1667** [database connections] and [prepared statements]. But other mutexes 1668** are enabled so that SQLite will be safe to use in a multi-threaded 1669** environment as long as no two threads attempt to use the same 1670** [database connection] at the same time. ^If SQLite is compiled with 1671** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1672** it is not possible to set the Multi-thread [threading mode] and 1673** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1674** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1675** 1676** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1677** <dd>There are no arguments to this option. ^This option sets the 1678** [threading mode] to Serialized. In other words, this option enables 1679** all mutexes including the recursive 1680** mutexes on [database connection] and [prepared statement] objects. 1681** In this mode (which is the default when SQLite is compiled with 1682** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1683** to [database connections] and [prepared statements] so that the 1684** application is free to use the same [database connection] or the 1685** same [prepared statement] in different threads at the same time. 1686** ^If SQLite is compiled with 1687** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1688** it is not possible to set the Serialized [threading mode] and 1689** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1690** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1691** 1692** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1693** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1694** a pointer to an instance of the [sqlite3_mem_methods] structure. 1695** The argument specifies 1696** alternative low-level memory allocation routines to be used in place of 1697** the memory allocation routines built into SQLite.)^ ^SQLite makes 1698** its own private copy of the content of the [sqlite3_mem_methods] structure 1699** before the [sqlite3_config()] call returns.</dd> 1700** 1701** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1702** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1703** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1704** The [sqlite3_mem_methods] 1705** structure is filled with the currently defined memory allocation routines.)^ 1706** This option can be used to overload the default memory allocation 1707** routines with a wrapper that simulations memory allocation failure or 1708** tracks memory usage, for example. </dd> 1709** 1710** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1711** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1712** type int, interpreted as a boolean, which if true provides a hint to 1713** SQLite that it should avoid large memory allocations if possible. 1714** SQLite will run faster if it is free to make large memory allocations, 1715** but some application might prefer to run slower in exchange for 1716** guarantees about memory fragmentation that are possible if large 1717** allocations are avoided. This hint is normally off. 1718** </dd> 1719** 1720** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1721** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1722** interpreted as a boolean, which enables or disables the collection of 1723** memory allocation statistics. ^(When memory allocation statistics are 1724** disabled, the following SQLite interfaces become non-operational: 1725** <ul> 1726** <li> [sqlite3_memory_used()] 1727** <li> [sqlite3_memory_highwater()] 1728** <li> [sqlite3_soft_heap_limit64()] 1729** <li> [sqlite3_status64()] 1730** </ul>)^ 1731** ^Memory allocation statistics are enabled by default unless SQLite is 1732** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1733** allocation statistics are disabled by default. 1734** </dd> 1735** 1736** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1737** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1738** </dd> 1739** 1740** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1741** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1742** that SQLite can use for the database page cache with the default page 1743** cache implementation. 1744** This configuration option is a no-op if an application-define page 1745** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1746** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1747** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1748** and the number of cache lines (N). 1749** The sz argument should be the size of the largest database page 1750** (a power of two between 512 and 65536) plus some extra bytes for each 1751** page header. ^The number of extra bytes needed by the page header 1752** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1753** ^It is harmless, apart from the wasted memory, 1754** for the sz parameter to be larger than necessary. The pMem 1755** argument must be either a NULL pointer or a pointer to an 8-byte 1756** aligned block of memory of at least sz*N bytes, otherwise 1757** subsequent behavior is undefined. 1758** ^When pMem is not NULL, SQLite will strive to use the memory provided 1759** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1760** a page cache line is larger than sz bytes or if all of the pMem buffer 1761** is exhausted. 1762** ^If pMem is NULL and N is non-zero, then each database connection 1763** does an initial bulk allocation for page cache memory 1764** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1765** of -1024*N bytes if N is negative, . ^If additional 1766** page cache memory is needed beyond what is provided by the initial 1767** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1768** additional cache line. </dd> 1769** 1770** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1771** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1772** that SQLite will use for all of its dynamic memory allocation needs 1773** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1774** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1775** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1776** [SQLITE_ERROR] if invoked otherwise. 1777** ^There are three arguments to SQLITE_CONFIG_HEAP: 1778** An 8-byte aligned pointer to the memory, 1779** the number of bytes in the memory buffer, and the minimum allocation size. 1780** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1781** to using its default memory allocator (the system malloc() implementation), 1782** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1783** memory pointer is not NULL then the alternative memory 1784** allocator is engaged to handle all of SQLites memory allocation needs. 1785** The first pointer (the memory pointer) must be aligned to an 8-byte 1786** boundary or subsequent behavior of SQLite will be undefined. 1787** The minimum allocation size is capped at 2**12. Reasonable values 1788** for the minimum allocation size are 2**5 through 2**8.</dd> 1789** 1790** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1791** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1792** pointer to an instance of the [sqlite3_mutex_methods] structure. 1793** The argument specifies alternative low-level mutex routines to be used 1794** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1795** the content of the [sqlite3_mutex_methods] structure before the call to 1796** [sqlite3_config()] returns. ^If SQLite is compiled with 1797** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1798** the entire mutexing subsystem is omitted from the build and hence calls to 1799** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1800** return [SQLITE_ERROR].</dd> 1801** 1802** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1803** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1804** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1805** [sqlite3_mutex_methods] 1806** structure is filled with the currently defined mutex routines.)^ 1807** This option can be used to overload the default mutex allocation 1808** routines with a wrapper used to track mutex usage for performance 1809** profiling or testing, for example. ^If SQLite is compiled with 1810** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1811** the entire mutexing subsystem is omitted from the build and hence calls to 1812** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1813** return [SQLITE_ERROR].</dd> 1814** 1815** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1816** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1817** the default size of lookaside memory on each [database connection]. 1818** The first argument is the 1819** size of each lookaside buffer slot and the second is the number of 1820** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1821** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1822** option to [sqlite3_db_config()] can be used to change the lookaside 1823** configuration on individual connections.)^ </dd> 1824** 1825** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1826** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1827** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1828** the interface to a custom page cache implementation.)^ 1829** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1830** 1831** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1832** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1833** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1834** the current page cache implementation into that object.)^ </dd> 1835** 1836** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1837** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1838** global [error log]. 1839** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1840** function with a call signature of void(*)(void*,int,const char*), 1841** and a pointer to void. ^If the function pointer is not NULL, it is 1842** invoked by [sqlite3_log()] to process each logging event. ^If the 1843** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1844** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1845** passed through as the first parameter to the application-defined logger 1846** function whenever that function is invoked. ^The second parameter to 1847** the logger function is a copy of the first parameter to the corresponding 1848** [sqlite3_log()] call and is intended to be a [result code] or an 1849** [extended result code]. ^The third parameter passed to the logger is 1850** log message after formatting via [sqlite3_snprintf()]. 1851** The SQLite logging interface is not reentrant; the logger function 1852** supplied by the application must not invoke any SQLite interface. 1853** In a multi-threaded application, the application-defined logger 1854** function must be threadsafe. </dd> 1855** 1856** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1857** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1858** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1859** then URI handling is globally disabled.)^ ^If URI handling is globally 1860** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1861** [sqlite3_open16()] or 1862** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1863** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1864** connection is opened. ^If it is globally disabled, filenames are 1865** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1866** database connection is opened. ^(By default, URI handling is globally 1867** disabled. The default value may be changed by compiling with the 1868** [SQLITE_USE_URI] symbol defined.)^ 1869** 1870** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1871** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1872** argument which is interpreted as a boolean in order to enable or disable 1873** the use of covering indices for full table scans in the query optimizer. 1874** ^The default setting is determined 1875** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1876** if that compile-time option is omitted. 1877** The ability to disable the use of covering indices for full table scans 1878** is because some incorrectly coded legacy applications might malfunction 1879** when the optimization is enabled. Providing the ability to 1880** disable the optimization allows the older, buggy application code to work 1881** without change even with newer versions of SQLite. 1882** 1883** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1884** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1885** <dd> These options are obsolete and should not be used by new code. 1886** They are retained for backwards compatibility but are now no-ops. 1887** </dd> 1888** 1889** [[SQLITE_CONFIG_SQLLOG]] 1890** <dt>SQLITE_CONFIG_SQLLOG 1891** <dd>This option is only available if sqlite is compiled with the 1892** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1893** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1894** The second should be of type (void*). The callback is invoked by the library 1895** in three separate circumstances, identified by the value passed as the 1896** fourth parameter. If the fourth parameter is 0, then the database connection 1897** passed as the second argument has just been opened. The third argument 1898** points to a buffer containing the name of the main database file. If the 1899** fourth parameter is 1, then the SQL statement that the third parameter 1900** points to has just been executed. Or, if the fourth parameter is 2, then 1901** the connection being passed as the second parameter is being closed. The 1902** third parameter is passed NULL In this case. An example of using this 1903** configuration option can be seen in the "test_sqllog.c" source file in 1904** the canonical SQLite source tree.</dd> 1905** 1906** [[SQLITE_CONFIG_MMAP_SIZE]] 1907** <dt>SQLITE_CONFIG_MMAP_SIZE 1908** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1909** that are the default mmap size limit (the default setting for 1910** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1911** ^The default setting can be overridden by each database connection using 1912** either the [PRAGMA mmap_size] command, or by using the 1913** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1914** will be silently truncated if necessary so that it does not exceed the 1915** compile-time maximum mmap size set by the 1916** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1917** ^If either argument to this option is negative, then that argument is 1918** changed to its compile-time default. 1919** 1920** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1921** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1922** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1923** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1924** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1925** that specifies the maximum size of the created heap. 1926** 1927** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1928** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1929** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1930** is a pointer to an integer and writes into that integer the number of extra 1931** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1932** The amount of extra space required can change depending on the compiler, 1933** target platform, and SQLite version. 1934** 1935** [[SQLITE_CONFIG_PMASZ]] 1936** <dt>SQLITE_CONFIG_PMASZ 1937** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1938** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1939** sorter to that integer. The default minimum PMA Size is set by the 1940** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1941** to help with sort operations when multithreaded sorting 1942** is enabled (using the [PRAGMA threads] command) and the amount of content 1943** to be sorted exceeds the page size times the minimum of the 1944** [PRAGMA cache_size] setting and this value. 1945** 1946** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1947** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1948** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1949** becomes the [statement journal] spill-to-disk threshold. 1950** [Statement journals] are held in memory until their size (in bytes) 1951** exceeds this threshold, at which point they are written to disk. 1952** Or if the threshold is -1, statement journals are always held 1953** exclusively in memory. 1954** Since many statement journals never become large, setting the spill 1955** threshold to a value such as 64KiB can greatly reduce the amount of 1956** I/O required to support statement rollback. 1957** The default value for this setting is controlled by the 1958** [SQLITE_STMTJRNL_SPILL] compile-time option. 1959** 1960** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1961** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1962** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1963** of type (int) - the new value of the sorter-reference size threshold. 1964** Usually, when SQLite uses an external sort to order records according 1965** to an ORDER BY clause, all fields required by the caller are present in the 1966** sorted records. However, if SQLite determines based on the declared type 1967** of a table column that its values are likely to be very large - larger 1968** than the configured sorter-reference size threshold - then a reference 1969** is stored in each sorted record and the required column values loaded 1970** from the database as records are returned in sorted order. The default 1971** value for this option is to never use this optimization. Specifying a 1972** negative value for this option restores the default behaviour. 1973** This option is only available if SQLite is compiled with the 1974** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1975** </dl> 1976*/ 1977#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1978#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1979#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1980#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1981#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1982#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1983#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1984#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1985#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1986#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1987#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1988/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1989#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1990#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1991#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1992#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1993#define SQLITE_CONFIG_URI 17 /* int */ 1994#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1995#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1996#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1997#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1998#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1999#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2000#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2001#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2002#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2003#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2004#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2005 2006/* 2007** CAPI3REF: Database Connection Configuration Options 2008** 2009** These constants are the available integer configuration options that 2010** can be passed as the second argument to the [sqlite3_db_config()] interface. 2011** 2012** New configuration options may be added in future releases of SQLite. 2013** Existing configuration options might be discontinued. Applications 2014** should check the return code from [sqlite3_db_config()] to make sure that 2015** the call worked. ^The [sqlite3_db_config()] interface will return a 2016** non-zero [error code] if a discontinued or unsupported configuration option 2017** is invoked. 2018** 2019** <dl> 2020** [[SQLITE_DBCONFIG_LOOKASIDE]] 2021** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2022** <dd> ^This option takes three additional arguments that determine the 2023** [lookaside memory allocator] configuration for the [database connection]. 2024** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2025** pointer to a memory buffer to use for lookaside memory. 2026** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2027** may be NULL in which case SQLite will allocate the 2028** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2029** size of each lookaside buffer slot. ^The third argument is the number of 2030** slots. The size of the buffer in the first argument must be greater than 2031** or equal to the product of the second and third arguments. The buffer 2032** must be aligned to an 8-byte boundary. ^If the second argument to 2033** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2034** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2035** configuration for a database connection can only be changed when that 2036** connection is not currently using lookaside memory, or in other words 2037** when the "current value" returned by 2038** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2039** Any attempt to change the lookaside memory configuration when lookaside 2040** memory is in use leaves the configuration unchanged and returns 2041** [SQLITE_BUSY].)^</dd> 2042** 2043** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2044** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2045** <dd> ^This option is used to enable or disable the enforcement of 2046** [foreign key constraints]. There should be two additional arguments. 2047** The first argument is an integer which is 0 to disable FK enforcement, 2048** positive to enable FK enforcement or negative to leave FK enforcement 2049** unchanged. The second parameter is a pointer to an integer into which 2050** is written 0 or 1 to indicate whether FK enforcement is off or on 2051** following this call. The second parameter may be a NULL pointer, in 2052** which case the FK enforcement setting is not reported back. </dd> 2053** 2054** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2055** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2056** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2057** There should be two additional arguments. 2058** The first argument is an integer which is 0 to disable triggers, 2059** positive to enable triggers or negative to leave the setting unchanged. 2060** The second parameter is a pointer to an integer into which 2061** is written 0 or 1 to indicate whether triggers are disabled or enabled 2062** following this call. The second parameter may be a NULL pointer, in 2063** which case the trigger setting is not reported back. </dd> 2064** 2065** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2066** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2067** <dd> ^This option is used to enable or disable the two-argument 2068** version of the [fts3_tokenizer()] function which is part of the 2069** [FTS3] full-text search engine extension. 2070** There should be two additional arguments. 2071** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2072** positive to enable fts3_tokenizer() or negative to leave the setting 2073** unchanged. 2074** The second parameter is a pointer to an integer into which 2075** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2076** following this call. The second parameter may be a NULL pointer, in 2077** which case the new setting is not reported back. </dd> 2078** 2079** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2080** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2081** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2082** interface independently of the [load_extension()] SQL function. 2083** The [sqlite3_enable_load_extension()] API enables or disables both the 2084** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2085** There should be two additional arguments. 2086** When the first argument to this interface is 1, then only the C-API is 2087** enabled and the SQL function remains disabled. If the first argument to 2088** this interface is 0, then both the C-API and the SQL function are disabled. 2089** If the first argument is -1, then no changes are made to state of either the 2090** C-API or the SQL function. 2091** The second parameter is a pointer to an integer into which 2092** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2093** is disabled or enabled following this call. The second parameter may 2094** be a NULL pointer, in which case the new setting is not reported back. 2095** </dd> 2096** 2097** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2098** <dd> ^This option is used to change the name of the "main" database 2099** schema. ^The sole argument is a pointer to a constant UTF8 string 2100** which will become the new schema name in place of "main". ^SQLite 2101** does not make a copy of the new main schema name string, so the application 2102** must ensure that the argument passed into this DBCONFIG option is unchanged 2103** until after the database connection closes. 2104** </dd> 2105** 2106** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2107** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2108** <dd> Usually, when a database in wal mode is closed or detached from a 2109** database handle, SQLite checks if this will mean that there are now no 2110** connections at all to the database. If so, it performs a checkpoint 2111** operation before closing the connection. This option may be used to 2112** override this behaviour. The first parameter passed to this operation 2113** is an integer - positive to disable checkpoints-on-close, or zero (the 2114** default) to enable them, and negative to leave the setting unchanged. 2115** The second parameter is a pointer to an integer 2116** into which is written 0 or 1 to indicate whether checkpoints-on-close 2117** have been disabled - 0 if they are not disabled, 1 if they are. 2118** </dd> 2119** 2120** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2121** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2122** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2123** a single SQL query statement will always use the same algorithm regardless 2124** of values of [bound parameters].)^ The QPSG disables some query optimizations 2125** that look at the values of bound parameters, which can make some queries 2126** slower. But the QPSG has the advantage of more predictable behavior. With 2127** the QPSG active, SQLite will always use the same query plan in the field as 2128** was used during testing in the lab. 2129** The first argument to this setting is an integer which is 0 to disable 2130** the QPSG, positive to enable QPSG, or negative to leave the setting 2131** unchanged. The second parameter is a pointer to an integer into which 2132** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2133** following this call. 2134** </dd> 2135** 2136** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2137** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2138** include output for any operations performed by trigger programs. This 2139** option is used to set or clear (the default) a flag that governs this 2140** behavior. The first parameter passed to this operation is an integer - 2141** positive to enable output for trigger programs, or zero to disable it, 2142** or negative to leave the setting unchanged. 2143** The second parameter is a pointer to an integer into which is written 2144** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2145** it is not disabled, 1 if it is. 2146** </dd> 2147** 2148** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2149** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2150** [VACUUM] in order to reset a database back to an empty database 2151** with no schema and no content. The following process works even for 2152** a badly corrupted database file: 2153** <ol> 2154** <li> If the database connection is newly opened, make sure it has read the 2155** database schema by preparing then discarding some query against the 2156** database, or calling sqlite3_table_column_metadata(), ignoring any 2157** errors. This step is only necessary if the application desires to keep 2158** the database in WAL mode after the reset if it was in WAL mode before 2159** the reset. 2160** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2161** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2162** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2163** </ol> 2164** Because resetting a database is destructive and irreversible, the 2165** process requires the use of this obscure API and multiple steps to help 2166** ensure that it does not happen by accident. 2167** 2168** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2169** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2170** "defensive" flag for a database connection. When the defensive 2171** flag is enabled, language features that allow ordinary SQL to 2172** deliberately corrupt the database file are disabled. The disabled 2173** features include but are not limited to the following: 2174** <ul> 2175** <li> The [PRAGMA writable_schema=ON] statement. 2176** <li> Writes to the [sqlite_dbpage] virtual table. 2177** <li> Direct writes to [shadow tables]. 2178** </ul> 2179** </dd> 2180** </dl> 2181*/ 2182#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2183#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2184#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2185#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2186#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2187#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2188#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2189#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2190#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2191#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2192#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2193#define SQLITE_DBCONFIG_MAX 1010 /* Largest DBCONFIG */ 2194 2195/* 2196** CAPI3REF: Enable Or Disable Extended Result Codes 2197** METHOD: sqlite3 2198** 2199** ^The sqlite3_extended_result_codes() routine enables or disables the 2200** [extended result codes] feature of SQLite. ^The extended result 2201** codes are disabled by default for historical compatibility. 2202*/ 2203SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2204 2205/* 2206** CAPI3REF: Last Insert Rowid 2207** METHOD: sqlite3 2208** 2209** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2210** has a unique 64-bit signed 2211** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2212** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2213** names are not also used by explicitly declared columns. ^If 2214** the table has a column of type [INTEGER PRIMARY KEY] then that column 2215** is another alias for the rowid. 2216** 2217** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2218** the most recent successful [INSERT] into a rowid table or [virtual table] 2219** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2220** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2221** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2222** zero. 2223** 2224** As well as being set automatically as rows are inserted into database 2225** tables, the value returned by this function may be set explicitly by 2226** [sqlite3_set_last_insert_rowid()] 2227** 2228** Some virtual table implementations may INSERT rows into rowid tables as 2229** part of committing a transaction (e.g. to flush data accumulated in memory 2230** to disk). In this case subsequent calls to this function return the rowid 2231** associated with these internal INSERT operations, which leads to 2232** unintuitive results. Virtual table implementations that do write to rowid 2233** tables in this way can avoid this problem by restoring the original 2234** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2235** control to the user. 2236** 2237** ^(If an [INSERT] occurs within a trigger then this routine will 2238** return the [rowid] of the inserted row as long as the trigger is 2239** running. Once the trigger program ends, the value returned 2240** by this routine reverts to what it was before the trigger was fired.)^ 2241** 2242** ^An [INSERT] that fails due to a constraint violation is not a 2243** successful [INSERT] and does not change the value returned by this 2244** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2245** and INSERT OR ABORT make no changes to the return value of this 2246** routine when their insertion fails. ^(When INSERT OR REPLACE 2247** encounters a constraint violation, it does not fail. The 2248** INSERT continues to completion after deleting rows that caused 2249** the constraint problem so INSERT OR REPLACE will always change 2250** the return value of this interface.)^ 2251** 2252** ^For the purposes of this routine, an [INSERT] is considered to 2253** be successful even if it is subsequently rolled back. 2254** 2255** This function is accessible to SQL statements via the 2256** [last_insert_rowid() SQL function]. 2257** 2258** If a separate thread performs a new [INSERT] on the same 2259** database connection while the [sqlite3_last_insert_rowid()] 2260** function is running and thus changes the last insert [rowid], 2261** then the value returned by [sqlite3_last_insert_rowid()] is 2262** unpredictable and might not equal either the old or the new 2263** last insert [rowid]. 2264*/ 2265SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2266 2267/* 2268** CAPI3REF: Set the Last Insert Rowid value. 2269** METHOD: sqlite3 2270** 2271** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2272** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2273** without inserting a row into the database. 2274*/ 2275SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2276 2277/* 2278** CAPI3REF: Count The Number Of Rows Modified 2279** METHOD: sqlite3 2280** 2281** ^This function returns the number of rows modified, inserted or 2282** deleted by the most recently completed INSERT, UPDATE or DELETE 2283** statement on the database connection specified by the only parameter. 2284** ^Executing any other type of SQL statement does not modify the value 2285** returned by this function. 2286** 2287** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2288** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2289** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2290** 2291** Changes to a view that are intercepted by 2292** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2293** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2294** DELETE statement run on a view is always zero. Only changes made to real 2295** tables are counted. 2296** 2297** Things are more complicated if the sqlite3_changes() function is 2298** executed while a trigger program is running. This may happen if the 2299** program uses the [changes() SQL function], or if some other callback 2300** function invokes sqlite3_changes() directly. Essentially: 2301** 2302** <ul> 2303** <li> ^(Before entering a trigger program the value returned by 2304** sqlite3_changes() function is saved. After the trigger program 2305** has finished, the original value is restored.)^ 2306** 2307** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2308** statement sets the value returned by sqlite3_changes() 2309** upon completion as normal. Of course, this value will not include 2310** any changes performed by sub-triggers, as the sqlite3_changes() 2311** value will be saved and restored after each sub-trigger has run.)^ 2312** </ul> 2313** 2314** ^This means that if the changes() SQL function (or similar) is used 2315** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2316** returns the value as set when the calling statement began executing. 2317** ^If it is used by the second or subsequent such statement within a trigger 2318** program, the value returned reflects the number of rows modified by the 2319** previous INSERT, UPDATE or DELETE statement within the same trigger. 2320** 2321** If a separate thread makes changes on the same database connection 2322** while [sqlite3_changes()] is running then the value returned 2323** is unpredictable and not meaningful. 2324** 2325** See also: 2326** <ul> 2327** <li> the [sqlite3_total_changes()] interface 2328** <li> the [count_changes pragma] 2329** <li> the [changes() SQL function] 2330** <li> the [data_version pragma] 2331** </ul> 2332*/ 2333SQLITE_API int sqlite3_changes(sqlite3*); 2334 2335/* 2336** CAPI3REF: Total Number Of Rows Modified 2337** METHOD: sqlite3 2338** 2339** ^This function returns the total number of rows inserted, modified or 2340** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2341** since the database connection was opened, including those executed as 2342** part of trigger programs. ^Executing any other type of SQL statement 2343** does not affect the value returned by sqlite3_total_changes(). 2344** 2345** ^Changes made as part of [foreign key actions] are included in the 2346** count, but those made as part of REPLACE constraint resolution are 2347** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2348** are not counted. 2349** 2350** This the [sqlite3_total_changes(D)] interface only reports the number 2351** of rows that changed due to SQL statement run against database 2352** connection D. Any changes by other database connections are ignored. 2353** To detect changes against a database file from other database 2354** connections use the [PRAGMA data_version] command or the 2355** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2356** 2357** If a separate thread makes changes on the same database connection 2358** while [sqlite3_total_changes()] is running then the value 2359** returned is unpredictable and not meaningful. 2360** 2361** See also: 2362** <ul> 2363** <li> the [sqlite3_changes()] interface 2364** <li> the [count_changes pragma] 2365** <li> the [changes() SQL function] 2366** <li> the [data_version pragma] 2367** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2368** </ul> 2369*/ 2370SQLITE_API int sqlite3_total_changes(sqlite3*); 2371 2372/* 2373** CAPI3REF: Interrupt A Long-Running Query 2374** METHOD: sqlite3 2375** 2376** ^This function causes any pending database operation to abort and 2377** return at its earliest opportunity. This routine is typically 2378** called in response to a user action such as pressing "Cancel" 2379** or Ctrl-C where the user wants a long query operation to halt 2380** immediately. 2381** 2382** ^It is safe to call this routine from a thread different from the 2383** thread that is currently running the database operation. But it 2384** is not safe to call this routine with a [database connection] that 2385** is closed or might close before sqlite3_interrupt() returns. 2386** 2387** ^If an SQL operation is very nearly finished at the time when 2388** sqlite3_interrupt() is called, then it might not have an opportunity 2389** to be interrupted and might continue to completion. 2390** 2391** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2392** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2393** that is inside an explicit transaction, then the entire transaction 2394** will be rolled back automatically. 2395** 2396** ^The sqlite3_interrupt(D) call is in effect until all currently running 2397** SQL statements on [database connection] D complete. ^Any new SQL statements 2398** that are started after the sqlite3_interrupt() call and before the 2399** running statements reaches zero are interrupted as if they had been 2400** running prior to the sqlite3_interrupt() call. ^New SQL statements 2401** that are started after the running statement count reaches zero are 2402** not effected by the sqlite3_interrupt(). 2403** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2404** SQL statements is a no-op and has no effect on SQL statements 2405** that are started after the sqlite3_interrupt() call returns. 2406*/ 2407SQLITE_API void sqlite3_interrupt(sqlite3*); 2408 2409/* 2410** CAPI3REF: Determine If An SQL Statement Is Complete 2411** 2412** These routines are useful during command-line input to determine if the 2413** currently entered text seems to form a complete SQL statement or 2414** if additional input is needed before sending the text into 2415** SQLite for parsing. ^These routines return 1 if the input string 2416** appears to be a complete SQL statement. ^A statement is judged to be 2417** complete if it ends with a semicolon token and is not a prefix of a 2418** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2419** string literals or quoted identifier names or comments are not 2420** independent tokens (they are part of the token in which they are 2421** embedded) and thus do not count as a statement terminator. ^Whitespace 2422** and comments that follow the final semicolon are ignored. 2423** 2424** ^These routines return 0 if the statement is incomplete. ^If a 2425** memory allocation fails, then SQLITE_NOMEM is returned. 2426** 2427** ^These routines do not parse the SQL statements thus 2428** will not detect syntactically incorrect SQL. 2429** 2430** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2431** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2432** automatically by sqlite3_complete16(). If that initialization fails, 2433** then the return value from sqlite3_complete16() will be non-zero 2434** regardless of whether or not the input SQL is complete.)^ 2435** 2436** The input to [sqlite3_complete()] must be a zero-terminated 2437** UTF-8 string. 2438** 2439** The input to [sqlite3_complete16()] must be a zero-terminated 2440** UTF-16 string in native byte order. 2441*/ 2442SQLITE_API int sqlite3_complete(const char *sql); 2443SQLITE_API int sqlite3_complete16(const void *sql); 2444 2445/* 2446** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2447** KEYWORDS: {busy-handler callback} {busy handler} 2448** METHOD: sqlite3 2449** 2450** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2451** that might be invoked with argument P whenever 2452** an attempt is made to access a database table associated with 2453** [database connection] D when another thread 2454** or process has the table locked. 2455** The sqlite3_busy_handler() interface is used to implement 2456** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2457** 2458** ^If the busy callback is NULL, then [SQLITE_BUSY] 2459** is returned immediately upon encountering the lock. ^If the busy callback 2460** is not NULL, then the callback might be invoked with two arguments. 2461** 2462** ^The first argument to the busy handler is a copy of the void* pointer which 2463** is the third argument to sqlite3_busy_handler(). ^The second argument to 2464** the busy handler callback is the number of times that the busy handler has 2465** been invoked previously for the same locking event. ^If the 2466** busy callback returns 0, then no additional attempts are made to 2467** access the database and [SQLITE_BUSY] is returned 2468** to the application. 2469** ^If the callback returns non-zero, then another attempt 2470** is made to access the database and the cycle repeats. 2471** 2472** The presence of a busy handler does not guarantee that it will be invoked 2473** when there is lock contention. ^If SQLite determines that invoking the busy 2474** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2475** to the application instead of invoking the 2476** busy handler. 2477** Consider a scenario where one process is holding a read lock that 2478** it is trying to promote to a reserved lock and 2479** a second process is holding a reserved lock that it is trying 2480** to promote to an exclusive lock. The first process cannot proceed 2481** because it is blocked by the second and the second process cannot 2482** proceed because it is blocked by the first. If both processes 2483** invoke the busy handlers, neither will make any progress. Therefore, 2484** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2485** will induce the first process to release its read lock and allow 2486** the second process to proceed. 2487** 2488** ^The default busy callback is NULL. 2489** 2490** ^(There can only be a single busy handler defined for each 2491** [database connection]. Setting a new busy handler clears any 2492** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2493** or evaluating [PRAGMA busy_timeout=N] will change the 2494** busy handler and thus clear any previously set busy handler. 2495** 2496** The busy callback should not take any actions which modify the 2497** database connection that invoked the busy handler. In other words, 2498** the busy handler is not reentrant. Any such actions 2499** result in undefined behavior. 2500** 2501** A busy handler must not close the database connection 2502** or [prepared statement] that invoked the busy handler. 2503*/ 2504SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2505 2506/* 2507** CAPI3REF: Set A Busy Timeout 2508** METHOD: sqlite3 2509** 2510** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2511** for a specified amount of time when a table is locked. ^The handler 2512** will sleep multiple times until at least "ms" milliseconds of sleeping 2513** have accumulated. ^After at least "ms" milliseconds of sleeping, 2514** the handler returns 0 which causes [sqlite3_step()] to return 2515** [SQLITE_BUSY]. 2516** 2517** ^Calling this routine with an argument less than or equal to zero 2518** turns off all busy handlers. 2519** 2520** ^(There can only be a single busy handler for a particular 2521** [database connection] at any given moment. If another busy handler 2522** was defined (using [sqlite3_busy_handler()]) prior to calling 2523** this routine, that other busy handler is cleared.)^ 2524** 2525** See also: [PRAGMA busy_timeout] 2526*/ 2527SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2528 2529/* 2530** CAPI3REF: Convenience Routines For Running Queries 2531** METHOD: sqlite3 2532** 2533** This is a legacy interface that is preserved for backwards compatibility. 2534** Use of this interface is not recommended. 2535** 2536** Definition: A <b>result table</b> is memory data structure created by the 2537** [sqlite3_get_table()] interface. A result table records the 2538** complete query results from one or more queries. 2539** 2540** The table conceptually has a number of rows and columns. But 2541** these numbers are not part of the result table itself. These 2542** numbers are obtained separately. Let N be the number of rows 2543** and M be the number of columns. 2544** 2545** A result table is an array of pointers to zero-terminated UTF-8 strings. 2546** There are (N+1)*M elements in the array. The first M pointers point 2547** to zero-terminated strings that contain the names of the columns. 2548** The remaining entries all point to query results. NULL values result 2549** in NULL pointers. All other values are in their UTF-8 zero-terminated 2550** string representation as returned by [sqlite3_column_text()]. 2551** 2552** A result table might consist of one or more memory allocations. 2553** It is not safe to pass a result table directly to [sqlite3_free()]. 2554** A result table should be deallocated using [sqlite3_free_table()]. 2555** 2556** ^(As an example of the result table format, suppose a query result 2557** is as follows: 2558** 2559** <blockquote><pre> 2560** Name | Age 2561** ----------------------- 2562** Alice | 43 2563** Bob | 28 2564** Cindy | 21 2565** </pre></blockquote> 2566** 2567** There are two column (M==2) and three rows (N==3). Thus the 2568** result table has 8 entries. Suppose the result table is stored 2569** in an array names azResult. Then azResult holds this content: 2570** 2571** <blockquote><pre> 2572** azResult[0] = "Name"; 2573** azResult[1] = "Age"; 2574** azResult[2] = "Alice"; 2575** azResult[3] = "43"; 2576** azResult[4] = "Bob"; 2577** azResult[5] = "28"; 2578** azResult[6] = "Cindy"; 2579** azResult[7] = "21"; 2580** </pre></blockquote>)^ 2581** 2582** ^The sqlite3_get_table() function evaluates one or more 2583** semicolon-separated SQL statements in the zero-terminated UTF-8 2584** string of its 2nd parameter and returns a result table to the 2585** pointer given in its 3rd parameter. 2586** 2587** After the application has finished with the result from sqlite3_get_table(), 2588** it must pass the result table pointer to sqlite3_free_table() in order to 2589** release the memory that was malloced. Because of the way the 2590** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2591** function must not try to call [sqlite3_free()] directly. Only 2592** [sqlite3_free_table()] is able to release the memory properly and safely. 2593** 2594** The sqlite3_get_table() interface is implemented as a wrapper around 2595** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2596** to any internal data structures of SQLite. It uses only the public 2597** interface defined here. As a consequence, errors that occur in the 2598** wrapper layer outside of the internal [sqlite3_exec()] call are not 2599** reflected in subsequent calls to [sqlite3_errcode()] or 2600** [sqlite3_errmsg()]. 2601*/ 2602SQLITE_API int sqlite3_get_table( 2603 sqlite3 *db, /* An open database */ 2604 const char *zSql, /* SQL to be evaluated */ 2605 char ***pazResult, /* Results of the query */ 2606 int *pnRow, /* Number of result rows written here */ 2607 int *pnColumn, /* Number of result columns written here */ 2608 char **pzErrmsg /* Error msg written here */ 2609); 2610SQLITE_API void sqlite3_free_table(char **result); 2611 2612/* 2613** CAPI3REF: Formatted String Printing Functions 2614** 2615** These routines are work-alikes of the "printf()" family of functions 2616** from the standard C library. 2617** These routines understand most of the common formatting options from 2618** the standard library printf() 2619** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2620** See the [built-in printf()] documentation for details. 2621** 2622** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2623** results into memory obtained from [sqlite3_malloc64()]. 2624** The strings returned by these two routines should be 2625** released by [sqlite3_free()]. ^Both routines return a 2626** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2627** memory to hold the resulting string. 2628** 2629** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2630** the standard C library. The result is written into the 2631** buffer supplied as the second parameter whose size is given by 2632** the first parameter. Note that the order of the 2633** first two parameters is reversed from snprintf().)^ This is an 2634** historical accident that cannot be fixed without breaking 2635** backwards compatibility. ^(Note also that sqlite3_snprintf() 2636** returns a pointer to its buffer instead of the number of 2637** characters actually written into the buffer.)^ We admit that 2638** the number of characters written would be a more useful return 2639** value but we cannot change the implementation of sqlite3_snprintf() 2640** now without breaking compatibility. 2641** 2642** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2643** guarantees that the buffer is always zero-terminated. ^The first 2644** parameter "n" is the total size of the buffer, including space for 2645** the zero terminator. So the longest string that can be completely 2646** written will be n-1 characters. 2647** 2648** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2649** 2650** See also: [built-in printf()], [printf() SQL function] 2651*/ 2652SQLITE_API char *sqlite3_mprintf(const char*,...); 2653SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2654SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2655SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2656 2657/* 2658** CAPI3REF: Memory Allocation Subsystem 2659** 2660** The SQLite core uses these three routines for all of its own 2661** internal memory allocation needs. "Core" in the previous sentence 2662** does not include operating-system specific VFS implementation. The 2663** Windows VFS uses native malloc() and free() for some operations. 2664** 2665** ^The sqlite3_malloc() routine returns a pointer to a block 2666** of memory at least N bytes in length, where N is the parameter. 2667** ^If sqlite3_malloc() is unable to obtain sufficient free 2668** memory, it returns a NULL pointer. ^If the parameter N to 2669** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2670** a NULL pointer. 2671** 2672** ^The sqlite3_malloc64(N) routine works just like 2673** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2674** of a signed 32-bit integer. 2675** 2676** ^Calling sqlite3_free() with a pointer previously returned 2677** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2678** that it might be reused. ^The sqlite3_free() routine is 2679** a no-op if is called with a NULL pointer. Passing a NULL pointer 2680** to sqlite3_free() is harmless. After being freed, memory 2681** should neither be read nor written. Even reading previously freed 2682** memory might result in a segmentation fault or other severe error. 2683** Memory corruption, a segmentation fault, or other severe error 2684** might result if sqlite3_free() is called with a non-NULL pointer that 2685** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2686** 2687** ^The sqlite3_realloc(X,N) interface attempts to resize a 2688** prior memory allocation X to be at least N bytes. 2689** ^If the X parameter to sqlite3_realloc(X,N) 2690** is a NULL pointer then its behavior is identical to calling 2691** sqlite3_malloc(N). 2692** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2693** negative then the behavior is exactly the same as calling 2694** sqlite3_free(X). 2695** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2696** of at least N bytes in size or NULL if insufficient memory is available. 2697** ^If M is the size of the prior allocation, then min(N,M) bytes 2698** of the prior allocation are copied into the beginning of buffer returned 2699** by sqlite3_realloc(X,N) and the prior allocation is freed. 2700** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2701** prior allocation is not freed. 2702** 2703** ^The sqlite3_realloc64(X,N) interfaces works the same as 2704** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2705** of a 32-bit signed integer. 2706** 2707** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2708** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2709** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2710** ^The value returned by sqlite3_msize(X) might be larger than the number 2711** of bytes requested when X was allocated. ^If X is a NULL pointer then 2712** sqlite3_msize(X) returns zero. If X points to something that is not 2713** the beginning of memory allocation, or if it points to a formerly 2714** valid memory allocation that has now been freed, then the behavior 2715** of sqlite3_msize(X) is undefined and possibly harmful. 2716** 2717** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2718** sqlite3_malloc64(), and sqlite3_realloc64() 2719** is always aligned to at least an 8 byte boundary, or to a 2720** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2721** option is used. 2722** 2723** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2724** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2725** implementation of these routines to be omitted. That capability 2726** is no longer provided. Only built-in memory allocators can be used. 2727** 2728** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2729** the system malloc() and free() directly when converting 2730** filenames between the UTF-8 encoding used by SQLite 2731** and whatever filename encoding is used by the particular Windows 2732** installation. Memory allocation errors were detected, but 2733** they were reported back as [SQLITE_CANTOPEN] or 2734** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2735** 2736** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2737** must be either NULL or else pointers obtained from a prior 2738** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2739** not yet been released. 2740** 2741** The application must not read or write any part of 2742** a block of memory after it has been released using 2743** [sqlite3_free()] or [sqlite3_realloc()]. 2744*/ 2745SQLITE_API void *sqlite3_malloc(int); 2746SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2747SQLITE_API void *sqlite3_realloc(void*, int); 2748SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2749SQLITE_API void sqlite3_free(void*); 2750SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2751 2752/* 2753** CAPI3REF: Memory Allocator Statistics 2754** 2755** SQLite provides these two interfaces for reporting on the status 2756** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2757** routines, which form the built-in memory allocation subsystem. 2758** 2759** ^The [sqlite3_memory_used()] routine returns the number of bytes 2760** of memory currently outstanding (malloced but not freed). 2761** ^The [sqlite3_memory_highwater()] routine returns the maximum 2762** value of [sqlite3_memory_used()] since the high-water mark 2763** was last reset. ^The values returned by [sqlite3_memory_used()] and 2764** [sqlite3_memory_highwater()] include any overhead 2765** added by SQLite in its implementation of [sqlite3_malloc()], 2766** but not overhead added by the any underlying system library 2767** routines that [sqlite3_malloc()] may call. 2768** 2769** ^The memory high-water mark is reset to the current value of 2770** [sqlite3_memory_used()] if and only if the parameter to 2771** [sqlite3_memory_highwater()] is true. ^The value returned 2772** by [sqlite3_memory_highwater(1)] is the high-water mark 2773** prior to the reset. 2774*/ 2775SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2776SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2777 2778/* 2779** CAPI3REF: Pseudo-Random Number Generator 2780** 2781** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2782** select random [ROWID | ROWIDs] when inserting new records into a table that 2783** already uses the largest possible [ROWID]. The PRNG is also used for 2784** the build-in random() and randomblob() SQL functions. This interface allows 2785** applications to access the same PRNG for other purposes. 2786** 2787** ^A call to this routine stores N bytes of randomness into buffer P. 2788** ^The P parameter can be a NULL pointer. 2789** 2790** ^If this routine has not been previously called or if the previous 2791** call had N less than one or a NULL pointer for P, then the PRNG is 2792** seeded using randomness obtained from the xRandomness method of 2793** the default [sqlite3_vfs] object. 2794** ^If the previous call to this routine had an N of 1 or more and a 2795** non-NULL P then the pseudo-randomness is generated 2796** internally and without recourse to the [sqlite3_vfs] xRandomness 2797** method. 2798*/ 2799SQLITE_API void sqlite3_randomness(int N, void *P); 2800 2801/* 2802** CAPI3REF: Compile-Time Authorization Callbacks 2803** METHOD: sqlite3 2804** KEYWORDS: {authorizer callback} 2805** 2806** ^This routine registers an authorizer callback with a particular 2807** [database connection], supplied in the first argument. 2808** ^The authorizer callback is invoked as SQL statements are being compiled 2809** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2810** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2811** and [sqlite3_prepare16_v3()]. ^At various 2812** points during the compilation process, as logic is being created 2813** to perform various actions, the authorizer callback is invoked to 2814** see if those actions are allowed. ^The authorizer callback should 2815** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2816** specific action but allow the SQL statement to continue to be 2817** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2818** rejected with an error. ^If the authorizer callback returns 2819** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2820** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2821** the authorizer will fail with an error message. 