1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are suppose 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** Add the ability to override 'extern' 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51 52/* 53** These no-op macros are used in front of interfaces to mark those 54** interfaces as either deprecated or experimental. New applications 55** should not use deprecated interfaces - they are support for backwards 56** compatibility only. Application writers should be aware that 57** experimental interfaces are subject to change in point releases. 58** 59** These macros used to resolve to various kinds of compiler magic that 60** would generate warning messages when they were used. But that 61** compiler magic ended up generating such a flurry of bug reports 62** that we have taken it all out and gone back to using simple 63** noop macros. 64*/ 65#define SQLITE_DEPRECATED 66#define SQLITE_EXPERIMENTAL 67 68/* 69** Ensure these symbols were not defined by some previous header file. 70*/ 71#ifdef SQLITE_VERSION 72# undef SQLITE_VERSION 73#endif 74#ifdef SQLITE_VERSION_NUMBER 75# undef SQLITE_VERSION_NUMBER 76#endif 77 78/* 79** CAPI3REF: Compile-Time Library Version Numbers 80** 81** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 82** evaluates to a string literal that is the SQLite version in the 83** format "X.Y.Z" where X is the major version number (always 3 for 84** SQLite3) and Y is the minor version number and Z is the release number.)^ 85** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 86** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 87** numbers used in [SQLITE_VERSION].)^ 88** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 89** be larger than the release from which it is derived. Either Y will 90** be held constant and Z will be incremented or else Y will be incremented 91** and Z will be reset to zero. 92** 93** Since version 3.6.18, SQLite source code has been stored in the 94** <a href="http://www.fossil-scm.org/">Fossil configuration management 95** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 96** a string which identifies a particular check-in of SQLite 97** within its configuration management system. ^The SQLITE_SOURCE_ID 98** string contains the date and time of the check-in (UTC) and an SHA1 99** hash of the entire source tree. 100** 101** See also: [sqlite3_libversion()], 102** [sqlite3_libversion_number()], [sqlite3_sourceid()], 103** [sqlite_version()] and [sqlite_source_id()]. 104*/ 105#define SQLITE_VERSION "--VERS--" 106#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 107#define SQLITE_SOURCE_ID "--SOURCE-ID--" 108 109/* 110** CAPI3REF: Run-Time Library Version Numbers 111** KEYWORDS: sqlite3_version, sqlite3_sourceid 112** 113** These interfaces provide the same information as the [SQLITE_VERSION], 114** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 115** but are associated with the library instead of the header file. ^(Cautious 116** programmers might include assert() statements in their application to 117** verify that values returned by these interfaces match the macros in 118** the header, and thus insure that the application is 119** compiled with matching library and header files. 120** 121** <blockquote><pre> 122** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 123** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 124** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 125** </pre></blockquote>)^ 126** 127** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 128** macro. ^The sqlite3_libversion() function returns a pointer to the 129** to the sqlite3_version[] string constant. The sqlite3_libversion() 130** function is provided for use in DLLs since DLL users usually do not have 131** direct access to string constants within the DLL. ^The 132** sqlite3_libversion_number() function returns an integer equal to 133** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 134** a pointer to a string constant whose value is the same as the 135** [SQLITE_SOURCE_ID] C preprocessor macro. 136** 137** See also: [sqlite_version()] and [sqlite_source_id()]. 138*/ 139SQLITE_EXTERN const char sqlite3_version[]; 140const char *sqlite3_libversion(void); 141const char *sqlite3_sourceid(void); 142int sqlite3_libversion_number(void); 143 144/* 145** CAPI3REF: Run-Time Library Compilation Options Diagnostics 146** 147** ^The sqlite3_compileoption_used() function returns 0 or 1 148** indicating whether the specified option was defined at 149** compile time. ^The SQLITE_ prefix may be omitted from the 150** option name passed to sqlite3_compileoption_used(). 151** 152** ^The sqlite3_compileoption_get() function allows iterating 153** over the list of options that were defined at compile time by 154** returning the N-th compile time option string. ^If N is out of range, 155** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 156** prefix is omitted from any strings returned by 157** sqlite3_compileoption_get(). 158** 159** ^Support for the diagnostic functions sqlite3_compileoption_used() 160** and sqlite3_compileoption_get() may be omitted by specifying the 161** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 162** 163** See also: SQL functions [sqlite_compileoption_used()] and 164** [sqlite_compileoption_get()] and the [compile_options pragma]. 