2822** 2823** When the callback returns [SQLITE_OK], that means the operation 2824** requested is ok. ^When the callback returns [SQLITE_DENY], the 2825** [sqlite3_prepare_v2()] or equivalent call that triggered the 2826** authorizer will fail with an error message explaining that 2827** access is denied. 2828** 2829** ^The first parameter to the authorizer callback is a copy of the third 2830** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2831** to the callback is an integer [SQLITE_COPY | action code] that specifies 2832** the particular action to be authorized. ^The third through sixth parameters 2833** to the callback are either NULL pointers or zero-terminated strings 2834** that contain additional details about the action to be authorized. 2835** Applications must always be prepared to encounter a NULL pointer in any 2836** of the third through the sixth parameters of the authorization callback. 2837** 2838** ^If the action code is [SQLITE_READ] 2839** and the callback returns [SQLITE_IGNORE] then the 2840** [prepared statement] statement is constructed to substitute 2841** a NULL value in place of the table column that would have 2842** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2843** return can be used to deny an untrusted user access to individual 2844** columns of a table. 2845** ^When a table is referenced by a [SELECT] but no column values are 2846** extracted from that table (for example in a query like 2847** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2848** is invoked once for that table with a column name that is an empty string. 2849** ^If the action code is [SQLITE_DELETE] and the callback returns 2850** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2851** [truncate optimization] is disabled and all rows are deleted individually. 2852** 2853** An authorizer is used when [sqlite3_prepare | preparing] 2854** SQL statements from an untrusted source, to ensure that the SQL statements 2855** do not try to access data they are not allowed to see, or that they do not 2856** try to execute malicious statements that damage the database. For 2857** example, an application may allow a user to enter arbitrary 2858** SQL queries for evaluation by a database. But the application does 2859** not want the user to be able to make arbitrary changes to the 2860** database. An authorizer could then be put in place while the 2861** user-entered SQL is being [sqlite3_prepare | prepared] that 2862** disallows everything except [SELECT] statements. 2863** 2864** Applications that need to process SQL from untrusted sources 2865** might also consider lowering resource limits using [sqlite3_limit()] 2866** and limiting database size using the [max_page_count] [PRAGMA] 2867** in addition to using an authorizer. 2868** 2869** ^(Only a single authorizer can be in place on a database connection 2870** at a time. Each call to sqlite3_set_authorizer overrides the 2871** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2872** The authorizer is disabled by default. 2873** 2874** The authorizer callback must not do anything that will modify 2875** the database connection that invoked the authorizer callback. 2876** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2877** database connections for the meaning of "modify" in this paragraph. 2878** 2879** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2880** statement might be re-prepared during [sqlite3_step()] due to a 2881** schema change. Hence, the application should ensure that the 2882** correct authorizer callback remains in place during the [sqlite3_step()]. 2883** 2884** ^Note that the authorizer callback is invoked only during 2885** [sqlite3_prepare()] or its variants. Authorization is not 2886** performed during statement evaluation in [sqlite3_step()], unless 2887** as stated in the previous paragraph, sqlite3_step() invokes 2888** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2889*/ 2890SQLITE_API int sqlite3_set_authorizer( 2891 sqlite3*, 2892 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2893 void *pUserData 2894); 2895 2896/* 2897** CAPI3REF: Authorizer Return Codes 2898** 2899** The [sqlite3_set_authorizer | authorizer callback function] must 2900** return either [SQLITE_OK] or one of these two constants in order 2901** to signal SQLite whether or not the action is permitted. See the 2902** [sqlite3_set_authorizer | authorizer documentation] for additional 2903** information. 2904** 2905** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2906** returned from the [sqlite3_vtab_on_conflict()] interface. 2907*/ 2908#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2909#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2910 2911/* 2912** CAPI3REF: Authorizer Action Codes 2913** 2914** The [sqlite3_set_authorizer()] interface registers a callback function 2915** that is invoked to authorize certain SQL statement actions. The 2916** second parameter to the callback is an integer code that specifies 2917** what action is being authorized. These are the integer action codes that 2918** the authorizer callback may be passed. 2919** 2920** These action code values signify what kind of operation is to be 2921** authorized. The 3rd and 4th parameters to the authorization 2922** callback function will be parameters or NULL depending on which of these 2923** codes is used as the second parameter. ^(The 5th parameter to the 2924** authorizer callback is the name of the database ("main", "temp", 2925** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2926** is the name of the inner-most trigger or view that is responsible for 2927** the access attempt or NULL if this access attempt is directly from 2928** top-level SQL code. 2929*/ 2930/******************************************* 3rd ************ 4th ***********/ 2931#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2932#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2933#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2934#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2935#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2936#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2937#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2938#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2939#define SQLITE_DELETE 9 /* Table Name NULL */ 2940#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2941#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2942#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2943#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2944#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2945#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2946#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2947#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2948#define SQLITE_INSERT 18 /* Table Name NULL */ 2949#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2950#define SQLITE_READ 20 /* Table Name Column Name */ 2951#define SQLITE_SELECT 21 /* NULL NULL */ 2952#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2953#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2954#define SQLITE_ATTACH 24 /* Filename NULL */ 2955#define SQLITE_DETACH 25 /* Database Name NULL */ 2956#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2957#define SQLITE_REINDEX 27 /* Index Name NULL */ 2958#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2959#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2960#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2961#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2962#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2963#define SQLITE_COPY 0 /* No longer used */ 2964#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2965 2966/* 2967** CAPI3REF: Tracing And Profiling Functions 2968** METHOD: sqlite3 2969** 2970** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2971** instead of the routines described here. 2972** 2973** These routines register callback functions that can be used for 2974** tracing and profiling the execution of SQL statements. 2975** 2976** ^The callback function registered by sqlite3_trace() is invoked at 2977** various times when an SQL statement is being run by [sqlite3_step()]. 2978** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2979** SQL statement text as the statement first begins executing. 2980** ^(Additional sqlite3_trace() callbacks might occur 2981** as each triggered subprogram is entered. The callbacks for triggers 2982** contain a UTF-8 SQL comment that identifies the trigger.)^ 2983** 2984** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2985** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2986** 2987** ^The callback function registered by sqlite3_profile() is invoked 2988** as each SQL statement finishes. ^The profile callback contains 2989** the original statement text and an estimate of wall-clock time 2990** of how long that statement took to run. ^The profile callback 2991** time is in units of nanoseconds, however the current implementation 2992** is only capable of millisecond resolution so the six least significant 2993** digits in the time are meaningless. Future versions of SQLite 2994** might provide greater resolution on the profiler callback. The 2995** sqlite3_profile() function is considered experimental and is 2996** subject to change in future versions of SQLite. 2997*/ 2998SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2999 void(*xTrace)(void*,const char*), void*); 3000SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3001 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3002 3003/* 3004** CAPI3REF: SQL Trace Event Codes 3005** KEYWORDS: SQLITE_TRACE 3006** 3007** These constants identify classes of events that can be monitored 3008** using the [sqlite3_trace_v2()] tracing logic. The M argument 3009** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3010** the following constants. ^The first argument to the trace callback 3011** is one of the following constants. 3012** 3013** New tracing constants may be added in future releases. 3014** 3015** ^A trace callback has four arguments: xCallback(T,C,P,X). 3016** ^The T argument is one of the integer type codes above. 3017** ^The C argument is a copy of the context pointer passed in as the 3018** fourth argument to [sqlite3_trace_v2()]. 3019** The P and X arguments are pointers whose meanings depend on T. 3020** 3021** <dl> 3022** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3023** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3024** first begins running and possibly at other times during the 3025** execution of the prepared statement, such as at the start of each 3026** trigger subprogram. ^The P argument is a pointer to the 3027** [prepared statement]. ^The X argument is a pointer to a string which 3028** is the unexpanded SQL text of the prepared statement or an SQL comment 3029** that indicates the invocation of a trigger. ^The callback can compute 3030** the same text that would have been returned by the legacy [sqlite3_trace()] 3031** interface by using the X argument when X begins with "--" and invoking 3032** [sqlite3_expanded_sql(P)] otherwise. 3033** 3034** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3035** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3036** information as is provided by the [sqlite3_profile()] callback. 3037** ^The P argument is a pointer to the [prepared statement] and the 3038** X argument points to a 64-bit integer which is the estimated of 3039** the number of nanosecond that the prepared statement took to run. 3040** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3041** 3042** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3043** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3044** statement generates a single row of result. 3045** ^The P argument is a pointer to the [prepared statement] and the 3046** X argument is unused. 3047** 3048** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3049** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3050** connection closes. 3051** ^The P argument is a pointer to the [database connection] object 3052** and the X argument is unused. 3053** </dl> 3054*/ 3055#define SQLITE_TRACE_STMT 0x01 3056#define SQLITE_TRACE_PROFILE 0x02 3057#define SQLITE_TRACE_ROW 0x04 3058#define SQLITE_TRACE_CLOSE 0x08 3059 3060/* 3061** CAPI3REF: SQL Trace Hook 3062** METHOD: sqlite3 3063** 3064** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3065** function X against [database connection] D, using property mask M 3066** and context pointer P. ^If the X callback is 3067** NULL or if the M mask is zero, then tracing is disabled. The 3068** M argument should be the bitwise OR-ed combination of 3069** zero or more [SQLITE_TRACE] constants. 3070** 3071** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3072** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3073** 3074** ^The X callback is invoked whenever any of the events identified by 3075** mask M occur. ^The integer return value from the callback is currently 3076** ignored, though this may change in future releases. Callback 3077** implementations should return zero to ensure future compatibility. 3078** 3079** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3080** ^The T argument is one of the [SQLITE_TRACE] 3081** constants to indicate why the callback was invoked. 3082** ^The C argument is a copy of the context pointer. 3083** The P and X arguments are pointers whose meanings depend on T. 3084** 3085** The sqlite3_trace_v2() interface is intended to replace the legacy 3086** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3087** are deprecated. 3088*/ 3089SQLITE_API int sqlite3_trace_v2( 3090 sqlite3*, 3091 unsigned uMask, 3092 int(*xCallback)(unsigned,void*,void*,void*), 3093 void *pCtx 3094); 3095 3096/* 3097** CAPI3REF: Query Progress Callbacks 3098** METHOD: sqlite3 3099** 3100** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3101** function X to be invoked periodically during long running calls to 3102** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3103** database connection D. An example use for this 3104** interface is to keep a GUI updated during a large query. 3105** 3106** ^The parameter P is passed through as the only parameter to the 3107** callback function X. ^The parameter N is the approximate number of 3108** [virtual machine instructions] that are evaluated between successive 3109** invocations of the callback X. ^If N is less than one then the progress 3110** handler is disabled. 3111** 3112** ^Only a single progress handler may be defined at one time per 3113** [database connection]; setting a new progress handler cancels the 3114** old one. ^Setting parameter X to NULL disables the progress handler. 3115** ^The progress handler is also disabled by setting N to a value less 3116** than 1. 3117** 3118** ^If the progress callback returns non-zero, the operation is 3119** interrupted. This feature can be used to implement a 3120** "Cancel" button on a GUI progress dialog box. 3121** 3122** The progress handler callback must not do anything that will modify 3123** the database connection that invoked the progress handler. 3124** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3125** database connections for the meaning of "modify" in this paragraph. 3126** 3127*/ 3128SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3129 3130/* 3131** CAPI3REF: Opening A New Database Connection 3132** CONSTRUCTOR: sqlite3 3133** 3134** ^These routines open an SQLite database file as specified by the 3135** filename argument. ^The filename argument is interpreted as UTF-8 for 3136** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3137** order for sqlite3_open16(). ^(A [database connection] handle is usually 3138** returned in *ppDb, even if an error occurs. The only exception is that 3139** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3140** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3141** object.)^ ^(If the database is opened (and/or created) successfully, then 3142** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3143** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3144** an English language description of the error following a failure of any 3145** of the sqlite3_open() routines. 3146** 3147** ^The default encoding will be UTF-8 for databases created using 3148** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3149** created using sqlite3_open16() will be UTF-16 in the native byte order. 3150** 3151** Whether or not an error occurs when it is opened, resources 3152** associated with the [database connection] handle should be released by 3153** passing it to [sqlite3_close()] when it is no longer required. 3154** 3155** The sqlite3_open_v2() interface works like sqlite3_open() 3156** except that it accepts two additional parameters for additional control 3157** over the new database connection. ^(The flags parameter to 3158** sqlite3_open_v2() can take one of 3159** the following three values, optionally combined with the 3160** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3161** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3162** 3163** <dl> 3164** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3165** <dd>The database is opened in read-only mode. If the database does not 3166** already exist, an error is returned.</dd>)^ 3167** 3168** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3169** <dd>The database is opened for reading and writing if possible, or reading 3170** only if the file is write protected by the operating system. In either 3171** case the database must already exist, otherwise an error is returned.</dd>)^ 3172** 3173** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3174** <dd>The database is opened for reading and writing, and is created if 3175** it does not already exist. This is the behavior that is always used for 3176** sqlite3_open() and sqlite3_open16().</dd>)^ 3177** </dl> 3178** 3179** If the 3rd parameter to sqlite3_open_v2() is not one of the 3180** combinations shown above optionally combined with other 3181** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3182** then the behavior is undefined. 3183** 3184** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3185** opens in the multi-thread [threading mode] as long as the single-thread 3186** mode has not been set at compile-time or start-time. ^If the 3187** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3188** in the serialized [threading mode] unless single-thread was 3189** previously selected at compile-time or start-time. 3190** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3191** eligible to use [shared cache mode], regardless of whether or not shared 3192** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3193** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3194** participate in [shared cache mode] even if it is enabled. 3195** 3196** ^The fourth parameter to sqlite3_open_v2() is the name of the 3197** [sqlite3_vfs] object that defines the operating system interface that 3198** the new database connection should use. ^If the fourth parameter is 3199** a NULL pointer then the default [sqlite3_vfs] object is used. 3200** 3201** ^If the filename is ":memory:", then a private, temporary in-memory database 3202** is created for the connection. ^This in-memory database will vanish when 3203** the database connection is closed. Future versions of SQLite might 3204** make use of additional special filenames that begin with the ":" character. 3205** It is recommended that when a database filename actually does begin with 3206** a ":" character you should prefix the filename with a pathname such as 3207** "./" to avoid ambiguity. 3208** 3209** ^If the filename is an empty string, then a private, temporary 3210** on-disk database will be created. ^This private database will be 3211** automatically deleted as soon as the database connection is closed. 3212** 3213** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3214** 3215** ^If [URI filename] interpretation is enabled, and the filename argument 3216** begins with "file:", then the filename is interpreted as a URI. ^URI 3217** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3218** set in the third argument to sqlite3_open_v2(), or if it has 3219** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3220** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3221** URI filename interpretation is turned off 3222** by default, but future releases of SQLite might enable URI filename 3223** interpretation by default. See "[URI filenames]" for additional 3224** information. 3225** 3226** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3227** authority, then it must be either an empty string or the string 3228** "localhost". ^If the authority is not an empty string or "localhost", an 3229** error is returned to the caller. ^The fragment component of a URI, if 3230** present, is ignored. 3231** 3232** ^SQLite uses the path component of the URI as the name of the disk file 3233** which contains the database. ^If the path begins with a '/' character, 3234** then it is interpreted as an absolute path. ^If the path does not begin 3235** with a '/' (meaning that the authority section is omitted from the URI) 3236** then the path is interpreted as a relative path. 3237** ^(On windows, the first component of an absolute path 3238** is a drive specification (e.g. "C:").)^ 3239** 3240** [[core URI query parameters]] 3241** The query component of a URI may contain parameters that are interpreted 3242** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3243** SQLite and its built-in [VFSes] interpret the 3244** following query parameters: 3245** 3246** <ul> 3247** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3248** a VFS object that provides the operating system interface that should 3249** be used to access the database file on disk. ^If this option is set to 3250** an empty string the default VFS object is used. ^Specifying an unknown 3251** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3252** present, then the VFS specified by the option takes precedence over 3253** the value passed as the fourth parameter to sqlite3_open_v2(). 3254** 3255** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3256** "rwc", or "memory". Attempting to set it to any other value is 3257** an error)^. 3258** ^If "ro" is specified, then the database is opened for read-only 3259** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3260** third argument to sqlite3_open_v2(). ^If the mode option is set to 3261** "rw", then the database is opened for read-write (but not create) 3262** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3263** been set. ^Value "rwc" is equivalent to setting both 3264** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3265** set to "memory" then a pure [in-memory database] that never reads 3266** or writes from disk is used. ^It is an error to specify a value for 3267** the mode parameter that is less restrictive than that specified by 3268** the flags passed in the third parameter to sqlite3_open_v2(). 3269** 3270** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3271** "private". ^Setting it to "shared" is equivalent to setting the 3272** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3273** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3274** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3275** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3276** a URI filename, its value overrides any behavior requested by setting 3277** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3278** 3279** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3280** [powersafe overwrite] property does or does not apply to the 3281** storage media on which the database file resides. 3282** 3283** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3284** which if set disables file locking in rollback journal modes. This 3285** is useful for accessing a database on a filesystem that does not 3286** support locking. Caution: Database corruption might result if two 3287** or more processes write to the same database and any one of those 3288** processes uses nolock=1. 3289** 3290** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3291** parameter that indicates that the database file is stored on 3292** read-only media. ^When immutable is set, SQLite assumes that the 3293** database file cannot be changed, even by a process with higher 3294** privilege, and so the database is opened read-only and all locking 3295** and change detection is disabled. Caution: Setting the immutable 3296** property on a database file that does in fact change can result 3297** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3298** See also: [SQLITE_IOCAP_IMMUTABLE]. 3299** 3300** </ul> 3301** 3302** ^Specifying an unknown parameter in the query component of a URI is not an 3303** error. Future versions of SQLite might understand additional query 3304** parameters. See "[query parameters with special meaning to SQLite]" for 3305** additional information. 3306** 3307** [[URI filename examples]] <h3>URI filename examples</h3> 3308** 3309** <table border="1" align=center cellpadding=5> 3310** <tr><th> URI filenames <th> Results 3311** <tr><td> file:data.db <td> 3312** Open the file "data.db" in the current directory. 3313** <tr><td> file:/home/fred/data.db<br> 3314** file:///home/fred/data.db <br> 3315** file://localhost/home/fred/data.db <br> <td> 3316** Open the database file "/home/fred/data.db". 3317** <tr><td> file://darkstar/home/fred/data.db <td> 3318** An error. "darkstar" is not a recognized authority. 3319** <tr><td style="white-space:nowrap"> 3320** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3321** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3322** C:. Note that the %20 escaping in this example is not strictly 3323** necessary - space characters can be used literally 3324** in URI filenames. 3325** <tr><td> file:data.db?mode=ro&cache=private <td> 3326** Open file "data.db" in the current directory for read-only access. 3327** Regardless of whether or not shared-cache mode is enabled by 3328** default, use a private cache. 3329** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3330** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3331** that uses dot-files in place of posix advisory locking. 3332** <tr><td> file:data.db?mode=readonly <td> 3333** An error. "readonly" is not a valid option for the "mode" parameter. 3334** </table> 3335** 3336** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3337** query components of a URI. A hexadecimal escape sequence consists of a 3338** percent sign - "%" - followed by exactly two hexadecimal digits 3339** specifying an octet value. ^Before the path or query components of a 3340** URI filename are interpreted, they are encoded using UTF-8 and all 3341** hexadecimal escape sequences replaced by a single byte containing the 3342** corresponding octet. If this process generates an invalid UTF-8 encoding, 3343** the results are undefined. 3344** 3345** <b>Note to Windows users:</b> The encoding used for the filename argument 3346** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3347** codepage is currently defined. Filenames containing international 3348** characters must be converted to UTF-8 prior to passing them into 3349** sqlite3_open() or sqlite3_open_v2(). 3350** 3351** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3352** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3353** features that require the use of temporary files may fail. 3354** 3355** See also: [sqlite3_temp_directory] 3356*/ 3357SQLITE_API int sqlite3_open( 3358 const char *filename, /* Database filename (UTF-8) */ 3359 sqlite3 **ppDb /* OUT: SQLite db handle */ 3360); 3361SQLITE_API int sqlite3_open16( 3362 const void *filename, /* Database filename (UTF-16) */ 3363 sqlite3 **ppDb /* OUT: SQLite db handle */ 3364); 3365SQLITE_API int sqlite3_open_v2( 3366 const char *filename, /* Database filename (UTF-8) */ 3367 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3368 int flags, /* Flags */ 3369 const char *zVfs /* Name of VFS module to use */ 3370); 3371 3372/* 3373** CAPI3REF: Obtain Values For URI Parameters 3374** 3375** These are utility routines, useful to VFS implementations, that check 3376** to see if a database file was a URI that contained a specific query 3377** parameter, and if so obtains the value of that query parameter. 3378** 3379** If F is the database filename pointer passed into the xOpen() method of 3380** a VFS implementation when the flags parameter to xOpen() has one or 3381** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3382** P is the name of the query parameter, then 3383** sqlite3_uri_parameter(F,P) returns the value of the P 3384** parameter if it exists or a NULL pointer if P does not appear as a 3385** query parameter on F. If P is a query parameter of F 3386** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3387** a pointer to an empty string. 3388** 3389** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3390** parameter and returns true (1) or false (0) according to the value 3391** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3392** value of query parameter P is one of "yes", "true", or "on" in any 3393** case or if the value begins with a non-zero number. The 3394** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3395** query parameter P is one of "no", "false", or "off" in any case or 3396** if the value begins with a numeric zero. If P is not a query 3397** parameter on F or if the value of P is does not match any of the 3398** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3399** 3400** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3401** 64-bit signed integer and returns that integer, or D if P does not 3402** exist. If the value of P is something other than an integer, then 3403** zero is returned. 3404** 3405** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3406** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3407** is not a database file pathname pointer that SQLite passed into the xOpen 3408** VFS method, then the behavior of this routine is undefined and probably 3409** undesirable. 3410*/ 3411SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3412SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3413SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3414 3415 3416/* 3417** CAPI3REF: Error Codes And Messages 3418** METHOD: sqlite3 3419** 3420** ^If the most recent sqlite3_* API call associated with 3421** [database connection] D failed, then the sqlite3_errcode(D) interface 3422** returns the numeric [result code] or [extended result code] for that 3423** API call. 3424** ^The sqlite3_extended_errcode() 3425** interface is the same except that it always returns the 3426** [extended result code] even when extended result codes are 3427** disabled. 3428** 3429** The values returned by sqlite3_errcode() and/or 3430** sqlite3_extended_errcode() might change with each API call. 3431** Except, there are some interfaces that are guaranteed to never 3432** change the value of the error code. The error-code preserving 3433** interfaces are: 3434** 3435** <ul> 3436** <li> sqlite3_errcode() 3437** <li> sqlite3_extended_errcode() 3438** <li> sqlite3_errmsg() 3439** <li> sqlite3_errmsg16() 3440** </ul> 3441** 3442** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3443** text that describes the error, as either UTF-8 or UTF-16 respectively. 3444** ^(Memory to hold the error message string is managed internally. 3445** The application does not need to worry about freeing the result. 3446** However, the error string might be overwritten or deallocated by 3447** subsequent calls to other SQLite interface functions.)^ 3448** 3449** ^The sqlite3_errstr() interface returns the English-language text 3450** that describes the [result code], as UTF-8. 3451** ^(Memory to hold the error message string is managed internally 3452** and must not be freed by the application)^. 3453** 3454** When the serialized [threading mode] is in use, it might be the 3455** case that a second error occurs on a separate thread in between 3456** the time of the first error and the call to these interfaces. 3457** When that happens, the second error will be reported since these 3458** interfaces always report the most recent result. To avoid 3459** this, each thread can obtain exclusive use of the [database connection] D 3460** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3461** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3462** all calls to the interfaces listed here are completed. 3463** 3464** If an interface fails with SQLITE_MISUSE, that means the interface 3465** was invoked incorrectly by the application. In that case, the 3466** error code and message may or may not be set. 3467*/ 3468SQLITE_API int sqlite3_errcode(sqlite3 *db); 3469SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3470SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3471SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3472SQLITE_API const char *sqlite3_errstr(int); 3473 3474/* 3475** CAPI3REF: Prepared Statement Object 3476** KEYWORDS: {prepared statement} {prepared statements} 3477** 3478** An instance of this object represents a single SQL statement that 3479** has been compiled into binary form and is ready to be evaluated. 3480** 3481** Think of each SQL statement as a separate computer program. The 3482** original SQL text is source code. A prepared statement object 3483** is the compiled object code. All SQL must be converted into a 3484** prepared statement before it can be run. 3485** 3486** The life-cycle of a prepared statement object usually goes like this: 3487** 3488** <ol> 3489** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3490** <li> Bind values to [parameters] using the sqlite3_bind_*() 3491** interfaces. 3492** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3493** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3494** to step 2. Do this zero or more times. 3495** <li> Destroy the object using [sqlite3_finalize()]. 3496** </ol> 3497*/ 3498typedef struct sqlite3_stmt sqlite3_stmt; 3499 3500/* 3501** CAPI3REF: Run-time Limits 3502** METHOD: sqlite3 3503** 3504** ^(This interface allows the size of various constructs to be limited 3505** on a connection by connection basis. The first parameter is the 3506** [database connection] whose limit is to be set or queried. The 3507** second parameter is one of the [limit categories] that define a 3508** class of constructs to be size limited. The third parameter is the 3509** new limit for that construct.)^ 3510** 3511** ^If the new limit is a negative number, the limit is unchanged. 3512** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3513** [limits | hard upper bound] 3514** set at compile-time by a C preprocessor macro called 3515** [limits | SQLITE_MAX_<i>NAME</i>]. 3516** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3517** ^Attempts to increase a limit above its hard upper bound are 3518** silently truncated to the hard upper bound. 3519** 3520** ^Regardless of whether or not the limit was changed, the 3521** [sqlite3_limit()] interface returns the prior value of the limit. 3522** ^Hence, to find the current value of a limit without changing it, 3523** simply invoke this interface with the third parameter set to -1. 3524** 3525** Run-time limits are intended for use in applications that manage 3526** both their own internal database and also databases that are controlled 3527** by untrusted external sources. An example application might be a 3528** web browser that has its own databases for storing history and 3529** separate databases controlled by JavaScript applications downloaded 3530** off the Internet. The internal databases can be given the 3531** large, default limits. Databases managed by external sources can 3532** be given much smaller limits designed to prevent a denial of service 3533** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3534** interface to further control untrusted SQL. The size of the database 3535** created by an untrusted script can be contained using the 3536** [max_page_count] [PRAGMA]. 3537** 3538** New run-time limit categories may be added in future releases. 3539*/ 3540SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3541 3542/* 3543** CAPI3REF: Run-Time Limit Categories 3544** KEYWORDS: {limit category} {*limit categories} 3545** 3546** These constants define various performance limits 3547** that can be lowered at run-time using [sqlite3_limit()]. 3548** The synopsis of the meanings of the various limits is shown below. 3549** Additional information is available at [limits | Limits in SQLite]. 3550** 3551** <dl> 3552** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3553** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3554** 3555** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3556** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3557** 3558** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3559** <dd>The maximum number of columns in a table definition or in the 3560** result set of a [SELECT] or the maximum number of columns in an index 3561** or in an ORDER BY or GROUP BY clause.</dd>)^ 3562** 3563** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3564** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3565** 3566** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3567** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3568** 3569** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3570** <dd>The maximum number of instructions in a virtual machine program 3571** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3572** the equivalent tries to allocate space for more than this many opcodes 3573** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3574** 3575** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3576** <dd>The maximum number of arguments on a function.</dd>)^ 3577** 3578** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3579** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3580** 3581** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3582** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3583** <dd>The maximum length of the pattern argument to the [LIKE] or 3584** [GLOB] operators.</dd>)^ 3585** 3586** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3587** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3588** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3589** 3590** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3591** <dd>The maximum depth of recursion for triggers.</dd>)^ 3592** 3593** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3594** <dd>The maximum number of auxiliary worker threads that a single 3595** [prepared statement] may start.</dd>)^ 3596** </dl> 3597*/ 3598#define SQLITE_LIMIT_LENGTH 0 3599#define SQLITE_LIMIT_SQL_LENGTH 1 3600#define SQLITE_LIMIT_COLUMN 2 3601#define SQLITE_LIMIT_EXPR_DEPTH 3 3602#define SQLITE_LIMIT_COMPOUND_SELECT 4 3603#define SQLITE_LIMIT_VDBE_OP 5 3604#define SQLITE_LIMIT_FUNCTION_ARG 6 3605#define SQLITE_LIMIT_ATTACHED 7 3606#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3607#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3608#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3609#define SQLITE_LIMIT_WORKER_THREADS 11 3610 3611/* 3612** CAPI3REF: Prepare Flags 3613** 3614** These constants define various flags that can be passed into 3615** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3616** [sqlite3_prepare16_v3()] interfaces. 3617** 3618** New flags may be added in future releases of SQLite. 3619** 3620** <dl> 3621** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3622** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3623** that the prepared statement will be retained for a long time and 3624** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3625** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3626** be used just once or at most a few times and then destroyed using 3627** [sqlite3_finalize()] relatively soon. The current implementation acts 3628** on this hint by avoiding the use of [lookaside memory] so as not to 3629** deplete the limited store of lookaside memory. Future versions of 3630** SQLite may act on this hint differently. 3631** 3632** [[SQLITE_PREPARE_NORMALIZE]] ^(<dt>SQLITE_PREPARE_NORMALIZE</dt> 3633** <dd>The SQLITE_PREPARE_NORMALIZE flag indicates that a normalized 3634** representation of the SQL statement should be calculated and then 3635** associated with the prepared statement, which can be obtained via 3636** the [sqlite3_normalized_sql()] interface.)^ The semantics used to 3637** normalize a SQL statement are unspecified and subject to change. 3638** At a minimum, literal values will be replaced with suitable 3639** placeholders. 3640** </dl> 3641*/ 3642#define SQLITE_PREPARE_PERSISTENT 0x01 3643#define SQLITE_PREPARE_NORMALIZE 0x02 3644 3645/* 3646** CAPI3REF: Compiling An SQL Statement 3647** KEYWORDS: {SQL statement compiler} 3648** METHOD: sqlite3 3649** CONSTRUCTOR: sqlite3_stmt 3650** 3651** To execute an SQL statement, it must first be compiled into a byte-code 3652** program using one of these routines. Or, in other words, these routines 3653** are constructors for the [prepared statement] object. 3654** 3655** The preferred routine to use is [sqlite3_prepare_v2()]. The 3656** [sqlite3_prepare()] interface is legacy and should be avoided. 3657** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3658** for special purposes. 3659** 3660** The use of the UTF-8 interfaces is preferred, as SQLite currently 3661** does all parsing using UTF-8. The UTF-16 interfaces are provided 3662** as a convenience. The UTF-16 interfaces work by converting the 3663** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3664** 3665** The first argument, "db", is a [database connection] obtained from a 3666** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3667** [sqlite3_open16()]. The database connection must not have been closed. 3668** 3669** The second argument, "zSql", is the statement to be compiled, encoded 3670** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3671** and sqlite3_prepare_v3() 3672** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3673** and sqlite3_prepare16_v3() use UTF-16. 3674** 3675** ^If the nByte argument is negative, then zSql is read up to the 3676** first zero terminator. ^If nByte is positive, then it is the 3677** number of bytes read from zSql. ^If nByte is zero, then no prepared 3678** statement is generated. 3679** If the caller knows that the supplied string is nul-terminated, then 3680** there is a small performance advantage to passing an nByte parameter that 3681** is the number of bytes in the input string <i>including</i> 3682** the nul-terminator. 3683** 3684** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3685** past the end of the first SQL statement in zSql. These routines only 3686** compile the first statement in zSql, so *pzTail is left pointing to 3687** what remains uncompiled. 3688** 3689** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3690** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3691** to NULL. ^If the input text contains no SQL (if the input is an empty 3692** string or a comment) then *ppStmt is set to NULL. 3693** The calling procedure is responsible for deleting the compiled 3694** SQL statement using [sqlite3_finalize()] after it has finished with it. 3695** ppStmt may not be NULL. 3696** 3697** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3698** otherwise an [error code] is returned. 3699** 3700** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3701** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3702** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3703** are retained for backwards compatibility, but their use is discouraged. 3704** ^In the "vX" interfaces, the prepared statement 3705** that is returned (the [sqlite3_stmt] object) contains a copy of the 3706** original SQL text. This causes the [sqlite3_step()] interface to 3707** behave differently in three ways: 3708** 3709** <ol> 3710** <li> 3711** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3712** always used to do, [sqlite3_step()] will automatically recompile the SQL 3713** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3714** retries will occur before sqlite3_step() gives up and returns an error. 3715** </li> 3716** 3717** <li> 3718** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3719** [error codes] or [extended error codes]. ^The legacy behavior was that 3720** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3721** and the application would have to make a second call to [sqlite3_reset()] 3722** in order to find the underlying cause of the problem. With the "v2" prepare 3723** interfaces, the underlying reason for the error is returned immediately. 3724** </li> 3725** 3726** <li> 3727** ^If the specific value bound to [parameter | host parameter] in the 3728** WHERE clause might influence the choice of query plan for a statement, 3729** then the statement will be automatically recompiled, as if there had been 3730** a schema change, on the first [sqlite3_step()] call following any change 3731** to the [sqlite3_bind_text | bindings] of that [parameter]. 3732** ^The specific value of WHERE-clause [parameter] might influence the 3733** choice of query plan if the parameter is the left-hand side of a [LIKE] 3734** or [GLOB] operator or if the parameter is compared to an indexed column 3735** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3736** </li> 3737** </ol> 3738** 3739** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3740** the extra prepFlags parameter, which is a bit array consisting of zero or 3741** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3742** sqlite3_prepare_v2() interface works exactly the same as 3743** sqlite3_prepare_v3() with a zero prepFlags parameter. 3744*/ 3745SQLITE_API int sqlite3_prepare( 3746 sqlite3 *db, /* Database handle */ 3747 const char *zSql, /* SQL statement, UTF-8 encoded */ 3748 int nByte, /* Maximum length of zSql in bytes. */ 3749 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3750 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3751); 3752SQLITE_API int sqlite3_prepare_v2( 3753 sqlite3 *db, /* Database handle */ 3754 const char *zSql, /* SQL statement, UTF-8 encoded */ 3755 int nByte, /* Maximum length of zSql in bytes. */ 3756 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3757 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3758); 3759SQLITE_API int sqlite3_prepare_v3( 3760 sqlite3 *db, /* Database handle */ 3761 const char *zSql, /* SQL statement, UTF-8 encoded */ 3762 int nByte, /* Maximum length of zSql in bytes. */ 3763 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3764 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3765 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3766); 3767SQLITE_API int sqlite3_prepare16( 3768 sqlite3 *db, /* Database handle */ 3769 const void *zSql, /* SQL statement, UTF-16 encoded */ 3770 int nByte, /* Maximum length of zSql in bytes. */ 3771 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3772 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3773); 3774SQLITE_API int sqlite3_prepare16_v2( 3775 sqlite3 *db, /* Database handle */ 3776 const void *zSql, /* SQL statement, UTF-16 encoded */ 3777 int nByte, /* Maximum length of zSql in bytes. */ 3778 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3779 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3780); 3781SQLITE_API int sqlite3_prepare16_v3( 3782 sqlite3 *db, /* Database handle */ 3783 const void *zSql, /* SQL statement, UTF-16 encoded */ 3784 int nByte, /* Maximum length of zSql in bytes. */ 3785 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3786 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3787 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3788); 3789 3790/* 3791** CAPI3REF: Retrieving Statement SQL 3792** METHOD: sqlite3_stmt 3793** 3794** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3795** SQL text used to create [prepared statement] P if P was 3796** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3797** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3798** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3799** string containing the SQL text of prepared statement P with 3800** [bound parameters] expanded. 3801** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3802** string containing the normalized SQL text of prepared statement P. The 3803** semantics used to normalize a SQL statement are unspecified and subject 3804** to change. At a minimum, literal values will be replaced with suitable 3805** placeholders. 3806** 3807** ^(For example, if a prepared statement is created using the SQL 3808** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3809** and parameter :xyz is unbound, then sqlite3_sql() will return 3810** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3811** will return "SELECT 2345,NULL".)^ 3812** 3813** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3814** is available to hold the result, or if the result would exceed the 3815** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3816** 3817** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3818** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3819** option causes sqlite3_expanded_sql() to always return NULL. 3820** 3821** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3822** are managed by SQLite and are automatically freed when the prepared 3823** statement is finalized. 3824** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3825** is obtained from [sqlite3_malloc()] and must be free by the application 3826** by passing it to [sqlite3_free()]. 3827*/ 3828SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3829SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3830SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3831 3832/* 3833** CAPI3REF: Determine If An SQL Statement Writes The Database 3834** METHOD: sqlite3_stmt 3835** 3836** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3837** and only if the [prepared statement] X makes no direct changes to 3838** the content of the database file. 3839** 3840** Note that [application-defined SQL functions] or 3841** [virtual tables] might change the database indirectly as a side effect. 3842** ^(For example, if an application defines a function "eval()" that 3843** calls [sqlite3_exec()], then the following SQL statement would 3844** change the database file through side-effects: 3845** 3846** <blockquote><pre> 3847** SELECT eval('DELETE FROM t1') FROM t2; 3848** </pre></blockquote> 3849** 3850** But because the [SELECT] statement does not change the database file 3851** directly, sqlite3_stmt_readonly() would still return true.)^ 3852** 3853** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3854** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3855** since the statements themselves do not actually modify the database but 3856** rather they control the timing of when other statements modify the 3857** database. ^The [ATTACH] and [DETACH] statements also cause 3858** sqlite3_stmt_readonly() to return true since, while those statements 3859** change the configuration of a database connection, they do not make 3860** changes to the content of the database files on disk. 3861** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3862** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3863** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3864** sqlite3_stmt_readonly() returns false for those commands. 3865*/ 3866SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3867 3868/* 3869** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3870** METHOD: sqlite3_stmt 3871** 3872** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3873** [prepared statement] S has been stepped at least once using 3874** [sqlite3_step(S)] but has neither run to completion (returned 3875** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3876** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3877** interface returns false if S is a NULL pointer. If S is not a 3878** NULL pointer and is not a pointer to a valid [prepared statement] 3879** object, then the behavior is undefined and probably undesirable. 3880** 3881** This interface can be used in combination [sqlite3_next_stmt()] 3882** to locate all prepared statements associated with a database 3883** connection that are in need of being reset. This can be used, 3884** for example, in diagnostic routines to search for prepared 3885** statements that are holding a transaction open. 3886*/ 3887SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3888 3889/* 3890** CAPI3REF: Dynamically Typed Value Object 3891** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3892** 3893** SQLite uses the sqlite3_value object to represent all values 3894** that can be stored in a database table. SQLite uses dynamic typing 3895** for the values it stores. ^Values stored in sqlite3_value objects 3896** can be integers, floating point values, strings, BLOBs, or NULL. 3897** 3898** An sqlite3_value object may be either "protected" or "unprotected". 3899** Some interfaces require a protected sqlite3_value. Other interfaces 3900** will accept either a protected or an unprotected sqlite3_value. 3901** Every interface that accepts sqlite3_value arguments specifies 3902** whether or not it requires a protected sqlite3_value. The 3903** [sqlite3_value_dup()] interface can be used to construct a new 3904** protected sqlite3_value from an unprotected sqlite3_value. 3905** 3906** The terms "protected" and "unprotected" refer to whether or not 3907** a mutex is held. An internal mutex is held for a protected 3908** sqlite3_value object but no mutex is held for an unprotected 3909** sqlite3_value object. If SQLite is compiled to be single-threaded 3910** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3911** or if SQLite is run in one of reduced mutex modes 3912** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3913** then there is no distinction between protected and unprotected 3914** sqlite3_value objects and they can be used interchangeably. However, 3915** for maximum code portability it is recommended that applications 3916** still make the distinction between protected and unprotected 3917** sqlite3_value objects even when not strictly required. 3918** 3919** ^The sqlite3_value objects that are passed as parameters into the 3920** implementation of [application-defined SQL functions] are protected. 3921** ^The sqlite3_value object returned by 3922** [sqlite3_column_value()] is unprotected. 3923** Unprotected sqlite3_value objects may only be used as arguments 3924** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3925** [sqlite3_value_dup()]. 3926** The [sqlite3_value_blob | sqlite3_value_type()] family of 3927** interfaces require protected sqlite3_value objects. 3928*/ 3929typedef struct sqlite3_value sqlite3_value; 3930 3931/* 3932** CAPI3REF: SQL Function Context Object 3933** 3934** The context in which an SQL function executes is stored in an 3935** sqlite3_context object. ^A pointer to an sqlite3_context object 3936** is always first parameter to [application-defined SQL functions]. 3937** The application-defined SQL function implementation will pass this 3938** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3939** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3940** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3941** and/or [sqlite3_set_auxdata()]. 3942*/ 3943typedef struct sqlite3_context sqlite3_context; 3944 3945/* 3946** CAPI3REF: Binding Values To Prepared Statements 3947** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3948** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3949** METHOD: sqlite3_stmt 3950** 3951** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3952** literals may be replaced by a [parameter] that matches one of following 3953** templates: 3954** 3955** <ul> 3956** <li> ? 3957** <li> ?NNN 3958** <li> :VVV 3959** <li> @VVV 3960** <li> $VVV 3961** </ul> 3962** 3963** In the templates above, NNN represents an integer literal, 3964** and VVV represents an alphanumeric identifier.)^ ^The values of these 3965** parameters (also called "host parameter names" or "SQL parameters") 3966** can be set using the sqlite3_bind_*() routines defined here. 3967** 3968** ^The first argument to the sqlite3_bind_*() routines is always 3969** a pointer to the [sqlite3_stmt] object returned from 3970** [sqlite3_prepare_v2()] or its variants. 3971** 3972** ^The second argument is the index of the SQL parameter to be set. 3973** ^The leftmost SQL parameter has an index of 1. ^When the same named 3974** SQL parameter is used more than once, second and subsequent 3975** occurrences have the same index as the first occurrence. 3976** ^The index for named parameters can be looked up using the 3977** [sqlite3_bind_parameter_index()] API if desired. ^The index 3978** for "?NNN" parameters is the value of NNN. 3979** ^The NNN value must be between 1 and the [sqlite3_limit()] 3980** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3981** 3982** ^The third argument is the value to bind to the parameter. 3983** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3984** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3985** is ignored and the end result is the same as sqlite3_bind_null(). 3986** 3987** ^(In those routines that have a fourth argument, its value is the 3988** number of bytes in the parameter. To be clear: the value is the 3989** number of <u>bytes</u> in the value, not the number of characters.)^ 3990** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3991** is negative, then the length of the string is 3992** the number of bytes up to the first zero terminator. 3993** If the fourth parameter to sqlite3_bind_blob() is negative, then 3994** the behavior is undefined. 3995** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3996** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3997** that parameter must be the byte offset 3998** where the NUL terminator would occur assuming the string were NUL 3999** terminated. If any NUL characters occur at byte offsets less than 4000** the value of the fourth parameter then the resulting string value will 4001** contain embedded NULs. The result of expressions involving strings 4002** with embedded NULs is undefined. 4003** 4004** ^The fifth argument to the BLOB and string binding interfaces 4005** is a destructor used to dispose of the BLOB or 4006** string after SQLite has finished with it. ^The destructor is called 4007** to dispose of the BLOB or string even if the call to bind API fails. 4008** ^If the fifth argument is 4009** the special value [SQLITE_STATIC], then SQLite assumes that the 4010** information is in static, unmanaged space and does not need to be freed. 4011** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4012** SQLite makes its own private copy of the data immediately, before 4013** the sqlite3_bind_*() routine returns. 4014** 4015** ^The sixth argument to sqlite3_bind_text64() must be one of 4016** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4017** to specify the encoding of the text in the third parameter. If 4018** the sixth argument to sqlite3_bind_text64() is not one of the 4019** allowed values shown above, or if the text encoding is different 4020** from the encoding specified by the sixth parameter, then the behavior 4021** is undefined. 4022** 4023** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4024** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4025** (just an integer to hold its size) while it is being processed. 4026** Zeroblobs are intended to serve as placeholders for BLOBs whose 4027** content is later written using 4028** [sqlite3_blob_open | incremental BLOB I/O] routines. 4029** ^A negative value for the zeroblob results in a zero-length BLOB. 4030** 4031** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4032** [prepared statement] S to have an SQL value of NULL, but to also be 4033** associated with the pointer P of type T. ^D is either a NULL pointer or 4034** a pointer to a destructor function for P. ^SQLite will invoke the 4035** destructor D with a single argument of P when it is finished using 4036** P. The T parameter should be a static string, preferably a string 4037** literal. The sqlite3_bind_pointer() routine is part of the 4038** [pointer passing interface] added for SQLite 3.20.0. 4039** 4040** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4041** for the [prepared statement] or with a prepared statement for which 4042** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4043** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4044** routine is passed a [prepared statement] that has been finalized, the 4045** result is undefined and probably harmful. 4046** 4047** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4048** ^Unbound parameters are interpreted as NULL. 4049** 4050** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4051** [error code] if anything goes wrong. 4052** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4053** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4054** [SQLITE_MAX_LENGTH]. 4055** ^[SQLITE_RANGE] is returned if the parameter 4056** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4057** 4058** See also: [sqlite3_bind_parameter_count()], 4059** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4060*/ 4061SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4062SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4063 void(*)(void*)); 4064SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4065SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4066SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4067SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4068SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4069SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4070SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4071 void(*)(void*), unsigned char encoding); 4072SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4073SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4074SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4075SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4076 4077/* 4078** CAPI3REF: Number Of SQL Parameters 4079** METHOD: sqlite3_stmt 4080** 4081** ^This routine can be used to find the number of [SQL parameters] 4082** in a [prepared statement]. SQL parameters are tokens of the 4083** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4084** placeholders for values that are [sqlite3_bind_blob | bound] 4085** to the parameters at a later time. 4086** 4087** ^(This routine actually returns the index of the largest (rightmost) 4088** parameter. For all forms except ?NNN, this will correspond to the 4089** number of unique parameters. If parameters of the ?NNN form are used, 4090** there may be gaps in the list.)^ 4091** 4092** See also: [sqlite3_bind_blob|sqlite3_bind()], 4093** [sqlite3_bind_parameter_name()], and 4094** [sqlite3_bind_parameter_index()]. 4095*/ 4096SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4097 4098/* 4099** CAPI3REF: Name Of A Host Parameter 4100** METHOD: sqlite3_stmt 4101** 4102** ^The sqlite3_bind_parameter_name(P,N) interface returns 4103** the name of the N-th [SQL parameter] in the [prepared statement] P. 4104** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4105** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4106** respectively. 4107** In other words, the initial ":" or "$" or "@" or "?" 4108** is included as part of the name.)^ 4109** ^Parameters of the form "?" without a following integer have no name 4110** and are referred to as "nameless" or "anonymous parameters". 4111** 4112** ^The first host parameter has an index of 1, not 0. 4113** 4114** ^If the value N is out of range or if the N-th parameter is 4115** nameless, then NULL is returned. ^The returned string is 4116** always in UTF-8 encoding even if the named parameter was 4117** originally specified as UTF-16 in [sqlite3_prepare16()], 4118** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4119** 4120** See also: [sqlite3_bind_blob|sqlite3_bind()], 4121** [sqlite3_bind_parameter_count()], and 4122** [sqlite3_bind_parameter_index()]. 4123*/ 4124SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4125 4126/* 4127** CAPI3REF: Index Of A Parameter With A Given Name 4128** METHOD: sqlite3_stmt 4129** 4130** ^Return the index of an SQL parameter given its name. ^The 4131** index value returned is suitable for use as the second 4132** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4133** is returned if no matching parameter is found. ^The parameter 4134** name must be given in UTF-8 even if the original statement 4135** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4136** [sqlite3_prepare16_v3()]. 4137** 4138** See also: [sqlite3_bind_blob|sqlite3_bind()], 4139** [sqlite3_bind_parameter_count()], and 4140** [sqlite3_bind_parameter_name()]. 4141*/ 4142SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4143 4144/* 4145** CAPI3REF: Reset All Bindings On A Prepared Statement 4146** METHOD: sqlite3_stmt 4147** 4148** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4149** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4150** ^Use this routine to reset all host parameters to NULL. 4151*/ 4152SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4153 4154/* 4155** CAPI3REF: Number Of Columns In A Result Set 4156** METHOD: sqlite3_stmt 4157** 4158** ^Return the number of columns in the result set returned by the 4159** [prepared statement]. ^If this routine returns 0, that means the 4160** [prepared statement] returns no data (for example an [UPDATE]). 4161** ^However, just because this routine returns a positive number does not 4162** mean that one or more rows of data will be returned. ^A SELECT statement 4163** will always have a positive sqlite3_column_count() but depending on the 4164** WHERE clause constraints and the table content, it might return no rows. 4165** 4166** See also: [sqlite3_data_count()] 4167*/ 4168SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4169 4170/* 4171** CAPI3REF: Column Names In A Result Set 4172** METHOD: sqlite3_stmt 4173** 4174** ^These routines return the name assigned to a particular column 4175** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4176** interface returns a pointer to a zero-terminated UTF-8 string 4177** and sqlite3_column_name16() returns a pointer to a zero-terminated 4178** UTF-16 string. ^The first parameter is the [prepared statement] 4179** that implements the [SELECT] statement. ^The second parameter is the 4180** column number. ^The leftmost column is number 0. 4181** 4182** ^The returned string pointer is valid until either the [prepared statement] 4183** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4184** reprepared by the first call to [sqlite3_step()] for a particular run 4185** or until the next call to 4186** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4187** 4188** ^If sqlite3_malloc() fails during the processing of either routine 4189** (for example during a conversion from UTF-8 to UTF-16) then a 4190** NULL pointer is returned. 4191** 4192** ^The name of a result column is the value of the "AS" clause for 4193** that column, if there is an AS clause. If there is no AS clause 4194** then the name of the column is unspecified and may change from 4195** one release of SQLite to the next. 4196*/ 4197SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4198SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4199 4200/* 4201** CAPI3REF: Source Of Data In A Query Result 4202** METHOD: sqlite3_stmt 4203** 4204** ^These routines provide a means to determine the database, table, and 4205** table column that is the origin of a particular result column in 4206** [SELECT] statement. 4207** ^The name of the database or table or column can be returned as 4208** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4209** the database name, the _table_ routines return the table name, and 4210** the origin_ routines return the column name. 4211** ^The returned string is valid until the [prepared statement] is destroyed 4212** using [sqlite3_finalize()] or until the statement is automatically 4213** reprepared by the first call to [sqlite3_step()] for a particular run 4214** or until the same information is requested 4215** again in a different encoding. 4216** 4217** ^The names returned are the original un-aliased names of the 4218** database, table, and column. 4219** 4220** ^The first argument to these interfaces is a [prepared statement]. 4221** ^These functions return information about the Nth result column returned by 4222** the statement, where N is the second function argument. 4223** ^The left-most column is column 0 for these routines. 4224** 4225** ^If the Nth column returned by the statement is an expression or 4226** subquery and is not a column value, then all of these functions return 4227** NULL. ^These routine might also return NULL if a memory allocation error 4228** occurs. ^Otherwise, they return the name of the attached database, table, 4229** or column that query result column was extracted from. 4230** 4231** ^As with all other SQLite APIs, those whose names end with "16" return 4232** UTF-16 encoded strings and the other functions return UTF-8. 4233** 4234** ^These APIs are only available if the library was compiled with the 4235** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4236** 4237** If two or more threads call one or more of these routines against the same 4238** prepared statement and column at the same time then the results are 4239** undefined. 4240** 4241** If two or more threads call one or more 4242** [sqlite3_column_database_name | column metadata interfaces] 4243** for the same [prepared statement] and result column 4244** at the same time then the results are undefined. 4245*/ 4246SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4247SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4248SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4249SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4250SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4251SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4252 4253/* 4254** CAPI3REF: Declared Datatype Of A Query Result 4255** METHOD: sqlite3_stmt 4256** 4257** ^(The first parameter is a [prepared statement]. 4258** If this statement is a [SELECT] statement and the Nth column of the 4259** returned result set of that [SELECT] is a table column (not an 4260** expression or subquery) then the declared type of the table 4261** column is returned.)^ ^If the Nth column of the result set is an 4262** expression or subquery, then a NULL pointer is returned. 4263** ^The returned string is always UTF-8 encoded. 4264** 4265** ^(For example, given the database schema: 4266** 4267** CREATE TABLE t1(c1 VARIANT); 4268** 4269** and the following statement to be compiled: 4270** 4271** SELECT c1 + 1, c1 FROM t1; 4272** 4273** this routine would return the string "VARIANT" for the second result 4274** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4275** 4276** ^SQLite uses dynamic run-time typing. ^So just because a column 4277** is declared to contain a particular type does not mean that the 4278** data stored in that column is of the declared type. SQLite is 4279** strongly typed, but the typing is dynamic not static. ^Type 4280** is associated with individual values, not with the containers 4281** used to hold those values. 4282*/ 4283SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4284SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4285 4286/* 4287** CAPI3REF: Evaluate An SQL Statement 4288** METHOD: sqlite3_stmt 4289** 4290** After a [prepared statement] has been prepared using any of 4291** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4292** or [sqlite3_prepare16_v3()] or one of the legacy 4293** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4294** must be called one or more times to evaluate the statement. 4295** 4296** The details of the behavior of the sqlite3_step() interface depend 4297** on whether the statement was prepared using the newer "vX" interfaces 4298** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4299** [sqlite3_prepare16_v2()] or the older legacy 4300** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4301** new "vX" interface is recommended for new applications but the legacy 4302** interface will continue to be supported. 4303** 4304** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4305** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4306** ^With the "v2" interface, any of the other [result codes] or 4307** [extended result codes] might be returned as well. 4308** 4309** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4310** database locks it needs to do its job. ^If the statement is a [COMMIT] 4311** or occurs outside of an explicit transaction, then you can retry the 4312** statement. If the statement is not a [COMMIT] and occurs within an 4313** explicit transaction then you should rollback the transaction before 4314** continuing. 4315** 4316** ^[SQLITE_DONE] means that the statement has finished executing 4317** successfully. sqlite3_step() should not be called again on this virtual 4318** machine without first calling [sqlite3_reset()] to reset the virtual 4319** machine back to its initial state. 4320** 4321** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4322** is returned each time a new row of data is ready for processing by the 4323** caller. The values may be accessed using the [column access functions]. 4324** sqlite3_step() is called again to retrieve the next row of data. 4325** 4326** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4327** violation) has occurred. sqlite3_step() should not be called again on 4328** the VM. More information may be found by calling [sqlite3_errmsg()]. 4329** ^With the legacy interface, a more specific error code (for example, 4330** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4331** can be obtained by calling [sqlite3_reset()] on the 4332** [prepared statement]. ^In the "v2" interface, 4333** the more specific error code is returned directly by sqlite3_step(). 4334** 4335** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4336** Perhaps it was called on a [prepared statement] that has 4337** already been [sqlite3_finalize | finalized] or on one that had 4338** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4339** be the case that the same database connection is being used by two or 4340** more threads at the same moment in time. 4341** 4342** For all versions of SQLite up to and including 3.6.23.1, a call to 4343** [sqlite3_reset()] was required after sqlite3_step() returned anything 4344** other than [SQLITE_ROW] before any subsequent invocation of 4345** sqlite3_step(). Failure to reset the prepared statement using 4346** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4347** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4348** sqlite3_step() began 4349** calling [sqlite3_reset()] automatically in this circumstance rather 4350** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4351** break because any application that ever receives an SQLITE_MISUSE error 4352** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4353** can be used to restore the legacy behavior. 4354** 4355** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4356** API always returns a generic error code, [SQLITE_ERROR], following any 4357** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4358** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4359** specific [error codes] that better describes the error. 4360** We admit that this is a goofy design. The problem has been fixed 4361** with the "v2" interface. If you prepare all of your SQL statements 4362** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4363** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4364** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4365** then the more specific [error codes] are returned directly 4366** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4367*/ 4368SQLITE_API int sqlite3_step(sqlite3_stmt*); 4369 4370/* 4371** CAPI3REF: Number of columns in a result set 4372** METHOD: sqlite3_stmt 4373** 4374** ^The sqlite3_data_count(P) interface returns the number of columns in the 4375** current row of the result set of [prepared statement] P. 4376** ^If prepared statement P does not have results ready to return 4377** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4378** interfaces) then sqlite3_data_count(P) returns 0. 4379** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4380** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4381** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4382** will return non-zero if previous call to [sqlite3_step](P) returned 4383** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4384** where it always returns zero since each step of that multi-step 4385** pragma returns 0 columns of data. 4386** 4387** See also: [sqlite3_column_count()] 4388*/ 4389SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4390 4391/* 4392** CAPI3REF: Fundamental Datatypes 4393** KEYWORDS: SQLITE_TEXT 4394** 4395** ^(Every value in SQLite has one of five fundamental datatypes: 4396** 4397** <ul> 4398** <li> 64-bit signed integer 4399** <li> 64-bit IEEE floating point number 4400** <li> string 4401** <li> BLOB 4402** <li> NULL 4403** </ul>)^ 4404** 4405** These constants are codes for each of those types. 4406** 4407** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4408** for a completely different meaning. Software that links against both 4409** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4410** SQLITE_TEXT. 4411*/ 4412#define SQLITE_INTEGER 1 4413#define SQLITE_FLOAT 2 4414#define SQLITE_BLOB 4 4415#define SQLITE_NULL 5 4416#ifdef SQLITE_TEXT 4417# undef SQLITE_TEXT 4418#else 4419# define SQLITE_TEXT 3 4420#endif 4421#define SQLITE3_TEXT 3 4422 4423/* 4424** CAPI3REF: Result Values From A Query 4425** KEYWORDS: {column access functions} 4426** METHOD: sqlite3_stmt 4427** 4428** <b>Summary:</b> 4429** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4430** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4431** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4432** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4433** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4434** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4435** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4436** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4437** [sqlite3_value|unprotected sqlite3_value] object. 4438** <tr><td> <td> <td> 4439** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4440** or a UTF-8 TEXT result in bytes 4441** <tr><td><b>sqlite3_column_bytes16 </b> 4442** <td>→ <td>Size of UTF-16 4443** TEXT in bytes 4444** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4445** datatype of the result 4446** </table></blockquote> 4447** 4448** <b>Details:</b> 4449** 4450** ^These routines return information about a single column of the current 4451** result row of a query. ^In every case the first argument is a pointer 4452** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4453** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4454** and the second argument is the index of the column for which information 4455** should be returned. ^The leftmost column of the result set has the index 0. 4456** ^The number of columns in the result can be determined using 4457** [sqlite3_column_count()]. 4458** 4459** If the SQL statement does not currently point to a valid row, or if the 4460** column index is out of range, the result is undefined. 4461** These routines may only be called when the most recent call to 4462** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4463** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4464** If any of these routines are called after [sqlite3_reset()] or 4465** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4466** something other than [SQLITE_ROW], the results are undefined. 4467** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4468** are called from a different thread while any of these routines 4469** are pending, then the results are undefined. 4470** 4471** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4472** each return the value of a result column in a specific data format. If 4473** the result column is not initially in the requested format (for example, 4474** if the query returns an integer but the sqlite3_column_text() interface 4475** is used to extract the value) then an automatic type conversion is performed. 4476** 4477** ^The sqlite3_column_type() routine returns the 4478** [SQLITE_INTEGER | datatype code] for the initial data type 4479** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4480** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4481** The return value of sqlite3_column_type() can be used to decide which 4482** of the first six interface should be used to extract the column value. 4483** The value returned by sqlite3_column_type() is only meaningful if no 4484** automatic type conversions have occurred for the value in question. 4485** After a type conversion, the result of calling sqlite3_column_type() 4486** is undefined, though harmless. Future 4487** versions of SQLite may change the behavior of sqlite3_column_type() 4488** following a type conversion. 4489** 4490** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4491** or sqlite3_column_bytes16() interfaces can be used to determine the size 4492** of that BLOB or string. 4493** 4494** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4495** routine returns the number of bytes in that BLOB or string. 4496** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4497** the string to UTF-8 and then returns the number of bytes. 4498** ^If the result is a numeric value then sqlite3_column_bytes() uses 4499** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4500** the number of bytes in that string. 4501** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4502** 4503** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4504** routine returns the number of bytes in that BLOB or string. 4505** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4506** the string to UTF-16 and then returns the number of bytes. 4507** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4508** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4509** the number of bytes in that string. 4510** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4511** 4512** ^The values returned by [sqlite3_column_bytes()] and 4513** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4514** of the string. ^For clarity: the values returned by 4515** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4516** bytes in the string, not the number of characters. 4517** 4518** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4519** even empty strings, are always zero-terminated. ^The return 4520** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4521** 4522** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4523** [unprotected sqlite3_value] object. In a multithreaded environment, 4524** an unprotected sqlite3_value object may only be used safely with 4525** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4526** If the [unprotected sqlite3_value] object returned by 4527** [sqlite3_column_value()] is used in any other way, including calls 4528** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4529** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4530** Hence, the sqlite3_column_value() interface 4531** is normally only useful within the implementation of 4532** [application-defined SQL functions] or [virtual tables], not within 4533** top-level application code. 4534** 4535** The these routines may attempt to convert the datatype of the result. 4536** ^For example, if the internal representation is FLOAT and a text result 4537** is requested, [sqlite3_snprintf()] is used internally to perform the 4538** conversion automatically. ^(The following table details the conversions 4539** that are applied: 4540** 4541** <blockquote> 4542** <table border="1"> 4543** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4544** 4545** <tr><td> NULL <td> INTEGER <td> Result is 0 4546** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4547** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4548** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4549** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4550** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4551** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4552** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4553** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4554** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4555** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4556** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4557** <tr><td> TEXT <td> BLOB <td> No change 4558** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4559** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4560** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4561** </table> 4562** </blockquote>)^ 4563** 4564** Note that when type conversions occur, pointers returned by prior 4565** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4566** sqlite3_column_text16() may be invalidated. 4567** Type conversions and pointer invalidations might occur 4568** in the following cases: 4569** 4570** <ul> 4571** <li> The initial content is a BLOB and sqlite3_column_text() or 4572** sqlite3_column_text16() is called. A zero-terminator might 4573** need to be added to the string.</li> 4574** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4575** sqlite3_column_text16() is called. The content must be converted 4576** to UTF-16.</li> 4577** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4578** sqlite3_column_text() is called. The content must be converted 4579** to UTF-8.</li> 4580** </ul> 4581** 4582** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4583** not invalidate a prior pointer, though of course the content of the buffer 4584** that the prior pointer references will have been modified. Other kinds 4585** of conversion are done in place when it is possible, but sometimes they 4586** are not possible and in those cases prior pointers are invalidated. 4587** 4588** The safest policy is to invoke these routines 4589** in one of the following ways: 4590** 4591** <ul> 4592** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4593** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4594** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4595** </ul> 4596** 4597** In other words, you should call sqlite3_column_text(), 4598** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4599** into the desired format, then invoke sqlite3_column_bytes() or 4600** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4601** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4602** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4603** with calls to sqlite3_column_bytes(). 4604** 4605** ^The pointers returned are valid until a type conversion occurs as 4606** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4607** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4608** and BLOBs is freed automatically. Do not pass the pointers returned 4609** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4610** [sqlite3_free()]. 4611** 4612** As long as the input parameters are correct, these routines will only 4613** fail if an out-of-memory error occurs during a format conversion. 4614** Only the following subset of interfaces are subject to out-of-memory 4615** errors: 4616** 4617** <ul> 4618** <li> sqlite3_column_blob() 4619** <li> sqlite3_column_text() 4620** <li> sqlite3_column_text16() 4621** <li> sqlite3_column_bytes() 4622** <li> sqlite3_column_bytes16() 4623** </ul> 4624** 4625** If an out-of-memory error occurs, then the return value from these 4626** routines is the same as if the column had contained an SQL NULL value. 4627** Valid SQL NULL returns can be distinguished from out-of-memory errors 4628** by invoking the [sqlite3_errcode()] immediately after the suspect 4629** return value is obtained and before any 4630** other SQLite interface is called on the same [database connection]. 4631*/ 4632SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4633SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4634SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4635SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4636SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4637SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4638SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4639SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4640SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4641SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4642 4643/* 4644** CAPI3REF: Destroy A Prepared Statement Object 4645** DESTRUCTOR: sqlite3_stmt 4646** 4647** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4648** ^If the most recent evaluation of the statement encountered no errors 4649** or if the statement is never been evaluated, then sqlite3_finalize() returns 4650** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4651** sqlite3_finalize(S) returns the appropriate [error code] or 4652** [extended error code]. 4653** 4654** ^The sqlite3_finalize(S) routine can be called at any point during 4655** the life cycle of [prepared statement] S: 4656** before statement S is ever evaluated, after 4657** one or more calls to [sqlite3_reset()], or after any call 4658** to [sqlite3_step()] regardless of whether or not the statement has 4659** completed execution. 4660** 4661** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4662** 4663** The application must finalize every [prepared statement] in order to avoid 4664** resource leaks. It is a grievous error for the application to try to use 4665** a prepared statement after it has been finalized. Any use of a prepared 4666** statement after it has been finalized can result in undefined and 4667** undesirable behavior such as segfaults and heap corruption. 4668*/ 4669SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4670 4671/* 4672** CAPI3REF: Reset A Prepared Statement Object 4673** METHOD: sqlite3_stmt 4674** 4675** The sqlite3_reset() function is called to reset a [prepared statement] 4676** object back to its initial state, ready to be re-executed. 4677** ^Any SQL statement variables that had values bound to them using 4678** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4679** Use [sqlite3_clear_bindings()] to reset the bindings. 4680** 4681** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4682** back to the beginning of its program. 4683** 4684** ^If the most recent call to [sqlite3_step(S)] for the 4685** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4686** or if [sqlite3_step(S)] has never before been called on S, 4687** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4688** 4689** ^If the most recent call to [sqlite3_step(S)] for the 4690** [prepared statement] S indicated an error, then 4691** [sqlite3_reset(S)] returns an appropriate [error code]. 4692** 4693** ^The [sqlite3_reset(S)] interface does not change the values 4694** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4695*/ 4696SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4697 4698/* 4699** CAPI3REF: Create Or Redefine SQL Functions 4700** KEYWORDS: {function creation routines} 4701** KEYWORDS: {application-defined SQL function} 4702** KEYWORDS: {application-defined SQL functions} 4703** METHOD: sqlite3 4704** 4705** ^These functions (collectively known as "function creation routines") 4706** are used to add SQL functions or aggregates or to redefine the behavior 4707** of existing SQL functions or aggregates. The only differences between 4708** the three "sqlite3_create_function*" routines are the text encoding 4709** expected for the second parameter (the name of the function being 4710** created) and the presence or absence of a destructor callback for 4711** the application data pointer. Function sqlite3_create_window_function() 4712** is similar, but allows the user to supply the extra callback functions 4713** needed by [aggregate window functions]. 4714** 4715** ^The first parameter is the [database connection] to which the SQL 4716** function is to be added. ^If an application uses more than one database 4717** connection then application-defined SQL functions must be added 4718** to each database connection separately. 4719** 4720** ^The second parameter is the name of the SQL function to be created or 4721** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4722** representation, exclusive of the zero-terminator. ^Note that the name 4723** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4724** ^Any attempt to create a function with a longer name 4725** will result in [SQLITE_MISUSE] being returned. 4726** 4727** ^The third parameter (nArg) 4728** is the number of arguments that the SQL function or 4729** aggregate takes. ^If this parameter is -1, then the SQL function or 4730** aggregate may take any number of arguments between 0 and the limit 4731** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4732** parameter is less than -1 or greater than 127 then the behavior is 4733** undefined. 4734** 4735** ^The fourth parameter, eTextRep, specifies what 4736** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4737** its parameters. The application should set this parameter to 4738** [SQLITE_UTF16LE] if the function implementation invokes 4739** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4740** implementation invokes [sqlite3_value_text16be()] on an input, or 4741** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4742** otherwise. ^The same SQL function may be registered multiple times using 4743** different preferred text encodings, with different implementations for 4744** each encoding. 4745** ^When multiple implementations of the same function are available, SQLite 4746** will pick the one that involves the least amount of data conversion. 4747** 4748** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4749** to signal that the function will always return the same result given 4750** the same inputs within a single SQL statement. Most SQL functions are 4751** deterministic. The built-in [random()] SQL function is an example of a 4752** function that is not deterministic. The SQLite query planner is able to 4753** perform additional optimizations on deterministic functions, so use 4754** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4755** 4756** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4757** function can gain access to this pointer using [sqlite3_user_data()].)^ 4758** 4759** ^The sixth, seventh and eighth parameters passed to the three 4760** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4761** pointers to C-language functions that implement the SQL function or 4762** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4763** callback only; NULL pointers must be passed as the xStep and xFinal 4764** parameters. ^An aggregate SQL function requires an implementation of xStep 4765** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4766** SQL function or aggregate, pass NULL pointers for all three function 4767** callbacks. 4768** 4769** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4770** and xInverse) passed to sqlite3_create_window_function are pointers to 4771** C-language callbacks that implement the new function. xStep and xFinal 4772** must both be non-NULL. xValue and xInverse may either both be NULL, in 4773** which case a regular aggregate function is created, or must both be 4774** non-NULL, in which case the new function may be used as either an aggregate 4775** or aggregate window function. More details regarding the implementation 4776** of aggregate window functions are 4777** [user-defined window functions|available here]. 4778** 4779** ^(If the final parameter to sqlite3_create_function_v2() or 4780** sqlite3_create_window_function() is not NULL, then it is destructor for 4781** the application data pointer. The destructor is invoked when the function 4782** is deleted, either by being overloaded or when the database connection 4783** closes.)^ ^The destructor is also invoked if the call to 4784** sqlite3_create_function_v2() fails. ^When the destructor callback is 4785** invoked, it is passed a single argument which is a copy of the application 4786** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4787** 4788** ^It is permitted to register multiple implementations of the same 4789** functions with the same name but with either differing numbers of 4790** arguments or differing preferred text encodings. ^SQLite will use 4791** the implementation that most closely matches the way in which the 4792** SQL function is used. ^A function implementation with a non-negative 4793** nArg parameter is a better match than a function implementation with 4794** a negative nArg. ^A function where the preferred text encoding 4795** matches the database encoding is a better 4796** match than a function where the encoding is different. 4797** ^A function where the encoding difference is between UTF16le and UTF16be 4798** is a closer match than a function where the encoding difference is 4799** between UTF8 and UTF16. 4800** 4801** ^Built-in functions may be overloaded by new application-defined functions. 4802** 4803** ^An application-defined function is permitted to call other 4804** SQLite interfaces. However, such calls must not 4805** close the database connection nor finalize or reset the prepared 4806** statement in which the function is running. 4807*/ 4808SQLITE_API int sqlite3_create_function( 4809 sqlite3 *db, 4810 const char *zFunctionName, 4811 int nArg, 4812 int eTextRep, 4813 void *pApp, 4814 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4815 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4816 void (*xFinal)(sqlite3_context*) 4817); 4818SQLITE_API int sqlite3_create_function16( 4819 sqlite3 *db, 4820 const void *zFunctionName, 4821 int nArg, 4822 int eTextRep, 4823 void *pApp, 4824 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4825 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4826 void (*xFinal)(sqlite3_context*) 4827); 4828SQLITE_API int sqlite3_create_function_v2( 4829 sqlite3 *db, 4830 const char *zFunctionName, 4831 int nArg, 4832 int eTextRep, 4833 void *pApp, 4834 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4835 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4836 void (*xFinal)(sqlite3_context*), 4837 void(*xDestroy)(void*) 4838); 4839SQLITE_API int sqlite3_create_window_function( 4840 sqlite3 *db, 4841 const char *zFunctionName, 4842 int nArg, 4843 int eTextRep, 4844 void *pApp, 4845 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4846 void (*xFinal)(sqlite3_context*), 4847 void (*xValue)(sqlite3_context*), 4848 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4849 void(*xDestroy)(void*) 4850); 4851 4852/* 4853** CAPI3REF: Text Encodings 4854** 4855** These constant define integer codes that represent the various 4856** text encodings supported by SQLite. 4857*/ 4858#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4859#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4860#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4861#define SQLITE_UTF16 4 /* Use native byte order */ 4862#define SQLITE_ANY 5 /* Deprecated */ 4863#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4864 4865/* 4866** CAPI3REF: Function Flags 4867** 4868** These constants may be ORed together with the 4869** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4870** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4871** [sqlite3_create_function_v2()]. 4872*/ 4873#define SQLITE_DETERMINISTIC 0x800 4874 4875/* 4876** CAPI3REF: Deprecated Functions 4877** DEPRECATED 4878** 4879** These functions are [deprecated]. In order to maintain 4880** backwards compatibility with older code, these functions continue 4881** to be supported. However, new applications should avoid 4882** the use of these functions. To encourage programmers to avoid 4883** these functions, we will not explain what they do. 4884*/ 4885#ifndef SQLITE_OMIT_DEPRECATED 4886SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4887SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4888SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4889SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4890SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4891SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4892 void*,sqlite3_int64); 4893#endif 4894 4895/* 4896** CAPI3REF: Obtaining SQL Values 4897** METHOD: sqlite3_value 4898** 4899** <b>Summary:</b> 4900** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4901** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4902** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4903** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4904** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4905** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4906** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4907** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4908** the native byteorder 4909** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4910** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4911** <tr><td> <td> <td> 4912** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4913** or a UTF-8 TEXT in bytes 4914** <tr><td><b>sqlite3_value_bytes16 </b> 4915** <td>→ <td>Size of UTF-16 4916** TEXT in bytes 4917** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4918** datatype of the value 4919** <tr><td><b>sqlite3_value_numeric_type </b> 4920** <td>→ <td>Best numeric datatype of the value 4921** <tr><td><b>sqlite3_value_nochange </b> 4922** <td>→ <td>True if the column is unchanged in an UPDATE 4923** against a virtual table. 4924** </table></blockquote> 4925** 4926** <b>Details:</b> 4927** 4928** These routines extract type, size, and content information from 4929** [protected sqlite3_value] objects. Protected sqlite3_value objects 4930** are used to pass parameter information into implementation of 4931** [application-defined SQL functions] and [virtual tables]. 4932** 4933** These routines work only with [protected sqlite3_value] objects. 4934** Any attempt to use these routines on an [unprotected sqlite3_value] 4935** is not threadsafe. 4936** 4937** ^These routines work just like the corresponding [column access functions] 4938** except that these routines take a single [protected sqlite3_value] object 4939** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4940** 4941** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4942** in the native byte-order of the host machine. ^The 4943** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4944** extract UTF-16 strings as big-endian and little-endian respectively. 4945** 4946** ^If [sqlite3_value] object V was initialized 4947** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4948** and if X and Y are strings that compare equal according to strcmp(X,Y), 4949** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4950** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4951** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4952** 4953** ^(The sqlite3_value_type(V) interface returns the 4954** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4955** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4956** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4957** Other interfaces might change the datatype for an sqlite3_value object. 4958** For example, if the datatype is initially SQLITE_INTEGER and 4959** sqlite3_value_text(V) is called to extract a text value for that 4960** integer, then subsequent calls to sqlite3_value_type(V) might return 4961** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4962** occurs is undefined and may change from one release of SQLite to the next. 4963** 4964** ^(The sqlite3_value_numeric_type() interface attempts to apply 4965** numeric affinity to the value. This means that an attempt is 4966** made to convert the value to an integer or floating point. If 4967** such a conversion is possible without loss of information (in other 4968** words, if the value is a string that looks like a number) 4969** then the conversion is performed. Otherwise no conversion occurs. 4970** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4971** 4972** ^Within the [xUpdate] method of a [virtual table], the 4973** sqlite3_value_nochange(X) interface returns true if and only if 4974** the column corresponding to X is unchanged by the UPDATE operation 4975** that the xUpdate method call was invoked to implement and if 4976** and the prior [xColumn] method call that was invoked to extracted 4977** the value for that column returned without setting a result (probably 4978** because it queried [sqlite3_vtab_nochange()] and found that the column 4979** was unchanging). ^Within an [xUpdate] method, any value for which 4980** sqlite3_value_nochange(X) is true will in all other respects appear 4981** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4982** than within an [xUpdate] method call for an UPDATE statement, then 4983** the return value is arbitrary and meaningless. 4984** 4985** Please pay particular attention to the fact that the pointer returned 4986** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4987** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4988** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4989** or [sqlite3_value_text16()]. 4990** 4991** These routines must be called from the same thread as 4992** the SQL function that supplied the [sqlite3_value*] parameters. 4993** 4994** As long as the input parameter is correct, these routines can only 4995** fail if an out-of-memory error occurs during a format conversion. 4996** Only the following subset of interfaces are subject to out-of-memory 4997** errors: 4998** 4999** <ul> 5000** <li> sqlite3_value_blob() 5001** <li> sqlite3_value_text() 5002** <li> sqlite3_value_text16() 5003** <li> sqlite3_value_text16le() 5004** <li> sqlite3_value_text16be() 5005** <li> sqlite3_value_bytes() 5006** <li> sqlite3_value_bytes16() 5007** </ul> 5008** 5009** If an out-of-memory error occurs, then the return value from these 5010** routines is the same as if the column had contained an SQL NULL value. 5011** Valid SQL NULL returns can be distinguished from out-of-memory errors 5012** by invoking the [sqlite3_errcode()] immediately after the suspect 5013** return value is obtained and before any 5014** other SQLite interface is called on the same [database connection]. 5015*/ 5016SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5017SQLITE_API double sqlite3_value_double(sqlite3_value*); 5018SQLITE_API int sqlite3_value_int(sqlite3_value*); 5019SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5020SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5021SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5022SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5023SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5024SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5025SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5026SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5027SQLITE_API int sqlite3_value_type(sqlite3_value*); 5028SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5029SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5030 5031/* 5032** CAPI3REF: Finding The Subtype Of SQL Values 5033** METHOD: sqlite3_value 5034** 5035** The sqlite3_value_subtype(V) function returns the subtype for 5036** an [application-defined SQL function] argument V. The subtype 5037** information can be used to pass a limited amount of context from 5038** one SQL function to another. Use the [sqlite3_result_subtype()] 5039** routine to set the subtype for the return value of an SQL function. 5040*/ 5041SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5042 5043/* 5044** CAPI3REF: Copy And Free SQL Values 5045** METHOD: sqlite3_value 5046** 5047** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5048** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5049** is a [protected sqlite3_value] object even if the input is not. 5050** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5051** memory allocation fails. 5052** 5053** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5054** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5055** then sqlite3_value_free(V) is a harmless no-op. 5056*/ 5057SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5058SQLITE_API void sqlite3_value_free(sqlite3_value*); 5059 5060/* 5061** CAPI3REF: Obtain Aggregate Function Context 5062** METHOD: sqlite3_context 5063** 5064** Implementations of aggregate SQL functions use this 5065** routine to allocate memory for storing their state. 5066** 5067** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5068** for a particular aggregate function, SQLite 5069** allocates N of memory, zeroes out that memory, and returns a pointer 5070** to the new memory. ^On second and subsequent calls to 5071** sqlite3_aggregate_context() for the same aggregate function instance, 5072** the same buffer is returned. Sqlite3_aggregate_context() is normally 5073** called once for each invocation of the xStep callback and then one 5074** last time when the xFinal callback is invoked. ^(When no rows match 5075** an aggregate query, the xStep() callback of the aggregate function 5076** implementation is never called and xFinal() is called exactly once. 5077** In those cases, sqlite3_aggregate_context() might be called for the 5078** first time from within xFinal().)^ 5079** 5080** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5081** when first called if N is less than or equal to zero or if a memory 5082** allocate error occurs. 5083** 5084** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5085** determined by the N parameter on first successful call. Changing the 5086** value of N in subsequent call to sqlite3_aggregate_context() within 5087** the same aggregate function instance will not resize the memory 5088** allocation.)^ Within the xFinal callback, it is customary to set 5089** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5090** pointless memory allocations occur. 5091** 5092** ^SQLite automatically frees the memory allocated by 5093** sqlite3_aggregate_context() when the aggregate query concludes. 5094** 5095** The first parameter must be a copy of the 5096** [sqlite3_context | SQL function context] that is the first parameter 5097** to the xStep or xFinal callback routine that implements the aggregate 5098** function. 5099** 5100** This routine must be called from the same thread in which 5101** the aggregate SQL function is running. 5102*/ 5103SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5104 5105/* 5106** CAPI3REF: User Data For Functions 5107** METHOD: sqlite3_context 5108** 5109** ^The sqlite3_user_data() interface returns a copy of 5110** the pointer that was the pUserData parameter (the 5th parameter) 5111** of the [sqlite3_create_function()] 5112** and [sqlite3_create_function16()] routines that originally 5113** registered the application defined function. 5114** 5115** This routine must be called from the same thread in which 5116** the application-defined function is running. 5117*/ 5118SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5119 5120/* 5121** CAPI3REF: Database Connection For Functions 5122** METHOD: sqlite3_context 5123** 5124** ^The sqlite3_context_db_handle() interface returns a copy of 5125** the pointer to the [database connection] (the 1st parameter) 5126** of the [sqlite3_create_function()] 5127** and [sqlite3_create_function16()] routines that originally 5128** registered the application defined function. 5129*/ 5130SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5131 5132/* 5133** CAPI3REF: Function Auxiliary Data 5134** METHOD: sqlite3_context 5135** 5136** These functions may be used by (non-aggregate) SQL functions to 5137** associate metadata with argument values. If the same value is passed to 5138** multiple invocations of the same SQL function during query execution, under 5139** some circumstances the associated metadata may be preserved. An example 5140** of where this might be useful is in a regular-expression matching 5141** function. The compiled version of the regular expression can be stored as 5142** metadata associated with the pattern string. 5143** Then as long as the pattern string remains the same, 5144** the compiled regular expression can be reused on multiple 5145** invocations of the same function. 5146** 5147** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5148** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5149** value to the application-defined function. ^N is zero for the left-most 5150** function argument. ^If there is no metadata 5151** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5152** returns a NULL pointer. 5153** 5154** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5155** argument of the application-defined function. ^Subsequent 5156** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5157** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5158** NULL if the metadata has been discarded. 5159** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5160** SQLite will invoke the destructor function X with parameter P exactly 5161** once, when the metadata is discarded. 5162** SQLite is free to discard the metadata at any time, including: <ul> 5163** <li> ^(when the corresponding function parameter changes)^, or 5164** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5165** SQL statement)^, or 5166** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5167** parameter)^, or 5168** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5169** allocation error occurs.)^ </ul> 5170** 5171** Note the last bullet in particular. The destructor X in 5172** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5173** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5174** should be called near the end of the function implementation and the 5175** function implementation should not make any use of P after 5176** sqlite3_set_auxdata() has been called. 5177** 5178** ^(In practice, metadata is preserved between function calls for 5179** function parameters that are compile-time constants, including literal 5180** values and [parameters] and expressions composed from the same.)^ 5181** 5182** The value of the N parameter to these interfaces should be non-negative. 5183** Future enhancements may make use of negative N values to define new 5184** kinds of function caching behavior. 5185** 5186** These routines must be called from the same thread in which 5187** the SQL function is running. 5188*/ 5189SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5190SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5191 5192 5193/* 5194** CAPI3REF: Constants Defining Special Destructor Behavior 5195** 5196** These are special values for the destructor that is passed in as the 5197** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5198** argument is SQLITE_STATIC, it means that the content pointer is constant 5199** and will never change. It does not need to be destroyed. ^The 5200** SQLITE_TRANSIENT value means that the content will likely change in 5201** the near future and that SQLite should make its own private copy of 5202** the content before returning. 5203** 5204** The typedef is necessary to work around problems in certain 5205** C++ compilers. 5206*/ 5207typedef void (*sqlite3_destructor_type)(void*); 5208#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5209#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5210 5211/* 5212** CAPI3REF: Setting The Result Of An SQL Function 5213** METHOD: sqlite3_context 5214** 5215** These routines are used by the xFunc or xFinal callbacks that 5216** implement SQL functions and aggregates. See 5217** [sqlite3_create_function()] and [sqlite3_create_function16()] 5218** for additional information. 5219** 5220** These functions work very much like the [parameter binding] family of 5221** functions used to bind values to host parameters in prepared statements. 5222** Refer to the [SQL parameter] documentation for additional information. 5223** 5224** ^The sqlite3_result_blob() interface sets the result from 5225** an application-defined function to be the BLOB whose content is pointed 5226** to by the second parameter and which is N bytes long where N is the 5227** third parameter. 5228** 5229** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5230** interfaces set the result of the application-defined function to be 5231** a BLOB containing all zero bytes and N bytes in size. 5232** 5233** ^The sqlite3_result_double() interface sets the result from 5234** an application-defined function to be a floating point value specified 5235** by its 2nd argument. 5236** 5237** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5238** cause the implemented SQL function to throw an exception. 5239** ^SQLite uses the string pointed to by the 5240** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5241** as the text of an error message. ^SQLite interprets the error 5242** message string from sqlite3_result_error() as UTF-8. ^SQLite 5243** interprets the string from sqlite3_result_error16() as UTF-16 in native 5244** byte order. ^If the third parameter to sqlite3_result_error() 5245** or sqlite3_result_error16() is negative then SQLite takes as the error 5246** message all text up through the first zero character. 5247** ^If the third parameter to sqlite3_result_error() or 5248** sqlite3_result_error16() is non-negative then SQLite takes that many 5249** bytes (not characters) from the 2nd parameter as the error message. 5250** ^The sqlite3_result_error() and sqlite3_result_error16() 5251** routines make a private copy of the error message text before 5252** they return. Hence, the calling function can deallocate or 5253** modify the text after they return without harm. 5254** ^The sqlite3_result_error_code() function changes the error code 5255** returned by SQLite as a result of an error in a function. ^By default, 5256** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5257** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5258** 5259** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5260** error indicating that a string or BLOB is too long to represent. 5261** 5262** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5263** error indicating that a memory allocation failed. 5264** 5265** ^The sqlite3_result_int() interface sets the return value 5266** of the application-defined function to be the 32-bit signed integer 5267** value given in the 2nd argument. 5268** ^The sqlite3_result_int64() interface sets the return value 5269** of the application-defined function to be the 64-bit signed integer 5270** value given in the 2nd argument. 5271** 5272** ^The sqlite3_result_null() interface sets the return value 5273** of the application-defined function to be NULL. 5274** 5275** ^The sqlite3_result_text(), sqlite3_result_text16(), 5276** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5277** set the return value of the application-defined function to be 5278** a text string which is represented as UTF-8, UTF-16 native byte order, 5279** UTF-16 little endian, or UTF-16 big endian, respectively. 