165*/ 166#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 167int sqlite3_compileoption_used(const char *zOptName); 168const char *sqlite3_compileoption_get(int N); 169#endif 170 171/* 172** CAPI3REF: Test To See If The Library Is Threadsafe 173** 174** ^The sqlite3_threadsafe() function returns zero if and only if 175** SQLite was compiled with mutexing code omitted due to the 176** [SQLITE_THREADSAFE] compile-time option being set to 0. 177** 178** SQLite can be compiled with or without mutexes. When 179** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 180** are enabled and SQLite is threadsafe. When the 181** [SQLITE_THREADSAFE] macro is 0, 182** the mutexes are omitted. Without the mutexes, it is not safe 183** to use SQLite concurrently from more than one thread. 184** 185** Enabling mutexes incurs a measurable performance penalty. 186** So if speed is of utmost importance, it makes sense to disable 187** the mutexes. But for maximum safety, mutexes should be enabled. 188** ^The default behavior is for mutexes to be enabled. 189** 190** This interface can be used by an application to make sure that the 191** version of SQLite that it is linking against was compiled with 192** the desired setting of the [SQLITE_THREADSAFE] macro. 193** 194** This interface only reports on the compile-time mutex setting 195** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 196** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 197** can be fully or partially disabled using a call to [sqlite3_config()] 198** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 199** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 200** sqlite3_threadsafe() function shows only the compile-time setting of 201** thread safety, not any run-time changes to that setting made by 202** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 203** is unchanged by calls to sqlite3_config().)^ 204** 205** See the [threading mode] documentation for additional information. 206*/ 207int sqlite3_threadsafe(void); 208 209/* 210** CAPI3REF: Database Connection Handle 211** KEYWORDS: {database connection} {database connections} 212** 213** Each open SQLite database is represented by a pointer to an instance of 214** the opaque structure named "sqlite3". It is useful to think of an sqlite3 215** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 216** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 217** and [sqlite3_close_v2()] are its destructors. There are many other 218** interfaces (such as 219** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 220** [sqlite3_busy_timeout()] to name but three) that are methods on an 221** sqlite3 object. 222*/ 223typedef struct sqlite3 sqlite3; 224 225/* 226** CAPI3REF: 64-Bit Integer Types 227** KEYWORDS: sqlite_int64 sqlite_uint64 228** 229** Because there is no cross-platform way to specify 64-bit integer types 230** SQLite includes typedefs for 64-bit signed and unsigned integers. 231** 232** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 233** The sqlite_int64 and sqlite_uint64 types are supported for backwards 234** compatibility only. 235** 236** ^The sqlite3_int64 and sqlite_int64 types can store integer values 237** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 238** sqlite3_uint64 and sqlite_uint64 types can store integer values 239** between 0 and +18446744073709551615 inclusive. 240*/ 241#ifdef SQLITE_INT64_TYPE 242 typedef SQLITE_INT64_TYPE sqlite_int64; 243 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 244#elif defined(_MSC_VER) || defined(__BORLANDC__) 245 typedef __int64 sqlite_int64; 246 typedef unsigned __int64 sqlite_uint64; 247#else 248 typedef long long int sqlite_int64; 249 typedef unsigned long long int sqlite_uint64; 250#endif 251typedef sqlite_int64 sqlite3_int64; 252typedef sqlite_uint64 sqlite3_uint64; 253 254/* 255** If compiling for a processor that lacks floating point support, 256** substitute integer for floating-point. 257*/ 258#ifdef SQLITE_OMIT_FLOATING_POINT 259# define double sqlite3_int64 260#endif 261 262/* 263** CAPI3REF: Closing A Database Connection 264** 265** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 266** for the [sqlite3] object. 267** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if 268** the [sqlite3] object is successfully destroyed and all associated 269** resources are deallocated. 270** 271** ^If the database connection is associated with unfinalized prepared 272** statements or unfinished sqlite3_backup objects then sqlite3_close() 273** will leave the database connection open and return [SQLITE_BUSY]. 274** ^If sqlite3_close_v2() is called with unfinalized prepared statements 275** and unfinished sqlite3_backups, then the database connection becomes 276** an unusable "zombie" which will automatically be deallocated when the 277** last prepared statement is finalized or the last sqlite3_backup is 278** finished. The sqlite3_close_v2() interface is intended for use with 279** host languages that are garbage collected, and where the order in which 280** destructors are called is arbitrary. 281** 282** Applications should [sqlite3_finalize | finalize] all [prepared statements], 283** [sqlite3_blob_close | close] all [BLOB handles], and 284** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 285** with the [sqlite3] object prior to attempting to close the object. ^If 286** sqlite3_close_v2() is called on a [database connection] that still has 287** outstanding [prepared statements], [BLOB handles], and/or 288** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation 289** of resources is deferred until all [prepared statements], [BLOB handles], 290** and [sqlite3_backup] objects are also destroyed. 