5280** ^The sqlite3_result_text64() interface sets the return value of an 5281** application-defined function to be a text string in an encoding 5282** specified by the fifth (and last) parameter, which must be one 5283** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5284** ^SQLite takes the text result from the application from 5285** the 2nd parameter of the sqlite3_result_text* interfaces. 5286** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5287** is negative, then SQLite takes result text from the 2nd parameter 5288** through the first zero character. 5289** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5290** is non-negative, then as many bytes (not characters) of the text 5291** pointed to by the 2nd parameter are taken as the application-defined 5292** function result. If the 3rd parameter is non-negative, then it 5293** must be the byte offset into the string where the NUL terminator would 5294** appear if the string where NUL terminated. If any NUL characters occur 5295** in the string at a byte offset that is less than the value of the 3rd 5296** parameter, then the resulting string will contain embedded NULs and the 5297** result of expressions operating on strings with embedded NULs is undefined. 5298** ^If the 4th parameter to the sqlite3_result_text* interfaces 5299** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5300** function as the destructor on the text or BLOB result when it has 5301** finished using that result. 5302** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5303** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5304** assumes that the text or BLOB result is in constant space and does not 5305** copy the content of the parameter nor call a destructor on the content 5306** when it has finished using that result. 5307** ^If the 4th parameter to the sqlite3_result_text* interfaces 5308** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5309** then SQLite makes a copy of the result into space obtained 5310** from [sqlite3_malloc()] before it returns. 5311** 5312** ^The sqlite3_result_value() interface sets the result of 5313** the application-defined function to be a copy of the 5314** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5315** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5316** so that the [sqlite3_value] specified in the parameter may change or 5317** be deallocated after sqlite3_result_value() returns without harm. 5318** ^A [protected sqlite3_value] object may always be used where an 5319** [unprotected sqlite3_value] object is required, so either 5320** kind of [sqlite3_value] object can be used with this interface. 5321** 5322** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5323** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5324** also associates the host-language pointer P or type T with that 5325** NULL value such that the pointer can be retrieved within an 5326** [application-defined SQL function] using [sqlite3_value_pointer()]. 5327** ^If the D parameter is not NULL, then it is a pointer to a destructor 5328** for the P parameter. ^SQLite invokes D with P as its only argument 5329** when SQLite is finished with P. The T parameter should be a static 5330** string and preferably a string literal. The sqlite3_result_pointer() 5331** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5332** 5333** If these routines are called from within the different thread 5334** than the one containing the application-defined function that received 5335** the [sqlite3_context] pointer, the results are undefined. 5336*/ 5337SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5338SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5339 sqlite3_uint64,void(*)(void*)); 5340SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5341SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5342SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5343SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5344SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5345SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5346SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5347SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5348SQLITE_API void sqlite3_result_null(sqlite3_context*); 5349SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5350SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5351 void(*)(void*), unsigned char encoding); 5352SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5353SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5354SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5355SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5356SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5357SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5358SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5359 5360 5361/* 5362** CAPI3REF: Setting The Subtype Of An SQL Function 5363** METHOD: sqlite3_context 5364** 5365** The sqlite3_result_subtype(C,T) function causes the subtype of 5366** the result from the [application-defined SQL function] with 5367** [sqlite3_context] C to be the value T. Only the lower 8 bits 5368** of the subtype T are preserved in current versions of SQLite; 5369** higher order bits are discarded. 5370** The number of subtype bytes preserved by SQLite might increase 5371** in future releases of SQLite. 5372*/ 5373SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5374 5375/* 5376** CAPI3REF: Define New Collating Sequences 5377** METHOD: sqlite3 5378** 5379** ^These functions add, remove, or modify a [collation] associated 5380** with the [database connection] specified as the first argument. 5381** 5382** ^The name of the collation is a UTF-8 string 5383** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5384** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5385** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5386** considered to be the same name. 5387** 5388** ^(The third argument (eTextRep) must be one of the constants: 5389** <ul> 5390** <li> [SQLITE_UTF8], 5391** <li> [SQLITE_UTF16LE], 5392** <li> [SQLITE_UTF16BE], 5393** <li> [SQLITE_UTF16], or 5394** <li> [SQLITE_UTF16_ALIGNED]. 5395** </ul>)^ 5396** ^The eTextRep argument determines the encoding of strings passed 5397** to the collating function callback, xCallback. 5398** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5399** force strings to be UTF16 with native byte order. 5400** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5401** on an even byte address. 5402** 5403** ^The fourth argument, pArg, is an application data pointer that is passed 5404** through as the first argument to the collating function callback. 5405** 5406** ^The fifth argument, xCallback, is a pointer to the collating function. 5407** ^Multiple collating functions can be registered using the same name but 5408** with different eTextRep parameters and SQLite will use whichever 5409** function requires the least amount of data transformation. 5410** ^If the xCallback argument is NULL then the collating function is 5411** deleted. ^When all collating functions having the same name are deleted, 5412** that collation is no longer usable. 5413** 5414** ^The collating function callback is invoked with a copy of the pArg 5415** application data pointer and with two strings in the encoding specified 5416** by the eTextRep argument. The collating function must return an 5417** integer that is negative, zero, or positive 5418** if the first string is less than, equal to, or greater than the second, 5419** respectively. A collating function must always return the same answer 5420** given the same inputs. If two or more collating functions are registered 5421** to the same collation name (using different eTextRep values) then all 5422** must give an equivalent answer when invoked with equivalent strings. 5423** The collating function must obey the following properties for all 5424** strings A, B, and C: 5425** 5426** <ol> 5427** <li> If A==B then B==A. 5428** <li> If A==B and B==C then A==C. 5429** <li> If A<B THEN B>A. 5430** <li> If A<B and B<C then A<C. 5431** </ol> 5432** 5433** If a collating function fails any of the above constraints and that 5434** collating function is registered and used, then the behavior of SQLite 5435** is undefined. 5436** 5437** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5438** with the addition that the xDestroy callback is invoked on pArg when 5439** the collating function is deleted. 5440** ^Collating functions are deleted when they are overridden by later 5441** calls to the collation creation functions or when the 5442** [database connection] is closed using [sqlite3_close()]. 5443** 5444** ^The xDestroy callback is <u>not</u> called if the 5445** sqlite3_create_collation_v2() function fails. Applications that invoke 5446** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5447** check the return code and dispose of the application data pointer 5448** themselves rather than expecting SQLite to deal with it for them. 5449** This is different from every other SQLite interface. The inconsistency 5450** is unfortunate but cannot be changed without breaking backwards 5451** compatibility. 5452** 5453** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5454*/ 5455SQLITE_API int sqlite3_create_collation( 5456 sqlite3*, 5457 const char *zName, 5458 int eTextRep, 5459 void *pArg, 5460 int(*xCompare)(void*,int,const void*,int,const void*) 5461); 5462SQLITE_API int sqlite3_create_collation_v2( 5463 sqlite3*, 5464 const char *zName, 5465 int eTextRep, 5466 void *pArg, 5467 int(*xCompare)(void*,int,const void*,int,const void*), 5468 void(*xDestroy)(void*) 5469); 5470SQLITE_API int sqlite3_create_collation16( 5471 sqlite3*, 5472 const void *zName, 5473 int eTextRep, 5474 void *pArg, 5475 int(*xCompare)(void*,int,const void*,int,const void*) 5476); 5477 5478/* 5479** CAPI3REF: Collation Needed Callbacks 5480** METHOD: sqlite3 5481** 5482** ^To avoid having to register all collation sequences before a database 5483** can be used, a single callback function may be registered with the 5484** [database connection] to be invoked whenever an undefined collation 5485** sequence is required. 5486** 5487** ^If the function is registered using the sqlite3_collation_needed() API, 5488** then it is passed the names of undefined collation sequences as strings 5489** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5490** the names are passed as UTF-16 in machine native byte order. 5491** ^A call to either function replaces the existing collation-needed callback. 5492** 5493** ^(When the callback is invoked, the first argument passed is a copy 5494** of the second argument to sqlite3_collation_needed() or 5495** sqlite3_collation_needed16(). The second argument is the database 5496** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5497** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5498** sequence function required. The fourth parameter is the name of the 5499** required collation sequence.)^ 5500** 5501** The callback function should register the desired collation using 5502** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5503** [sqlite3_create_collation_v2()]. 5504*/ 5505SQLITE_API int sqlite3_collation_needed( 5506 sqlite3*, 5507 void*, 5508 void(*)(void*,sqlite3*,int eTextRep,const char*) 5509); 5510SQLITE_API int sqlite3_collation_needed16( 5511 sqlite3*, 5512 void*, 5513 void(*)(void*,sqlite3*,int eTextRep,const void*) 5514); 5515 5516#ifdef SQLITE_HAS_CODEC 5517/* 5518** Specify the key for an encrypted database. This routine should be 5519** called right after sqlite3_open(). 5520** 5521** The code to implement this API is not available in the public release 5522** of SQLite. 5523*/ 5524SQLITE_API int sqlite3_key( 5525 sqlite3 *db, /* Database to be rekeyed */ 5526 const void *pKey, int nKey /* The key */ 5527); 5528SQLITE_API int sqlite3_key_v2( 5529 sqlite3 *db, /* Database to be rekeyed */ 5530 const char *zDbName, /* Name of the database */ 5531 const void *pKey, int nKey /* The key */ 5532); 5533 5534/* 5535** Change the key on an open database. If the current database is not 5536** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5537** database is decrypted. 5538** 5539** The code to implement this API is not available in the public release 5540** of SQLite. 5541*/ 5542SQLITE_API int sqlite3_rekey( 5543 sqlite3 *db, /* Database to be rekeyed */ 5544 const void *pKey, int nKey /* The new key */ 5545); 5546SQLITE_API int sqlite3_rekey_v2( 5547 sqlite3 *db, /* Database to be rekeyed */ 5548 const char *zDbName, /* Name of the database */ 5549 const void *pKey, int nKey /* The new key */ 5550); 5551 5552/* 5553** Specify the activation key for a SEE database. Unless 5554** activated, none of the SEE routines will work. 5555*/ 5556SQLITE_API void sqlite3_activate_see( 5557 const char *zPassPhrase /* Activation phrase */ 5558); 5559#endif 5560 5561#ifdef SQLITE_ENABLE_CEROD 5562/* 5563** Specify the activation key for a CEROD database. Unless 5564** activated, none of the CEROD routines will work. 5565*/ 5566SQLITE_API void sqlite3_activate_cerod( 5567 const char *zPassPhrase /* Activation phrase */ 5568); 5569#endif 5570 5571/* 5572** CAPI3REF: Suspend Execution For A Short Time 5573** 5574** The sqlite3_sleep() function causes the current thread to suspend execution 5575** for at least a number of milliseconds specified in its parameter. 5576** 5577** If the operating system does not support sleep requests with 5578** millisecond time resolution, then the time will be rounded up to 5579** the nearest second. The number of milliseconds of sleep actually 5580** requested from the operating system is returned. 5581** 5582** ^SQLite implements this interface by calling the xSleep() 5583** method of the default [sqlite3_vfs] object. If the xSleep() method 5584** of the default VFS is not implemented correctly, or not implemented at 5585** all, then the behavior of sqlite3_sleep() may deviate from the description 5586** in the previous paragraphs. 5587*/ 5588SQLITE_API int sqlite3_sleep(int); 5589 5590/* 5591** CAPI3REF: Name Of The Folder Holding Temporary Files 5592** 5593** ^(If this global variable is made to point to a string which is 5594** the name of a folder (a.k.a. directory), then all temporary files 5595** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5596** will be placed in that directory.)^ ^If this variable 5597** is a NULL pointer, then SQLite performs a search for an appropriate 5598** temporary file directory. 5599** 5600** Applications are strongly discouraged from using this global variable. 5601** It is required to set a temporary folder on Windows Runtime (WinRT). 5602** But for all other platforms, it is highly recommended that applications 5603** neither read nor write this variable. This global variable is a relic 5604** that exists for backwards compatibility of legacy applications and should 5605** be avoided in new projects. 5606** 5607** It is not safe to read or modify this variable in more than one 5608** thread at a time. It is not safe to read or modify this variable 5609** if a [database connection] is being used at the same time in a separate 5610** thread. 5611** It is intended that this variable be set once 5612** as part of process initialization and before any SQLite interface 5613** routines have been called and that this variable remain unchanged 5614** thereafter. 5615** 5616** ^The [temp_store_directory pragma] may modify this variable and cause 5617** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5618** the [temp_store_directory pragma] always assumes that any string 5619** that this variable points to is held in memory obtained from 5620** [sqlite3_malloc] and the pragma may attempt to free that memory 5621** using [sqlite3_free]. 5622** Hence, if this variable is modified directly, either it should be 5623** made NULL or made to point to memory obtained from [sqlite3_malloc] 5624** or else the use of the [temp_store_directory pragma] should be avoided. 5625** Except when requested by the [temp_store_directory pragma], SQLite 5626** does not free the memory that sqlite3_temp_directory points to. If 5627** the application wants that memory to be freed, it must do 5628** so itself, taking care to only do so after all [database connection] 5629** objects have been destroyed. 5630** 5631** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5632** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5633** features that require the use of temporary files may fail. Here is an 5634** example of how to do this using C++ with the Windows Runtime: 5635** 5636** <blockquote><pre> 5637** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5638** TemporaryFolder->Path->Data(); 5639** char zPathBuf[MAX_PATH + 1]; 5640** memset(zPathBuf, 0, sizeof(zPathBuf)); 5641** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5642** NULL, NULL); 5643** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5644** </pre></blockquote> 5645*/ 5646SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5647 5648/* 5649** CAPI3REF: Name Of The Folder Holding Database Files 5650** 5651** ^(If this global variable is made to point to a string which is 5652** the name of a folder (a.k.a. directory), then all database files 5653** specified with a relative pathname and created or accessed by 5654** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5655** to be relative to that directory.)^ ^If this variable is a NULL 5656** pointer, then SQLite assumes that all database files specified 5657** with a relative pathname are relative to the current directory 5658** for the process. Only the windows VFS makes use of this global 5659** variable; it is ignored by the unix VFS. 5660** 5661** Changing the value of this variable while a database connection is 5662** open can result in a corrupt database. 5663** 5664** It is not safe to read or modify this variable in more than one 5665** thread at a time. It is not safe to read or modify this variable 5666** if a [database connection] is being used at the same time in a separate 5667** thread. 5668** It is intended that this variable be set once 5669** as part of process initialization and before any SQLite interface 5670** routines have been called and that this variable remain unchanged 5671** thereafter. 5672** 5673** ^The [data_store_directory pragma] may modify this variable and cause 5674** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5675** the [data_store_directory pragma] always assumes that any string 5676** that this variable points to is held in memory obtained from 5677** [sqlite3_malloc] and the pragma may attempt to free that memory 5678** using [sqlite3_free]. 5679** Hence, if this variable is modified directly, either it should be 5680** made NULL or made to point to memory obtained from [sqlite3_malloc] 5681** or else the use of the [data_store_directory pragma] should be avoided. 5682*/ 5683SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5684 5685/* 5686** CAPI3REF: Win32 Specific Interface 5687** 5688** These interfaces are available only on Windows. The 5689** [sqlite3_win32_set_directory] interface is used to set the value associated 5690** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5691** zValue, depending on the value of the type parameter. The zValue parameter 5692** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5693** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5694** prior to being used. The [sqlite3_win32_set_directory] interface returns 5695** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5696** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5697** [sqlite3_data_directory] variable is intended to act as a replacement for 5698** the current directory on the sub-platforms of Win32 where that concept is 5699** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5700** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5701** sqlite3_win32_set_directory interface except the string parameter must be 5702** UTF-8 or UTF-16, respectively. 5703*/ 5704SQLITE_API int sqlite3_win32_set_directory( 5705 unsigned long type, /* Identifier for directory being set or reset */ 5706 void *zValue /* New value for directory being set or reset */ 5707); 5708SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5709SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5710 5711/* 5712** CAPI3REF: Win32 Directory Types 5713** 5714** These macros are only available on Windows. They define the allowed values 5715** for the type argument to the [sqlite3_win32_set_directory] interface. 5716*/ 5717#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5718#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5719 5720/* 5721** CAPI3REF: Test For Auto-Commit Mode 5722** KEYWORDS: {autocommit mode} 5723** METHOD: sqlite3 5724** 5725** ^The sqlite3_get_autocommit() interface returns non-zero or 5726** zero if the given database connection is or is not in autocommit mode, 5727** respectively. ^Autocommit mode is on by default. 5728** ^Autocommit mode is disabled by a [BEGIN] statement. 5729** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5730** 5731** If certain kinds of errors occur on a statement within a multi-statement 5732** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5733** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5734** transaction might be rolled back automatically. The only way to 5735** find out whether SQLite automatically rolled back the transaction after 5736** an error is to use this function. 5737** 5738** If another thread changes the autocommit status of the database 5739** connection while this routine is running, then the return value 5740** is undefined. 5741*/ 5742SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5743 5744/* 5745** CAPI3REF: Find The Database Handle Of A Prepared Statement 5746** METHOD: sqlite3_stmt 5747** 5748** ^The sqlite3_db_handle interface returns the [database connection] handle 5749** to which a [prepared statement] belongs. ^The [database connection] 5750** returned by sqlite3_db_handle is the same [database connection] 5751** that was the first argument 5752** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5753** create the statement in the first place. 5754*/ 5755SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5756 5757/* 5758** CAPI3REF: Return The Filename For A Database Connection 5759** METHOD: sqlite3 5760** 5761** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5762** associated with database N of connection D. ^The main database file 5763** has the name "main". If there is no attached database N on the database 5764** connection D, or if database N is a temporary or in-memory database, then 5765** a NULL pointer is returned. 5766** 5767** ^The filename returned by this function is the output of the 5768** xFullPathname method of the [VFS]. ^In other words, the filename 5769** will be an absolute pathname, even if the filename used 5770** to open the database originally was a URI or relative pathname. 5771*/ 5772SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5773 5774/* 5775** CAPI3REF: Determine if a database is read-only 5776** METHOD: sqlite3 5777** 5778** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5779** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5780** the name of a database on connection D. 5781*/ 5782SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5783 5784/* 5785** CAPI3REF: Find the next prepared statement 5786** METHOD: sqlite3 5787** 5788** ^This interface returns a pointer to the next [prepared statement] after 5789** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5790** then this interface returns a pointer to the first prepared statement 5791** associated with the database connection pDb. ^If no prepared statement 5792** satisfies the conditions of this routine, it returns NULL. 5793** 5794** The [database connection] pointer D in a call to 5795** [sqlite3_next_stmt(D,S)] must refer to an open database 5796** connection and in particular must not be a NULL pointer. 5797*/ 5798SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5799 5800/* 5801** CAPI3REF: Commit And Rollback Notification Callbacks 5802** METHOD: sqlite3 5803** 5804** ^The sqlite3_commit_hook() interface registers a callback 5805** function to be invoked whenever a transaction is [COMMIT | committed]. 5806** ^Any callback set by a previous call to sqlite3_commit_hook() 5807** for the same database connection is overridden. 5808** ^The sqlite3_rollback_hook() interface registers a callback 5809** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5810** ^Any callback set by a previous call to sqlite3_rollback_hook() 5811** for the same database connection is overridden. 5812** ^The pArg argument is passed through to the callback. 5813** ^If the callback on a commit hook function returns non-zero, 5814** then the commit is converted into a rollback. 5815** 5816** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5817** return the P argument from the previous call of the same function 5818** on the same [database connection] D, or NULL for 5819** the first call for each function on D. 5820** 5821** The commit and rollback hook callbacks are not reentrant. 5822** The callback implementation must not do anything that will modify 5823** the database connection that invoked the callback. Any actions 5824** to modify the database connection must be deferred until after the 5825** completion of the [sqlite3_step()] call that triggered the commit 5826** or rollback hook in the first place. 5827** Note that running any other SQL statements, including SELECT statements, 5828** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5829** the database connections for the meaning of "modify" in this paragraph. 5830** 5831** ^Registering a NULL function disables the callback. 5832** 5833** ^When the commit hook callback routine returns zero, the [COMMIT] 5834** operation is allowed to continue normally. ^If the commit hook 5835** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5836** ^The rollback hook is invoked on a rollback that results from a commit 5837** hook returning non-zero, just as it would be with any other rollback. 5838** 5839** ^For the purposes of this API, a transaction is said to have been 5840** rolled back if an explicit "ROLLBACK" statement is executed, or 5841** an error or constraint causes an implicit rollback to occur. 5842** ^The rollback callback is not invoked if a transaction is 5843** automatically rolled back because the database connection is closed. 5844** 5845** See also the [sqlite3_update_hook()] interface. 5846*/ 5847SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5848SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5849 5850/* 5851** CAPI3REF: Data Change Notification Callbacks 5852** METHOD: sqlite3 5853** 5854** ^The sqlite3_update_hook() interface registers a callback function 5855** with the [database connection] identified by the first argument 5856** to be invoked whenever a row is updated, inserted or deleted in 5857** a [rowid table]. 5858** ^Any callback set by a previous call to this function 5859** for the same database connection is overridden. 5860** 5861** ^The second argument is a pointer to the function to invoke when a 5862** row is updated, inserted or deleted in a rowid table. 5863** ^The first argument to the callback is a copy of the third argument 5864** to sqlite3_update_hook(). 5865** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5866** or [SQLITE_UPDATE], depending on the operation that caused the callback 5867** to be invoked. 5868** ^The third and fourth arguments to the callback contain pointers to the 5869** database and table name containing the affected row. 5870** ^The final callback parameter is the [rowid] of the row. 5871** ^In the case of an update, this is the [rowid] after the update takes place. 5872** 5873** ^(The update hook is not invoked when internal system tables are 5874** modified (i.e. sqlite_master and sqlite_sequence).)^ 5875** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5876** 5877** ^In the current implementation, the update hook 5878** is not invoked when conflicting rows are deleted because of an 5879** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5880** invoked when rows are deleted using the [truncate optimization]. 5881** The exceptions defined in this paragraph might change in a future 5882** release of SQLite. 5883** 5884** The update hook implementation must not do anything that will modify 5885** the database connection that invoked the update hook. Any actions 5886** to modify the database connection must be deferred until after the 5887** completion of the [sqlite3_step()] call that triggered the update hook. 5888** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5889** database connections for the meaning of "modify" in this paragraph. 5890** 5891** ^The sqlite3_update_hook(D,C,P) function 5892** returns the P argument from the previous call 5893** on the same [database connection] D, or NULL for 5894** the first call on D. 5895** 5896** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5897** and [sqlite3_preupdate_hook()] interfaces. 5898*/ 5899SQLITE_API void *sqlite3_update_hook( 5900 sqlite3*, 5901 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5902 void* 5903); 5904 5905/* 5906** CAPI3REF: Enable Or Disable Shared Pager Cache 5907** 5908** ^(This routine enables or disables the sharing of the database cache 5909** and schema data structures between [database connection | connections] 5910** to the same database. Sharing is enabled if the argument is true 5911** and disabled if the argument is false.)^ 5912** 5913** ^Cache sharing is enabled and disabled for an entire process. 5914** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5915** In prior versions of SQLite, 5916** sharing was enabled or disabled for each thread separately. 5917** 5918** ^(The cache sharing mode set by this interface effects all subsequent 5919** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5920** Existing database connections continue use the sharing mode 5921** that was in effect at the time they were opened.)^ 5922** 5923** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5924** successfully. An [error code] is returned otherwise.)^ 5925** 5926** ^Shared cache is disabled by default. But this might change in 5927** future releases of SQLite. Applications that care about shared 5928** cache setting should set it explicitly. 5929** 5930** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5931** and will always return SQLITE_MISUSE. On those systems, 5932** shared cache mode should be enabled per-database connection via 5933** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5934** 5935** This interface is threadsafe on processors where writing a 5936** 32-bit integer is atomic. 5937** 5938** See Also: [SQLite Shared-Cache Mode] 5939*/ 5940SQLITE_API int sqlite3_enable_shared_cache(int); 5941 5942/* 5943** CAPI3REF: Attempt To Free Heap Memory 5944** 5945** ^The sqlite3_release_memory() interface attempts to free N bytes 5946** of heap memory by deallocating non-essential memory allocations 5947** held by the database library. Memory used to cache database 5948** pages to improve performance is an example of non-essential memory. 5949** ^sqlite3_release_memory() returns the number of bytes actually freed, 5950** which might be more or less than the amount requested. 5951** ^The sqlite3_release_memory() routine is a no-op returning zero 5952** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5953** 5954** See also: [sqlite3_db_release_memory()] 5955*/ 5956SQLITE_API int sqlite3_release_memory(int); 5957 5958/* 5959** CAPI3REF: Free Memory Used By A Database Connection 5960** METHOD: sqlite3 5961** 5962** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5963** memory as possible from database connection D. Unlike the 5964** [sqlite3_release_memory()] interface, this interface is in effect even 5965** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5966** omitted. 5967** 5968** See also: [sqlite3_release_memory()] 5969*/ 5970SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5971 5972/* 5973** CAPI3REF: Impose A Limit On Heap Size 5974** 5975** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5976** soft limit on the amount of heap memory that may be allocated by SQLite. 5977** ^SQLite strives to keep heap memory utilization below the soft heap 5978** limit by reducing the number of pages held in the page cache 5979** as heap memory usages approaches the limit. 5980** ^The soft heap limit is "soft" because even though SQLite strives to stay 5981** below the limit, it will exceed the limit rather than generate 5982** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5983** is advisory only. 5984** 5985** ^The return value from sqlite3_soft_heap_limit64() is the size of 5986** the soft heap limit prior to the call, or negative in the case of an 5987** error. ^If the argument N is negative 5988** then no change is made to the soft heap limit. Hence, the current 5989** size of the soft heap limit can be determined by invoking 5990** sqlite3_soft_heap_limit64() with a negative argument. 5991** 5992** ^If the argument N is zero then the soft heap limit is disabled. 5993** 5994** ^(The soft heap limit is not enforced in the current implementation 5995** if one or more of following conditions are true: 5996** 5997** <ul> 5998** <li> The soft heap limit is set to zero. 5999** <li> Memory accounting is disabled using a combination of the 6000** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6001** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6002** <li> An alternative page cache implementation is specified using 6003** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6004** <li> The page cache allocates from its own memory pool supplied 6005** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6006** from the heap. 6007** </ul>)^ 6008** 6009** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 6010** the soft heap limit is enforced 6011** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 6012** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 6013** the soft heap limit is enforced on every memory allocation. Without 6014** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 6015** when memory is allocated by the page cache. Testing suggests that because 6016** the page cache is the predominate memory user in SQLite, most 6017** applications will achieve adequate soft heap limit enforcement without 6018** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6019** 6020** The circumstances under which SQLite will enforce the soft heap limit may 6021** changes in future releases of SQLite. 6022*/ 6023SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6024 6025/* 6026** CAPI3REF: Deprecated Soft Heap Limit Interface 6027** DEPRECATED 6028** 6029** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6030** interface. This routine is provided for historical compatibility 6031** only. All new applications should use the 6032** [sqlite3_soft_heap_limit64()] interface rather than this one. 6033*/ 6034SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6035 6036 6037/* 6038** CAPI3REF: Extract Metadata About A Column Of A Table 6039** METHOD: sqlite3 6040** 6041** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6042** information about column C of table T in database D 6043** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6044** interface returns SQLITE_OK and fills in the non-NULL pointers in 6045** the final five arguments with appropriate values if the specified 6046** column exists. ^The sqlite3_table_column_metadata() interface returns 6047** SQLITE_ERROR and if the specified column does not exist. 6048** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6049** NULL pointer, then this routine simply checks for the existence of the 6050** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6051** does not. If the table name parameter T in a call to 6052** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6053** undefined behavior. 6054** 6055** ^The column is identified by the second, third and fourth parameters to 6056** this function. ^(The second parameter is either the name of the database 6057** (i.e. "main", "temp", or an attached database) containing the specified 6058** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6059** for the table using the same algorithm used by the database engine to 6060** resolve unqualified table references. 6061** 6062** ^The third and fourth parameters to this function are the table and column 6063** name of the desired column, respectively. 6064** 6065** ^Metadata is returned by writing to the memory locations passed as the 5th 6066** and subsequent parameters to this function. ^Any of these arguments may be 6067** NULL, in which case the corresponding element of metadata is omitted. 6068** 6069** ^(<blockquote> 6070** <table border="1"> 6071** <tr><th> Parameter <th> Output<br>Type <th> Description 6072** 6073** <tr><td> 5th <td> const char* <td> Data type 6074** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6075** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6076** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6077** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6078** </table> 6079** </blockquote>)^ 6080** 6081** ^The memory pointed to by the character pointers returned for the 6082** declaration type and collation sequence is valid until the next 6083** call to any SQLite API function. 6084** 6085** ^If the specified table is actually a view, an [error code] is returned. 6086** 6087** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6088** is not a [WITHOUT ROWID] table and an 6089** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6090** parameters are set for the explicitly declared column. ^(If there is no 6091** [INTEGER PRIMARY KEY] column, then the outputs 6092** for the [rowid] are set as follows: 6093** 6094** <pre> 6095** data type: "INTEGER" 6096** collation sequence: "BINARY" 6097** not null: 0 6098** primary key: 1 6099** auto increment: 0 6100** </pre>)^ 6101** 6102** ^This function causes all database schemas to be read from disk and 6103** parsed, if that has not already been done, and returns an error if 6104** any errors are encountered while loading the schema. 6105*/ 6106SQLITE_API int sqlite3_table_column_metadata( 6107 sqlite3 *db, /* Connection handle */ 6108 const char *zDbName, /* Database name or NULL */ 6109 const char *zTableName, /* Table name */ 6110 const char *zColumnName, /* Column name */ 6111 char const **pzDataType, /* OUTPUT: Declared data type */ 6112 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6113 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6114 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6115 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6116); 6117 6118/* 6119** CAPI3REF: Load An Extension 6120** METHOD: sqlite3 6121** 6122** ^This interface loads an SQLite extension library from the named file. 6123** 6124** ^The sqlite3_load_extension() interface attempts to load an 6125** [SQLite extension] library contained in the file zFile. If 6126** the file cannot be loaded directly, attempts are made to load 6127** with various operating-system specific extensions added. 6128** So for example, if "samplelib" cannot be loaded, then names like 6129** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6130** be tried also. 6131** 6132** ^The entry point is zProc. 6133** ^(zProc may be 0, in which case SQLite will try to come up with an 6134** entry point name on its own. It first tries "sqlite3_extension_init". 6135** If that does not work, it constructs a name "sqlite3_X_init" where the 6136** X is consists of the lower-case equivalent of all ASCII alphabetic 6137** characters in the filename from the last "/" to the first following 6138** "." and omitting any initial "lib".)^ 6139** ^The sqlite3_load_extension() interface returns 6140** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6141** ^If an error occurs and pzErrMsg is not 0, then the 6142** [sqlite3_load_extension()] interface shall attempt to 6143** fill *pzErrMsg with error message text stored in memory 6144** obtained from [sqlite3_malloc()]. The calling function 6145** should free this memory by calling [sqlite3_free()]. 6146** 6147** ^Extension loading must be enabled using 6148** [sqlite3_enable_load_extension()] or 6149** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6150** prior to calling this API, 6151** otherwise an error will be returned. 6152** 6153** <b>Security warning:</b> It is recommended that the 6154** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6155** interface. The use of the [sqlite3_enable_load_extension()] interface 6156** should be avoided. This will keep the SQL function [load_extension()] 6157** disabled and prevent SQL injections from giving attackers 6158** access to extension loading capabilities. 6159** 6160** See also the [load_extension() SQL function]. 6161*/ 6162SQLITE_API int sqlite3_load_extension( 6163 sqlite3 *db, /* Load the extension into this database connection */ 6164 const char *zFile, /* Name of the shared library containing extension */ 6165 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6166 char **pzErrMsg /* Put error message here if not 0 */ 6167); 6168 6169/* 6170** CAPI3REF: Enable Or Disable Extension Loading 6171** METHOD: sqlite3 6172** 6173** ^So as not to open security holes in older applications that are 6174** unprepared to deal with [extension loading], and as a means of disabling 6175** [extension loading] while evaluating user-entered SQL, the following API 6176** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6177** 6178** ^Extension loading is off by default. 6179** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6180** to turn extension loading on and call it with onoff==0 to turn 6181** it back off again. 6182** 6183** ^This interface enables or disables both the C-API 6184** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6185** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6186** to enable or disable only the C-API.)^ 6187** 6188** <b>Security warning:</b> It is recommended that extension loading 6189** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6190** rather than this interface, so the [load_extension()] SQL function 6191** remains disabled. This will prevent SQL injections from giving attackers 6192** access to extension loading capabilities. 6193*/ 6194SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6195 6196/* 6197** CAPI3REF: Automatically Load Statically Linked Extensions 6198** 6199** ^This interface causes the xEntryPoint() function to be invoked for 6200** each new [database connection] that is created. The idea here is that 6201** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6202** that is to be automatically loaded into all new database connections. 6203** 6204** ^(Even though the function prototype shows that xEntryPoint() takes 6205** no arguments and returns void, SQLite invokes xEntryPoint() with three 6206** arguments and expects an integer result as if the signature of the 6207** entry point where as follows: 6208** 6209** <blockquote><pre> 6210** int xEntryPoint( 6211** sqlite3 *db, 6212** const char **pzErrMsg, 6213** const struct sqlite3_api_routines *pThunk 6214** ); 6215** </pre></blockquote>)^ 6216** 6217** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6218** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6219** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6220** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6221** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6222** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6223** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6224** 6225** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6226** on the list of automatic extensions is a harmless no-op. ^No entry point 6227** will be called more than once for each database connection that is opened. 6228** 6229** See also: [sqlite3_reset_auto_extension()] 6230** and [sqlite3_cancel_auto_extension()] 6231*/ 6232SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6233 6234/* 6235** CAPI3REF: Cancel Automatic Extension Loading 6236** 6237** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6238** initialization routine X that was registered using a prior call to 6239** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6240** routine returns 1 if initialization routine X was successfully 6241** unregistered and it returns 0 if X was not on the list of initialization 6242** routines. 6243*/ 6244SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6245 6246/* 6247** CAPI3REF: Reset Automatic Extension Loading 6248** 6249** ^This interface disables all automatic extensions previously 6250** registered using [sqlite3_auto_extension()]. 6251*/ 6252SQLITE_API void sqlite3_reset_auto_extension(void); 6253 6254/* 6255** The interface to the virtual-table mechanism is currently considered 6256** to be experimental. The interface might change in incompatible ways. 6257** If this is a problem for you, do not use the interface at this time. 6258** 6259** When the virtual-table mechanism stabilizes, we will declare the 6260** interface fixed, support it indefinitely, and remove this comment. 6261*/ 6262 6263/* 6264** Structures used by the virtual table interface 6265*/ 6266typedef struct sqlite3_vtab sqlite3_vtab; 6267typedef struct sqlite3_index_info sqlite3_index_info; 6268typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6269typedef struct sqlite3_module sqlite3_module; 6270 6271/* 6272** CAPI3REF: Virtual Table Object 6273** KEYWORDS: sqlite3_module {virtual table module} 6274** 6275** This structure, sometimes called a "virtual table module", 6276** defines the implementation of a [virtual tables]. 6277** This structure consists mostly of methods for the module. 6278** 6279** ^A virtual table module is created by filling in a persistent 6280** instance of this structure and passing a pointer to that instance 6281** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6282** ^The registration remains valid until it is replaced by a different 6283** module or until the [database connection] closes. The content 6284** of this structure must not change while it is registered with 6285** any database connection. 6286*/ 6287struct sqlite3_module { 6288 int iVersion; 6289 int (*xCreate)(sqlite3*, void *pAux, 6290 int argc, const char *const*argv, 6291 sqlite3_vtab **ppVTab, char**); 6292 int (*xConnect)(sqlite3*, void *pAux, 6293 int argc, const char *const*argv, 6294 sqlite3_vtab **ppVTab, char**); 6295 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6296 int (*xDisconnect)(sqlite3_vtab *pVTab); 6297 int (*xDestroy)(sqlite3_vtab *pVTab); 6298 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6299 int (*xClose)(sqlite3_vtab_cursor*); 6300 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6301 int argc, sqlite3_value **argv); 6302 int (*xNext)(sqlite3_vtab_cursor*); 6303 int (*xEof)(sqlite3_vtab_cursor*); 6304 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6305 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6306 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6307 int (*xBegin)(sqlite3_vtab *pVTab); 6308 int (*xSync)(sqlite3_vtab *pVTab); 6309 int (*xCommit)(sqlite3_vtab *pVTab); 6310 int (*xRollback)(sqlite3_vtab *pVTab); 6311 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6312 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6313 void **ppArg); 6314 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6315 /* The methods above are in version 1 of the sqlite_module object. Those 6316 ** below are for version 2 and greater. */ 6317 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6318 int (*xRelease)(sqlite3_vtab *pVTab, int); 6319 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6320 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6321 ** Those below are for version 3 and greater. */ 6322 int (*xShadowName)(const char*); 6323}; 6324 6325/* 6326** CAPI3REF: Virtual Table Indexing Information 6327** KEYWORDS: sqlite3_index_info 6328** 6329** The sqlite3_index_info structure and its substructures is used as part 6330** of the [virtual table] interface to 6331** pass information into and receive the reply from the [xBestIndex] 6332** method of a [virtual table module]. The fields under **Inputs** are the 6333** inputs to xBestIndex and are read-only. xBestIndex inserts its 6334** results into the **Outputs** fields. 6335** 6336** ^(The aConstraint[] array records WHERE clause constraints of the form: 6337** 6338** <blockquote>column OP expr</blockquote> 6339** 6340** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6341** stored in aConstraint[].op using one of the 6342** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6343** ^(The index of the column is stored in 6344** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6345** expr on the right-hand side can be evaluated (and thus the constraint 6346** is usable) and false if it cannot.)^ 6347** 6348** ^The optimizer automatically inverts terms of the form "expr OP column" 6349** and makes other simplifications to the WHERE clause in an attempt to 6350** get as many WHERE clause terms into the form shown above as possible. 6351** ^The aConstraint[] array only reports WHERE clause terms that are 6352** relevant to the particular virtual table being queried. 6353** 6354** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6355** ^Each term of aOrderBy records a column of the ORDER BY clause. 6356** 6357** The colUsed field indicates which columns of the virtual table may be 6358** required by the current scan. Virtual table columns are numbered from 6359** zero in the order in which they appear within the CREATE TABLE statement 6360** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6361** the corresponding bit is set within the colUsed mask if the column may be 6362** required by SQLite. If the table has at least 64 columns and any column 6363** to the right of the first 63 is required, then bit 63 of colUsed is also 6364** set. In other words, column iCol may be required if the expression 6365** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6366** non-zero. 6367** 6368** The [xBestIndex] method must fill aConstraintUsage[] with information 6369** about what parameters to pass to xFilter. ^If argvIndex>0 then 6370** the right-hand side of the corresponding aConstraint[] is evaluated 6371** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6372** is true, then the constraint is assumed to be fully handled by the 6373** virtual table and is not checked again by SQLite.)^ 6374** 6375** ^The idxNum and idxPtr values are recorded and passed into the 6376** [xFilter] method. 6377** ^[sqlite3_free()] is used to free idxPtr if and only if 6378** needToFreeIdxPtr is true. 6379** 6380** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6381** the correct order to satisfy the ORDER BY clause so that no separate 6382** sorting step is required. 6383** 6384** ^The estimatedCost value is an estimate of the cost of a particular 6385** strategy. A cost of N indicates that the cost of the strategy is similar 6386** to a linear scan of an SQLite table with N rows. A cost of log(N) 6387** indicates that the expense of the operation is similar to that of a 6388** binary search on a unique indexed field of an SQLite table with N rows. 6389** 6390** ^The estimatedRows value is an estimate of the number of rows that 6391** will be returned by the strategy. 6392** 6393** The xBestIndex method may optionally populate the idxFlags field with a 6394** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6395** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6396** assumes that the strategy may visit at most one row. 6397** 6398** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6399** SQLite also assumes that if a call to the xUpdate() method is made as 6400** part of the same statement to delete or update a virtual table row and the 6401** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6402** any database changes. In other words, if the xUpdate() returns 6403** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6404** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6405** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6406** the xUpdate method are automatically rolled back by SQLite. 6407** 6408** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6409** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6410** If a virtual table extension is 6411** used with an SQLite version earlier than 3.8.2, the results of attempting 6412** to read or write the estimatedRows field are undefined (but are likely 6413** to included crashing the application). The estimatedRows field should 6414** therefore only be used if [sqlite3_libversion_number()] returns a 6415** value greater than or equal to 3008002. Similarly, the idxFlags field 6416** was added for [version 3.9.0] ([dateof:3.9.0]). 6417** It may therefore only be used if 6418** sqlite3_libversion_number() returns a value greater than or equal to 6419** 3009000. 6420*/ 6421struct sqlite3_index_info { 6422 /* Inputs */ 6423 int nConstraint; /* Number of entries in aConstraint */ 6424 struct sqlite3_index_constraint { 6425 int iColumn; /* Column constrained. -1 for ROWID */ 6426 unsigned char op; /* Constraint operator */ 6427 unsigned char usable; /* True if this constraint is usable */ 6428 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6429 } *aConstraint; /* Table of WHERE clause constraints */ 6430 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6431 struct sqlite3_index_orderby { 6432 int iColumn; /* Column number */ 6433 unsigned char desc; /* True for DESC. False for ASC. */ 6434 } *aOrderBy; /* The ORDER BY clause */ 6435 /* Outputs */ 6436 struct sqlite3_index_constraint_usage { 6437 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6438 unsigned char omit; /* Do not code a test for this constraint */ 6439 } *aConstraintUsage; 6440 int idxNum; /* Number used to identify the index */ 6441 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6442 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6443 int orderByConsumed; /* True if output is already ordered */ 6444 double estimatedCost; /* Estimated cost of using this index */ 6445 /* Fields below are only available in SQLite 3.8.2 and later */ 6446 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6447 /* Fields below are only available in SQLite 3.9.0 and later */ 6448 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6449 /* Fields below are only available in SQLite 3.10.0 and later */ 6450 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6451}; 6452 6453/* 6454** CAPI3REF: Virtual Table Scan Flags 6455** 6456** Virtual table implementations are allowed to set the 6457** [sqlite3_index_info].idxFlags field to some combination of 6458** these bits. 6459*/ 6460#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6461 6462/* 6463** CAPI3REF: Virtual Table Constraint Operator Codes 6464** 6465** These macros defined the allowed values for the 6466** [sqlite3_index_info].aConstraint[].op field. Each value represents 6467** an operator that is part of a constraint term in the wHERE clause of 6468** a query that uses a [virtual table]. 6469*/ 6470#define SQLITE_INDEX_CONSTRAINT_EQ 2 6471#define SQLITE_INDEX_CONSTRAINT_GT 4 6472#define SQLITE_INDEX_CONSTRAINT_LE 8 6473#define SQLITE_INDEX_CONSTRAINT_LT 16 6474#define SQLITE_INDEX_CONSTRAINT_GE 32 6475#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6476#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6477#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6478#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6479#define SQLITE_INDEX_CONSTRAINT_NE 68 6480#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6481#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6482#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6483#define SQLITE_INDEX_CONSTRAINT_IS 72 6484#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6485 6486/* 6487** CAPI3REF: Register A Virtual Table Implementation 6488** METHOD: sqlite3 6489** 6490** ^These routines are used to register a new [virtual table module] name. 6491** ^Module names must be registered before 6492** creating a new [virtual table] using the module and before using a 6493** preexisting [virtual table] for the module. 6494** 6495** ^The module name is registered on the [database connection] specified 6496** by the first parameter. ^The name of the module is given by the 6497** second parameter. ^The third parameter is a pointer to 6498** the implementation of the [virtual table module]. ^The fourth 6499** parameter is an arbitrary client data pointer that is passed through 6500** into the [xCreate] and [xConnect] methods of the virtual table module 6501** when a new virtual table is be being created or reinitialized. 6502** 6503** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6504** is a pointer to a destructor for the pClientData. ^SQLite will 6505** invoke the destructor function (if it is not NULL) when SQLite 6506** no longer needs the pClientData pointer. ^The destructor will also 6507** be invoked if the call to sqlite3_create_module_v2() fails. 6508** ^The sqlite3_create_module() 6509** interface is equivalent to sqlite3_create_module_v2() with a NULL 6510** destructor. 6511*/ 6512SQLITE_API int sqlite3_create_module( 6513 sqlite3 *db, /* SQLite connection to register module with */ 6514 const char *zName, /* Name of the module */ 6515 const sqlite3_module *p, /* Methods for the module */ 6516 void *pClientData /* Client data for xCreate/xConnect */ 6517); 6518SQLITE_API int sqlite3_create_module_v2( 6519 sqlite3 *db, /* SQLite connection to register module with */ 6520 const char *zName, /* Name of the module */ 6521 const sqlite3_module *p, /* Methods for the module */ 6522 void *pClientData, /* Client data for xCreate/xConnect */ 6523 void(*xDestroy)(void*) /* Module destructor function */ 6524); 6525 6526/* 6527** CAPI3REF: Virtual Table Instance Object 6528** KEYWORDS: sqlite3_vtab 6529** 6530** Every [virtual table module] implementation uses a subclass 6531** of this object to describe a particular instance 6532** of the [virtual table]. Each subclass will 6533** be tailored to the specific needs of the module implementation. 6534** The purpose of this superclass is to define certain fields that are 6535** common to all module implementations. 6536** 6537** ^Virtual tables methods can set an error message by assigning a 6538** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6539** take care that any prior string is freed by a call to [sqlite3_free()] 6540** prior to assigning a new string to zErrMsg. ^After the error message 6541** is delivered up to the client application, the string will be automatically 6542** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6543*/ 6544struct sqlite3_vtab { 6545 const sqlite3_module *pModule; /* The module for this virtual table */ 6546 int nRef; /* Number of open cursors */ 6547 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6548 /* Virtual table implementations will typically add additional fields */ 6549}; 6550 6551/* 6552** CAPI3REF: Virtual Table Cursor Object 6553** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6554** 6555** Every [virtual table module] implementation uses a subclass of the 6556** following structure to describe cursors that point into the 6557** [virtual table] and are used 6558** to loop through the virtual table. Cursors are created using the 6559** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6560** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6561** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6562** of the module. Each module implementation will define 6563** the content of a cursor structure to suit its own needs. 