291** 292** ^If an [sqlite3] object is destroyed while a transaction is open, 293** the transaction is automatically rolled back. 294** 295** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 296** must be either a NULL 297** pointer or an [sqlite3] object pointer obtained 298** from [sqlite3_open()], [sqlite3_open16()], or 299** [sqlite3_open_v2()], and not previously closed. 300** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 301** argument is a harmless no-op. 302*/ 303int sqlite3_close(sqlite3*); 304int sqlite3_close_v2(sqlite3*); 305 306/* 307** The type for a callback function. 308** This is legacy and deprecated. It is included for historical 309** compatibility and is not documented. 310*/ 311typedef int (*sqlite3_callback)(void*,int,char**, char**); 312 313/* 314** CAPI3REF: One-Step Query Execution Interface 315** 316** The sqlite3_exec() interface is a convenience wrapper around 317** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 318** that allows an application to run multiple statements of SQL 319** without having to use a lot of C code. 320** 321** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 322** semicolon-separate SQL statements passed into its 2nd argument, 323** in the context of the [database connection] passed in as its 1st 324** argument. ^If the callback function of the 3rd argument to 325** sqlite3_exec() is not NULL, then it is invoked for each result row 326** coming out of the evaluated SQL statements. ^The 4th argument to 327** sqlite3_exec() is relayed through to the 1st argument of each 328** callback invocation. ^If the callback pointer to sqlite3_exec() 329** is NULL, then no callback is ever invoked and result rows are 330** ignored. 331** 332** ^If an error occurs while evaluating the SQL statements passed into 333** sqlite3_exec(), then execution of the current statement stops and 334** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 335** is not NULL then any error message is written into memory obtained 336** from [sqlite3_malloc()] and passed back through the 5th parameter. 337** To avoid memory leaks, the application should invoke [sqlite3_free()] 338** on error message strings returned through the 5th parameter of 339** of sqlite3_exec() after the error message string is no longer needed. 340** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 341** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 342** NULL before returning. 343** 344** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 345** routine returns SQLITE_ABORT without invoking the callback again and 346** without running any subsequent SQL statements. 347** 348** ^The 2nd argument to the sqlite3_exec() callback function is the 349** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 350** callback is an array of pointers to strings obtained as if from 351** [sqlite3_column_text()], one for each column. ^If an element of a 352** result row is NULL then the corresponding string pointer for the 353** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 354** sqlite3_exec() callback is an array of pointers to strings where each 355** entry represents the name of corresponding result column as obtained 356** from [sqlite3_column_name()]. 357** 358** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 359** to an empty string, or a pointer that contains only whitespace and/or 360** SQL comments, then no SQL statements are evaluated and the database 361** is not changed. 362** 363** Restrictions: 364** 365** <ul> 366** <li> The application must insure that the 1st parameter to sqlite3_exec() 367** is a valid and open [database connection]. 368** <li> The application must not close the [database connection] specified by 369** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 370** <li> The application must not modify the SQL statement text passed into 371** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 372** </ul> 373*/ 374int sqlite3_exec( 375 sqlite3*, /* An open database */ 376 const char *sql, /* SQL to be evaluated */ 377 int (*callback)(void*,int,char**,char**), /* Callback function */ 378 void *, /* 1st argument to callback */ 379 char **errmsg /* Error msg written here */ 380); 381 382/* 383** CAPI3REF: Result Codes 384** KEYWORDS: SQLITE_OK {error code} {error codes} 385** KEYWORDS: {result code} {result codes} 386** 387** Many SQLite functions return an integer result code from the set shown 388** here in order to indicate success or failure. 389** 390** New error codes may be added in future versions of SQLite. 391** 392** See also: [SQLITE_IOERR_READ | extended result codes], 393** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 394*/ 395#define SQLITE_OK 0 /* Successful result */ 396/* beginning-of-error-codes */ 397#define SQLITE_ERROR 1 /* SQL error or missing database */ 398#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 399#define SQLITE_PERM 3 /* Access permission denied */ 400#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 401#define SQLITE_BUSY 5 /* The database file is locked */ 402#define SQLITE_LOCKED 6 /* A table in the database is locked */ 403#define SQLITE_NOMEM 7 /* A malloc() failed */ 404#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 405#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 406#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 407#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 408#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 409#define SQLITE_FULL 13 /* Insertion failed because database is full */ 410#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 411#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 412#define SQLITE_EMPTY 16 /* Database is empty */ 413#define SQLITE_SCHEMA 17 /* The database schema changed */ 414#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 415#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 416#define SQLITE_MISMATCH 20 /* Data type mismatch */ 417#define SQLITE_MISUSE 21 /* Library used incorrectly */ 418#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 419#define SQLITE_AUTH 23 /* Authorization denied */ 420#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 421#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 422#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 423#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 424#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 425#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 426#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 427/* end-of-error-codes */ 428 429/* 430** CAPI3REF: Extended Result Codes 431** KEYWORDS: {extended error code} {extended error codes} 432** KEYWORDS: {extended result code} {extended result codes} 433** 434** In its default configuration, SQLite API routines return one of 26 integer 435** [SQLITE_OK | result codes]. However, experience has shown that many of 436** these result codes are too coarse-grained. They do not provide as 437** much information about problems as programmers might like. In an effort to 438** address this, newer versions of SQLite (version 3.3.8 and later) include 439** support for additional result codes that provide more detailed information 440** about errors. The extended result codes are enabled or disabled 441** on a per database connection basis using the 442** [sqlite3_extended_result_codes()] API. 443** 444** Some of the available extended result codes are listed here. 445** One may expect the number of extended result codes will increase 446** over time. Software that uses extended result codes should expect 447** to see new result codes in future releases of SQLite. 448** 449** The SQLITE_OK result code will never be extended. It will always 450** be exactly zero. 451*/ 452#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 453#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 454#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 455#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 456#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 457#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 458#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 459#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 460#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 461#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 462#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 463#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 464#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 465#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 466#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 467#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 468#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 469#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 470#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 471#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 472#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 473#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 474#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 475#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 476#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 477#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 478#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 479#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 480#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 481#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 482#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 483#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 484#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 485#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 486#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 487#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 488#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 489#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 490#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 491#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 492#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 493#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 494#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 495#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 496#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 497#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 498#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 499#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 500#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 501#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 502#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 503#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 