6564** 6565** This superclass exists in order to define fields of the cursor that 6566** are common to all implementations. 6567*/ 6568struct sqlite3_vtab_cursor { 6569 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6570 /* Virtual table implementations will typically add additional fields */ 6571}; 6572 6573/* 6574** CAPI3REF: Declare The Schema Of A Virtual Table 6575** 6576** ^The [xCreate] and [xConnect] methods of a 6577** [virtual table module] call this interface 6578** to declare the format (the names and datatypes of the columns) of 6579** the virtual tables they implement. 6580*/ 6581SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6582 6583/* 6584** CAPI3REF: Overload A Function For A Virtual Table 6585** METHOD: sqlite3 6586** 6587** ^(Virtual tables can provide alternative implementations of functions 6588** using the [xFindFunction] method of the [virtual table module]. 6589** But global versions of those functions 6590** must exist in order to be overloaded.)^ 6591** 6592** ^(This API makes sure a global version of a function with a particular 6593** name and number of parameters exists. If no such function exists 6594** before this API is called, a new function is created.)^ ^The implementation 6595** of the new function always causes an exception to be thrown. So 6596** the new function is not good for anything by itself. Its only 6597** purpose is to be a placeholder function that can be overloaded 6598** by a [virtual table]. 6599*/ 6600SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6601 6602/* 6603** The interface to the virtual-table mechanism defined above (back up 6604** to a comment remarkably similar to this one) is currently considered 6605** to be experimental. The interface might change in incompatible ways. 6606** If this is a problem for you, do not use the interface at this time. 6607** 6608** When the virtual-table mechanism stabilizes, we will declare the 6609** interface fixed, support it indefinitely, and remove this comment. 6610*/ 6611 6612/* 6613** CAPI3REF: A Handle To An Open BLOB 6614** KEYWORDS: {BLOB handle} {BLOB handles} 6615** 6616** An instance of this object represents an open BLOB on which 6617** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6618** ^Objects of this type are created by [sqlite3_blob_open()] 6619** and destroyed by [sqlite3_blob_close()]. 6620** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6621** can be used to read or write small subsections of the BLOB. 6622** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6623*/ 6624typedef struct sqlite3_blob sqlite3_blob; 6625 6626/* 6627** CAPI3REF: Open A BLOB For Incremental I/O 6628** METHOD: sqlite3 6629** CONSTRUCTOR: sqlite3_blob 6630** 6631** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6632** in row iRow, column zColumn, table zTable in database zDb; 6633** in other words, the same BLOB that would be selected by: 6634** 6635** <pre> 6636** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6637** </pre>)^ 6638** 6639** ^(Parameter zDb is not the filename that contains the database, but 6640** rather the symbolic name of the database. For attached databases, this is 6641** the name that appears after the AS keyword in the [ATTACH] statement. 6642** For the main database file, the database name is "main". For TEMP 6643** tables, the database name is "temp".)^ 6644** 6645** ^If the flags parameter is non-zero, then the BLOB is opened for read 6646** and write access. ^If the flags parameter is zero, the BLOB is opened for 6647** read-only access. 6648** 6649** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6650** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6651** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6652** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6653** on *ppBlob after this function it returns. 6654** 6655** This function fails with SQLITE_ERROR if any of the following are true: 6656** <ul> 6657** <li> ^(Database zDb does not exist)^, 6658** <li> ^(Table zTable does not exist within database zDb)^, 6659** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6660** <li> ^(Column zColumn does not exist)^, 6661** <li> ^(Row iRow is not present in the table)^, 6662** <li> ^(The specified column of row iRow contains a value that is not 6663** a TEXT or BLOB value)^, 6664** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6665** constraint and the blob is being opened for read/write access)^, 6666** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6667** column zColumn is part of a [child key] definition and the blob is 6668** being opened for read/write access)^. 6669** </ul> 6670** 6671** ^Unless it returns SQLITE_MISUSE, this function sets the 6672** [database connection] error code and message accessible via 6673** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6674** 6675** A BLOB referenced by sqlite3_blob_open() may be read using the 6676** [sqlite3_blob_read()] interface and modified by using 6677** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6678** different row of the same table using the [sqlite3_blob_reopen()] 6679** interface. However, the column, table, or database of a [BLOB handle] 6680** cannot be changed after the [BLOB handle] is opened. 6681** 6682** ^(If the row that a BLOB handle points to is modified by an 6683** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6684** then the BLOB handle is marked as "expired". 6685** This is true if any column of the row is changed, even a column 6686** other than the one the BLOB handle is open on.)^ 6687** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6688** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6689** ^(Changes written into a BLOB prior to the BLOB expiring are not 6690** rolled back by the expiration of the BLOB. Such changes will eventually 6691** commit if the transaction continues to completion.)^ 6692** 6693** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6694** the opened blob. ^The size of a blob may not be changed by this 6695** interface. Use the [UPDATE] SQL command to change the size of a 6696** blob. 6697** 6698** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6699** and the built-in [zeroblob] SQL function may be used to create a 6700** zero-filled blob to read or write using the incremental-blob interface. 6701** 6702** To avoid a resource leak, every open [BLOB handle] should eventually 6703** be released by a call to [sqlite3_blob_close()]. 6704** 6705** See also: [sqlite3_blob_close()], 6706** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6707** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6708*/ 6709SQLITE_API int sqlite3_blob_open( 6710 sqlite3*, 6711 const char *zDb, 6712 const char *zTable, 6713 const char *zColumn, 6714 sqlite3_int64 iRow, 6715 int flags, 6716 sqlite3_blob **ppBlob 6717); 6718 6719/* 6720** CAPI3REF: Move a BLOB Handle to a New Row 6721** METHOD: sqlite3_blob 6722** 6723** ^This function is used to move an existing [BLOB handle] so that it points 6724** to a different row of the same database table. ^The new row is identified 6725** by the rowid value passed as the second argument. Only the row can be 6726** changed. ^The database, table and column on which the blob handle is open 6727** remain the same. Moving an existing [BLOB handle] to a new row is 6728** faster than closing the existing handle and opening a new one. 6729** 6730** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6731** it must exist and there must be either a blob or text value stored in 6732** the nominated column.)^ ^If the new row is not present in the table, or if 6733** it does not contain a blob or text value, or if another error occurs, an 6734** SQLite error code is returned and the blob handle is considered aborted. 6735** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6736** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6737** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6738** always returns zero. 6739** 6740** ^This function sets the database handle error code and message. 6741*/ 6742SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6743 6744/* 6745** CAPI3REF: Close A BLOB Handle 6746** DESTRUCTOR: sqlite3_blob 6747** 6748** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6749** unconditionally. Even if this routine returns an error code, the 6750** handle is still closed.)^ 6751** 6752** ^If the blob handle being closed was opened for read-write access, and if 6753** the database is in auto-commit mode and there are no other open read-write 6754** blob handles or active write statements, the current transaction is 6755** committed. ^If an error occurs while committing the transaction, an error 6756** code is returned and the transaction rolled back. 6757** 6758** Calling this function with an argument that is not a NULL pointer or an 6759** open blob handle results in undefined behaviour. ^Calling this routine 6760** with a null pointer (such as would be returned by a failed call to 6761** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6762** is passed a valid open blob handle, the values returned by the 6763** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6764*/ 6765SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6766 6767/* 6768** CAPI3REF: Return The Size Of An Open BLOB 6769** METHOD: sqlite3_blob 6770** 6771** ^Returns the size in bytes of the BLOB accessible via the 6772** successfully opened [BLOB handle] in its only argument. ^The 6773** incremental blob I/O routines can only read or overwriting existing 6774** blob content; they cannot change the size of a blob. 6775** 6776** This routine only works on a [BLOB handle] which has been created 6777** by a prior successful call to [sqlite3_blob_open()] and which has not 6778** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6779** to this routine results in undefined and probably undesirable behavior. 6780*/ 6781SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6782 6783/* 6784** CAPI3REF: Read Data From A BLOB Incrementally 6785** METHOD: sqlite3_blob 6786** 6787** ^(This function is used to read data from an open [BLOB handle] into a 6788** caller-supplied buffer. N bytes of data are copied into buffer Z 6789** from the open BLOB, starting at offset iOffset.)^ 6790** 6791** ^If offset iOffset is less than N bytes from the end of the BLOB, 6792** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6793** less than zero, [SQLITE_ERROR] is returned and no data is read. 6794** ^The size of the blob (and hence the maximum value of N+iOffset) 6795** can be determined using the [sqlite3_blob_bytes()] interface. 6796** 6797** ^An attempt to read from an expired [BLOB handle] fails with an 6798** error code of [SQLITE_ABORT]. 6799** 6800** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6801** Otherwise, an [error code] or an [extended error code] is returned.)^ 6802** 6803** This routine only works on a [BLOB handle] which has been created 6804** by a prior successful call to [sqlite3_blob_open()] and which has not 6805** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6806** to this routine results in undefined and probably undesirable behavior. 6807** 6808** See also: [sqlite3_blob_write()]. 6809*/ 6810SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6811 6812/* 6813** CAPI3REF: Write Data Into A BLOB Incrementally 6814** METHOD: sqlite3_blob 6815** 6816** ^(This function is used to write data into an open [BLOB handle] from a 6817** caller-supplied buffer. N bytes of data are copied from the buffer Z 6818** into the open BLOB, starting at offset iOffset.)^ 6819** 6820** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6821** Otherwise, an [error code] or an [extended error code] is returned.)^ 6822** ^Unless SQLITE_MISUSE is returned, this function sets the 6823** [database connection] error code and message accessible via 6824** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6825** 6826** ^If the [BLOB handle] passed as the first argument was not opened for 6827** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6828** this function returns [SQLITE_READONLY]. 6829** 6830** This function may only modify the contents of the BLOB; it is 6831** not possible to increase the size of a BLOB using this API. 6832** ^If offset iOffset is less than N bytes from the end of the BLOB, 6833** [SQLITE_ERROR] is returned and no data is written. The size of the 6834** BLOB (and hence the maximum value of N+iOffset) can be determined 6835** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6836** than zero [SQLITE_ERROR] is returned and no data is written. 6837** 6838** ^An attempt to write to an expired [BLOB handle] fails with an 6839** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6840** before the [BLOB handle] expired are not rolled back by the 6841** expiration of the handle, though of course those changes might 6842** have been overwritten by the statement that expired the BLOB handle 6843** or by other independent statements. 6844** 6845** This routine only works on a [BLOB handle] which has been created 6846** by a prior successful call to [sqlite3_blob_open()] and which has not 6847** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6848** to this routine results in undefined and probably undesirable behavior. 6849** 6850** See also: [sqlite3_blob_read()]. 6851*/ 6852SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6853 6854/* 6855** CAPI3REF: Virtual File System Objects 6856** 6857** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6858** that SQLite uses to interact 6859** with the underlying operating system. Most SQLite builds come with a 6860** single default VFS that is appropriate for the host computer. 6861** New VFSes can be registered and existing VFSes can be unregistered. 6862** The following interfaces are provided. 6863** 6864** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6865** ^Names are case sensitive. 6866** ^Names are zero-terminated UTF-8 strings. 6867** ^If there is no match, a NULL pointer is returned. 6868** ^If zVfsName is NULL then the default VFS is returned. 6869** 6870** ^New VFSes are registered with sqlite3_vfs_register(). 6871** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6872** ^The same VFS can be registered multiple times without injury. 6873** ^To make an existing VFS into the default VFS, register it again 6874** with the makeDflt flag set. If two different VFSes with the 6875** same name are registered, the behavior is undefined. If a 6876** VFS is registered with a name that is NULL or an empty string, 6877** then the behavior is undefined. 6878** 6879** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6880** ^(If the default VFS is unregistered, another VFS is chosen as 6881** the default. The choice for the new VFS is arbitrary.)^ 6882*/ 6883SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6884SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6885SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6886 6887/* 6888** CAPI3REF: Mutexes 6889** 6890** The SQLite core uses these routines for thread 6891** synchronization. Though they are intended for internal 6892** use by SQLite, code that links against SQLite is 6893** permitted to use any of these routines. 6894** 6895** The SQLite source code contains multiple implementations 6896** of these mutex routines. An appropriate implementation 6897** is selected automatically at compile-time. The following 6898** implementations are available in the SQLite core: 6899** 6900** <ul> 6901** <li> SQLITE_MUTEX_PTHREADS 6902** <li> SQLITE_MUTEX_W32 6903** <li> SQLITE_MUTEX_NOOP 6904** </ul> 6905** 6906** The SQLITE_MUTEX_NOOP implementation is a set of routines 6907** that does no real locking and is appropriate for use in 6908** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6909** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6910** and Windows. 6911** 6912** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6913** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6914** implementation is included with the library. In this case the 6915** application must supply a custom mutex implementation using the 6916** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6917** before calling sqlite3_initialize() or any other public sqlite3_ 6918** function that calls sqlite3_initialize(). 6919** 6920** ^The sqlite3_mutex_alloc() routine allocates a new 6921** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6922** routine returns NULL if it is unable to allocate the requested 6923** mutex. The argument to sqlite3_mutex_alloc() must one of these 6924** integer constants: 6925** 6926** <ul> 6927** <li> SQLITE_MUTEX_FAST 6928** <li> SQLITE_MUTEX_RECURSIVE 6929** <li> SQLITE_MUTEX_STATIC_MASTER 6930** <li> SQLITE_MUTEX_STATIC_MEM 6931** <li> SQLITE_MUTEX_STATIC_OPEN 6932** <li> SQLITE_MUTEX_STATIC_PRNG 6933** <li> SQLITE_MUTEX_STATIC_LRU 6934** <li> SQLITE_MUTEX_STATIC_PMEM 6935** <li> SQLITE_MUTEX_STATIC_APP1 6936** <li> SQLITE_MUTEX_STATIC_APP2 6937** <li> SQLITE_MUTEX_STATIC_APP3 6938** <li> SQLITE_MUTEX_STATIC_VFS1 6939** <li> SQLITE_MUTEX_STATIC_VFS2 6940** <li> SQLITE_MUTEX_STATIC_VFS3 6941** </ul> 6942** 6943** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6944** cause sqlite3_mutex_alloc() to create 6945** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6946** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6947** The mutex implementation does not need to make a distinction 6948** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6949** not want to. SQLite will only request a recursive mutex in 6950** cases where it really needs one. If a faster non-recursive mutex 6951** implementation is available on the host platform, the mutex subsystem 6952** might return such a mutex in response to SQLITE_MUTEX_FAST. 6953** 6954** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6955** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6956** a pointer to a static preexisting mutex. ^Nine static mutexes are 6957** used by the current version of SQLite. Future versions of SQLite 6958** may add additional static mutexes. Static mutexes are for internal 6959** use by SQLite only. Applications that use SQLite mutexes should 6960** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6961** SQLITE_MUTEX_RECURSIVE. 6962** 6963** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6964** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6965** returns a different mutex on every call. ^For the static 6966** mutex types, the same mutex is returned on every call that has 6967** the same type number. 6968** 6969** ^The sqlite3_mutex_free() routine deallocates a previously 6970** allocated dynamic mutex. Attempting to deallocate a static 6971** mutex results in undefined behavior. 6972** 6973** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6974** to enter a mutex. ^If another thread is already within the mutex, 6975** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6976** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6977** upon successful entry. ^(Mutexes created using 6978** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6979** In such cases, the 6980** mutex must be exited an equal number of times before another thread 6981** can enter.)^ If the same thread tries to enter any mutex other 6982** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6983** 6984** ^(Some systems (for example, Windows 95) do not support the operation 6985** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6986** will always return SQLITE_BUSY. The SQLite core only ever uses 6987** sqlite3_mutex_try() as an optimization so this is acceptable 6988** behavior.)^ 6989** 6990** ^The sqlite3_mutex_leave() routine exits a mutex that was 6991** previously entered by the same thread. The behavior 6992** is undefined if the mutex is not currently entered by the 6993** calling thread or is not currently allocated. 6994** 6995** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6996** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6997** behave as no-ops. 6998** 6999** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7000*/ 7001SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7002SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7003SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7004SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7005SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7006 7007/* 7008** CAPI3REF: Mutex Methods Object 7009** 7010** An instance of this structure defines the low-level routines 7011** used to allocate and use mutexes. 7012** 7013** Usually, the default mutex implementations provided by SQLite are 7014** sufficient, however the application has the option of substituting a custom 7015** implementation for specialized deployments or systems for which SQLite 7016** does not provide a suitable implementation. In this case, the application 7017** creates and populates an instance of this structure to pass 7018** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7019** Additionally, an instance of this structure can be used as an 7020** output variable when querying the system for the current mutex 7021** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7022** 7023** ^The xMutexInit method defined by this structure is invoked as 7024** part of system initialization by the sqlite3_initialize() function. 7025** ^The xMutexInit routine is called by SQLite exactly once for each 7026** effective call to [sqlite3_initialize()]. 7027** 7028** ^The xMutexEnd method defined by this structure is invoked as 7029** part of system shutdown by the sqlite3_shutdown() function. The 7030** implementation of this method is expected to release all outstanding 7031** resources obtained by the mutex methods implementation, especially 7032** those obtained by the xMutexInit method. ^The xMutexEnd() 7033** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7034** 7035** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7036** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7037** xMutexNotheld) implement the following interfaces (respectively): 7038** 7039** <ul> 7040** <li> [sqlite3_mutex_alloc()] </li> 7041** <li> [sqlite3_mutex_free()] </li> 7042** <li> [sqlite3_mutex_enter()] </li> 7043** <li> [sqlite3_mutex_try()] </li> 7044** <li> [sqlite3_mutex_leave()] </li> 7045** <li> [sqlite3_mutex_held()] </li> 7046** <li> [sqlite3_mutex_notheld()] </li> 7047** </ul>)^ 7048** 7049** The only difference is that the public sqlite3_XXX functions enumerated 7050** above silently ignore any invocations that pass a NULL pointer instead 7051** of a valid mutex handle. The implementations of the methods defined 7052** by this structure are not required to handle this case, the results 7053** of passing a NULL pointer instead of a valid mutex handle are undefined 7054** (i.e. it is acceptable to provide an implementation that segfaults if 7055** it is passed a NULL pointer). 7056** 7057** The xMutexInit() method must be threadsafe. It must be harmless to 7058** invoke xMutexInit() multiple times within the same process and without 7059** intervening calls to xMutexEnd(). Second and subsequent calls to 7060** xMutexInit() must be no-ops. 7061** 7062** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7063** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7064** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7065** memory allocation for a fast or recursive mutex. 7066** 7067** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7068** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7069** If xMutexInit fails in any way, it is expected to clean up after itself 7070** prior to returning. 7071*/ 7072typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7073struct sqlite3_mutex_methods { 7074 int (*xMutexInit)(void); 7075 int (*xMutexEnd)(void); 7076 sqlite3_mutex *(*xMutexAlloc)(int); 7077 void (*xMutexFree)(sqlite3_mutex *); 7078 void (*xMutexEnter)(sqlite3_mutex *); 7079 int (*xMutexTry)(sqlite3_mutex *); 7080 void (*xMutexLeave)(sqlite3_mutex *); 7081 int (*xMutexHeld)(sqlite3_mutex *); 7082 int (*xMutexNotheld)(sqlite3_mutex *); 7083}; 7084 7085/* 7086** CAPI3REF: Mutex Verification Routines 7087** 7088** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7089** are intended for use inside assert() statements. The SQLite core 7090** never uses these routines except inside an assert() and applications 7091** are advised to follow the lead of the core. The SQLite core only 7092** provides implementations for these routines when it is compiled 7093** with the SQLITE_DEBUG flag. External mutex implementations 7094** are only required to provide these routines if SQLITE_DEBUG is 7095** defined and if NDEBUG is not defined. 7096** 7097** These routines should return true if the mutex in their argument 7098** is held or not held, respectively, by the calling thread. 7099** 7100** The implementation is not required to provide versions of these 7101** routines that actually work. If the implementation does not provide working 7102** versions of these routines, it should at least provide stubs that always 7103** return true so that one does not get spurious assertion failures. 7104** 7105** If the argument to sqlite3_mutex_held() is a NULL pointer then 7106** the routine should return 1. This seems counter-intuitive since 7107** clearly the mutex cannot be held if it does not exist. But 7108** the reason the mutex does not exist is because the build is not 7109** using mutexes. And we do not want the assert() containing the 7110** call to sqlite3_mutex_held() to fail, so a non-zero return is 7111** the appropriate thing to do. The sqlite3_mutex_notheld() 7112** interface should also return 1 when given a NULL pointer. 7113*/ 7114#ifndef NDEBUG 7115SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7116SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7117#endif 7118 7119/* 7120** CAPI3REF: Mutex Types 7121** 7122** The [sqlite3_mutex_alloc()] interface takes a single argument 7123** which is one of these integer constants. 7124** 7125** The set of static mutexes may change from one SQLite release to the 7126** next. Applications that override the built-in mutex logic must be 7127** prepared to accommodate additional static mutexes. 7128*/ 7129#define SQLITE_MUTEX_FAST 0 7130#define SQLITE_MUTEX_RECURSIVE 1 7131#define SQLITE_MUTEX_STATIC_MASTER 2 7132#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7133#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7134#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7135#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7136#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7137#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7138#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7139#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7140#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7141#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7142#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7143#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7144#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7145 7146/* 7147** CAPI3REF: Retrieve the mutex for a database connection 7148** METHOD: sqlite3 7149** 7150** ^This interface returns a pointer the [sqlite3_mutex] object that 7151** serializes access to the [database connection] given in the argument 7152** when the [threading mode] is Serialized. 7153** ^If the [threading mode] is Single-thread or Multi-thread then this 7154** routine returns a NULL pointer. 7155*/ 7156SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7157 7158/* 7159** CAPI3REF: Low-Level Control Of Database Files 7160** METHOD: sqlite3 7161** KEYWORDS: {file control} 7162** 7163** ^The [sqlite3_file_control()] interface makes a direct call to the 7164** xFileControl method for the [sqlite3_io_methods] object associated 7165** with a particular database identified by the second argument. ^The 7166** name of the database is "main" for the main database or "temp" for the 7167** TEMP database, or the name that appears after the AS keyword for 7168** databases that are added using the [ATTACH] SQL command. 7169** ^A NULL pointer can be used in place of "main" to refer to the 7170** main database file. 7171** ^The third and fourth parameters to this routine 7172** are passed directly through to the second and third parameters of 7173** the xFileControl method. ^The return value of the xFileControl 7174** method becomes the return value of this routine. 7175** 7176** A few opcodes for [sqlite3_file_control()] are handled directly 7177** by the SQLite core and never invoke the 7178** sqlite3_io_methods.xFileControl method. 7179** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7180** a pointer to the underlying [sqlite3_file] object to be written into 7181** the space pointed to by the 4th parameter. The 7182** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7183** the [sqlite3_file] object associated with the journal file instead of 7184** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7185** a pointer to the underlying [sqlite3_vfs] object for the file. 7186** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7187** from the pager. 7188** 7189** ^If the second parameter (zDbName) does not match the name of any 7190** open database file, then SQLITE_ERROR is returned. ^This error 7191** code is not remembered and will not be recalled by [sqlite3_errcode()] 7192** or [sqlite3_errmsg()]. The underlying xFileControl method might 7193** also return SQLITE_ERROR. There is no way to distinguish between 7194** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7195** xFileControl method. 7196** 7197** See also: [file control opcodes] 7198*/ 7199SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7200 7201/* 7202** CAPI3REF: Testing Interface 7203** 7204** ^The sqlite3_test_control() interface is used to read out internal 7205** state of SQLite and to inject faults into SQLite for testing 7206** purposes. ^The first parameter is an operation code that determines 7207** the number, meaning, and operation of all subsequent parameters. 7208** 7209** This interface is not for use by applications. It exists solely 7210** for verifying the correct operation of the SQLite library. Depending 7211** on how the SQLite library is compiled, this interface might not exist. 7212** 7213** The details of the operation codes, their meanings, the parameters 7214** they take, and what they do are all subject to change without notice. 7215** Unlike most of the SQLite API, this function is not guaranteed to 7216** operate consistently from one release to the next. 7217*/ 7218SQLITE_API int sqlite3_test_control(int op, ...); 7219 7220/* 7221** CAPI3REF: Testing Interface Operation Codes 7222** 7223** These constants are the valid operation code parameters used 7224** as the first argument to [sqlite3_test_control()]. 7225** 7226** These parameters and their meanings are subject to change 7227** without notice. These values are for testing purposes only. 7228** Applications should not use any of these parameters or the 7229** [sqlite3_test_control()] interface. 7230*/ 7231#define SQLITE_TESTCTRL_FIRST 5 7232#define SQLITE_TESTCTRL_PRNG_SAVE 5 7233#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7234#define SQLITE_TESTCTRL_PRNG_RESET 7 7235#define SQLITE_TESTCTRL_BITVEC_TEST 8 7236#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7237#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7238#define SQLITE_TESTCTRL_PENDING_BYTE 11 7239#define SQLITE_TESTCTRL_ASSERT 12 7240#define SQLITE_TESTCTRL_ALWAYS 13 7241#define SQLITE_TESTCTRL_RESERVE 14 7242#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7243#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7244#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7245#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7246#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7247#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7248#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7249#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7250#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7251#define SQLITE_TESTCTRL_BYTEORDER 22 7252#define SQLITE_TESTCTRL_ISINIT 23 7253#define SQLITE_TESTCTRL_SORTER_MMAP 24 7254#define SQLITE_TESTCTRL_IMPOSTER 25 7255#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7256#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7257 7258/* 7259** CAPI3REF: SQL Keyword Checking 7260** 7261** These routines provide access to the set of SQL language keywords 7262** recognized by SQLite. Applications can uses these routines to determine 7263** whether or not a specific identifier needs to be escaped (for example, 7264** by enclosing in double-quotes) so as not to confuse the parser. 7265** 7266** The sqlite3_keyword_count() interface returns the number of distinct 7267** keywords understood by SQLite. 7268** 7269** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7270** makes *Z point to that keyword expressed as UTF8 and writes the number 7271** of bytes in the keyword into *L. The string that *Z points to is not 7272** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7273** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7274** or L are NULL or invalid pointers then calls to 7275** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7276** 7277** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7278** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7279** if it is and zero if not. 7280** 7281** The parser used by SQLite is forgiving. It is often possible to use 7282** a keyword as an identifier as long as such use does not result in a 7283** parsing ambiguity. For example, the statement 7284** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7285** creates a new table named "BEGIN" with three columns named 7286** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7287** using keywords as identifiers. Common techniques used to avoid keyword 7288** name collisions include: 7289** <ul> 7290** <li> Put all identifier names inside double-quotes. This is the official 7291** SQL way to escape identifier names. 7292** <li> Put identifier names inside [...]. This is not standard SQL, 7293** but it is what SQL Server does and so lots of programmers use this 7294** technique. 7295** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7296** with "Z". 7297** <li> Include a digit somewhere in every identifier name. 7298** </ul> 7299** 7300** Note that the number of keywords understood by SQLite can depend on 7301** compile-time options. For example, "VACUUM" is not a keyword if 7302** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7303** new keywords may be added to future releases of SQLite. 7304*/ 7305SQLITE_API int sqlite3_keyword_count(void); 7306SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7307SQLITE_API int sqlite3_keyword_check(const char*,int); 7308 7309/* 7310** CAPI3REF: Dynamic String Object 7311** KEYWORDS: {dynamic string} 7312** 7313** An instance of the sqlite3_str object contains a dynamically-sized 7314** string under construction. 7315** 7316** The lifecycle of an sqlite3_str object is as follows: 7317** <ol> 7318** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7319** <li> ^Text is appended to the sqlite3_str object using various 7320** methods, such as [sqlite3_str_appendf()]. 7321** <li> ^The sqlite3_str object is destroyed and the string it created 7322** is returned using the [sqlite3_str_finish()] interface. 7323** </ol> 7324*/ 7325typedef struct sqlite3_str sqlite3_str; 7326 7327/* 7328** CAPI3REF: Create A New Dynamic String Object 7329** CONSTRUCTOR: sqlite3_str 7330** 7331** ^The [sqlite3_str_new(D)] interface allocates and initializes 7332** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7333** [sqlite3_str_new()] must be freed by a subsequent call to 7334** [sqlite3_str_finish(X)]. 7335** 7336** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7337** valid [sqlite3_str] object, though in the event of an out-of-memory 7338** error the returned object might be a special singleton that will 7339** silently reject new text, always return SQLITE_NOMEM from 7340** [sqlite3_str_errcode()], always return 0 for 7341** [sqlite3_str_length()], and always return NULL from 7342** [sqlite3_str_finish(X)]. It is always safe to use the value 7343** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7344** to any of the other [sqlite3_str] methods. 7345** 7346** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7347** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7348** length of the string contained in the [sqlite3_str] object will be 7349** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7350** of [SQLITE_MAX_LENGTH]. 7351*/ 7352SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7353 7354/* 7355** CAPI3REF: Finalize A Dynamic String 7356** DESTRUCTOR: sqlite3_str 7357** 7358** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7359** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7360** that contains the constructed string. The calling application should 7361** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7362** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7363** errors were encountered during construction of the string. ^The 7364** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7365** string in [sqlite3_str] object X is zero bytes long. 7366*/ 7367SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7368 7369/* 7370** CAPI3REF: Add Content To A Dynamic String 7371** METHOD: sqlite3_str 7372** 7373** These interfaces add content to an sqlite3_str object previously obtained 7374** from [sqlite3_str_new()]. 7375** 7376** ^The [sqlite3_str_appendf(X,F,...)] and 7377** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7378** functionality of SQLite to append formatted text onto the end of 7379** [sqlite3_str] object X. 7380** 7381** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7382** onto the end of the [sqlite3_str] object X. N must be non-negative. 7383** S must contain at least N non-zero bytes of content. To append a 7384** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7385** method instead. 7386** 7387** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7388** zero-terminated string S onto the end of [sqlite3_str] object X. 7389** 7390** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7391** single-byte character C onto the end of [sqlite3_str] object X. 7392** ^This method can be used, for example, to add whitespace indentation. 7393** 7394** ^The [sqlite3_str_reset(X)] method resets the string under construction 7395** inside [sqlite3_str] object X back to zero bytes in length. 7396** 7397** These methods do not return a result code. ^If an error occurs, that fact 7398** is recorded in the [sqlite3_str] object and can be recovered by a 7399** subsequent call to [sqlite3_str_errcode(X)]. 7400*/ 7401SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7402SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7403SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7404SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7405SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7406SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7407 7408/* 7409** CAPI3REF: Status Of A Dynamic String 7410** METHOD: sqlite3_str 7411** 7412** These interfaces return the current status of an [sqlite3_str] object. 7413** 7414** ^If any prior errors have occurred while constructing the dynamic string 7415** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7416** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7417** [SQLITE_NOMEM] following any out-of-memory error, or 7418** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7419** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7420** 7421** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7422** of the dynamic string under construction in [sqlite3_str] object X. 7423** ^The length returned by [sqlite3_str_length(X)] does not include the 7424** zero-termination byte. 7425** 7426** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7427** content of the dynamic string under construction in X. The value 7428** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7429** and might be freed or altered by any subsequent method on the same 7430** [sqlite3_str] object. Applications must not used the pointer returned 7431** [sqlite3_str_value(X)] after any subsequent method call on the same 7432** object. ^Applications may change the content of the string returned 7433** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7434** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7435** write any byte after any subsequent sqlite3_str method call. 7436*/ 7437SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7438SQLITE_API int sqlite3_str_length(sqlite3_str*); 7439SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7440 7441/* 7442** CAPI3REF: SQLite Runtime Status 7443** 7444** ^These interfaces are used to retrieve runtime status information 7445** about the performance of SQLite, and optionally to reset various 7446** highwater marks. ^The first argument is an integer code for 7447** the specific parameter to measure. ^(Recognized integer codes 7448** are of the form [status parameters | SQLITE_STATUS_...].)^ 7449** ^The current value of the parameter is returned into *pCurrent. 7450** ^The highest recorded value is returned in *pHighwater. ^If the 7451** resetFlag is true, then the highest record value is reset after 7452** *pHighwater is written. ^(Some parameters do not record the highest 7453** value. For those parameters 7454** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7455** ^(Other parameters record only the highwater mark and not the current 7456** value. For these latter parameters nothing is written into *pCurrent.)^ 7457** 7458** ^The sqlite3_status() and sqlite3_status64() routines return 7459** SQLITE_OK on success and a non-zero [error code] on failure. 7460** 7461** If either the current value or the highwater mark is too large to 7462** be represented by a 32-bit integer, then the values returned by 7463** sqlite3_status() are undefined. 7464** 7465** See also: [sqlite3_db_status()] 7466*/ 7467SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7468SQLITE_API int sqlite3_status64( 7469 int op, 7470 sqlite3_int64 *pCurrent, 7471 sqlite3_int64 *pHighwater, 7472 int resetFlag 7473); 7474 7475 7476/* 7477** CAPI3REF: Status Parameters 7478** KEYWORDS: {status parameters} 7479** 7480** These integer constants designate various run-time status parameters 7481** that can be returned by [sqlite3_status()]. 7482** 7483** <dl> 7484** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7485** <dd>This parameter is the current amount of memory checked out 7486** using [sqlite3_malloc()], either directly or indirectly. The 7487** figure includes calls made to [sqlite3_malloc()] by the application 7488** and internal memory usage by the SQLite library. Auxiliary page-cache 7489** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7490** this parameter. The amount returned is the sum of the allocation 7491** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7492** 7493** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7494** <dd>This parameter records the largest memory allocation request 7495** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7496** internal equivalents). Only the value returned in the 7497** *pHighwater parameter to [sqlite3_status()] is of interest. 7498** The value written into the *pCurrent parameter is undefined.</dd>)^ 7499** 7500** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7501** <dd>This parameter records the number of separate memory allocations 7502** currently checked out.</dd>)^ 7503** 7504** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7505** <dd>This parameter returns the number of pages used out of the 7506** [pagecache memory allocator] that was configured using 7507** [SQLITE_CONFIG_PAGECACHE]. The 7508** value returned is in pages, not in bytes.</dd>)^ 7509** 7510** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7511** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7512** <dd>This parameter returns the number of bytes of page cache 7513** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7514** buffer and where forced to overflow to [sqlite3_malloc()]. The 7515** returned value includes allocations that overflowed because they 7516** where too large (they were larger than the "sz" parameter to 7517** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7518** no space was left in the page cache.</dd>)^ 7519** 7520** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7521** <dd>This parameter records the largest memory allocation request 7522** handed to [pagecache memory allocator]. Only the value returned in the 7523** *pHighwater parameter to [sqlite3_status()] is of interest. 7524** The value written into the *pCurrent parameter is undefined.</dd>)^ 7525** 7526** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7527** <dd>No longer used.</dd> 7528** 7529** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7530** <dd>No longer used.</dd> 7531** 7532** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7533** <dd>No longer used.</dd> 7534** 7535** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7536** <dd>The *pHighwater parameter records the deepest parser stack. 7537** The *pCurrent value is undefined. The *pHighwater value is only 7538** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7539** </dl> 7540** 7541** New status parameters may be added from time to time. 7542*/ 7543#define SQLITE_STATUS_MEMORY_USED 0 7544#define SQLITE_STATUS_PAGECACHE_USED 1 7545#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7546#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7547#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7548#define SQLITE_STATUS_MALLOC_SIZE 5 7549#define SQLITE_STATUS_PARSER_STACK 6 7550#define SQLITE_STATUS_PAGECACHE_SIZE 7 7551#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7552#define SQLITE_STATUS_MALLOC_COUNT 9 7553 7554/* 7555** CAPI3REF: Database Connection Status 7556** METHOD: sqlite3 7557** 7558** ^This interface is used to retrieve runtime status information 7559** about a single [database connection]. ^The first argument is the 7560** database connection object to be interrogated. ^The second argument 7561** is an integer constant, taken from the set of 7562** [SQLITE_DBSTATUS options], that 7563** determines the parameter to interrogate. The set of 7564** [SQLITE_DBSTATUS options] is likely 7565** to grow in future releases of SQLite. 7566** 7567** ^The current value of the requested parameter is written into *pCur 7568** and the highest instantaneous value is written into *pHiwtr. ^If 7569** the resetFlg is true, then the highest instantaneous value is 7570** reset back down to the current value. 7571** 7572** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7573** non-zero [error code] on failure. 7574** 7575** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7576*/ 7577SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7578 7579/* 7580** CAPI3REF: Status Parameters for database connections 7581** KEYWORDS: {SQLITE_DBSTATUS options} 7582** 7583** These constants are the available integer "verbs" that can be passed as 7584** the second argument to the [sqlite3_db_status()] interface. 7585** 7586** New verbs may be added in future releases of SQLite. Existing verbs 7587** might be discontinued. Applications should check the return code from 7588** [sqlite3_db_status()] to make sure that the call worked. 7589** The [sqlite3_db_status()] interface will return a non-zero error code 7590** if a discontinued or unsupported verb is invoked. 7591** 7592** <dl> 7593** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7594** <dd>This parameter returns the number of lookaside memory slots currently 7595** checked out.</dd>)^ 7596** 7597** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7598** <dd>This parameter returns the number malloc attempts that were 7599** satisfied using lookaside memory. Only the high-water value is meaningful; 7600** the current value is always zero.)^ 7601** 7602** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7603** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7604** <dd>This parameter returns the number malloc attempts that might have 7605** been satisfied using lookaside memory but failed due to the amount of 7606** memory requested being larger than the lookaside slot size. 7607** Only the high-water value is meaningful; 7608** the current value is always zero.)^ 7609** 7610** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7611** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7612** <dd>This parameter returns the number malloc attempts that might have 7613** been satisfied using lookaside memory but failed due to all lookaside 7614** memory already being in use. 7615** Only the high-water value is meaningful; 7616** the current value is always zero.)^ 7617** 7618** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7619** <dd>This parameter returns the approximate number of bytes of heap 7620** memory used by all pager caches associated with the database connection.)^ 7621** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7622** 7623** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7624** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7625** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7626** pager cache is shared between two or more connections the bytes of heap 7627** memory used by that pager cache is divided evenly between the attached 7628** connections.)^ In other words, if none of the pager caches associated 7629** with the database connection are shared, this request returns the same 7630** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7631** shared, the value returned by this call will be smaller than that returned 7632** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7633** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7634** 7635** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7636** <dd>This parameter returns the approximate number of bytes of heap 7637** memory used to store the schema for all databases associated 7638** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7639** ^The full amount of memory used by the schemas is reported, even if the 7640** schema memory is shared with other database connections due to 7641** [shared cache mode] being enabled. 7642** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7643** 7644** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7645** <dd>This parameter returns the approximate number of bytes of heap 7646** and lookaside memory used by all prepared statements associated with 7647** the database connection.)^ 7648** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7649** </dd> 7650** 7651** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7652** <dd>This parameter returns the number of pager cache hits that have 7653** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7654** is always 0. 7655** </dd> 7656** 7657** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7658** <dd>This parameter returns the number of pager cache misses that have 7659** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7660** is always 0. 7661** </dd> 7662** 7663** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7664** <dd>This parameter returns the number of dirty cache entries that have 7665** been written to disk. Specifically, the number of pages written to the 7666** wal file in wal mode databases, or the number of pages written to the 7667** database file in rollback mode databases. Any pages written as part of 7668** transaction rollback or database recovery operations are not included. 7669** If an IO or other error occurs while writing a page to disk, the effect 7670** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7671** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7672** </dd> 7673** 7674** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7675** <dd>This parameter returns the number of dirty cache entries that have 7676** been written to disk in the middle of a transaction due to the page 7677** cache overflowing. Transactions are more efficient if they are written 7678** to disk all at once. When pages spill mid-transaction, that introduces 7679** additional overhead. This parameter can be used help identify 7680** inefficiencies that can be resolve by increasing the cache size. 7681** </dd> 7682** 7683** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7684** <dd>This parameter returns zero for the current value if and only if 7685** all foreign key constraints (deferred or immediate) have been 7686** resolved.)^ ^The highwater mark is always 0. 7687** </dd> 7688** </dl> 7689*/ 7690#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7691#define SQLITE_DBSTATUS_CACHE_USED 1 7692#define SQLITE_DBSTATUS_SCHEMA_USED 2 7693#define SQLITE_DBSTATUS_STMT_USED 3 7694#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7695#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7696#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7697#define SQLITE_DBSTATUS_CACHE_HIT 7 7698#define SQLITE_DBSTATUS_CACHE_MISS 8 7699#define SQLITE_DBSTATUS_CACHE_WRITE 9 7700#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7701#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7702#define SQLITE_DBSTATUS_CACHE_SPILL 12 7703#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7704 7705 7706/* 7707** CAPI3REF: Prepared Statement Status 7708** METHOD: sqlite3_stmt 7709** 7710** ^(Each prepared statement maintains various 7711** [SQLITE_STMTSTATUS counters] that measure the number 7712** of times it has performed specific operations.)^ These counters can 7713** be used to monitor the performance characteristics of the prepared 7714** statements. For example, if the number of table steps greatly exceeds 7715** the number of table searches or result rows, that would tend to indicate 7716** that the prepared statement is using a full table scan rather than 7717** an index. 7718** 7719** ^(This interface is used to retrieve and reset counter values from 7720** a [prepared statement]. The first argument is the prepared statement 7721** object to be interrogated. The second argument 7722** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7723** to be interrogated.)^ 7724** ^The current value of the requested counter is returned. 7725** ^If the resetFlg is true, then the counter is reset to zero after this 7726** interface call returns. 7727** 7728** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7729*/ 7730SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7731 7732/* 7733** CAPI3REF: Status Parameters for prepared statements 7734** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7735** 7736** These preprocessor macros define integer codes that name counter 7737** values associated with the [sqlite3_stmt_status()] interface. 7738** The meanings of the various counters are as follows: 7739** 7740** <dl> 7741** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7742** <dd>^This is the number of times that SQLite has stepped forward in 7743** a table as part of a full table scan. Large numbers for this counter 7744** may indicate opportunities for performance improvement through 7745** careful use of indices.</dd> 7746** 7747** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7748** <dd>^This is the number of sort operations that have occurred. 7749** A non-zero value in this counter may indicate an opportunity to 7750** improvement performance through careful use of indices.</dd> 7751** 7752** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7753** <dd>^This is the number of rows inserted into transient indices that 7754** were created automatically in order to help joins run faster. 7755** A non-zero value in this counter may indicate an opportunity to 7756** improvement performance by adding permanent indices that do not 7757** need to be reinitialized each time the statement is run.</dd> 7758** 7759** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7760** <dd>^This is the number of virtual machine operations executed 7761** by the prepared statement if that number is less than or equal 7762** to 2147483647. The number of virtual machine operations can be 7763** used as a proxy for the total work done by the prepared statement. 7764** If the number of virtual machine operations exceeds 2147483647 7765** then the value returned by this statement status code is undefined. 7766** 7767** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7768** <dd>^This is the number of times that the prepare statement has been 7769** automatically regenerated due to schema changes or change to 7770** [bound parameters] that might affect the query plan. 7771** 7772** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7773** <dd>^This is the number of times that the prepared statement has 7774** been run. A single "run" for the purposes of this counter is one 7775** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7776** The counter is incremented on the first [sqlite3_step()] call of each 7777** cycle. 7778** 7779** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7780** <dd>^This is the approximate number of bytes of heap memory 7781** used to store the prepared statement. ^This value is not actually 7782** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7783** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7784** </dd> 7785** </dl> 7786*/ 7787#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7788#define SQLITE_STMTSTATUS_SORT 2 7789#define SQLITE_STMTSTATUS_AUTOINDEX 3 7790#define SQLITE_STMTSTATUS_VM_STEP 4 7791#define SQLITE_STMTSTATUS_REPREPARE 5 7792#define SQLITE_STMTSTATUS_RUN 6 7793#define SQLITE_STMTSTATUS_MEMUSED 99 7794 7795/* 7796** CAPI3REF: Custom Page Cache Object 7797** 7798** The sqlite3_pcache type is opaque. It is implemented by 7799** the pluggable module. The SQLite core has no knowledge of 7800** its size or internal structure and never deals with the 7801** sqlite3_pcache object except by holding and passing pointers 7802** to the object. 7803** 7804** See [sqlite3_pcache_methods2] for additional information. 7805*/ 7806typedef struct sqlite3_pcache sqlite3_pcache; 7807 7808/* 7809** CAPI3REF: Custom Page Cache Object 7810** 7811** The sqlite3_pcache_page object represents a single page in the 7812** page cache. The page cache will allocate instances of this 7813** object. Various methods of the page cache use pointers to instances 7814** of this object as parameters or as their return value. 7815** 7816** See [sqlite3_pcache_methods2] for additional information. 7817*/ 7818typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7819struct sqlite3_pcache_page { 7820 void *pBuf; /* The content of the page */ 7821 void *pExtra; /* Extra information associated with the page */ 7822}; 7823 7824/* 7825** CAPI3REF: Application Defined Page Cache. 7826** KEYWORDS: {page cache} 7827** 7828** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7829** register an alternative page cache implementation by passing in an 7830** instance of the sqlite3_pcache_methods2 structure.)^ 7831** In many applications, most of the heap memory allocated by 7832** SQLite is used for the page cache. 7833** By implementing a 7834** custom page cache using this API, an application can better control 7835** the amount of memory consumed by SQLite, the way in which 7836** that memory is allocated and released, and the policies used to 7837** determine exactly which parts of a database file are cached and for 7838** how long. 7839** 7840** The alternative page cache mechanism is an 7841** extreme measure that is only needed by the most demanding applications. 