504 505/* 506** CAPI3REF: Flags For File Open Operations 507** 508** These bit values are intended for use in the 509** 3rd parameter to the [sqlite3_open_v2()] interface and 510** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 511*/ 512#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 513#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 514#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 515#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 516#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 517#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 518#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 519#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 520#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 521#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 522#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 523#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 524#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 525#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 526#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 527#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 528#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 529#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 530#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 531#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 532 533/* Reserved: 0x00F00000 */ 534 535/* 536** CAPI3REF: Device Characteristics 537** 538** The xDeviceCharacteristics method of the [sqlite3_io_methods] 539** object returns an integer which is a vector of these 540** bit values expressing I/O characteristics of the mass storage 541** device that holds the file that the [sqlite3_io_methods] 542** refers to. 543** 544** The SQLITE_IOCAP_ATOMIC property means that all writes of 545** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 546** mean that writes of blocks that are nnn bytes in size and 547** are aligned to an address which is an integer multiple of 548** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 549** that when data is appended to a file, the data is appended 550** first then the size of the file is extended, never the other 551** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 552** information is written to disk in the same order as calls 553** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 554** after reboot following a crash or power loss, the only bytes in a 555** file that were written at the application level might have changed 556** and that adjacent bytes, even bytes within the same sector are 557** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 558** flag indicate that a file cannot be deleted when open. 559*/ 560#define SQLITE_IOCAP_ATOMIC 0x00000001 561#define SQLITE_IOCAP_ATOMIC512 0x00000002 562#define SQLITE_IOCAP_ATOMIC1K 0x00000004 563#define SQLITE_IOCAP_ATOMIC2K 0x00000008 564#define SQLITE_IOCAP_ATOMIC4K 0x00000010 565#define SQLITE_IOCAP_ATOMIC8K 0x00000020 566#define SQLITE_IOCAP_ATOMIC16K 0x00000040 567#define SQLITE_IOCAP_ATOMIC32K 0x00000080 568#define SQLITE_IOCAP_ATOMIC64K 0x00000100 569#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 570#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 571#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 572#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 573 574/* 575** CAPI3REF: File Locking Levels 576** 577** SQLite uses one of these integer values as the second 578** argument to calls it makes to the xLock() and xUnlock() methods 579** of an [sqlite3_io_methods] object. 580*/ 581#define SQLITE_LOCK_NONE 0 582#define SQLITE_LOCK_SHARED 1 583#define SQLITE_LOCK_RESERVED 2 584#define SQLITE_LOCK_PENDING 3 585#define SQLITE_LOCK_EXCLUSIVE 4 586 587/* 588** CAPI3REF: Synchronization Type Flags 589** 590** When SQLite invokes the xSync() method of an 591** [sqlite3_io_methods] object it uses a combination of 592** these integer values as the second argument. 593** 594** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 595** sync operation only needs to flush data to mass storage. Inode 596** information need not be flushed. If the lower four bits of the flag 597** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 598** If the lower four bits equal SQLITE_SYNC_FULL, that means 599** to use Mac OS X style fullsync instead of fsync(). 600** 601** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 602** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 603** settings. The [synchronous pragma] determines when calls to the 604** xSync VFS method occur and applies uniformly across all platforms. 605** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 606** energetic or rigorous or forceful the sync operations are and 607** only make a difference on Mac OSX for the default SQLite code. 608** (Third-party VFS implementations might also make the distinction 609** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 610** operating systems natively supported by SQLite, only Mac OSX 611** cares about the difference.) 