7842** The built-in page cache is recommended for most uses. 7843** 7844** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7845** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7846** the application may discard the parameter after the call to 7847** [sqlite3_config()] returns.)^ 7848** 7849** [[the xInit() page cache method]] 7850** ^(The xInit() method is called once for each effective 7851** call to [sqlite3_initialize()])^ 7852** (usually only once during the lifetime of the process). ^(The xInit() 7853** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7854** The intent of the xInit() method is to set up global data structures 7855** required by the custom page cache implementation. 7856** ^(If the xInit() method is NULL, then the 7857** built-in default page cache is used instead of the application defined 7858** page cache.)^ 7859** 7860** [[the xShutdown() page cache method]] 7861** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7862** It can be used to clean up 7863** any outstanding resources before process shutdown, if required. 7864** ^The xShutdown() method may be NULL. 7865** 7866** ^SQLite automatically serializes calls to the xInit method, 7867** so the xInit method need not be threadsafe. ^The 7868** xShutdown method is only called from [sqlite3_shutdown()] so it does 7869** not need to be threadsafe either. All other methods must be threadsafe 7870** in multithreaded applications. 7871** 7872** ^SQLite will never invoke xInit() more than once without an intervening 7873** call to xShutdown(). 7874** 7875** [[the xCreate() page cache methods]] 7876** ^SQLite invokes the xCreate() method to construct a new cache instance. 7877** SQLite will typically create one cache instance for each open database file, 7878** though this is not guaranteed. ^The 7879** first parameter, szPage, is the size in bytes of the pages that must 7880** be allocated by the cache. ^szPage will always a power of two. ^The 7881** second parameter szExtra is a number of bytes of extra storage 7882** associated with each page cache entry. ^The szExtra parameter will 7883** a number less than 250. SQLite will use the 7884** extra szExtra bytes on each page to store metadata about the underlying 7885** database page on disk. The value passed into szExtra depends 7886** on the SQLite version, the target platform, and how SQLite was compiled. 7887** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7888** created will be used to cache database pages of a file stored on disk, or 7889** false if it is used for an in-memory database. The cache implementation 7890** does not have to do anything special based with the value of bPurgeable; 7891** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7892** never invoke xUnpin() except to deliberately delete a page. 7893** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7894** false will always have the "discard" flag set to true. 7895** ^Hence, a cache created with bPurgeable false will 7896** never contain any unpinned pages. 7897** 7898** [[the xCachesize() page cache method]] 7899** ^(The xCachesize() method may be called at any time by SQLite to set the 7900** suggested maximum cache-size (number of pages stored by) the cache 7901** instance passed as the first argument. This is the value configured using 7902** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7903** parameter, the implementation is not required to do anything with this 7904** value; it is advisory only. 7905** 7906** [[the xPagecount() page cache methods]] 7907** The xPagecount() method must return the number of pages currently 7908** stored in the cache, both pinned and unpinned. 7909** 7910** [[the xFetch() page cache methods]] 7911** The xFetch() method locates a page in the cache and returns a pointer to 7912** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7913** The pBuf element of the returned sqlite3_pcache_page object will be a 7914** pointer to a buffer of szPage bytes used to store the content of a 7915** single database page. The pExtra element of sqlite3_pcache_page will be 7916** a pointer to the szExtra bytes of extra storage that SQLite has requested 7917** for each entry in the page cache. 7918** 7919** The page to be fetched is determined by the key. ^The minimum key value 7920** is 1. After it has been retrieved using xFetch, the page is considered 7921** to be "pinned". 7922** 7923** If the requested page is already in the page cache, then the page cache 7924** implementation must return a pointer to the page buffer with its content 7925** intact. If the requested page is not already in the cache, then the 7926** cache implementation should use the value of the createFlag 7927** parameter to help it determined what action to take: 7928** 7929** <table border=1 width=85% align=center> 7930** <tr><th> createFlag <th> Behavior when page is not already in cache 7931** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7932** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7933** Otherwise return NULL. 7934** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7935** NULL if allocating a new page is effectively impossible. 7936** </table> 7937** 7938** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7939** will only use a createFlag of 2 after a prior call with a createFlag of 1 7940** failed.)^ In between the to xFetch() calls, SQLite may 7941** attempt to unpin one or more cache pages by spilling the content of 7942** pinned pages to disk and synching the operating system disk cache. 7943** 7944** [[the xUnpin() page cache method]] 7945** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7946** as its second argument. If the third parameter, discard, is non-zero, 7947** then the page must be evicted from the cache. 7948** ^If the discard parameter is 7949** zero, then the page may be discarded or retained at the discretion of 7950** page cache implementation. ^The page cache implementation 7951** may choose to evict unpinned pages at any time. 7952** 7953** The cache must not perform any reference counting. A single 7954** call to xUnpin() unpins the page regardless of the number of prior calls 7955** to xFetch(). 7956** 7957** [[the xRekey() page cache methods]] 7958** The xRekey() method is used to change the key value associated with the 7959** page passed as the second argument. If the cache 7960** previously contains an entry associated with newKey, it must be 7961** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7962** to be pinned. 7963** 7964** When SQLite calls the xTruncate() method, the cache must discard all 7965** existing cache entries with page numbers (keys) greater than or equal 7966** to the value of the iLimit parameter passed to xTruncate(). If any 7967** of these pages are pinned, they are implicitly unpinned, meaning that 7968** they can be safely discarded. 7969** 7970** [[the xDestroy() page cache method]] 7971** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7972** All resources associated with the specified cache should be freed. ^After 7973** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7974** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7975** functions. 7976** 7977** [[the xShrink() page cache method]] 7978** ^SQLite invokes the xShrink() method when it wants the page cache to 7979** free up as much of heap memory as possible. The page cache implementation 7980** is not obligated to free any memory, but well-behaved implementations should 7981** do their best. 7982*/ 7983typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7984struct sqlite3_pcache_methods2 { 7985 int iVersion; 7986 void *pArg; 7987 int (*xInit)(void*); 7988 void (*xShutdown)(void*); 7989 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7990 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7991 int (*xPagecount)(sqlite3_pcache*); 7992 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7993 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7994 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7995 unsigned oldKey, unsigned newKey); 7996 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7997 void (*xDestroy)(sqlite3_pcache*); 7998 void (*xShrink)(sqlite3_pcache*); 7999}; 8000 8001/* 8002** This is the obsolete pcache_methods object that has now been replaced 8003** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8004** retained in the header file for backwards compatibility only. 8005*/ 8006typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8007struct sqlite3_pcache_methods { 8008 void *pArg; 8009 int (*xInit)(void*); 8010 void (*xShutdown)(void*); 8011 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8012 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8013 int (*xPagecount)(sqlite3_pcache*); 8014 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8015 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8016 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8017 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8018 void (*xDestroy)(sqlite3_pcache*); 8019}; 8020 8021 8022/* 8023** CAPI3REF: Online Backup Object 8024** 8025** The sqlite3_backup object records state information about an ongoing 8026** online backup operation. ^The sqlite3_backup object is created by 8027** a call to [sqlite3_backup_init()] and is destroyed by a call to 8028** [sqlite3_backup_finish()]. 8029** 8030** See Also: [Using the SQLite Online Backup API] 8031*/ 8032typedef struct sqlite3_backup sqlite3_backup; 8033 8034/* 8035** CAPI3REF: Online Backup API. 8036** 8037** The backup API copies the content of one database into another. 8038** It is useful either for creating backups of databases or 8039** for copying in-memory databases to or from persistent files. 8040** 8041** See Also: [Using the SQLite Online Backup API] 8042** 8043** ^SQLite holds a write transaction open on the destination database file 8044** for the duration of the backup operation. 8045** ^The source database is read-locked only while it is being read; 8046** it is not locked continuously for the entire backup operation. 8047** ^Thus, the backup may be performed on a live source database without 8048** preventing other database connections from 8049** reading or writing to the source database while the backup is underway. 8050** 8051** ^(To perform a backup operation: 8052** <ol> 8053** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8054** backup, 8055** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8056** the data between the two databases, and finally 8057** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8058** associated with the backup operation. 8059** </ol>)^ 8060** There should be exactly one call to sqlite3_backup_finish() for each 8061** successful call to sqlite3_backup_init(). 8062** 8063** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8064** 8065** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8066** [database connection] associated with the destination database 8067** and the database name, respectively. 8068** ^The database name is "main" for the main database, "temp" for the 8069** temporary database, or the name specified after the AS keyword in 8070** an [ATTACH] statement for an attached database. 8071** ^The S and M arguments passed to 8072** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8073** and database name of the source database, respectively. 8074** ^The source and destination [database connections] (parameters S and D) 8075** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8076** an error. 8077** 8078** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8079** there is already a read or read-write transaction open on the 8080** destination database. 8081** 8082** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8083** returned and an error code and error message are stored in the 8084** destination [database connection] D. 8085** ^The error code and message for the failed call to sqlite3_backup_init() 8086** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8087** [sqlite3_errmsg16()] functions. 8088** ^A successful call to sqlite3_backup_init() returns a pointer to an 8089** [sqlite3_backup] object. 8090** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8091** sqlite3_backup_finish() functions to perform the specified backup 8092** operation. 8093** 8094** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8095** 8096** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8097** the source and destination databases specified by [sqlite3_backup] object B. 8098** ^If N is negative, all remaining source pages are copied. 8099** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8100** are still more pages to be copied, then the function returns [SQLITE_OK]. 8101** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8102** from source to destination, then it returns [SQLITE_DONE]. 8103** ^If an error occurs while running sqlite3_backup_step(B,N), 8104** then an [error code] is returned. ^As well as [SQLITE_OK] and 8105** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8106** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8107** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8108** 8109** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8110** <ol> 8111** <li> the destination database was opened read-only, or 8112** <li> the destination database is using write-ahead-log journaling 8113** and the destination and source page sizes differ, or 8114** <li> the destination database is an in-memory database and the 8115** destination and source page sizes differ. 8116** </ol>)^ 8117** 8118** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8119** the [sqlite3_busy_handler | busy-handler function] 8120** is invoked (if one is specified). ^If the 8121** busy-handler returns non-zero before the lock is available, then 8122** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8123** sqlite3_backup_step() can be retried later. ^If the source 8124** [database connection] 8125** is being used to write to the source database when sqlite3_backup_step() 8126** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8127** case the call to sqlite3_backup_step() can be retried later on. ^(If 8128** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8129** [SQLITE_READONLY] is returned, then 8130** there is no point in retrying the call to sqlite3_backup_step(). These 8131** errors are considered fatal.)^ The application must accept 8132** that the backup operation has failed and pass the backup operation handle 8133** to the sqlite3_backup_finish() to release associated resources. 8134** 8135** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8136** on the destination file. ^The exclusive lock is not released until either 8137** sqlite3_backup_finish() is called or the backup operation is complete 8138** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8139** sqlite3_backup_step() obtains a [shared lock] on the source database that 8140** lasts for the duration of the sqlite3_backup_step() call. 8141** ^Because the source database is not locked between calls to 8142** sqlite3_backup_step(), the source database may be modified mid-way 8143** through the backup process. ^If the source database is modified by an 8144** external process or via a database connection other than the one being 8145** used by the backup operation, then the backup will be automatically 8146** restarted by the next call to sqlite3_backup_step(). ^If the source 8147** database is modified by the using the same database connection as is used 8148** by the backup operation, then the backup database is automatically 8149** updated at the same time. 8150** 8151** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8152** 8153** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8154** application wishes to abandon the backup operation, the application 8155** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8156** ^The sqlite3_backup_finish() interfaces releases all 8157** resources associated with the [sqlite3_backup] object. 8158** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8159** active write-transaction on the destination database is rolled back. 8160** The [sqlite3_backup] object is invalid 8161** and may not be used following a call to sqlite3_backup_finish(). 8162** 8163** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8164** sqlite3_backup_step() errors occurred, regardless or whether or not 8165** sqlite3_backup_step() completed. 8166** ^If an out-of-memory condition or IO error occurred during any prior 8167** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8168** sqlite3_backup_finish() returns the corresponding [error code]. 8169** 8170** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8171** is not a permanent error and does not affect the return value of 8172** sqlite3_backup_finish(). 8173** 8174** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8175** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8176** 8177** ^The sqlite3_backup_remaining() routine returns the number of pages still 8178** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8179** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8180** in the source database at the conclusion of the most recent 8181** sqlite3_backup_step(). 8182** ^(The values returned by these functions are only updated by 8183** sqlite3_backup_step(). If the source database is modified in a way that 8184** changes the size of the source database or the number of pages remaining, 8185** those changes are not reflected in the output of sqlite3_backup_pagecount() 8186** and sqlite3_backup_remaining() until after the next 8187** sqlite3_backup_step().)^ 8188** 8189** <b>Concurrent Usage of Database Handles</b> 8190** 8191** ^The source [database connection] may be used by the application for other 8192** purposes while a backup operation is underway or being initialized. 8193** ^If SQLite is compiled and configured to support threadsafe database 8194** connections, then the source database connection may be used concurrently 8195** from within other threads. 8196** 8197** However, the application must guarantee that the destination 8198** [database connection] is not passed to any other API (by any thread) after 8199** sqlite3_backup_init() is called and before the corresponding call to 8200** sqlite3_backup_finish(). SQLite does not currently check to see 8201** if the application incorrectly accesses the destination [database connection] 8202** and so no error code is reported, but the operations may malfunction 8203** nevertheless. Use of the destination database connection while a 8204** backup is in progress might also also cause a mutex deadlock. 8205** 8206** If running in [shared cache mode], the application must 8207** guarantee that the shared cache used by the destination database 8208** is not accessed while the backup is running. In practice this means 8209** that the application must guarantee that the disk file being 8210** backed up to is not accessed by any connection within the process, 8211** not just the specific connection that was passed to sqlite3_backup_init(). 8212** 8213** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8214** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8215** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8216** APIs are not strictly speaking threadsafe. If they are invoked at the 8217** same time as another thread is invoking sqlite3_backup_step() it is 8218** possible that they return invalid values. 8219*/ 8220SQLITE_API sqlite3_backup *sqlite3_backup_init( 8221 sqlite3 *pDest, /* Destination database handle */ 8222 const char *zDestName, /* Destination database name */ 8223 sqlite3 *pSource, /* Source database handle */ 8224 const char *zSourceName /* Source database name */ 8225); 8226SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8227SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8228SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8229SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8230 8231/* 8232** CAPI3REF: Unlock Notification 8233** METHOD: sqlite3 8234** 8235** ^When running in shared-cache mode, a database operation may fail with 8236** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8237** individual tables within the shared-cache cannot be obtained. See 8238** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8239** ^This API may be used to register a callback that SQLite will invoke 8240** when the connection currently holding the required lock relinquishes it. 8241** ^This API is only available if the library was compiled with the 8242** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8243** 8244** See Also: [Using the SQLite Unlock Notification Feature]. 8245** 8246** ^Shared-cache locks are released when a database connection concludes 8247** its current transaction, either by committing it or rolling it back. 8248** 8249** ^When a connection (known as the blocked connection) fails to obtain a 8250** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8251** identity of the database connection (the blocking connection) that 8252** has locked the required resource is stored internally. ^After an 8253** application receives an SQLITE_LOCKED error, it may call the 8254** sqlite3_unlock_notify() method with the blocked connection handle as 8255** the first argument to register for a callback that will be invoked 8256** when the blocking connections current transaction is concluded. ^The 8257** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8258** call that concludes the blocking connections transaction. 8259** 8260** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8261** there is a chance that the blocking connection will have already 8262** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8263** If this happens, then the specified callback is invoked immediately, 8264** from within the call to sqlite3_unlock_notify().)^ 8265** 8266** ^If the blocked connection is attempting to obtain a write-lock on a 8267** shared-cache table, and more than one other connection currently holds 8268** a read-lock on the same table, then SQLite arbitrarily selects one of 8269** the other connections to use as the blocking connection. 8270** 8271** ^(There may be at most one unlock-notify callback registered by a 8272** blocked connection. If sqlite3_unlock_notify() is called when the 8273** blocked connection already has a registered unlock-notify callback, 8274** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8275** called with a NULL pointer as its second argument, then any existing 8276** unlock-notify callback is canceled. ^The blocked connections 8277** unlock-notify callback may also be canceled by closing the blocked 8278** connection using [sqlite3_close()]. 8279** 8280** The unlock-notify callback is not reentrant. If an application invokes 8281** any sqlite3_xxx API functions from within an unlock-notify callback, a 8282** crash or deadlock may be the result. 8283** 8284** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8285** returns SQLITE_OK. 8286** 8287** <b>Callback Invocation Details</b> 8288** 8289** When an unlock-notify callback is registered, the application provides a 8290** single void* pointer that is passed to the callback when it is invoked. 8291** However, the signature of the callback function allows SQLite to pass 8292** it an array of void* context pointers. The first argument passed to 8293** an unlock-notify callback is a pointer to an array of void* pointers, 8294** and the second is the number of entries in the array. 8295** 8296** When a blocking connections transaction is concluded, there may be 8297** more than one blocked connection that has registered for an unlock-notify 8298** callback. ^If two or more such blocked connections have specified the 8299** same callback function, then instead of invoking the callback function 8300** multiple times, it is invoked once with the set of void* context pointers 8301** specified by the blocked connections bundled together into an array. 8302** This gives the application an opportunity to prioritize any actions 8303** related to the set of unblocked database connections. 8304** 8305** <b>Deadlock Detection</b> 8306** 8307** Assuming that after registering for an unlock-notify callback a 8308** database waits for the callback to be issued before taking any further 8309** action (a reasonable assumption), then using this API may cause the 8310** application to deadlock. For example, if connection X is waiting for 8311** connection Y's transaction to be concluded, and similarly connection 8312** Y is waiting on connection X's transaction, then neither connection 8313** will proceed and the system may remain deadlocked indefinitely. 8314** 8315** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8316** detection. ^If a given call to sqlite3_unlock_notify() would put the 8317** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8318** unlock-notify callback is registered. The system is said to be in 8319** a deadlocked state if connection A has registered for an unlock-notify 8320** callback on the conclusion of connection B's transaction, and connection 8321** B has itself registered for an unlock-notify callback when connection 8322** A's transaction is concluded. ^Indirect deadlock is also detected, so 8323** the system is also considered to be deadlocked if connection B has 8324** registered for an unlock-notify callback on the conclusion of connection 8325** C's transaction, where connection C is waiting on connection A. ^Any 8326** number of levels of indirection are allowed. 8327** 8328** <b>The "DROP TABLE" Exception</b> 8329** 8330** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8331** always appropriate to call sqlite3_unlock_notify(). There is however, 8332** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8333** SQLite checks if there are any currently executing SELECT statements 8334** that belong to the same connection. If there are, SQLITE_LOCKED is 8335** returned. In this case there is no "blocking connection", so invoking 8336** sqlite3_unlock_notify() results in the unlock-notify callback being 8337** invoked immediately. If the application then re-attempts the "DROP TABLE" 8338** or "DROP INDEX" query, an infinite loop might be the result. 8339** 8340** One way around this problem is to check the extended error code returned 8341** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8342** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8343** the special "DROP TABLE/INDEX" case, the extended error code is just 8344** SQLITE_LOCKED.)^ 8345*/ 8346SQLITE_API int sqlite3_unlock_notify( 8347 sqlite3 *pBlocked, /* Waiting connection */ 8348 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8349 void *pNotifyArg /* Argument to pass to xNotify */ 8350); 8351 8352 8353/* 8354** CAPI3REF: String Comparison 8355** 8356** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8357** and extensions to compare the contents of two buffers containing UTF-8 8358** strings in a case-independent fashion, using the same definition of "case 8359** independence" that SQLite uses internally when comparing identifiers. 8360*/ 8361SQLITE_API int sqlite3_stricmp(const char *, const char *); 8362SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8363 8364/* 8365** CAPI3REF: String Globbing 8366* 8367** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8368** string X matches the [GLOB] pattern P. 8369** ^The definition of [GLOB] pattern matching used in 8370** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8371** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8372** is case sensitive. 8373** 8374** Note that this routine returns zero on a match and non-zero if the strings 8375** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8376** 8377** See also: [sqlite3_strlike()]. 8378*/ 8379SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8380 8381/* 8382** CAPI3REF: String LIKE Matching 8383* 8384** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8385** string X matches the [LIKE] pattern P with escape character E. 8386** ^The definition of [LIKE] pattern matching used in 8387** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8388** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8389** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8390** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8391** insensitive - equivalent upper and lower case ASCII characters match 8392** one another. 8393** 8394** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8395** only ASCII characters are case folded. 8396** 8397** Note that this routine returns zero on a match and non-zero if the strings 8398** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8399** 8400** See also: [sqlite3_strglob()]. 8401*/ 8402SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8403 8404/* 8405** CAPI3REF: Error Logging Interface 8406** 8407** ^The [sqlite3_log()] interface writes a message into the [error log] 8408** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8409** ^If logging is enabled, the zFormat string and subsequent arguments are 8410** used with [sqlite3_snprintf()] to generate the final output string. 8411** 8412** The sqlite3_log() interface is intended for use by extensions such as 8413** virtual tables, collating functions, and SQL functions. While there is 8414** nothing to prevent an application from calling sqlite3_log(), doing so 8415** is considered bad form. 8416** 8417** The zFormat string must not be NULL. 8418** 8419** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8420** will not use dynamically allocated memory. The log message is stored in 8421** a fixed-length buffer on the stack. If the log message is longer than 8422** a few hundred characters, it will be truncated to the length of the 8423** buffer. 8424*/ 8425SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8426 8427/* 8428** CAPI3REF: Write-Ahead Log Commit Hook 8429** METHOD: sqlite3 8430** 8431** ^The [sqlite3_wal_hook()] function is used to register a callback that 8432** is invoked each time data is committed to a database in wal mode. 8433** 8434** ^(The callback is invoked by SQLite after the commit has taken place and 8435** the associated write-lock on the database released)^, so the implementation 8436** may read, write or [checkpoint] the database as required. 8437** 8438** ^The first parameter passed to the callback function when it is invoked 8439** is a copy of the third parameter passed to sqlite3_wal_hook() when 8440** registering the callback. ^The second is a copy of the database handle. 8441** ^The third parameter is the name of the database that was written to - 8442** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8443** is the number of pages currently in the write-ahead log file, 8444** including those that were just committed. 8445** 8446** The callback function should normally return [SQLITE_OK]. ^If an error 8447** code is returned, that error will propagate back up through the 8448** SQLite code base to cause the statement that provoked the callback 8449** to report an error, though the commit will have still occurred. If the 8450** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8451** that does not correspond to any valid SQLite error code, the results 8452** are undefined. 8453** 8454** A single database handle may have at most a single write-ahead log callback 8455** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8456** previously registered write-ahead log callback. ^Note that the 8457** [sqlite3_wal_autocheckpoint()] interface and the 8458** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8459** overwrite any prior [sqlite3_wal_hook()] settings. 8460*/ 8461SQLITE_API void *sqlite3_wal_hook( 8462 sqlite3*, 8463 int(*)(void *,sqlite3*,const char*,int), 8464 void* 8465); 8466 8467/* 8468** CAPI3REF: Configure an auto-checkpoint 8469** METHOD: sqlite3 8470** 8471** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8472** [sqlite3_wal_hook()] that causes any database on [database connection] D 8473** to automatically [checkpoint] 8474** after committing a transaction if there are N or 8475** more frames in the [write-ahead log] file. ^Passing zero or 8476** a negative value as the nFrame parameter disables automatic 8477** checkpoints entirely. 8478** 8479** ^The callback registered by this function replaces any existing callback 8480** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8481** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8482** configured by this function. 8483** 8484** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8485** from SQL. 8486** 8487** ^Checkpoints initiated by this mechanism are 8488** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8489** 8490** ^Every new [database connection] defaults to having the auto-checkpoint 8491** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8492** pages. The use of this interface 8493** is only necessary if the default setting is found to be suboptimal 8494** for a particular application. 8495*/ 8496SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8497 8498/* 8499** CAPI3REF: Checkpoint a database 8500** METHOD: sqlite3 8501** 8502** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8503** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8504** 8505** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8506** [write-ahead log] for database X on [database connection] D to be 8507** transferred into the database file and for the write-ahead log to 8508** be reset. See the [checkpointing] documentation for addition 8509** information. 8510** 8511** This interface used to be the only way to cause a checkpoint to 8512** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8513** interface was added. This interface is retained for backwards 8514** compatibility and as a convenience for applications that need to manually 8515** start a callback but which do not need the full power (and corresponding 8516** complication) of [sqlite3_wal_checkpoint_v2()]. 8517*/ 8518SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8519 8520/* 8521** CAPI3REF: Checkpoint a database 8522** METHOD: sqlite3 8523** 8524** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8525** operation on database X of [database connection] D in mode M. Status 8526** information is written back into integers pointed to by L and C.)^ 8527** ^(The M parameter must be a valid [checkpoint mode]:)^ 8528** 8529** <dl> 8530** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8531** ^Checkpoint as many frames as possible without waiting for any database 8532** readers or writers to finish, then sync the database file if all frames 8533** in the log were checkpointed. ^The [busy-handler callback] 8534** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8535** ^On the other hand, passive mode might leave the checkpoint unfinished 8536** if there are concurrent readers or writers. 8537** 8538** <dt>SQLITE_CHECKPOINT_FULL<dd> 8539** ^This mode blocks (it invokes the 8540** [sqlite3_busy_handler|busy-handler callback]) until there is no 8541** database writer and all readers are reading from the most recent database 8542** snapshot. ^It then checkpoints all frames in the log file and syncs the 8543** database file. ^This mode blocks new database writers while it is pending, 8544** but new database readers are allowed to continue unimpeded. 8545** 8546** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8547** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8548** that after checkpointing the log file it blocks (calls the 8549** [busy-handler callback]) 8550** until all readers are reading from the database file only. ^This ensures 8551** that the next writer will restart the log file from the beginning. 8552** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8553** database writer attempts while it is pending, but does not impede readers. 8554** 8555** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8556** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8557** addition that it also truncates the log file to zero bytes just prior 8558** to a successful return. 8559** </dl> 8560** 8561** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8562** the log file or to -1 if the checkpoint could not run because 8563** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8564** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8565** log file (including any that were already checkpointed before the function 8566** was called) or to -1 if the checkpoint could not run due to an error or 8567** because the database is not in WAL mode. ^Note that upon successful 8568** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8569** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8570** 8571** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8572** any other process is running a checkpoint operation at the same time, the 8573** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8574** busy-handler configured, it will not be invoked in this case. 8575** 8576** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8577** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8578** obtained immediately, and a busy-handler is configured, it is invoked and 8579** the writer lock retried until either the busy-handler returns 0 or the lock 8580** is successfully obtained. ^The busy-handler is also invoked while waiting for 8581** database readers as described above. ^If the busy-handler returns 0 before 8582** the writer lock is obtained or while waiting for database readers, the 8583** checkpoint operation proceeds from that point in the same way as 8584** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8585** without blocking any further. ^SQLITE_BUSY is returned in this case. 8586** 8587** ^If parameter zDb is NULL or points to a zero length string, then the 8588** specified operation is attempted on all WAL databases [attached] to 8589** [database connection] db. In this case the 8590** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8591** an SQLITE_BUSY error is encountered when processing one or more of the 8592** attached WAL databases, the operation is still attempted on any remaining 8593** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8594** error occurs while processing an attached database, processing is abandoned 8595** and the error code is returned to the caller immediately. ^If no error 8596** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8597** databases, SQLITE_OK is returned. 8598** 8599** ^If database zDb is the name of an attached database that is not in WAL 8600** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8601** zDb is not NULL (or a zero length string) and is not the name of any 8602** attached database, SQLITE_ERROR is returned to the caller. 8603** 8604** ^Unless it returns SQLITE_MISUSE, 8605** the sqlite3_wal_checkpoint_v2() interface 8606** sets the error information that is queried by 8607** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8608** 8609** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8610** from SQL. 8611*/ 8612SQLITE_API int sqlite3_wal_checkpoint_v2( 8613 sqlite3 *db, /* Database handle */ 8614 const char *zDb, /* Name of attached database (or NULL) */ 8615 int eMode, /* SQLITE_CHECKPOINT_* value */ 8616 int *pnLog, /* OUT: Size of WAL log in frames */ 8617 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8618); 8619 8620/* 8621** CAPI3REF: Checkpoint Mode Values 8622** KEYWORDS: {checkpoint mode} 8623** 8624** These constants define all valid values for the "checkpoint mode" passed 8625** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8626** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8627** meaning of each of these checkpoint modes. 8628*/ 8629#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8630#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8631#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8632#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8633 8634/* 8635** CAPI3REF: Virtual Table Interface Configuration 8636** 8637** This function may be called by either the [xConnect] or [xCreate] method 8638** of a [virtual table] implementation to configure 8639** various facets of the virtual table interface. 8640** 8641** If this interface is invoked outside the context of an xConnect or 8642** xCreate virtual table method then the behavior is undefined. 8643** 8644** At present, there is only one option that may be configured using 8645** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8646** may be added in the future. 8647*/ 8648SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8649 8650/* 8651** CAPI3REF: Virtual Table Configuration Options 8652** 8653** These macros define the various options to the 8654** [sqlite3_vtab_config()] interface that [virtual table] implementations 8655** can use to customize and optimize their behavior. 8656** 8657** <dl> 8658** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8659** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8660** <dd>Calls of the form 8661** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8662** where X is an integer. If X is zero, then the [virtual table] whose 8663** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8664** support constraints. In this configuration (which is the default) if 8665** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8666** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8667** specified as part of the users SQL statement, regardless of the actual 8668** ON CONFLICT mode specified. 8669** 8670** If X is non-zero, then the virtual table implementation guarantees 8671** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8672** any modifications to internal or persistent data structures have been made. 8673** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8674** is able to roll back a statement or database transaction, and abandon 8675** or continue processing the current SQL statement as appropriate. 8676** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8677** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8678** had been ABORT. 8679** 8680** Virtual table implementations that are required to handle OR REPLACE 8681** must do so within the [xUpdate] method. If a call to the 8682** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8683** CONFLICT policy is REPLACE, the virtual table implementation should 8684** silently replace the appropriate rows within the xUpdate callback and 8685** return SQLITE_OK. Or, if this is not possible, it may return 8686** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8687** constraint handling. 8688** </dl> 8689*/ 8690#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8691 8692/* 8693** CAPI3REF: Determine The Virtual Table Conflict Policy 8694** 8695** This function may only be called from within a call to the [xUpdate] method 8696** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8697** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8698** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8699** of the SQL statement that triggered the call to the [xUpdate] method of the 8700** [virtual table]. 8701*/ 8702SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8703 8704/* 8705** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8706** 8707** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8708** method of a [virtual table], then it returns true if and only if the 8709** column is being fetched as part of an UPDATE operation during which the 8710** column value will not change. Applications might use this to substitute 8711** a return value that is less expensive to compute and that the corresponding 8712** [xUpdate] method understands as a "no-change" value. 8713** 8714** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8715** the column is not changed by the UPDATE statement, then the xColumn 8716** method can optionally return without setting a result, without calling 8717** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8718** In that case, [sqlite3_value_nochange(X)] will return true for the 8719** same column in the [xUpdate] method. 8720*/ 8721SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8722 8723/* 8724** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8725** 8726** This function may only be called from within a call to the [xBestIndex] 8727** method of a [virtual table]. 8728** 8729** The first argument must be the sqlite3_index_info object that is the 8730** first parameter to the xBestIndex() method. The second argument must be 8731** an index into the aConstraint[] array belonging to the sqlite3_index_info 8732** structure passed to xBestIndex. This function returns a pointer to a buffer 8733** containing the name of the collation sequence for the corresponding 8734** constraint. 8735*/ 8736SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8737 8738/* 8739** CAPI3REF: Conflict resolution modes 8740** KEYWORDS: {conflict resolution mode} 8741** 8742** These constants are returned by [sqlite3_vtab_on_conflict()] to 8743** inform a [virtual table] implementation what the [ON CONFLICT] mode 8744** is for the SQL statement being evaluated. 8745** 8746** Note that the [SQLITE_IGNORE] constant is also used as a potential 8747** return value from the [sqlite3_set_authorizer()] callback and that 8748** [SQLITE_ABORT] is also a [result code]. 8749*/ 8750#define SQLITE_ROLLBACK 1 8751/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8752#define SQLITE_FAIL 3 8753/* #define SQLITE_ABORT 4 // Also an error code */ 8754#define SQLITE_REPLACE 5 8755 8756/* 8757** CAPI3REF: Prepared Statement Scan Status Opcodes 8758** KEYWORDS: {scanstatus options} 8759** 8760** The following constants can be used for the T parameter to the 8761** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8762** different metric for sqlite3_stmt_scanstatus() to return. 8763** 8764** When the value returned to V is a string, space to hold that string is 8765** managed by the prepared statement S and will be automatically freed when 8766** S is finalized. 8767** 8768** <dl> 8769** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8770** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8771** set to the total number of times that the X-th loop has run.</dd> 8772** 8773** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8774** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8775** to the total number of rows examined by all iterations of the X-th loop.</dd> 8776** 8777** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8778** <dd>^The "double" variable pointed to by the T parameter will be set to the 8779** query planner's estimate for the average number of rows output from each 8780** iteration of the X-th loop. If the query planner's estimates was accurate, 8781** then this value will approximate the quotient NVISIT/NLOOP and the 8782** product of this value for all prior loops with the same SELECTID will 8783** be the NLOOP value for the current loop. 8784** 8785** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8786** <dd>^The "const char *" variable pointed to by the T parameter will be set 8787** to a zero-terminated UTF-8 string containing the name of the index or table 8788** used for the X-th loop. 8789** 8790** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8791** <dd>^The "const char *" variable pointed to by the T parameter will be set 8792** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8793** description for the X-th loop. 8794** 8795** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8796** <dd>^The "int" variable pointed to by the T parameter will be set to the 8797** "select-id" for the X-th loop. The select-id identifies which query or 8798** subquery the loop is part of. The main query has a select-id of zero. 8799** The select-id is the same value as is output in the first column 8800** of an [EXPLAIN QUERY PLAN] query. 8801** </dl> 8802*/ 8803#define SQLITE_SCANSTAT_NLOOP 0 8804#define SQLITE_SCANSTAT_NVISIT 1 8805#define SQLITE_SCANSTAT_EST 2 8806#define SQLITE_SCANSTAT_NAME 3 8807#define SQLITE_SCANSTAT_EXPLAIN 4 8808#define SQLITE_SCANSTAT_SELECTID 5 8809 8810/* 8811** CAPI3REF: Prepared Statement Scan Status 8812** METHOD: sqlite3_stmt 8813** 8814** This interface returns information about the predicted and measured 8815** performance for pStmt. Advanced applications can use this 8816** interface to compare the predicted and the measured performance and 8817** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8818** 8819** Since this interface is expected to be rarely used, it is only 8820** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8821** compile-time option. 8822** 8823** The "iScanStatusOp" parameter determines which status information to return. 8824** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8825** of this interface is undefined. 8826** ^The requested measurement is written into a variable pointed to by 8827** the "pOut" parameter. 8828** Parameter "idx" identifies the specific loop to retrieve statistics for. 8829** Loops are numbered starting from zero. ^If idx is out of range - less than 8830** zero or greater than or equal to the total number of loops used to implement 8831** the statement - a non-zero value is returned and the variable that pOut 8832** points to is unchanged. 8833** 8834** ^Statistics might not be available for all loops in all statements. ^In cases 8835** where there exist loops with no available statistics, this function behaves 8836** as if the loop did not exist - it returns non-zero and leave the variable 8837** that pOut points to unchanged. 8838** 8839** See also: [sqlite3_stmt_scanstatus_reset()] 8840*/ 8841SQLITE_API int sqlite3_stmt_scanstatus( 8842 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8843 int idx, /* Index of loop to report on */ 8844 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8845 void *pOut /* Result written here */ 8846); 8847 8848/* 8849** CAPI3REF: Zero Scan-Status Counters 8850** METHOD: sqlite3_stmt 8851** 8852** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8853** 8854** This API is only available if the library is built with pre-processor 8855** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8856*/ 8857SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8858 8859/* 8860** CAPI3REF: Flush caches to disk mid-transaction 8861** 8862** ^If a write-transaction is open on [database connection] D when the 8863** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8864** pages in the pager-cache that are not currently in use are written out 8865** to disk. A dirty page may be in use if a database cursor created by an 8866** active SQL statement is reading from it, or if it is page 1 of a database 8867** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8868** interface flushes caches for all schemas - "main", "temp", and 8869** any [attached] databases. 8870** 8871** ^If this function needs to obtain extra database locks before dirty pages 8872** can be flushed to disk, it does so. ^If those locks cannot be obtained 8873** immediately and there is a busy-handler callback configured, it is invoked 8874** in the usual manner. ^If the required lock still cannot be obtained, then 8875** the database is skipped and an attempt made to flush any dirty pages 8876** belonging to the next (if any) database. ^If any databases are skipped 8877** because locks cannot be obtained, but no other error occurs, this 8878** function returns SQLITE_BUSY. 8879** 8880** ^If any other error occurs while flushing dirty pages to disk (for 8881** example an IO error or out-of-memory condition), then processing is 8882** abandoned and an SQLite [error code] is returned to the caller immediately. 8883** 8884** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8885** 8886** ^This function does not set the database handle error code or message 8887** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8888*/ 8889SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8890 8891/* 8892** CAPI3REF: The pre-update hook. 8893** 8894** ^These interfaces are only available if SQLite is compiled using the 8895** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8896** 8897** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8898** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8899** on a database table. 8900** ^At most one preupdate hook may be registered at a time on a single 8901** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8902** the previous setting. 8903** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8904** with a NULL pointer as the second parameter. 8905** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8906** the first parameter to callbacks. 8907** 8908** ^The preupdate hook only fires for changes to real database tables; the 8909** preupdate hook is not invoked for changes to [virtual tables] or to 8910** system tables like sqlite_master or sqlite_stat1. 8911** 8912** ^The second parameter to the preupdate callback is a pointer to 8913** the [database connection] that registered the preupdate hook. 8914** ^The third parameter to the preupdate callback is one of the constants 8915** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8916** kind of update operation that is about to occur. 8917** ^(The fourth parameter to the preupdate callback is the name of the 8918** database within the database connection that is being modified. This 8919** will be "main" for the main database or "temp" for TEMP tables or 8920** the name given after the AS keyword in the [ATTACH] statement for attached 8921** databases.)^ 8922** ^The fifth parameter to the preupdate callback is the name of the 8923** table that is being modified. 8924** 8925** For an UPDATE or DELETE operation on a [rowid table], the sixth 8926** parameter passed to the preupdate callback is the initial [rowid] of the 8927** row being modified or deleted. For an INSERT operation on a rowid table, 8928** or any operation on a WITHOUT ROWID table, the value of the sixth 8929** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8930** seventh parameter is the final rowid value of the row being inserted 8931** or updated. The value of the seventh parameter passed to the callback 8932** function is not defined for operations on WITHOUT ROWID tables, or for 8933** INSERT operations on rowid tables. 8934** 8935** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8936** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8937** provide additional information about a preupdate event. These routines 8938** may only be called from within a preupdate callback. Invoking any of 8939** these routines from outside of a preupdate callback or with a 8940** [database connection] pointer that is different from the one supplied 8941** to the preupdate callback results in undefined and probably undesirable 8942** behavior. 8943** 8944** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8945** in the row that is being inserted, updated, or deleted. 8946** 8947** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8948** a [protected sqlite3_value] that contains the value of the Nth column of 8949** the table row before it is updated. The N parameter must be between 0 8950** and one less than the number of columns or the behavior will be 8951** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8952** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8953** behavior is undefined. The [sqlite3_value] that P points to 8954** will be destroyed when the preupdate callback returns. 8955** 8956** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8957** a [protected sqlite3_value] that contains the value of the Nth column of 8958** the table row after it is updated. The N parameter must be between 0 8959** and one less than the number of columns or the behavior will be 8960** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8961** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8962** behavior is undefined. The [sqlite3_value] that P points to 8963** will be destroyed when the preupdate callback returns. 8964** 8965** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8966** callback was invoked as a result of a direct insert, update, or delete 8967** operation; or 1 for inserts, updates, or deletes invoked by top-level 8968** triggers; or 2 for changes resulting from triggers called by top-level 8969** triggers; and so forth. 8970** 8971** See also: [sqlite3_update_hook()] 8972*/ 8973#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8974SQLITE_API void *sqlite3_preupdate_hook( 8975 sqlite3 *db, 8976 void(*xPreUpdate)( 8977 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8978 sqlite3 *db, /* Database handle */ 8979 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8980 char const *zDb, /* Database name */ 8981 char const *zName, /* Table name */ 8982 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8983 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8984 ), 8985 void* 8986); 8987SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8988SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8989SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8990SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8991#endif 8992 8993/* 8994** CAPI3REF: Low-level system error code 8995** 8996** ^Attempt to return the underlying operating system error code or error 8997** number that caused the most recent I/O error or failure to open a file. 8998** The return value is OS-dependent. For example, on unix systems, after 8999** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9000** called to get back the underlying "errno" that caused the problem, such 9001** as ENOSPC, EAUTH, EISDIR, and so forth. 9002*/ 9003SQLITE_API int sqlite3_system_errno(sqlite3*); 9004 9005/* 9006** CAPI3REF: Database Snapshot 9007** KEYWORDS: {snapshot} {sqlite3_snapshot} 9008** 9009** An instance of the snapshot object records the state of a [WAL mode] 9010** database for some specific point in history. 9011** 9012** In [WAL mode], multiple [database connections] that are open on the 9013** same database file can each be reading a different historical version 9014** of the database file. When a [database connection] begins a read 9015** transaction, that connection sees an unchanging copy of the database 9016** as it existed for the point in time when the transaction first started. 9017** Subsequent changes to the database from other connections are not seen 9018** by the reader until a new read transaction is started. 9019** 9020** The sqlite3_snapshot object records state information about an historical 9021** version of the database file so that it is possible to later open a new read 9022** transaction that sees that historical version of the database rather than 9023** the most recent version. 9024*/ 9025typedef struct sqlite3_snapshot { 9026 unsigned char hidden[48]; 9027} sqlite3_snapshot; 9028 9029/* 9030** CAPI3REF: Record A Database Snapshot 9031** CONSTRUCTOR: sqlite3_snapshot 9032** 9033** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9034** new [sqlite3_snapshot] object that records the current state of 9035** schema S in database connection D. ^On success, the 9036** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9037** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9038** If there is not already a read-transaction open on schema S when 9039** this function is called, one is opened automatically. 9040** 9041** The following must be true for this function to succeed. If any of 9042** the following statements are false when sqlite3_snapshot_get() is 9043** called, SQLITE_ERROR is returned. The final value of *P is undefined 9044** in this case. 9045** 9046** <ul> 9047** <li> The database handle must not be in [autocommit mode]. 9048** 9049** <li> Schema S of [database connection] D must be a [WAL mode] database. 