612*/ 613#define SQLITE_SYNC_NORMAL 0x00002 614#define SQLITE_SYNC_FULL 0x00003 615#define SQLITE_SYNC_DATAONLY 0x00010 616 617/* 618** CAPI3REF: OS Interface Open File Handle 619** 620** An [sqlite3_file] object represents an open file in the 621** [sqlite3_vfs | OS interface layer]. Individual OS interface 622** implementations will 623** want to subclass this object by appending additional fields 624** for their own use. The pMethods entry is a pointer to an 625** [sqlite3_io_methods] object that defines methods for performing 626** I/O operations on the open file. 627*/ 628typedef struct sqlite3_file sqlite3_file; 629struct sqlite3_file { 630 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 631}; 632 633/* 634** CAPI3REF: OS Interface File Virtual Methods Object 635** 636** Every file opened by the [sqlite3_vfs.xOpen] method populates an 637** [sqlite3_file] object (or, more commonly, a subclass of the 638** [sqlite3_file] object) with a pointer to an instance of this object. 639** This object defines the methods used to perform various operations 640** against the open file represented by the [sqlite3_file] object. 641** 642** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 643** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 644** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 645** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 646** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 647** to NULL. 648** 649** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 650** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 651** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 652** flag may be ORed in to indicate that only the data of the file 653** and not its inode needs to be synced. 654** 655** The integer values to xLock() and xUnlock() are one of 656** <ul> 657** <li> [SQLITE_LOCK_NONE], 658** <li> [SQLITE_LOCK_SHARED], 659** <li> [SQLITE_LOCK_RESERVED], 660** <li> [SQLITE_LOCK_PENDING], or 661** <li> [SQLITE_LOCK_EXCLUSIVE]. 662** </ul> 663** xLock() increases the lock. xUnlock() decreases the lock. 664** The xCheckReservedLock() method checks whether any database connection, 665** either in this process or in some other process, is holding a RESERVED, 666** PENDING, or EXCLUSIVE lock on the file. It returns true 667** if such a lock exists and false otherwise. 668** 669** The xFileControl() method is a generic interface that allows custom 670** VFS implementations to directly control an open file using the 671** [sqlite3_file_control()] interface. The second "op" argument is an 672** integer opcode. The third argument is a generic pointer intended to 673** point to a structure that may contain arguments or space in which to 674** write return values. Potential uses for xFileControl() might be 675** functions to enable blocking locks with timeouts, to change the 676** locking strategy (for example to use dot-file locks), to inquire 677** about the status of a lock, or to break stale locks. The SQLite 678** core reserves all opcodes less than 100 for its own use. 679** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 680** Applications that define a custom xFileControl method should use opcodes 681** greater than 100 to avoid conflicts. VFS implementations should 682** return [SQLITE_NOTFOUND] for file control opcodes that they do not 683** recognize. 684** 685** The xSectorSize() method returns the sector size of the 686** device that underlies the file. The sector size is the 687** minimum write that can be performed without disturbing 688** other bytes in the file. The xDeviceCharacteristics() 689** method returns a bit vector describing behaviors of the 690** underlying device: 691** 692** <ul> 693** <li> [SQLITE_IOCAP_ATOMIC] 694** <li> [SQLITE_IOCAP_ATOMIC512] 695** <li> [SQLITE_IOCAP_ATOMIC1K] 696** <li> [SQLITE_IOCAP_ATOMIC2K] 697** <li> [SQLITE_IOCAP_ATOMIC4K] 698** <li> [SQLITE_IOCAP_ATOMIC8K] 699** <li> [SQLITE_IOCAP_ATOMIC16K] 700** <li> [SQLITE_IOCAP_ATOMIC32K] 701** <li> [SQLITE_IOCAP_ATOMIC64K] 702** <li> [SQLITE_IOCAP_SAFE_APPEND] 703** <li> [SQLITE_IOCAP_SEQUENTIAL] 704** </ul> 705** 706** The SQLITE_IOCAP_ATOMIC property means that all writes of 707** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 708** mean that writes of blocks that are nnn bytes in size and 709** are aligned to an address which is an integer multiple of 710** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 711** that when data is appended to a file, the data is appended 712** first then the size of the file is extended, never the other 713** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 714** information is written to disk in the same order as calls 715** to xWrite(). 716** 717** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 718** in the unread portions of the buffer with zeros. A VFS that 719** fails to zero-fill short reads might seem to work. However, 720** failure to zero-fill short reads will eventually lead to 721** database corruption. 722*/ 723typedef struct sqlite3_io_methods sqlite3_io_methods; 724struct sqlite3_io_methods { 725 int iVersion; 726 int (*xClose)(sqlite3_file*); 727 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 728 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 729 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 730 int (*xSync)(sqlite3_file*, int flags); 731 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 732 int (*xLock)(sqlite3_file*, int); 733 int (*xUnlock)(sqlite3_file*, int); 734 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 735 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 736 int (*xSectorSize)(sqlite3_file*); 737 int (*xDeviceCharacteristics)(sqlite3_file*); 738 /* Methods above are valid for version 1 */ 739 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 740 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 741 void (*xShmBarrier)(sqlite3_file*); 742 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 743 /* Methods above are valid for version 2 */ 744 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 745 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 746 /* Methods above are valid for version 3 */ 747 /* Additional methods may be added in future releases */ 748}; 749 750/* 751** CAPI3REF: Standard File Control Opcodes 752** 753** These integer constants are opcodes for the xFileControl method 754** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 755** interface. 