9050** 9051** <li> There must not be a write transaction open on schema S of database 9052** connection D. 9053** 9054** <li> One or more transactions must have been written to the current wal 9055** file since it was created on disk (by any connection). This means 9056** that a snapshot cannot be taken on a wal mode database with no wal 9057** file immediately after it is first opened. At least one transaction 9058** must be written to it first. 9059** </ul> 9060** 9061** This function may also return SQLITE_NOMEM. If it is called with the 9062** database handle in autocommit mode but fails for some other reason, 9063** whether or not a read transaction is opened on schema S is undefined. 9064** 9065** The [sqlite3_snapshot] object returned from a successful call to 9066** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9067** to avoid a memory leak. 9068** 9069** The [sqlite3_snapshot_get()] interface is only available when the 9070** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9071*/ 9072SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9073 sqlite3 *db, 9074 const char *zSchema, 9075 sqlite3_snapshot **ppSnapshot 9076); 9077 9078/* 9079** CAPI3REF: Start a read transaction on an historical snapshot 9080** METHOD: sqlite3_snapshot 9081** 9082** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9083** transaction or upgrades an existing one for schema S of 9084** [database connection] D such that the read transaction refers to 9085** historical [snapshot] P, rather than the most recent change to the 9086** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9087** on success or an appropriate [error code] if it fails. 9088** 9089** ^In order to succeed, the database connection must not be in 9090** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9091** is already a read transaction open on schema S, then the database handle 9092** must have no active statements (SELECT statements that have been passed 9093** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9094** SQLITE_ERROR is returned if either of these conditions is violated, or 9095** if schema S does not exist, or if the snapshot object is invalid. 9096** 9097** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9098** snapshot has been overwritten by a [checkpoint]. In this case 9099** SQLITE_ERROR_SNAPSHOT is returned. 9100** 9101** If there is already a read transaction open when this function is 9102** invoked, then the same read transaction remains open (on the same 9103** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9104** is returned. If another error code - for example SQLITE_PROTOCOL or an 9105** SQLITE_IOERR error code - is returned, then the final state of the 9106** read transaction is undefined. If SQLITE_OK is returned, then the 9107** read transaction is now open on database snapshot P. 9108** 9109** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9110** database connection D does not know that the database file for 9111** schema S is in [WAL mode]. A database connection might not know 9112** that the database file is in [WAL mode] if there has been no prior 9113** I/O on that database connection, or if the database entered [WAL mode] 9114** after the most recent I/O on the database connection.)^ 9115** (Hint: Run "[PRAGMA application_id]" against a newly opened 9116** database connection in order to make it ready to use snapshots.) 9117** 9118** The [sqlite3_snapshot_open()] interface is only available when the 9119** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9120*/ 9121SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9122 sqlite3 *db, 9123 const char *zSchema, 9124 sqlite3_snapshot *pSnapshot 9125); 9126 9127/* 9128** CAPI3REF: Destroy a snapshot 9129** DESTRUCTOR: sqlite3_snapshot 9130** 9131** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9132** The application must eventually free every [sqlite3_snapshot] object 9133** using this routine to avoid a memory leak. 9134** 9135** The [sqlite3_snapshot_free()] interface is only available when the 9136** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9137*/ 9138SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9139 9140/* 9141** CAPI3REF: Compare the ages of two snapshot handles. 9142** METHOD: sqlite3_snapshot 9143** 9144** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9145** of two valid snapshot handles. 9146** 9147** If the two snapshot handles are not associated with the same database 9148** file, the result of the comparison is undefined. 9149** 9150** Additionally, the result of the comparison is only valid if both of the 9151** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9152** last time the wal file was deleted. The wal file is deleted when the 9153** database is changed back to rollback mode or when the number of database 9154** clients drops to zero. If either snapshot handle was obtained before the 9155** wal file was last deleted, the value returned by this function 9156** is undefined. 9157** 9158** Otherwise, this API returns a negative value if P1 refers to an older 9159** snapshot than P2, zero if the two handles refer to the same database 9160** snapshot, and a positive value if P1 is a newer snapshot than P2. 9161** 9162** This interface is only available if SQLite is compiled with the 9163** [SQLITE_ENABLE_SNAPSHOT] option. 9164*/ 9165SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9166 sqlite3_snapshot *p1, 9167 sqlite3_snapshot *p2 9168); 9169 9170/* 9171** CAPI3REF: Recover snapshots from a wal file 9172** METHOD: sqlite3_snapshot 9173** 9174** If a [WAL file] remains on disk after all database connections close 9175** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9176** or because the last process to have the database opened exited without 9177** calling [sqlite3_close()]) and a new connection is subsequently opened 9178** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9179** will only be able to open the last transaction added to the WAL file 9180** even though the WAL file contains other valid transactions. 9181** 9182** This function attempts to scan the WAL file associated with database zDb 9183** of database handle db and make all valid snapshots available to 9184** sqlite3_snapshot_open(). It is an error if there is already a read 9185** transaction open on the database, or if the database is not a WAL mode 9186** database. 9187** 9188** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9189** 9190** This interface is only available if SQLite is compiled with the 9191** [SQLITE_ENABLE_SNAPSHOT] option. 9192*/ 9193SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9194 9195/* 9196** CAPI3REF: Serialize a database 9197** 9198** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9199** that is a serialization of the S database on [database connection] D. 9200** If P is not a NULL pointer, then the size of the database in bytes 9201** is written into *P. 9202** 9203** For an ordinary on-disk database file, the serialization is just a 9204** copy of the disk file. For an in-memory database or a "TEMP" database, 9205** the serialization is the same sequence of bytes which would be written 9206** to disk if that database where backed up to disk. 9207** 9208** The usual case is that sqlite3_serialize() copies the serialization of 9209** the database into memory obtained from [sqlite3_malloc64()] and returns 9210** a pointer to that memory. The caller is responsible for freeing the 9211** returned value to avoid a memory leak. However, if the F argument 9212** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9213** are made, and the sqlite3_serialize() function will return a pointer 9214** to the contiguous memory representation of the database that SQLite 9215** is currently using for that database, or NULL if the no such contiguous 9216** memory representation of the database exists. A contiguous memory 9217** representation of the database will usually only exist if there has 9218** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9219** values of D and S. 9220** The size of the database is written into *P even if the 9221** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9222** of the database exists. 9223** 9224** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9225** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9226** allocation error occurs. 9227** 9228** This interface is only available if SQLite is compiled with the 9229** [SQLITE_ENABLE_DESERIALIZE] option. 9230*/ 9231SQLITE_API unsigned char *sqlite3_serialize( 9232 sqlite3 *db, /* The database connection */ 9233 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9234 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9235 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9236); 9237 9238/* 9239** CAPI3REF: Flags for sqlite3_serialize 9240** 9241** Zero or more of the following constants can be OR-ed together for 9242** the F argument to [sqlite3_serialize(D,S,P,F)]. 9243** 9244** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9245** a pointer to contiguous in-memory database that it is currently using, 9246** without making a copy of the database. If SQLite is not currently using 9247** a contiguous in-memory database, then this option causes 9248** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9249** using a contiguous in-memory database if it has been initialized by a 9250** prior call to [sqlite3_deserialize()]. 9251*/ 9252#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9253 9254/* 9255** CAPI3REF: Deserialize a database 9256** 9257** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9258** [database connection] D to disconnect from database S and then 9259** reopen S as an in-memory database based on the serialization contained 9260** in P. The serialized database P is N bytes in size. M is the size of 9261** the buffer P, which might be larger than N. If M is larger than N, and 9262** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9263** permitted to add content to the in-memory database as long as the total 9264** size does not exceed M bytes. 9265** 9266** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9267** invoke sqlite3_free() on the serialization buffer when the database 9268** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9269** SQLite will try to increase the buffer size using sqlite3_realloc64() 9270** if writes on the database cause it to grow larger than M bytes. 9271** 9272** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9273** database is currently in a read transaction or is involved in a backup 9274** operation. 9275** 9276** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9277** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9278** [sqlite3_free()] is invoked on argument P prior to returning. 9279** 9280** This interface is only available if SQLite is compiled with the 9281** [SQLITE_ENABLE_DESERIALIZE] option. 9282*/ 9283SQLITE_API int sqlite3_deserialize( 9284 sqlite3 *db, /* The database connection */ 9285 const char *zSchema, /* Which DB to reopen with the deserialization */ 9286 unsigned char *pData, /* The serialized database content */ 9287 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9288 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9289 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9290); 9291 9292/* 9293** CAPI3REF: Flags for sqlite3_deserialize() 9294** 9295** The following are allowed values for 6th argument (the F argument) to 9296** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9297** 9298** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9299** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9300** and that SQLite should take ownership of this memory and automatically 9301** free it when it has finished using it. Without this flag, the caller 9302** is responsible for freeing any dynamically allocated memory. 9303** 9304** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9305** grow the size of the database using calls to [sqlite3_realloc64()]. This 9306** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9307** Without this flag, the deserialized database cannot increase in size beyond 9308** the number of bytes specified by the M parameter. 9309** 9310** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9311** should be treated as read-only. 9312*/ 9313#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9314#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9315#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9316 9317/* 9318** Undo the hack that converts floating point types to integer for 9319** builds on processors without floating point support. 9320*/ 9321#ifdef SQLITE_OMIT_FLOATING_POINT 9322# undef double 9323#endif 9324 9325#ifdef __cplusplus 9326} /* End of the 'extern "C"' block */ 9327#endif 9328#endif /* SQLITE3_H */ 9329 9330/******** Begin file sqlite3rtree.h *********/ 9331/* 9332** 2010 August 30 9333** 9334** The author disclaims copyright to this source code. In place of 9335** a legal notice, here is a blessing: 9336** 9337** May you do good and not evil. 9338** May you find forgiveness for yourself and forgive others. 9339** May you share freely, never taking more than you give. 9340** 9341************************************************************************* 9342*/ 9343 9344#ifndef _SQLITE3RTREE_H_ 9345#define _SQLITE3RTREE_H_ 9346 9347 9348#ifdef __cplusplus 9349extern "C" { 9350#endif 9351 9352typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9353typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9354 9355/* The double-precision datatype used by RTree depends on the 9356** SQLITE_RTREE_INT_ONLY compile-time option. 9357*/ 9358#ifdef SQLITE_RTREE_INT_ONLY 9359 typedef sqlite3_int64 sqlite3_rtree_dbl; 9360#else 9361 typedef double sqlite3_rtree_dbl; 9362#endif 9363 9364/* 9365** Register a geometry callback named zGeom that can be used as part of an 9366** R-Tree geometry query as follows: 9367** 9368** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9369*/ 9370SQLITE_API int sqlite3_rtree_geometry_callback( 9371 sqlite3 *db, 9372 const char *zGeom, 9373 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9374 void *pContext 9375); 9376 9377 9378/* 9379** A pointer to a structure of the following type is passed as the first 9380** argument to callbacks registered using rtree_geometry_callback(). 9381*/ 9382struct sqlite3_rtree_geometry { 9383 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9384 int nParam; /* Size of array aParam[] */ 9385 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9386 void *pUser; /* Callback implementation user data */ 9387 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9388}; 9389 9390/* 9391** Register a 2nd-generation geometry callback named zScore that can be 9392** used as part of an R-Tree geometry query as follows: 9393** 9394** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9395*/ 9396SQLITE_API int sqlite3_rtree_query_callback( 9397 sqlite3 *db, 9398 const char *zQueryFunc, 9399 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9400 void *pContext, 9401 void (*xDestructor)(void*) 9402); 9403 9404 9405/* 9406** A pointer to a structure of the following type is passed as the 9407** argument to scored geometry callback registered using 9408** sqlite3_rtree_query_callback(). 9409** 9410** Note that the first 5 fields of this structure are identical to 9411** sqlite3_rtree_geometry. This structure is a subclass of 9412** sqlite3_rtree_geometry. 9413*/ 9414struct sqlite3_rtree_query_info { 9415 void *pContext; /* pContext from when function registered */ 9416 int nParam; /* Number of function parameters */ 9417 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9418 void *pUser; /* callback can use this, if desired */ 9419 void (*xDelUser)(void*); /* function to free pUser */ 9420 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9421 unsigned int *anQueue; /* Number of pending entries in the queue */ 9422 int nCoord; /* Number of coordinates */ 9423 int iLevel; /* Level of current node or entry */ 9424 int mxLevel; /* The largest iLevel value in the tree */ 9425 sqlite3_int64 iRowid; /* Rowid for current entry */ 9426 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9427 int eParentWithin; /* Visibility of parent node */ 9428 int eWithin; /* OUT: Visibility */ 9429 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9430 /* The following fields are only available in 3.8.11 and later */ 9431 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9432}; 9433 9434/* 9435** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9436*/ 9437#define NOT_WITHIN 0 /* Object completely outside of query region */ 9438#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9439#define FULLY_WITHIN 2 /* Object fully contained within query region */ 9440 9441 9442#ifdef __cplusplus 9443} /* end of the 'extern "C"' block */ 9444#endif 9445 9446#endif /* ifndef _SQLITE3RTREE_H_ */ 9447 9448/******** End of sqlite3rtree.h *********/ 9449/******** Begin file sqlite3session.h *********/ 9450 9451#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9452#define __SQLITESESSION_H_ 1 9453 9454/* 9455** Make sure we can call this stuff from C++. 9456*/ 9457#ifdef __cplusplus 9458extern "C" { 9459#endif 9460 9461 9462/* 9463** CAPI3REF: Session Object Handle 9464** 9465** An instance of this object is a [session] that can be used to 9466** record changes to a database. 9467*/ 9468typedef struct sqlite3_session sqlite3_session; 9469 9470/* 9471** CAPI3REF: Changeset Iterator Handle 9472** 9473** An instance of this object acts as a cursor for iterating 9474** over the elements of a [changeset] or [patchset]. 9475*/ 9476typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9477 9478/* 9479** CAPI3REF: Create A New Session Object 9480** CONSTRUCTOR: sqlite3_session 9481** 9482** Create a new session object attached to database handle db. If successful, 9483** a pointer to the new object is written to *ppSession and SQLITE_OK is 9484** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9485** error code (e.g. SQLITE_NOMEM) is returned. 9486** 9487** It is possible to create multiple session objects attached to a single 9488** database handle. 9489** 9490** Session objects created using this function should be deleted using the 9491** [sqlite3session_delete()] function before the database handle that they 9492** are attached to is itself closed. If the database handle is closed before 9493** the session object is deleted, then the results of calling any session 9494** module function, including [sqlite3session_delete()] on the session object 9495** are undefined. 9496** 9497** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9498** is not possible for an application to register a pre-update hook on a 9499** database handle that has one or more session objects attached. Nor is 9500** it possible to create a session object attached to a database handle for 9501** which a pre-update hook is already defined. The results of attempting 9502** either of these things are undefined. 9503** 9504** The session object will be used to create changesets for tables in 9505** database zDb, where zDb is either "main", or "temp", or the name of an 9506** attached database. It is not an error if database zDb is not attached 9507** to the database when the session object is created. 9508*/ 9509SQLITE_API int sqlite3session_create( 9510 sqlite3 *db, /* Database handle */ 9511 const char *zDb, /* Name of db (e.g. "main") */ 9512 sqlite3_session **ppSession /* OUT: New session object */ 9513); 9514 9515/* 9516** CAPI3REF: Delete A Session Object 9517** DESTRUCTOR: sqlite3_session 9518** 9519** Delete a session object previously allocated using 9520** [sqlite3session_create()]. Once a session object has been deleted, the 9521** results of attempting to use pSession with any other session module 9522** function are undefined. 9523** 9524** Session objects must be deleted before the database handle to which they 9525** are attached is closed. Refer to the documentation for 9526** [sqlite3session_create()] for details. 9527*/ 9528SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9529 9530 9531/* 9532** CAPI3REF: Enable Or Disable A Session Object 9533** METHOD: sqlite3_session 9534** 9535** Enable or disable the recording of changes by a session object. When 9536** enabled, a session object records changes made to the database. When 9537** disabled - it does not. A newly created session object is enabled. 9538** Refer to the documentation for [sqlite3session_changeset()] for further 9539** details regarding how enabling and disabling a session object affects 9540** the eventual changesets. 9541** 9542** Passing zero to this function disables the session. Passing a value 9543** greater than zero enables it. Passing a value less than zero is a 9544** no-op, and may be used to query the current state of the session. 9545** 9546** The return value indicates the final state of the session object: 0 if 9547** the session is disabled, or 1 if it is enabled. 9548*/ 9549SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9550 9551/* 9552** CAPI3REF: Set Or Clear the Indirect Change Flag 9553** METHOD: sqlite3_session 9554** 9555** Each change recorded by a session object is marked as either direct or 9556** indirect. A change is marked as indirect if either: 9557** 9558** <ul> 9559** <li> The session object "indirect" flag is set when the change is 9560** made, or 9561** <li> The change is made by an SQL trigger or foreign key action 9562** instead of directly as a result of a users SQL statement. 9563** </ul> 9564** 9565** If a single row is affected by more than one operation within a session, 9566** then the change is considered indirect if all operations meet the criteria 9567** for an indirect change above, or direct otherwise. 9568** 9569** This function is used to set, clear or query the session object indirect 9570** flag. If the second argument passed to this function is zero, then the 9571** indirect flag is cleared. If it is greater than zero, the indirect flag 9572** is set. Passing a value less than zero does not modify the current value 9573** of the indirect flag, and may be used to query the current state of the 9574** indirect flag for the specified session object. 9575** 9576** The return value indicates the final state of the indirect flag: 0 if 9577** it is clear, or 1 if it is set. 9578*/ 9579SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9580 9581/* 9582** CAPI3REF: Attach A Table To A Session Object 9583** METHOD: sqlite3_session 9584** 9585** If argument zTab is not NULL, then it is the name of a table to attach 9586** to the session object passed as the first argument. All subsequent changes 9587** made to the table while the session object is enabled will be recorded. See 9588** documentation for [sqlite3session_changeset()] for further details. 9589** 9590** Or, if argument zTab is NULL, then changes are recorded for all tables 9591** in the database. If additional tables are added to the database (by 9592** executing "CREATE TABLE" statements) after this call is made, changes for 9593** the new tables are also recorded. 9594** 9595** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9596** defined as part of their CREATE TABLE statement. It does not matter if the 9597** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9598** KEY may consist of a single column, or may be a composite key. 9599** 9600** It is not an error if the named table does not exist in the database. Nor 9601** is it an error if the named table does not have a PRIMARY KEY. However, 9602** no changes will be recorded in either of these scenarios. 9603** 9604** Changes are not recorded for individual rows that have NULL values stored 9605** in one or more of their PRIMARY KEY columns. 9606** 9607** SQLITE_OK is returned if the call completes without error. Or, if an error 9608** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9609** 9610** <h3>Special sqlite_stat1 Handling</h3> 9611** 9612** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9613** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9614** <pre> 9615** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9616** </pre> 9617** 9618** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9619** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9620** are recorded for rows for which (idx IS NULL) is true. However, for such 9621** rows a zero-length blob (SQL value X'') is stored in the changeset or 9622** patchset instead of a NULL value. This allows such changesets to be 9623** manipulated by legacy implementations of sqlite3changeset_invert(), 9624** concat() and similar. 9625** 9626** The sqlite3changeset_apply() function automatically converts the 9627** zero-length blob back to a NULL value when updating the sqlite_stat1 9628** table. However, if the application calls sqlite3changeset_new(), 9629** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9630** iterator directly (including on a changeset iterator passed to a 9631** conflict-handler callback) then the X'' value is returned. The application 9632** must translate X'' to NULL itself if required. 9633** 9634** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9635** changes made to the sqlite_stat1 table. Legacy versions of the 9636** sqlite3changeset_apply() function silently ignore any modifications to the 9637** sqlite_stat1 table that are part of a changeset or patchset. 9638*/ 9639SQLITE_API int sqlite3session_attach( 9640 sqlite3_session *pSession, /* Session object */ 9641 const char *zTab /* Table name */ 9642); 9643 9644/* 9645** CAPI3REF: Set a table filter on a Session Object. 9646** METHOD: sqlite3_session 9647** 9648** The second argument (xFilter) is the "filter callback". For changes to rows 9649** in tables that are not attached to the Session object, the filter is called 9650** to determine whether changes to the table's rows should be tracked or not. 9651** If xFilter returns 0, changes is not tracked. Note that once a table is 9652** attached, xFilter will not be called again. 9653*/ 9654SQLITE_API void sqlite3session_table_filter( 9655 sqlite3_session *pSession, /* Session object */ 9656 int(*xFilter)( 9657 void *pCtx, /* Copy of third arg to _filter_table() */ 9658 const char *zTab /* Table name */ 9659 ), 9660 void *pCtx /* First argument passed to xFilter */ 9661); 9662 9663/* 9664** CAPI3REF: Generate A Changeset From A Session Object 9665** METHOD: sqlite3_session 9666** 9667** Obtain a changeset containing changes to the tables attached to the 9668** session object passed as the first argument. If successful, 9669** set *ppChangeset to point to a buffer containing the changeset 9670** and *pnChangeset to the size of the changeset in bytes before returning 9671** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9672** zero and return an SQLite error code. 9673** 9674** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9675** each representing a change to a single row of an attached table. An INSERT 9676** change contains the values of each field of a new database row. A DELETE 9677** contains the original values of each field of a deleted database row. An 9678** UPDATE change contains the original values of each field of an updated 9679** database row along with the updated values for each updated non-primary-key 9680** column. It is not possible for an UPDATE change to represent a change that 9681** modifies the values of primary key columns. If such a change is made, it 9682** is represented in a changeset as a DELETE followed by an INSERT. 9683** 9684** Changes are not recorded for rows that have NULL values stored in one or 9685** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9686** no corresponding change is present in the changesets returned by this 9687** function. If an existing row with one or more NULL values stored in 9688** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9689** only an INSERT is appears in the changeset. Similarly, if an existing row 9690** with non-NULL PRIMARY KEY values is updated so that one or more of its 9691** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9692** DELETE change only. 9693** 9694** The contents of a changeset may be traversed using an iterator created 9695** using the [sqlite3changeset_start()] API. A changeset may be applied to 9696** a database with a compatible schema using the [sqlite3changeset_apply()] 9697** API. 9698** 9699** Within a changeset generated by this function, all changes related to a 9700** single table are grouped together. In other words, when iterating through 9701** a changeset or when applying a changeset to a database, all changes related 9702** to a single table are processed before moving on to the next table. Tables 9703** are sorted in the same order in which they were attached (or auto-attached) 9704** to the sqlite3_session object. The order in which the changes related to 9705** a single table are stored is undefined. 9706** 9707** Following a successful call to this function, it is the responsibility of 9708** the caller to eventually free the buffer that *ppChangeset points to using 9709** [sqlite3_free()]. 9710** 9711** <h3>Changeset Generation</h3> 9712** 9713** Once a table has been attached to a session object, the session object 9714** records the primary key values of all new rows inserted into the table. 9715** It also records the original primary key and other column values of any 9716** deleted or updated rows. For each unique primary key value, data is only 9717** recorded once - the first time a row with said primary key is inserted, 9718** updated or deleted in the lifetime of the session. 9719** 9720** There is one exception to the previous paragraph: when a row is inserted, 9721** updated or deleted, if one or more of its primary key columns contain a 9722** NULL value, no record of the change is made. 9723** 9724** The session object therefore accumulates two types of records - those 9725** that consist of primary key values only (created when the user inserts 9726** a new record) and those that consist of the primary key values and the 9727** original values of other table columns (created when the users deletes 9728** or updates a record). 9729** 9730** When this function is called, the requested changeset is created using 9731** both the accumulated records and the current contents of the database 9732** file. Specifically: 9733** 9734** <ul> 9735** <li> For each record generated by an insert, the database is queried 9736** for a row with a matching primary key. If one is found, an INSERT 9737** change is added to the changeset. If no such row is found, no change 9738** is added to the changeset. 9739** 9740** <li> For each record generated by an update or delete, the database is 9741** queried for a row with a matching primary key. If such a row is 9742** found and one or more of the non-primary key fields have been 9743** modified from their original values, an UPDATE change is added to 9744** the changeset. Or, if no such row is found in the table, a DELETE 9745** change is added to the changeset. If there is a row with a matching 9746** primary key in the database, but all fields contain their original 9747** values, no change is added to the changeset. 9748** </ul> 9749** 9750** This means, amongst other things, that if a row is inserted and then later 9751** deleted while a session object is active, neither the insert nor the delete 9752** will be present in the changeset. Or if a row is deleted and then later a 9753** row with the same primary key values inserted while a session object is 9754** active, the resulting changeset will contain an UPDATE change instead of 9755** a DELETE and an INSERT. 9756** 9757** When a session object is disabled (see the [sqlite3session_enable()] API), 9758** it does not accumulate records when rows are inserted, updated or deleted. 9759** This may appear to have some counter-intuitive effects if a single row 9760** is written to more than once during a session. For example, if a row 9761** is inserted while a session object is enabled, then later deleted while 9762** the same session object is disabled, no INSERT record will appear in the 9763** changeset, even though the delete took place while the session was disabled. 9764** Or, if one field of a row is updated while a session is disabled, and 9765** another field of the same row is updated while the session is enabled, the 9766** resulting changeset will contain an UPDATE change that updates both fields. 9767*/ 9768SQLITE_API int sqlite3session_changeset( 9769 sqlite3_session *pSession, /* Session object */ 9770 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9771 void **ppChangeset /* OUT: Buffer containing changeset */ 9772); 9773 9774/* 9775** CAPI3REF: Load The Difference Between Tables Into A Session 9776** METHOD: sqlite3_session 9777** 9778** If it is not already attached to the session object passed as the first 9779** argument, this function attaches table zTbl in the same manner as the 9780** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9781** does not have a primary key, this function is a no-op (but does not return 9782** an error). 9783** 9784** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9785** attached to the same database handle as the session object that contains 9786** a table compatible with the table attached to the session by this function. 9787** A table is considered compatible if it: 9788** 9789** <ul> 9790** <li> Has the same name, 9791** <li> Has the same set of columns declared in the same order, and 9792** <li> Has the same PRIMARY KEY definition. 9793** </ul> 9794** 9795** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9796** are compatible but do not have any PRIMARY KEY columns, it is not an error 9797** but no changes are added to the session object. As with other session 9798** APIs, tables without PRIMARY KEYs are simply ignored. 9799** 9800** This function adds a set of changes to the session object that could be 9801** used to update the table in database zFrom (call this the "from-table") 9802** so that its content is the same as the table attached to the session 9803** object (call this the "to-table"). Specifically: 9804** 9805** <ul> 9806** <li> For each row (primary key) that exists in the to-table but not in 9807** the from-table, an INSERT record is added to the session object. 9808** 9809** <li> For each row (primary key) that exists in the to-table but not in 9810** the from-table, a DELETE record is added to the session object. 9811** 9812** <li> For each row (primary key) that exists in both tables, but features 9813** different non-PK values in each, an UPDATE record is added to the 9814** session. 9815** </ul> 9816** 9817** To clarify, if this function is called and then a changeset constructed 9818** using [sqlite3session_changeset()], then after applying that changeset to 9819** database zFrom the contents of the two compatible tables would be 9820** identical. 9821** 9822** It an error if database zFrom does not exist or does not contain the 9823** required compatible table. 9824** 9825** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9826** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9827** may be set to point to a buffer containing an English language error 9828** message. It is the responsibility of the caller to free this buffer using 9829** sqlite3_free(). 9830*/ 9831SQLITE_API int sqlite3session_diff( 9832 sqlite3_session *pSession, 9833 const char *zFromDb, 9834 const char *zTbl, 9835 char **pzErrMsg 9836); 9837 9838 9839/* 9840** CAPI3REF: Generate A Patchset From A Session Object 9841** METHOD: sqlite3_session 9842** 9843** The differences between a patchset and a changeset are that: 9844** 9845** <ul> 9846** <li> DELETE records consist of the primary key fields only. The 9847** original values of other fields are omitted. 9848** <li> The original values of any modified fields are omitted from 9849** UPDATE records. 9850** </ul> 9851** 9852** A patchset blob may be used with up to date versions of all 9853** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9854** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9855** attempting to use a patchset blob with old versions of the 9856** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9857** 9858** Because the non-primary key "old.*" fields are omitted, no 9859** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9860** is passed to the sqlite3changeset_apply() API. Other conflict types work 9861** in the same way as for changesets. 9862** 9863** Changes within a patchset are ordered in the same way as for changesets 9864** generated by the sqlite3session_changeset() function (i.e. all changes for 9865** a single table are grouped together, tables appear in the order in which 9866** they were attached to the session object). 9867*/ 9868SQLITE_API int sqlite3session_patchset( 9869 sqlite3_session *pSession, /* Session object */ 9870 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 9871 void **ppPatchset /* OUT: Buffer containing patchset */ 9872); 9873 9874/* 9875** CAPI3REF: Test if a changeset has recorded any changes. 9876** 9877** Return non-zero if no changes to attached tables have been recorded by 9878** the session object passed as the first argument. Otherwise, if one or 9879** more changes have been recorded, return zero. 9880** 9881** Even if this function returns zero, it is possible that calling 9882** [sqlite3session_changeset()] on the session handle may still return a 9883** changeset that contains no changes. This can happen when a row in 9884** an attached table is modified and then later on the original values 9885** are restored. However, if this function returns non-zero, then it is 9886** guaranteed that a call to sqlite3session_changeset() will return a 9887** changeset containing zero changes. 9888*/ 9889SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9890 9891/* 9892** CAPI3REF: Create An Iterator To Traverse A Changeset 9893** CONSTRUCTOR: sqlite3_changeset_iter 9894** 9895** Create an iterator used to iterate through the contents of a changeset. 9896** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9897** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9898** SQLite error code is returned. 9899** 9900** The following functions can be used to advance and query a changeset 9901** iterator created by this function: 9902** 9903** <ul> 9904** <li> [sqlite3changeset_next()] 9905** <li> [sqlite3changeset_op()] 9906** <li> [sqlite3changeset_new()] 9907** <li> [sqlite3changeset_old()] 9908** </ul> 9909** 9910** It is the responsibility of the caller to eventually destroy the iterator 9911** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9912** changeset (pChangeset) must remain valid until after the iterator is 9913** destroyed. 9914** 9915** Assuming the changeset blob was created by one of the 9916** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9917** [sqlite3changeset_invert()] functions, all changes within the changeset 9918** that apply to a single table are grouped together. This means that when 9919** an application iterates through a changeset using an iterator created by 9920** this function, all changes that relate to a single table are visited 9921** consecutively. There is no chance that the iterator will visit a change 9922** the applies to table X, then one for table Y, and then later on visit 9923** another change for table X. 9924** 9925** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 9926** may be modified by passing a combination of 9927** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 9928** 9929** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 9930** and therefore subject to change. 9931*/ 9932SQLITE_API int sqlite3changeset_start( 9933 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9934 int nChangeset, /* Size of changeset blob in bytes */ 9935 void *pChangeset /* Pointer to blob containing changeset */ 9936); 9937SQLITE_API int sqlite3changeset_start_v2( 9938 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9939 int nChangeset, /* Size of changeset blob in bytes */ 9940 void *pChangeset, /* Pointer to blob containing changeset */ 9941 int flags /* SESSION_CHANGESETSTART_* flags */ 9942); 9943 9944/* 9945** CAPI3REF: Flags for sqlite3changeset_start_v2 9946** 9947** The following flags may passed via the 4th parameter to 9948** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 9949** 9950** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 9951** Invert the changeset while iterating through it. This is equivalent to 9952** inverting a changeset using sqlite3changeset_invert() before applying it. 9953** It is an error to specify this flag with a patchset. 9954*/ 9955#define SQLITE_CHANGESETSTART_INVERT 0x0002 9956 9957 9958/* 9959** CAPI3REF: Advance A Changeset Iterator 9960** METHOD: sqlite3_changeset_iter 9961** 9962** This function may only be used with iterators created by function 9963** [sqlite3changeset_start()]. If it is called on an iterator passed to 9964** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9965** is returned and the call has no effect. 9966** 9967** Immediately after an iterator is created by sqlite3changeset_start(), it 9968** does not point to any change in the changeset. Assuming the changeset 9969** is not empty, the first call to this function advances the iterator to 9970** point to the first change in the changeset. Each subsequent call advances 9971** the iterator to point to the next change in the changeset (if any). If 9972** no error occurs and the iterator points to a valid change after a call 9973** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9974** Otherwise, if all changes in the changeset have already been visited, 9975** SQLITE_DONE is returned. 9976** 9977** If an error occurs, an SQLite error code is returned. Possible error 9978** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9979** SQLITE_NOMEM. 9980*/ 9981SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9982 9983/* 9984** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9985** METHOD: sqlite3_changeset_iter 9986** 9987** The pIter argument passed to this function may either be an iterator 9988** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9989** created by [sqlite3changeset_start()]. In the latter case, the most recent 9990** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9991** is not the case, this function returns [SQLITE_MISUSE]. 9992** 9993** If argument pzTab is not NULL, then *pzTab is set to point to a 9994** nul-terminated utf-8 encoded string containing the name of the table 9995** affected by the current change. The buffer remains valid until either 9996** sqlite3changeset_next() is called on the iterator or until the 9997** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9998** set to the number of columns in the table affected by the change. If 9999** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 10000** is an indirect change, or false (0) otherwise. See the documentation for 10001** [sqlite3session_indirect()] for a description of direct and indirect 10002** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10003** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10004** type of change that the iterator currently points to. 10005** 10006** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10007** SQLite error code is returned. The values of the output variables may not 10008** be trusted in this case. 10009*/ 10010SQLITE_API int sqlite3changeset_op( 10011 sqlite3_changeset_iter *pIter, /* Iterator object */ 10012 const char **pzTab, /* OUT: Pointer to table name */ 10013 int *pnCol, /* OUT: Number of columns in table */ 10014 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10015 int *pbIndirect /* OUT: True for an 'indirect' change */ 10016); 10017 10018/* 10019** CAPI3REF: Obtain The Primary Key Definition Of A Table 10020** METHOD: sqlite3_changeset_iter 10021** 10022** For each modified table, a changeset includes the following: 10023** 10024** <ul> 10025** <li> The number of columns in the table, and 10026** <li> Which of those columns make up the tables PRIMARY KEY. 10027** </ul> 10028** 10029** This function is used to find which columns comprise the PRIMARY KEY of 10030** the table modified by the change that iterator pIter currently points to. 10031** If successful, *pabPK is set to point to an array of nCol entries, where 10032** nCol is the number of columns in the table. Elements of *pabPK are set to 10033** 0x01 if the corresponding column is part of the tables primary key, or 10034** 0x00 if it is not. 10035** 10036** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10037** in the table. 10038** 10039** If this function is called when the iterator does not point to a valid 10040** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10041** SQLITE_OK is returned and the output variables populated as described 10042** above. 10043*/ 10044SQLITE_API int sqlite3changeset_pk( 10045 sqlite3_changeset_iter *pIter, /* Iterator object */ 10046 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10047 int *pnCol /* OUT: Number of entries in output array */ 10048); 10049 10050/* 10051** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10052** METHOD: sqlite3_changeset_iter 10053** 10054** The pIter argument passed to this function may either be an iterator 10055** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10056** created by [sqlite3changeset_start()]. In the latter case, the most recent 10057** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10058** Furthermore, it may only be called if the type of change that the iterator 10059** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10060** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10061** 10062** Argument iVal must be greater than or equal to 0, and less than the number 10063** of columns in the table affected by the current change. Otherwise, 10064** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10065** 10066** If successful, this function sets *ppValue to point to a protected 10067** sqlite3_value object containing the iVal'th value from the vector of 10068** original row values stored as part of the UPDATE or DELETE change and 10069** returns SQLITE_OK. The name of the function comes from the fact that this 10070** is similar to the "old.*" columns available to update or delete triggers. 10071** 10072** If some other error occurs (e.g. an OOM condition), an SQLite error code 10073** is returned and *ppValue is set to NULL. 10074*/ 10075SQLITE_API int sqlite3changeset_old( 10076 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10077 int iVal, /* Column number */ 10078 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10079); 10080 10081/* 10082** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10083** METHOD: sqlite3_changeset_iter 10084** 10085** The pIter argument passed to this function may either be an iterator 10086** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10087** created by [sqlite3changeset_start()]. In the latter case, the most recent 10088** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10089** Furthermore, it may only be called if the type of change that the iterator 10090** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10091** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10092** 10093** Argument iVal must be greater than or equal to 0, and less than the number 10094** of columns in the table affected by the current change. Otherwise, 10095** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10096** 10097** If successful, this function sets *ppValue to point to a protected 10098** sqlite3_value object containing the iVal'th value from the vector of 10099** new row values stored as part of the UPDATE or INSERT change and 10100** returns SQLITE_OK. If the change is an UPDATE and does not include 10101** a new value for the requested column, *ppValue is set to NULL and 10102** SQLITE_OK returned. The name of the function comes from the fact that 10103** this is similar to the "new.*" columns available to update or delete 10104** triggers. 10105** 10106** If some other error occurs (e.g. an OOM condition), an SQLite error code 10107** is returned and *ppValue is set to NULL. 10108*/ 10109SQLITE_API int sqlite3changeset_new( 10110 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10111 int iVal, /* Column number */ 10112 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10113); 10114 10115/* 10116** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10117** METHOD: sqlite3_changeset_iter 10118** 10119** This function should only be used with iterator objects passed to a 10120** conflict-handler callback by [sqlite3changeset_apply()] with either 10121** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10122** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10123** is set to NULL. 10124** 10125** Argument iVal must be greater than or equal to 0, and less than the number 10126** of columns in the table affected by the current change. Otherwise, 10127** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10128** 10129** If successful, this function sets *ppValue to point to a protected 10130** sqlite3_value object containing the iVal'th value from the 10131** "conflicting row" associated with the current conflict-handler callback 10132** and returns SQLITE_OK. 10133** 10134** If some other error occurs (e.g. an OOM condition), an SQLite error code 10135** is returned and *ppValue is set to NULL. 10136*/ 10137SQLITE_API int sqlite3changeset_conflict( 10138 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10139 int iVal, /* Column number */ 10140 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10141); 10142 10143/* 10144** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10145** METHOD: sqlite3_changeset_iter 10146** 10147** This function may only be called with an iterator passed to an 10148** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10149** it sets the output variable to the total number of known foreign key 10150** violations in the destination database and returns SQLITE_OK. 10151** 10152** In all other cases this function returns SQLITE_MISUSE. 10153*/ 10154SQLITE_API int sqlite3changeset_fk_conflicts( 10155 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10156 int *pnOut /* OUT: Number of FK violations */ 10157); 10158 10159 10160/* 10161** CAPI3REF: Finalize A Changeset Iterator 10162** METHOD: sqlite3_changeset_iter 10163** 10164** This function is used to finalize an iterator allocated with 10165** [sqlite3changeset_start()]. 10166** 10167** This function should only be called on iterators created using the 10168** [sqlite3changeset_start()] function. If an application calls this 10169** function with an iterator passed to a conflict-handler by 10170** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10171** call has no effect. 10172** 10173** If an error was encountered within a call to an sqlite3changeset_xxx() 10174** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10175** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10176** to that error is returned by this function. Otherwise, SQLITE_OK is 10177** returned. This is to allow the following pattern (pseudo-code): 10178** 10179** <pre> 10180** sqlite3changeset_start(); 10181** while( SQLITE_ROW==sqlite3changeset_next() ){ 10182** // Do something with change. 10183** } 10184** rc = sqlite3changeset_finalize(); 10185** if( rc!=SQLITE_OK ){ 10186** // An error has occurred 10187** } 10188** </pre> 10189*/ 10190SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10191 10192/* 10193** CAPI3REF: Invert A Changeset 10194** 10195** This function is used to "invert" a changeset object. Applying an inverted 10196** changeset to a database reverses the effects of applying the uninverted 10197** changeset. Specifically: 10198** 10199** <ul> 10200** <li> Each DELETE change is changed to an INSERT, and 10201** <li> Each INSERT change is changed to a DELETE, and 10202** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10203** </ul> 10204** 10205** This function does not change the order in which changes appear within 10206** the changeset. It merely reverses the sense of each individual change. 10207** 10208** If successful, a pointer to a buffer containing the inverted changeset 10209** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10210** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10211** zeroed and an SQLite error code returned. 10212** 10213** It is the responsibility of the caller to eventually call sqlite3_free() 10214** on the *ppOut pointer to free the buffer allocation following a successful 10215** call to this function. 10216** 10217** WARNING/TODO: This function currently assumes that the input is a valid 10218** changeset. If it is not, the results are undefined. 10219*/ 10220SQLITE_API int sqlite3changeset_invert( 10221 int nIn, const void *pIn, /* Input changeset */ 10222 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10223); 10224 10225/* 10226** CAPI3REF: Concatenate Two Changeset Objects 10227** 10228** This function is used to concatenate two changesets, A and B, into a 10229** single changeset. The result is a changeset equivalent to applying 10230** changeset A followed by changeset B. 10231** 10232** This function combines the two input changesets using an 10233** sqlite3_changegroup object. Calling it produces similar results as the 10234** following code fragment: 10235** 10236** <pre> 10237** sqlite3_changegroup *pGrp; 10238** rc = sqlite3_changegroup_new(&pGrp); 10239** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10240** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10241** if( rc==SQLITE_OK ){ 10242** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10243** }else{ 10244** *ppOut = 0; 10245** *pnOut = 0; 10246** } 10247** </pre> 10248** 10249** Refer to the sqlite3_changegroup documentation below for details. 10250*/ 10251SQLITE_API int sqlite3changeset_concat( 10252 int nA, /* Number of bytes in buffer pA */ 10253 void *pA, /* Pointer to buffer containing changeset A */ 10254 int nB, /* Number of bytes in buffer pB */ 10255 void *pB, /* Pointer to buffer containing changeset B */ 10256 int *pnOut, /* OUT: Number of bytes in output changeset */ 10257 void **ppOut /* OUT: Buffer containing output changeset */ 10258); 10259 10260 10261/* 10262** CAPI3REF: Changegroup Handle 10263** 10264** A changegroup is an object used to combine two or more 10265** [changesets] or [patchsets] 10266*/ 10267typedef struct sqlite3_changegroup sqlite3_changegroup; 10268 10269/* 10270** CAPI3REF: Create A New Changegroup Object 10271** CONSTRUCTOR: sqlite3_changegroup 10272** 10273** An sqlite3_changegroup object is used to combine two or more changesets 10274** (or patchsets) into a single changeset (or patchset). A single changegroup 10275** object may combine changesets or patchsets, but not both. The output is 10276** always in the same format as the input. 10277** 10278** If successful, this function returns SQLITE_OK and populates (*pp) with 10279** a pointer to a new sqlite3_changegroup object before returning. The caller 10280** should eventually free the returned object using a call to 10281** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10282** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10283** 10284** The usual usage pattern for an sqlite3_changegroup object is as follows: 10285** 10286** <ul> 10287** <li> It is created using a call to sqlite3changegroup_new(). 10288** 10289** <li> Zero or more changesets (or patchsets) are added to the object 10290** by calling sqlite3changegroup_add(). 10291** 10292** <li> The result of combining all input changesets together is obtained 10293** by the application via a call to sqlite3changegroup_output(). 10294** 10295** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10296** </ul> 10297** 10298** Any number of calls to add() and output() may be made between the calls to 10299** new() and delete(), and in any order. 10300** 10301** As well as the regular sqlite3changegroup_add() and 10302** sqlite3changegroup_output() functions, also available are the streaming 10303** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10304*/ 10305SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10306 10307/* 10308** CAPI3REF: Add A Changeset To A Changegroup 10309** METHOD: sqlite3_changegroup 10310** 10311** Add all changes within the changeset (or patchset) in buffer pData (size 10312** nData bytes) to the changegroup. 10313** 10314** If the buffer contains a patchset, then all prior calls to this function 10315** on the same changegroup object must also have specified patchsets. Or, if 10316** the buffer contains a changeset, so must have the earlier calls to this 10317** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10318** to the changegroup. 10319** 10320** Rows within the changeset and changegroup are identified by the values in 10321** their PRIMARY KEY columns. A change in the changeset is considered to 10322** apply to the same row as a change already present in the changegroup if 10323** the two rows have the same primary key. 10324** 10325** Changes to rows that do not already appear in the changegroup are 10326** simply copied into it. Or, if both the new changeset and the changegroup 10327** contain changes that apply to a single row, the final contents of the 10328** changegroup depends on the type of each change, as follows: 10329** 10330** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10331** <tr><th style="white-space:pre">Existing Change </th> 10332** <th style="white-space:pre">New Change </th> 10333** <th>Output Change 10334** <tr><td>INSERT <td>INSERT <td> 10335** The new change is ignored. This case does not occur if the new 10336** changeset was recorded immediately after the changesets already 10337** added to the changegroup. 10338** <tr><td>INSERT <td>UPDATE <td> 10339** The INSERT change remains in the changegroup. The values in the 10340** INSERT change are modified as if the row was inserted by the 10341** existing change and then updated according to the new change. 10342** <tr><td>INSERT <td>DELETE <td> 10343** The existing INSERT is removed from the changegroup. The DELETE is 10344** not added. 10345** <tr><td>UPDATE <td>INSERT <td> 10346** The new change is ignored. This case does not occur if the new 10347** changeset was recorded immediately after the changesets already 10348** added to the changegroup. 10349** <tr><td>UPDATE <td>UPDATE <td> 10350** The existing UPDATE remains within the changegroup. It is amended 10351** so that the accompanying values are as if the row was updated once 10352** by the existing change and then again by the new change. 10353** <tr><td>UPDATE <td>DELETE <td> 10354** The existing UPDATE is replaced by the new DELETE within the 10355** changegroup. 10356** <tr><td>DELETE <td>INSERT <td> 10357** If one or more of the column values in the row inserted by the 10358** new change differ from those in the row deleted by the existing 10359** change, the existing DELETE is replaced by an UPDATE within the 10360** changegroup. Otherwise, if the inserted row is exactly the same 10361** as the deleted row, the existing DELETE is simply discarded. 10362** <tr><td>DELETE <td>UPDATE <td> 10363** The new change is ignored. This case does not occur if the new 10364** changeset was recorded immediately after the changesets already 10365** added to the changegroup. 10366** <tr><td>DELETE <td>DELETE <td> 10367** The new change is ignored. This case does not occur if the new 10368** changeset was recorded immediately after the changesets already 10369** added to the changegroup. 10370** </table> 10371** 10372** If the new changeset contains changes to a table that is already present 10373** in the changegroup, then the number of columns and the position of the 10374** primary key columns for the table must be consistent. If this is not the 10375** case, this function fails with SQLITE_SCHEMA. If the input changeset 10376** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10377** returned. Or, if an out-of-memory condition occurs during processing, this 10378** function returns SQLITE_NOMEM. In all cases, if an error occurs the 10379** final contents of the changegroup is undefined. 