756** 757** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 758** opcode causes the xFileControl method to write the current state of 759** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 760** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 761** into an integer that the pArg argument points to. This capability 762** is used during testing and only needs to be supported when SQLITE_TEST 763** is defined. 764** <ul> 765** <li>[[SQLITE_FCNTL_SIZE_HINT]] 766** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 767** layer a hint of how large the database file will grow to be during the 768** current transaction. This hint is not guaranteed to be accurate but it 769** is often close. The underlying VFS might choose to preallocate database 770** file space based on this hint in order to help writes to the database 771** file run faster. 772** 773** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 774** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 775** extends and truncates the database file in chunks of a size specified 776** by the user. The fourth argument to [sqlite3_file_control()] should 777** point to an integer (type int) containing the new chunk-size to use 778** for the nominated database. Allocating database file space in large 779** chunks (say 1MB at a time), may reduce file-system fragmentation and 780** improve performance on some systems. 781** 782** <li>[[SQLITE_FCNTL_FILE_POINTER]] 783** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 784** to the [sqlite3_file] object associated with a particular database 785** connection. See the [sqlite3_file_control()] documentation for 786** additional information. 787** 788** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 789** No longer in use. 790** 791** <li>[[SQLITE_FCNTL_SYNC]] 792** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 793** sent to the VFS immediately before the xSync method is invoked on a 794** database file descriptor. Or, if the xSync method is not invoked 795** because the user has configured SQLite with 796** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 797** of the xSync method. In most cases, the pointer argument passed with 798** this file-control is NULL. However, if the database file is being synced 799** as part of a multi-database commit, the argument points to a nul-terminated 800** string containing the transactions master-journal file name. VFSes that 801** do not need this signal should silently ignore this opcode. Applications 802** should not call [sqlite3_file_control()] with this opcode as doing so may 803** disrupt the operation of the specialized VFSes that do require it. 804** 805** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 806** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 807** and sent to the VFS after a transaction has been committed immediately 808** but before the database is unlocked. VFSes that do not need this signal 809** should silently ignore this opcode. Applications should not call 810** [sqlite3_file_control()] with this opcode as doing so may disrupt the 811** operation of the specialized VFSes that do require it. 812** 813** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 814** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 815** retry counts and intervals for certain disk I/O operations for the 816** windows [VFS] in order to provide robustness in the presence of 817** anti-virus programs. By default, the windows VFS will retry file read, 818** file write, and file delete operations up to 10 times, with a delay 819** of 25 milliseconds before the first retry and with the delay increasing 820** by an additional 25 milliseconds with each subsequent retry. This 821** opcode allows these two values (10 retries and 25 milliseconds of delay) 822** to be adjusted. The values are changed for all database connections 823** within the same process. The argument is a pointer to an array of two 824** integers where the first integer i the new retry count and the second 825** integer is the delay. If either integer is negative, then the setting 826** is not changed but instead the prior value of that setting is written 827** into the array entry, allowing the current retry settings to be 828** interrogated. The zDbName parameter is ignored. 829** 830** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 831** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 832** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 833** write ahead log and shared memory files used for transaction control 834** are automatically deleted when the latest connection to the database 835** closes. Setting persistent WAL mode causes those files to persist after 836** close. Persisting the files is useful when other processes that do not 837** have write permission on the directory containing the database file want 838** to read the database file, as the WAL and shared memory files must exist 839** in order for the database to be readable. The fourth parameter to 840** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 841** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 842** WAL mode. If the integer is -1, then it is overwritten with the current 843** WAL persistence setting. 