10380** 10381** If no error occurs, SQLITE_OK is returned. 10382*/ 10383SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10384 10385/* 10386** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10387** METHOD: sqlite3_changegroup 10388** 10389** Obtain a buffer containing a changeset (or patchset) representing the 10390** current contents of the changegroup. If the inputs to the changegroup 10391** were themselves changesets, the output is a changeset. Or, if the 10392** inputs were patchsets, the output is also a patchset. 10393** 10394** As with the output of the sqlite3session_changeset() and 10395** sqlite3session_patchset() functions, all changes related to a single 10396** table are grouped together in the output of this function. Tables appear 10397** in the same order as for the very first changeset added to the changegroup. 10398** If the second or subsequent changesets added to the changegroup contain 10399** changes for tables that do not appear in the first changeset, they are 10400** appended onto the end of the output changeset, again in the order in 10401** which they are first encountered. 10402** 10403** If an error occurs, an SQLite error code is returned and the output 10404** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10405** is returned and the output variables are set to the size of and a 10406** pointer to the output buffer, respectively. In this case it is the 10407** responsibility of the caller to eventually free the buffer using a 10408** call to sqlite3_free(). 10409*/ 10410SQLITE_API int sqlite3changegroup_output( 10411 sqlite3_changegroup*, 10412 int *pnData, /* OUT: Size of output buffer in bytes */ 10413 void **ppData /* OUT: Pointer to output buffer */ 10414); 10415 10416/* 10417** CAPI3REF: Delete A Changegroup Object 10418** DESTRUCTOR: sqlite3_changegroup 10419*/ 10420SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10421 10422/* 10423** CAPI3REF: Apply A Changeset To A Database 10424** 10425** Apply a changeset or patchset to a database. These functions attempt to 10426** update the "main" database attached to handle db with the changes found in 10427** the changeset passed via the second and third arguments. 10428** 10429** The fourth argument (xFilter) passed to these functions is the "filter 10430** callback". If it is not NULL, then for each table affected by at least one 10431** change in the changeset, the filter callback is invoked with 10432** the table name as the second argument, and a copy of the context pointer 10433** passed as the sixth argument as the first. If the "filter callback" 10434** returns zero, then no attempt is made to apply any changes to the table. 10435** Otherwise, if the return value is non-zero or the xFilter argument to 10436** is NULL, all changes related to the table are attempted. 10437** 10438** For each table that is not excluded by the filter callback, this function 10439** tests that the target database contains a compatible table. A table is 10440** considered compatible if all of the following are true: 10441** 10442** <ul> 10443** <li> The table has the same name as the name recorded in the 10444** changeset, and 10445** <li> The table has at least as many columns as recorded in the 10446** changeset, and 10447** <li> The table has primary key columns in the same position as 10448** recorded in the changeset. 10449** </ul> 10450** 10451** If there is no compatible table, it is not an error, but none of the 10452** changes associated with the table are applied. A warning message is issued 10453** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10454** one such warning is issued for each table in the changeset. 10455** 10456** For each change for which there is a compatible table, an attempt is made 10457** to modify the table contents according to the UPDATE, INSERT or DELETE 10458** change. If a change cannot be applied cleanly, the conflict handler 10459** function passed as the fifth argument to sqlite3changeset_apply() may be 10460** invoked. A description of exactly when the conflict handler is invoked for 10461** each type of change is below. 10462** 10463** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10464** of passing anything other than a valid function pointer as the xConflict 10465** argument are undefined. 10466** 10467** Each time the conflict handler function is invoked, it must return one 10468** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10469** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10470** if the second argument passed to the conflict handler is either 10471** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10472** returns an illegal value, any changes already made are rolled back and 10473** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10474** actions are taken by sqlite3changeset_apply() depending on the value 10475** returned by each invocation of the conflict-handler function. Refer to 10476** the documentation for the three 10477** [SQLITE_CHANGESET_OMIT|available return values] for details. 10478** 10479** <dl> 10480** <dt>DELETE Changes<dd> 10481** For each DELETE change, the function checks if the target database 10482** contains a row with the same primary key value (or values) as the 10483** original row values stored in the changeset. If it does, and the values 10484** stored in all non-primary key columns also match the values stored in 10485** the changeset the row is deleted from the target database. 10486** 10487** If a row with matching primary key values is found, but one or more of 10488** the non-primary key fields contains a value different from the original 10489** row value stored in the changeset, the conflict-handler function is 10490** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10491** database table has more columns than are recorded in the changeset, 10492** only the values of those non-primary key fields are compared against 10493** the current database contents - any trailing database table columns 10494** are ignored. 10495** 10496** If no row with matching primary key values is found in the database, 10497** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10498** passed as the second argument. 10499** 10500** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10501** (which can only happen if a foreign key constraint is violated), the 10502** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10503** passed as the second argument. This includes the case where the DELETE 10504** operation is attempted because an earlier call to the conflict handler 10505** function returned [SQLITE_CHANGESET_REPLACE]. 10506** 10507** <dt>INSERT Changes<dd> 10508** For each INSERT change, an attempt is made to insert the new row into 10509** the database. If the changeset row contains fewer fields than the 10510** database table, the trailing fields are populated with their default 10511** values. 10512** 10513** If the attempt to insert the row fails because the database already 10514** contains a row with the same primary key values, the conflict handler 10515** function is invoked with the second argument set to 10516** [SQLITE_CHANGESET_CONFLICT]. 10517** 10518** If the attempt to insert the row fails because of some other constraint 10519** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10520** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10521** This includes the case where the INSERT operation is re-attempted because 10522** an earlier call to the conflict handler function returned 10523** [SQLITE_CHANGESET_REPLACE]. 10524** 10525** <dt>UPDATE Changes<dd> 10526** For each UPDATE change, the function checks if the target database 10527** contains a row with the same primary key value (or values) as the 10528** original row values stored in the changeset. If it does, and the values 10529** stored in all modified non-primary key columns also match the values 10530** stored in the changeset the row is updated within the target database. 10531** 10532** If a row with matching primary key values is found, but one or more of 10533** the modified non-primary key fields contains a value different from an 10534** original row value stored in the changeset, the conflict-handler function 10535** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10536** UPDATE changes only contain values for non-primary key fields that are 10537** to be modified, only those fields need to match the original values to 10538** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10539** 10540** If no row with matching primary key values is found in the database, 10541** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10542** passed as the second argument. 10543** 10544** If the UPDATE operation is attempted, but SQLite returns 10545** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10546** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10547** This includes the case where the UPDATE operation is attempted after 10548** an earlier call to the conflict handler function returned 10549** [SQLITE_CHANGESET_REPLACE]. 10550** </dl> 10551** 10552** It is safe to execute SQL statements, including those that write to the 10553** table that the callback related to, from within the xConflict callback. 10554** This can be used to further customize the applications conflict 10555** resolution strategy. 10556** 10557** All changes made by these functions are enclosed in a savepoint transaction. 10558** If any other error (aside from a constraint failure when attempting to 10559** write to the target database) occurs, then the savepoint transaction is 10560** rolled back, restoring the target database to its original state, and an 10561** SQLite error code returned. 10562** 10563** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10564** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10565** may set (*ppRebase) to point to a "rebase" that may be used with the 10566** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10567** is set to the size of the buffer in bytes. It is the responsibility of the 10568** caller to eventually free any such buffer using sqlite3_free(). The buffer 10569** is only allocated and populated if one or more conflicts were encountered 10570** while applying the patchset. See comments surrounding the sqlite3_rebaser 10571** APIs for further details. 10572** 10573** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10574** may be modified by passing a combination of 10575** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10576** 10577** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10578** and therefore subject to change. 10579*/ 10580SQLITE_API int sqlite3changeset_apply( 10581 sqlite3 *db, /* Apply change to "main" db of this handle */ 10582 int nChangeset, /* Size of changeset in bytes */ 10583 void *pChangeset, /* Changeset blob */ 10584 int(*xFilter)( 10585 void *pCtx, /* Copy of sixth arg to _apply() */ 10586 const char *zTab /* Table name */ 10587 ), 10588 int(*xConflict)( 10589 void *pCtx, /* Copy of sixth arg to _apply() */ 10590 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10591 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10592 ), 10593 void *pCtx /* First argument passed to xConflict */ 10594); 10595SQLITE_API int sqlite3changeset_apply_v2( 10596 sqlite3 *db, /* Apply change to "main" db of this handle */ 10597 int nChangeset, /* Size of changeset in bytes */ 10598 void *pChangeset, /* Changeset blob */ 10599 int(*xFilter)( 10600 void *pCtx, /* Copy of sixth arg to _apply() */ 10601 const char *zTab /* Table name */ 10602 ), 10603 int(*xConflict)( 10604 void *pCtx, /* Copy of sixth arg to _apply() */ 10605 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10606 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10607 ), 10608 void *pCtx, /* First argument passed to xConflict */ 10609 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10610 int flags /* SESSION_CHANGESETAPPLY_* flags */ 10611); 10612 10613/* 10614** CAPI3REF: Flags for sqlite3changeset_apply_v2 10615** 10616** The following flags may passed via the 9th parameter to 10617** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10618** 10619** <dl> 10620** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10621** Usually, the sessions module encloses all operations performed by 10622** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10623** SAVEPOINT is committed if the changeset or patchset is successfully 10624** applied, or rolled back if an error occurs. Specifying this flag 10625** causes the sessions module to omit this savepoint. In this case, if the 10626** caller has an open transaction or savepoint when apply_v2() is called, 10627** it may revert the partially applied changeset by rolling it back. 10628** 10629** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10630** Invert the changeset before applying it. This is equivalent to inverting 10631** a changeset using sqlite3changeset_invert() before applying it. It is 10632** an error to specify this flag with a patchset. 10633*/ 10634#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10635#define SQLITE_CHANGESETAPPLY_INVERT 0x0002 10636 10637/* 10638** CAPI3REF: Constants Passed To The Conflict Handler 10639** 10640** Values that may be passed as the second argument to a conflict-handler. 10641** 10642** <dl> 10643** <dt>SQLITE_CHANGESET_DATA<dd> 10644** The conflict handler is invoked with CHANGESET_DATA as the second argument 10645** when processing a DELETE or UPDATE change if a row with the required 10646** PRIMARY KEY fields is present in the database, but one or more other 10647** (non primary-key) fields modified by the update do not contain the 10648** expected "before" values. 10649** 10650** The conflicting row, in this case, is the database row with the matching 10651** primary key. 10652** 10653** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10654** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10655** argument when processing a DELETE or UPDATE change if a row with the 10656** required PRIMARY KEY fields is not present in the database. 10657** 10658** There is no conflicting row in this case. The results of invoking the 10659** sqlite3changeset_conflict() API are undefined. 10660** 10661** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10662** CHANGESET_CONFLICT is passed as the second argument to the conflict 10663** handler while processing an INSERT change if the operation would result 10664** in duplicate primary key values. 10665** 10666** The conflicting row in this case is the database row with the matching 10667** primary key. 10668** 10669** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10670** If foreign key handling is enabled, and applying a changeset leaves the 10671** database in a state containing foreign key violations, the conflict 10672** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10673** exactly once before the changeset is committed. If the conflict handler 10674** returns CHANGESET_OMIT, the changes, including those that caused the 10675** foreign key constraint violation, are committed. Or, if it returns 10676** CHANGESET_ABORT, the changeset is rolled back. 10677** 10678** No current or conflicting row information is provided. The only function 10679** it is possible to call on the supplied sqlite3_changeset_iter handle 10680** is sqlite3changeset_fk_conflicts(). 10681** 10682** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10683** If any other constraint violation occurs while applying a change (i.e. 10684** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10685** invoked with CHANGESET_CONSTRAINT as the second argument. 10686** 10687** There is no conflicting row in this case. The results of invoking the 10688** sqlite3changeset_conflict() API are undefined. 10689** 10690** </dl> 10691*/ 10692#define SQLITE_CHANGESET_DATA 1 10693#define SQLITE_CHANGESET_NOTFOUND 2 10694#define SQLITE_CHANGESET_CONFLICT 3 10695#define SQLITE_CHANGESET_CONSTRAINT 4 10696#define SQLITE_CHANGESET_FOREIGN_KEY 5 10697 10698/* 10699** CAPI3REF: Constants Returned By The Conflict Handler 10700** 10701** A conflict handler callback must return one of the following three values. 10702** 10703** <dl> 10704** <dt>SQLITE_CHANGESET_OMIT<dd> 10705** If a conflict handler returns this value no special action is taken. The 10706** change that caused the conflict is not applied. The session module 10707** continues to the next change in the changeset. 10708** 10709** <dt>SQLITE_CHANGESET_REPLACE<dd> 10710** This value may only be returned if the second argument to the conflict 10711** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10712** is not the case, any changes applied so far are rolled back and the 10713** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10714** 10715** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10716** handler, then the conflicting row is either updated or deleted, depending 10717** on the type of change. 10718** 10719** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10720** handler, then the conflicting row is removed from the database and a 10721** second attempt to apply the change is made. If this second attempt fails, 10722** the original row is restored to the database before continuing. 10723** 10724** <dt>SQLITE_CHANGESET_ABORT<dd> 10725** If this value is returned, any changes applied so far are rolled back 10726** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10727** </dl> 10728*/ 10729#define SQLITE_CHANGESET_OMIT 0 10730#define SQLITE_CHANGESET_REPLACE 1 10731#define SQLITE_CHANGESET_ABORT 2 10732 10733/* 10734** CAPI3REF: Rebasing changesets 10735** EXPERIMENTAL 10736** 10737** Suppose there is a site hosting a database in state S0. And that 10738** modifications are made that move that database to state S1 and a 10739** changeset recorded (the "local" changeset). Then, a changeset based 10740** on S0 is received from another site (the "remote" changeset) and 10741** applied to the database. The database is then in state 10742** (S1+"remote"), where the exact state depends on any conflict 10743** resolution decisions (OMIT or REPLACE) made while applying "remote". 10744** Rebasing a changeset is to update it to take those conflict 10745** resolution decisions into account, so that the same conflicts 10746** do not have to be resolved elsewhere in the network. 10747** 10748** For example, if both the local and remote changesets contain an 10749** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10750** 10751** local: INSERT INTO t1 VALUES(1, 'v1'); 10752** remote: INSERT INTO t1 VALUES(1, 'v2'); 10753** 10754** and the conflict resolution is REPLACE, then the INSERT change is 10755** removed from the local changeset (it was overridden). Or, if the 10756** conflict resolution was "OMIT", then the local changeset is modified 10757** to instead contain: 10758** 10759** UPDATE t1 SET b = 'v2' WHERE a=1; 10760** 10761** Changes within the local changeset are rebased as follows: 10762** 10763** <dl> 10764** <dt>Local INSERT<dd> 10765** This may only conflict with a remote INSERT. If the conflict 10766** resolution was OMIT, then add an UPDATE change to the rebased 10767** changeset. Or, if the conflict resolution was REPLACE, add 10768** nothing to the rebased changeset. 10769** 10770** <dt>Local DELETE<dd> 10771** This may conflict with a remote UPDATE or DELETE. In both cases the 10772** only possible resolution is OMIT. If the remote operation was a 10773** DELETE, then add no change to the rebased changeset. If the remote 10774** operation was an UPDATE, then the old.* fields of change are updated 10775** to reflect the new.* values in the UPDATE. 10776** 10777** <dt>Local UPDATE<dd> 10778** This may conflict with a remote UPDATE or DELETE. If it conflicts 10779** with a DELETE, and the conflict resolution was OMIT, then the update 10780** is changed into an INSERT. Any undefined values in the new.* record 10781** from the update change are filled in using the old.* values from 10782** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10783** the UPDATE change is simply omitted from the rebased changeset. 10784** 10785** If conflict is with a remote UPDATE and the resolution is OMIT, then 10786** the old.* values are rebased using the new.* values in the remote 10787** change. Or, if the resolution is REPLACE, then the change is copied 10788** into the rebased changeset with updates to columns also updated by 10789** the conflicting remote UPDATE removed. If this means no columns would 10790** be updated, the change is omitted. 10791** </dl> 10792** 10793** A local change may be rebased against multiple remote changes 10794** simultaneously. If a single key is modified by multiple remote 10795** changesets, they are combined as follows before the local changeset 10796** is rebased: 10797** 10798** <ul> 10799** <li> If there has been one or more REPLACE resolutions on a 10800** key, it is rebased according to a REPLACE. 10801** 10802** <li> If there have been no REPLACE resolutions on a key, then 10803** the local changeset is rebased according to the most recent 10804** of the OMIT resolutions. 10805** </ul> 10806** 10807** Note that conflict resolutions from multiple remote changesets are 10808** combined on a per-field basis, not per-row. This means that in the 10809** case of multiple remote UPDATE operations, some fields of a single 10810** local change may be rebased for REPLACE while others are rebased for 10811** OMIT. 10812** 10813** In order to rebase a local changeset, the remote changeset must first 10814** be applied to the local database using sqlite3changeset_apply_v2() and 10815** the buffer of rebase information captured. Then: 10816** 10817** <ol> 10818** <li> An sqlite3_rebaser object is created by calling 10819** sqlite3rebaser_create(). 10820** <li> The new object is configured with the rebase buffer obtained from 10821** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10822** If the local changeset is to be rebased against multiple remote 10823** changesets, then sqlite3rebaser_configure() should be called 10824** multiple times, in the same order that the multiple 10825** sqlite3changeset_apply_v2() calls were made. 10826** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10827** <li> The sqlite3_rebaser object is deleted by calling 10828** sqlite3rebaser_delete(). 10829** </ol> 10830*/ 10831typedef struct sqlite3_rebaser sqlite3_rebaser; 10832 10833/* 10834** CAPI3REF: Create a changeset rebaser object. 10835** EXPERIMENTAL 10836** 10837** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 10838** point to the new object and return SQLITE_OK. Otherwise, if an error 10839** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 10840** to NULL. 10841*/ 10842SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 10843 10844/* 10845** CAPI3REF: Configure a changeset rebaser object. 10846** EXPERIMENTAL 10847** 10848** Configure the changeset rebaser object to rebase changesets according 10849** to the conflict resolutions described by buffer pRebase (size nRebase 10850** bytes), which must have been obtained from a previous call to 10851** sqlite3changeset_apply_v2(). 10852*/ 10853SQLITE_API int sqlite3rebaser_configure( 10854 sqlite3_rebaser*, 10855 int nRebase, const void *pRebase 10856); 10857 10858/* 10859** CAPI3REF: Rebase a changeset 10860** EXPERIMENTAL 10861** 10862** Argument pIn must point to a buffer containing a changeset nIn bytes 10863** in size. This function allocates and populates a buffer with a copy 10864** of the changeset rebased rebased according to the configuration of the 10865** rebaser object passed as the first argument. If successful, (*ppOut) 10866** is set to point to the new buffer containing the rebased changset and 10867** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 10868** responsibility of the caller to eventually free the new buffer using 10869** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 10870** are set to zero and an SQLite error code returned. 10871*/ 10872SQLITE_API int sqlite3rebaser_rebase( 10873 sqlite3_rebaser*, 10874 int nIn, const void *pIn, 10875 int *pnOut, void **ppOut 10876); 10877 10878/* 10879** CAPI3REF: Delete a changeset rebaser object. 10880** EXPERIMENTAL 10881** 10882** Delete the changeset rebaser object and all associated resources. There 10883** should be one call to this function for each successful invocation 10884** of sqlite3rebaser_create(). 10885*/ 10886SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 10887 10888/* 10889** CAPI3REF: Streaming Versions of API functions. 10890** 10891** The six streaming API xxx_strm() functions serve similar purposes to the 10892** corresponding non-streaming API functions: 10893** 10894** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10895** <tr><th>Streaming function<th>Non-streaming equivalent</th> 10896** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 10897** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 10898** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 10899** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 10900** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 10901** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 10902** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 10903** </table> 10904** 10905** Non-streaming functions that accept changesets (or patchsets) as input 10906** require that the entire changeset be stored in a single buffer in memory. 10907** Similarly, those that return a changeset or patchset do so by returning 10908** a pointer to a single large buffer allocated using sqlite3_malloc(). 10909** Normally this is convenient. However, if an application running in a 10910** low-memory environment is required to handle very large changesets, the 10911** large contiguous memory allocations required can become onerous. 10912** 10913** In order to avoid this problem, instead of a single large buffer, input 10914** is passed to a streaming API functions by way of a callback function that 10915** the sessions module invokes to incrementally request input data as it is 10916** required. In all cases, a pair of API function parameters such as 10917** 10918** <pre> 10919** int nChangeset, 10920** void *pChangeset, 10921** </pre> 10922** 10923** Is replaced by: 10924** 10925** <pre> 10926** int (*xInput)(void *pIn, void *pData, int *pnData), 10927** void *pIn, 10928** </pre> 10929** 10930** Each time the xInput callback is invoked by the sessions module, the first 10931** argument passed is a copy of the supplied pIn context pointer. The second 10932** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 10933** error occurs the xInput method should copy up to (*pnData) bytes of data 10934** into the buffer and set (*pnData) to the actual number of bytes copied 10935** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 10936** should be set to zero to indicate this. Or, if an error occurs, an SQLite 10937** error code should be returned. In all cases, if an xInput callback returns 10938** an error, all processing is abandoned and the streaming API function 10939** returns a copy of the error code to the caller. 10940** 10941** In the case of sqlite3changeset_start_strm(), the xInput callback may be 10942** invoked by the sessions module at any point during the lifetime of the 10943** iterator. If such an xInput callback returns an error, the iterator enters 10944** an error state, whereby all subsequent calls to iterator functions 10945** immediately fail with the same error code as returned by xInput. 10946** 10947** Similarly, streaming API functions that return changesets (or patchsets) 10948** return them in chunks by way of a callback function instead of via a 10949** pointer to a single large buffer. In this case, a pair of parameters such 10950** as: 10951** 10952** <pre> 10953** int *pnChangeset, 10954** void **ppChangeset, 10955** </pre> 10956** 10957** Is replaced by: 10958** 10959** <pre> 10960** int (*xOutput)(void *pOut, const void *pData, int nData), 10961** void *pOut 10962** </pre> 10963** 10964** The xOutput callback is invoked zero or more times to return data to 10965** the application. The first parameter passed to each call is a copy of the 10966** pOut pointer supplied by the application. The second parameter, pData, 10967** points to a buffer nData bytes in size containing the chunk of output 10968** data being returned. If the xOutput callback successfully processes the 10969** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 10970** it should return some other SQLite error code. In this case processing 10971** is immediately abandoned and the streaming API function returns a copy 10972** of the xOutput error code to the application. 10973** 10974** The sessions module never invokes an xOutput callback with the third 10975** parameter set to a value less than or equal to zero. Other than this, 10976** no guarantees are made as to the size of the chunks of data returned. 10977*/ 10978SQLITE_API int sqlite3changeset_apply_strm( 10979 sqlite3 *db, /* Apply change to "main" db of this handle */ 10980 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10981 void *pIn, /* First arg for xInput */ 10982 int(*xFilter)( 10983 void *pCtx, /* Copy of sixth arg to _apply() */ 10984 const char *zTab /* Table name */ 10985 ), 10986 int(*xConflict)( 10987 void *pCtx, /* Copy of sixth arg to _apply() */ 10988 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10989 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10990 ), 10991 void *pCtx /* First argument passed to xConflict */ 10992); 10993SQLITE_API int sqlite3changeset_apply_v2_strm( 10994 sqlite3 *db, /* Apply change to "main" db of this handle */ 10995 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10996 void *pIn, /* First arg for xInput */ 10997 int(*xFilter)( 10998 void *pCtx, /* Copy of sixth arg to _apply() */ 10999 const char *zTab /* Table name */ 11000 ), 11001 int(*xConflict)( 11002 void *pCtx, /* Copy of sixth arg to _apply() */ 11003 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11004 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11005 ), 11006 void *pCtx, /* First argument passed to xConflict */ 11007 void **ppRebase, int *pnRebase, 11008 int flags 11009); 11010SQLITE_API int sqlite3changeset_concat_strm( 11011 int (*xInputA)(void *pIn, void *pData, int *pnData), 11012 void *pInA, 11013 int (*xInputB)(void *pIn, void *pData, int *pnData), 11014 void *pInB, 11015 int (*xOutput)(void *pOut, const void *pData, int nData), 11016 void *pOut 11017); 11018SQLITE_API int sqlite3changeset_invert_strm( 11019 int (*xInput)(void *pIn, void *pData, int *pnData), 11020 void *pIn, 11021 int (*xOutput)(void *pOut, const void *pData, int nData), 11022 void *pOut 11023); 11024SQLITE_API int sqlite3changeset_start_strm( 11025 sqlite3_changeset_iter **pp, 11026 int (*xInput)(void *pIn, void *pData, int *pnData), 11027 void *pIn 11028); 11029SQLITE_API int sqlite3changeset_start_v2_strm( 11030 sqlite3_changeset_iter **pp, 11031 int (*xInput)(void *pIn, void *pData, int *pnData), 11032 void *pIn, 11033 int flags 11034); 11035SQLITE_API int sqlite3session_changeset_strm( 11036 sqlite3_session *pSession, 11037 int (*xOutput)(void *pOut, const void *pData, int nData), 11038 void *pOut 11039); 11040SQLITE_API int sqlite3session_patchset_strm( 11041 sqlite3_session *pSession, 11042 int (*xOutput)(void *pOut, const void *pData, int nData), 11043 void *pOut 11044); 11045SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11046 int (*xInput)(void *pIn, void *pData, int *pnData), 11047 void *pIn 11048); 11049SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11050 int (*xOutput)(void *pOut, const void *pData, int nData), 11051 void *pOut 11052); 11053SQLITE_API int sqlite3rebaser_rebase_strm( 11054 sqlite3_rebaser *pRebaser, 11055 int (*xInput)(void *pIn, void *pData, int *pnData), 11056 void *pIn, 11057 int (*xOutput)(void *pOut, const void *pData, int nData), 11058 void *pOut 11059); 11060 11061/* 11062** CAPI3REF: Configure global parameters 11063** 11064** The sqlite3session_config() interface is used to make global configuration 11065** changes to the sessions module in order to tune it to the specific needs 11066** of the application. 11067** 11068** The sqlite3session_config() interface is not threadsafe. If it is invoked 11069** while any other thread is inside any other sessions method then the 11070** results are undefined. Furthermore, if it is invoked after any sessions 11071** related objects have been created, the results are also undefined. 11072** 11073** The first argument to the sqlite3session_config() function must be one 11074** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11075** interpretation of the (void*) value passed as the second parameter and 11076** the effect of calling this function depends on the value of the first 11077** parameter. 11078** 11079** <dl> 11080** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11081** By default, the sessions module streaming interfaces attempt to input 11082** and output data in approximately 1 KiB chunks. This operand may be used 11083** to set and query the value of this configuration setting. The pointer 11084** passed as the second argument must point to a value of type (int). 11085** If this value is greater than 0, it is used as the new streaming data 11086** chunk size for both input and output. Before returning, the (int) value 11087** pointed to by pArg is set to the final value of the streaming interface 11088** chunk size. 11089** </dl> 11090** 11091** This function returns SQLITE_OK if successful, or an SQLite error code 11092** otherwise. 11093*/ 11094SQLITE_API int sqlite3session_config(int op, void *pArg); 11095 11096/* 11097** CAPI3REF: Values for sqlite3session_config(). 11098*/ 11099#define SQLITE_SESSION_CONFIG_STRMSIZE 1 11100 11101/* 11102** Make sure we can call this stuff from C++. 11103*/ 11104#ifdef __cplusplus 11105} 11106#endif 11107 11108#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11109 11110/******** End of sqlite3session.h *********/ 11111/******** Begin file fts5.h *********/ 11112/* 11113** 2014 May 31 11114** 11115** The author disclaims copyright to this source code. In place of 11116** a legal notice, here is a blessing: 11117** 11118** May you do good and not evil. 11119** May you find forgiveness for yourself and forgive others. 11120** May you share freely, never taking more than you give. 11121** 11122****************************************************************************** 11123** 11124** Interfaces to extend FTS5. Using the interfaces defined in this file, 11125** FTS5 may be extended with: 11126** 11127** * custom tokenizers, and 11128** * custom auxiliary functions. 11129*/ 11130 11131 11132#ifndef _FTS5_H 11133#define _FTS5_H 11134 11135 11136#ifdef __cplusplus 11137extern "C" { 11138#endif 11139 11140/************************************************************************* 11141** CUSTOM AUXILIARY FUNCTIONS 11142** 11143** Virtual table implementations may overload SQL functions by implementing 11144** the sqlite3_module.xFindFunction() method. 11145*/ 11146 11147typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11148typedef struct Fts5Context Fts5Context; 11149typedef struct Fts5PhraseIter Fts5PhraseIter; 11150 11151typedef void (*fts5_extension_function)( 11152 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11153 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11154 sqlite3_context *pCtx, /* Context for returning result/error */ 11155 int nVal, /* Number of values in apVal[] array */ 11156 sqlite3_value **apVal /* Array of trailing arguments */ 11157); 11158 11159struct Fts5PhraseIter { 11160 const unsigned char *a; 11161 const unsigned char *b; 11162}; 11163 11164/* 11165** EXTENSION API FUNCTIONS 11166** 11167** xUserData(pFts): 11168** Return a copy of the context pointer the extension function was 11169** registered with. 11170** 11171** xColumnTotalSize(pFts, iCol, pnToken): 11172** If parameter iCol is less than zero, set output variable *pnToken 11173** to the total number of tokens in the FTS5 table. Or, if iCol is 11174** non-negative but less than the number of columns in the table, return 11175** the total number of tokens in column iCol, considering all rows in 11176** the FTS5 table. 11177** 11178** If parameter iCol is greater than or equal to the number of columns 11179** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11180** an OOM condition or IO error), an appropriate SQLite error code is 11181** returned. 11182** 11183** xColumnCount(pFts): 11184** Return the number of columns in the table. 11185** 11186** xColumnSize(pFts, iCol, pnToken): 11187** If parameter iCol is less than zero, set output variable *pnToken 11188** to the total number of tokens in the current row. Or, if iCol is 11189** non-negative but less than the number of columns in the table, set 11190** *pnToken to the number of tokens in column iCol of the current row. 11191** 11192** If parameter iCol is greater than or equal to the number of columns 11193** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11194** an OOM condition or IO error), an appropriate SQLite error code is 11195** returned. 11196** 11197** This function may be quite inefficient if used with an FTS5 table 11198** created with the "columnsize=0" option. 11199** 11200** xColumnText: 11201** This function attempts to retrieve the text of column iCol of the 11202** current document. If successful, (*pz) is set to point to a buffer 11203** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11204** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11205** if an error occurs, an SQLite error code is returned and the final values 11206** of (*pz) and (*pn) are undefined. 11207** 11208** xPhraseCount: 11209** Returns the number of phrases in the current query expression. 11210** 11211** xPhraseSize: 11212** Returns the number of tokens in phrase iPhrase of the query. Phrases 11213** are numbered starting from zero. 11214** 11215** xInstCount: 11216** Set *pnInst to the total number of occurrences of all phrases within 11217** the query within the current row. Return SQLITE_OK if successful, or 11218** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11219** 11220** This API can be quite slow if used with an FTS5 table created with the 11221** "detail=none" or "detail=column" option. If the FTS5 table is created 11222** with either "detail=none" or "detail=column" and "content=" option 11223** (i.e. if it is a contentless table), then this API always returns 0. 11224** 11225** xInst: 11226** Query for the details of phrase match iIdx within the current row. 11227** Phrase matches are numbered starting from zero, so the iIdx argument 11228** should be greater than or equal to zero and smaller than the value 11229** output by xInstCount(). 11230** 11231** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11232** to the column in which it occurs and *piOff the token offset of the 11233** first token of the phrase. The exception is if the table was created 11234** with the offsets=0 option specified. In this case *piOff is always 11235** set to -1. 11236** 11237** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 11238** if an error occurs. 11239** 11240** This API can be quite slow if used with an FTS5 table created with the 11241** "detail=none" or "detail=column" option. 11242** 11243** xRowid: 11244** Returns the rowid of the current row. 11245** 11246** xTokenize: 11247** Tokenize text using the tokenizer belonging to the FTS5 table. 11248** 11249** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11250** This API function is used to query the FTS table for phrase iPhrase 11251** of the current query. Specifically, a query equivalent to: 11252** 11253** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11254** 11255** with $p set to a phrase equivalent to the phrase iPhrase of the 11256** current query is executed. Any column filter that applies to 11257** phrase iPhrase of the current query is included in $p. For each 11258** row visited, the callback function passed as the fourth argument 11259** is invoked. The context and API objects passed to the callback 11260** function may be used to access the properties of each matched row. 11261** Invoking Api.xUserData() returns a copy of the pointer passed as 11262** the third argument to pUserData. 11263** 11264** If the callback function returns any value other than SQLITE_OK, the 11265** query is abandoned and the xQueryPhrase function returns immediately. 11266** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11267** Otherwise, the error code is propagated upwards. 11268** 11269** If the query runs to completion without incident, SQLITE_OK is returned. 11270** Or, if some error occurs before the query completes or is aborted by 11271** the callback, an SQLite error code is returned. 11272** 11273** 11274** xSetAuxdata(pFts5, pAux, xDelete) 11275** 11276** Save the pointer passed as the second argument as the extension functions 11277** "auxiliary data". The pointer may then be retrieved by the current or any 11278** future invocation of the same fts5 extension function made as part of 11279** of the same MATCH query using the xGetAuxdata() API. 11280** 11281** Each extension function is allocated a single auxiliary data slot for 11282** each FTS query (MATCH expression). If the extension function is invoked 11283** more than once for a single FTS query, then all invocations share a 11284** single auxiliary data context. 11285** 11286** If there is already an auxiliary data pointer when this function is 11287** invoked, then it is replaced by the new pointer. If an xDelete callback 11288** was specified along with the original pointer, it is invoked at this 11289** point. 11290** 11291** The xDelete callback, if one is specified, is also invoked on the 11292** auxiliary data pointer after the FTS5 query has finished. 11293** 11294** If an error (e.g. an OOM condition) occurs within this function, an 11295** the auxiliary data is set to NULL and an error code returned. If the 11296** xDelete parameter was not NULL, it is invoked on the auxiliary data 11297** pointer before returning. 11298** 11299** 11300** xGetAuxdata(pFts5, bClear) 11301** 11302** Returns the current auxiliary data pointer for the fts5 extension 11303** function. See the xSetAuxdata() method for details. 11304** 11305** If the bClear argument is non-zero, then the auxiliary data is cleared 11306** (set to NULL) before this function returns. In this case the xDelete, 11307** if any, is not invoked. 11308** 11309** 11310** xRowCount(pFts5, pnRow) 11311** 11312** This function is used to retrieve the total number of rows in the table. 11313** In other words, the same value that would be returned by: 11314** 11315** SELECT count(*) FROM ftstable; 11316** 11317** xPhraseFirst() 11318** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11319** method, to iterate through all instances of a single query phrase within 11320** the current row. This is the same information as is accessible via the 11321** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11322** to use, this API may be faster under some circumstances. To iterate 11323** through instances of phrase iPhrase, use the following code: 11324** 11325** Fts5PhraseIter iter; 11326** int iCol, iOff; 11327** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11328** iCol>=0; 11329** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11330** ){ 11331** // An instance of phrase iPhrase at offset iOff of column iCol 11332** } 11333** 11334** The Fts5PhraseIter structure is defined above. Applications should not 11335** modify this structure directly - it should only be used as shown above 11336** with the xPhraseFirst() and xPhraseNext() API methods (and by 11337** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11338** 11339** This API can be quite slow if used with an FTS5 table created with the 11340** "detail=none" or "detail=column" option. If the FTS5 table is created 11341** with either "detail=none" or "detail=column" and "content=" option 11342** (i.e. if it is a contentless table), then this API always iterates 11343** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11344** 11345** xPhraseNext() 11346** See xPhraseFirst above. 11347** 11348** xPhraseFirstColumn() 11349** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11350** and xPhraseNext() APIs described above. The difference is that instead 11351** of iterating through all instances of a phrase in the current row, these 11352** APIs are used to iterate through the set of columns in the current row 11353** that contain one or more instances of a specified phrase. For example: 11354** 11355** Fts5PhraseIter iter; 11356** int iCol; 11357** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11358** iCol>=0; 11359** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11360** ){ 11361** // Column iCol contains at least one instance of phrase iPhrase 11362** } 11363** 11364** This API can be quite slow if used with an FTS5 table created with the 11365** "detail=none" option. If the FTS5 table is created with either 11366** "detail=none" "content=" option (i.e. if it is a contentless table), 11367** then this API always iterates through an empty set (all calls to 11368** xPhraseFirstColumn() set iCol to -1). 11369** 11370** The information accessed using this API and its companion 11371** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11372** (or xInst/xInstCount). The chief advantage of this API is that it is 11373** significantly more efficient than those alternatives when used with 11374** "detail=column" tables. 11375** 11376** xPhraseNextColumn() 11377** See xPhraseFirstColumn above. 11378*/ 11379struct Fts5ExtensionApi { 11380 int iVersion; /* Currently always set to 3 */ 11381 11382 void *(*xUserData)(Fts5Context*); 11383 11384 int (*xColumnCount)(Fts5Context*); 11385 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11386 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11387 11388 int (*xTokenize)(Fts5Context*, 11389 const char *pText, int nText, /* Text to tokenize */ 11390 void *pCtx, /* Context passed to xToken() */ 11391 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11392 ); 11393 11394 int (*xPhraseCount)(Fts5Context*); 11395 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11396 11397 int (*xInstCount)(Fts5Context*, int *pnInst); 11398 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11399 11400 sqlite3_int64 (*xRowid)(Fts5Context*); 11401 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11402 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11403 11404 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11405 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11406 ); 11407 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11408 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11409 11410 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11411 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11412 11413 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11414 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11415}; 11416 11417/* 11418** CUSTOM AUXILIARY FUNCTIONS 11419*************************************************************************/ 11420 11421/************************************************************************* 11422** CUSTOM TOKENIZERS 11423** 11424** Applications may also register custom tokenizer types. A tokenizer 11425** is registered by providing fts5 with a populated instance of the 11426** following structure. All structure methods must be defined, setting 11427** any member of the fts5_tokenizer struct to NULL leads to undefined 11428** behaviour. The structure methods are expected to function as follows: 11429** 11430** xCreate: 11431** This function is used to allocate and initialize a tokenizer instance. 11432** A tokenizer instance is required to actually tokenize text. 11433** 11434** The first argument passed to this function is a copy of the (void*) 11435** pointer provided by the application when the fts5_tokenizer object 11436** was registered with FTS5 (the third argument to xCreateTokenizer()). 11437** The second and third arguments are an array of nul-terminated strings 11438** containing the tokenizer arguments, if any, specified following the 11439** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11440** to create the FTS5 table. 11441** 11442** The final argument is an output variable. If successful, (*ppOut) 11443** should be set to point to the new tokenizer handle and SQLITE_OK 11444** returned. If an error occurs, some value other than SQLITE_OK should 11445** be returned. In this case, fts5 assumes that the final value of *ppOut 11446** is undefined. 11447** 11448** xDelete: 11449** This function is invoked to delete a tokenizer handle previously 11450** allocated using xCreate(). Fts5 guarantees that this function will 11451** be invoked exactly once for each successful call to xCreate(). 11452** 11453** xTokenize: 11454** This function is expected to tokenize the nText byte string indicated 11455** by argument pText. pText may or may not be nul-terminated. The first 11456** argument passed to this function is a pointer to an Fts5Tokenizer object 11457** returned by an earlier call to xCreate(). 11458** 11459** The second argument indicates the reason that FTS5 is requesting 11460** tokenization of the supplied text. This is always one of the following 11461** four values: 11462** 11463** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11464** or removed from the FTS table. The tokenizer is being invoked to 11465** determine the set of tokens to add to (or delete from) the 11466** FTS index. 11467** 11468** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11469** against the FTS index. The tokenizer is being called to tokenize 11470** a bareword or quoted string specified as part of the query. 11471** 11472** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11473** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11474** followed by a "*" character, indicating that the last token 11475** returned by the tokenizer will be treated as a token prefix. 11476** 11477** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11478** satisfy an fts5_api.xTokenize() request made by an auxiliary 11479** function. Or an fts5_api.xColumnSize() request made by the same 11480** on a columnsize=0 database. 11481** </ul> 11482** 11483** For each token in the input string, the supplied callback xToken() must 11484** be invoked. The first argument to it should be a copy of the pointer 11485** passed as the second argument to xTokenize(). The third and fourth 11486** arguments are a pointer to a buffer containing the token text, and the 11487** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11488** of the first byte of and first byte immediately following the text from 11489** which the token is derived within the input. 11490** 11491** The second argument passed to the xToken() callback ("tflags") should 11492** normally be set to 0. The exception is if the tokenizer supports 11493** synonyms. In this case see the discussion below for details. 11494** 11495** FTS5 assumes the xToken() callback is invoked for each token in the 11496** order that they occur within the input text. 11497** 11498** If an xToken() callback returns any value other than SQLITE_OK, then 11499** the tokenization should be abandoned and the xTokenize() method should 11500** immediately return a copy of the xToken() return value. Or, if the 11501** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11502** if an error occurs with the xTokenize() implementation itself, it 11503** may abandon the tokenization and return any error code other than 11504** SQLITE_OK or SQLITE_DONE. 11505** 11506** SYNONYM SUPPORT 11507** 11508** Custom tokenizers may also support synonyms. Consider a case in which a 11509** user wishes to query for a phrase such as "first place". Using the 11510** built-in tokenizers, the FTS5 query 'first + place' will match instances 11511** of "first place" within the document set, but not alternative forms 11512** such as "1st place". In some applications, it would be better to match 11513** all instances of "first place" or "1st place" regardless of which form 11514** the user specified in the MATCH query text. 11515** 11516** There are several ways to approach this in FTS5: 11517** 11518** <ol><li> By mapping all synonyms to a single token. In this case, the 11519** In the above example, this means that the tokenizer returns the 11520** same token for inputs "first" and "1st". Say that token is in 11521** fact "first", so that when the user inserts the document "I won 11522** 1st place" entries are added to the index for tokens "i", "won", 11523** "first" and "place". If the user then queries for '1st + place', 11524** the tokenizer substitutes "first" for "1st" and the query works 11525** as expected. 11526** 11527** <li> By adding multiple synonyms for a single term to the FTS index. 11528** In this case, when tokenizing query text, the tokenizer may 11529** provide multiple synonyms for a single term within the document. 11530** FTS5 then queries the index for each synonym individually. For 11531** example, faced with the query: 11532** 11533** <codeblock> 11534** ... MATCH 'first place'</codeblock> 11535** 11536** the tokenizer offers both "1st" and "first" as synonyms for the 11537** first token in the MATCH query and FTS5 effectively runs a query 11538** similar to: 11539** 11540** <codeblock> 11541** ... MATCH '(first OR 1st) place'</codeblock> 11542** 11543** except that, for the purposes of auxiliary functions, the query 11544** still appears to contain just two phrases - "(first OR 1st)" 11545** being treated as a single phrase. 11546** 11547** <li> By adding multiple synonyms for a single term to the FTS index. 11548** Using this method, when tokenizing document text, the tokenizer 11549** provides multiple synonyms for each token. So that when a 11550** document such as "I won first place" is tokenized, entries are 11551** added to the FTS index for "i", "won", "first", "1st" and 11552** "place". 11553** 11554** This way, even if the tokenizer does not provide synonyms 11555** when tokenizing query text (it should not - to do would be 11556** inefficient), it doesn't matter if the user queries for 11557** 'first + place' or '1st + place', as there are entries in the 11558** FTS index corresponding to both forms of the first token. 11559** </ol> 11560** 11561** Whether it is parsing document or query text, any call to xToken that 11562** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11563** is considered to supply a synonym for the previous token. For example, 11564** when parsing the document "I won first place", a tokenizer that supports 11565** synonyms would call xToken() 5 times, as follows: 11566** 11567** <codeblock> 11568** xToken(pCtx, 0, "i", 1, 0, 1); 11569** xToken(pCtx, 0, "won", 3, 2, 5); 11570** xToken(pCtx, 0, "first", 5, 6, 11); 11571** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11572** xToken(pCtx, 0, "place", 5, 12, 17); 11573**</codeblock> 11574** 11575** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11576** xToken() is called. Multiple synonyms may be specified for a single token 11577** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11578** There is no limit to the number of synonyms that may be provided for a 11579** single token. 11580** 11581** In many cases, method (1) above is the best approach. It does not add 11582** extra data to the FTS index or require FTS5 to query for multiple terms, 11583** so it is efficient in terms of disk space and query speed. However, it 11584** does not support prefix queries very well. If, as suggested above, the 11585** token "first" is substituted for "1st" by the tokenizer, then the query: 11586** 11587** <codeblock> 11588** ... MATCH '1s*'</codeblock> 11589** 11590** will not match documents that contain the token "1st" (as the tokenizer 11591** will probably not map "1s" to any prefix of "first"). 11592** 11593** For full prefix support, method (3) may be preferred. In this case, 11594** because the index contains entries for both "first" and "1st", prefix 11595** queries such as 'fi*' or '1s*' will match correctly. However, because 11596** extra entries are added to the FTS index, this method uses more space 11597** within the database. 11598** 11599** Method (2) offers a midpoint between (1) and (3). Using this method, 11600** a query such as '1s*' will match documents that contain the literal 11601** token "1st", but not "first" (assuming the tokenizer is not able to 11602** provide synonyms for prefixes). However, a non-prefix query like '1st' 11603** will match against "1st" and "first". This method does not require 11604** extra disk space, as no extra entries are added to the FTS index. 11605** On the other hand, it may require more CPU cycles to run MATCH queries, 11606** as separate queries of the FTS index are required for each synonym. 11607** 11608** When using methods (2) or (3), it is important that the tokenizer only 11609** provide synonyms when tokenizing document text (method (2)) or query 11610** text (method (3)), not both. Doing so will not cause any errors, but is 11611** inefficient. 11612*/ 11613typedef struct Fts5Tokenizer Fts5Tokenizer; 11614typedef struct fts5_tokenizer fts5_tokenizer; 11615struct fts5_tokenizer { 11616 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11617 void (*xDelete)(Fts5Tokenizer*); 11618 int (*xTokenize)(Fts5Tokenizer*, 11619 void *pCtx, 11620 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11621 const char *pText, int nText, 11622 int (*xToken)( 11623 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11624 int tflags, /* Mask of FTS5_TOKEN_* flags */ 11625 const char *pToken, /* Pointer to buffer containing token */ 11626 int nToken, /* Size of token in bytes */ 11627 int iStart, /* Byte offset of token within input text */ 11628 int iEnd /* Byte offset of end of token within input text */ 11629 ) 11630 ); 11631}; 11632 11633/* Flags that may be passed as the third argument to xTokenize() */ 11634#define FTS5_TOKENIZE_QUERY 0x0001 11635#define FTS5_TOKENIZE_PREFIX 0x0002 11636#define FTS5_TOKENIZE_DOCUMENT 0x0004 11637#define FTS5_TOKENIZE_AUX 0x0008 11638 11639/* Flags that may be passed by the tokenizer implementation back to FTS5 11640** as the third argument to the supplied xToken callback. */ 11641#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11642 11643/* 11644** END OF CUSTOM TOKENIZERS 11645*************************************************************************/ 11646 11647/************************************************************************* 11648** FTS5 EXTENSION REGISTRATION API 11649*/ 11650typedef struct fts5_api fts5_api; 11651struct fts5_api { 11652 int iVersion; /* Currently always set to 2 */ 11653 11654 /* Create a new tokenizer */ 11655 int (*xCreateTokenizer)( 11656 fts5_api *pApi, 11657 const char *zName, 11658 void *pContext, 11659 fts5_tokenizer *pTokenizer, 11660 void (*xDestroy)(void*) 11661 ); 11662 11663 /* Find an existing tokenizer */ 11664 int (*xFindTokenizer)( 11665 fts5_api *pApi, 11666 const char *zName, 11667 void **ppContext, 11668 fts5_tokenizer *pTokenizer 11669 ); 11670 11671 /* Create a new auxiliary function */ 11672 int (*xCreateFunction)( 11673 fts5_api *pApi, 11674 const char *zName, 11675 void *pContext, 11676 fts5_extension_function xFunction, 11677 void (*xDestroy)(void*) 11678 ); 11679}; 11680 11681/* 11682** END OF REGISTRATION API 11683*************************************************************************/ 11684 11685#ifdef __cplusplus 11686} /* end of the 'extern "C"' block */ 11687#endif 11688 11689#endif /* _FTS5_H */ 11690 11691/******** End of fts5.h *********/ 11692