844** 845** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 846** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 847** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 848** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 849** xDeviceCharacteristics methods. The fourth parameter to 850** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 851** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 852** mode. If the integer is -1, then it is overwritten with the current 853** zero-damage mode setting. 854** 855** <li>[[SQLITE_FCNTL_OVERWRITE]] 856** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 857** a write transaction to indicate that, unless it is rolled back for some 858** reason, the entire database file will be overwritten by the current 859** transaction. This is used by VACUUM operations. 860** 861** <li>[[SQLITE_FCNTL_VFSNAME]] 862** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 863** all [VFSes] in the VFS stack. The names are of all VFS shims and the 864** final bottom-level VFS are written into memory obtained from 865** [sqlite3_malloc()] and the result is stored in the char* variable 866** that the fourth parameter of [sqlite3_file_control()] points to. 867** The caller is responsible for freeing the memory when done. As with 868** all file-control actions, there is no guarantee that this will actually 869** do anything. Callers should initialize the char* variable to a NULL 870** pointer in case this file-control is not implemented. This file-control 871** is intended for diagnostic use only. 872** 873** <li>[[SQLITE_FCNTL_PRAGMA]] 874** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 875** file control is sent to the open [sqlite3_file] object corresponding 876** to the database file to which the pragma statement refers. ^The argument 877** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 878** pointers to strings (char**) in which the second element of the array 879** is the name of the pragma and the third element is the argument to the 880** pragma or NULL if the pragma has no argument. ^The handler for an 881** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 882** of the char** argument point to a string obtained from [sqlite3_mprintf()] 883** or the equivalent and that string will become the result of the pragma or 884** the error message if the pragma fails. ^If the 885** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 886** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 887** file control returns [SQLITE_OK], then the parser assumes that the 888** VFS has handled the PRAGMA itself and the parser generates a no-op 889** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 890** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 891** that the VFS encountered an error while handling the [PRAGMA] and the 892** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 893** file control occurs at the beginning of pragma statement analysis and so 894** it is able to override built-in [PRAGMA] statements. 895** 896** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 897** ^The [SQLITE_FCNTL_BUSYHANDLER] 898** file-control may be invoked by SQLite on the database file handle 899** shortly after it is opened in order to provide a custom VFS with access 900** to the connections busy-handler callback. The argument is of type (void **) 901** - an array of two (void *) values. The first (void *) actually points 902** to a function of type (int (*)(void *)). In order to invoke the connections 903** busy-handler, this function should be invoked with the second (void *) in 904** the array as the only argument. If it returns non-zero, then the operation 905** should be retried. If it returns zero, the custom VFS should abandon the 906** current operation. 907** 908** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 909** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 910** to have SQLite generate a 911** temporary filename using the same algorithm that is followed to generate 912** temporary filenames for TEMP tables and other internal uses. The 913** argument should be a char** which will be filled with the filename 914** written into memory obtained from [sqlite3_malloc()]. The caller should 915** invoke [sqlite3_free()] on the result to avoid a memory leak. 916** 917** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 918** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 919** maximum number of bytes that will be used for memory-mapped I/O. 920** The argument is a pointer to a value of type sqlite3_int64 that 921** is an advisory maximum number of bytes in the file to memory map. The 922** pointer is overwritten with the old value. The limit is not changed if 923** the value originally pointed to is negative, and so the current limit 924** can be queried by passing in a pointer to a negative number. This 925** file-control is used internally to implement [PRAGMA mmap_size]. 926** 927** <li>[[SQLITE_FCNTL_TRACE]] 928** The [SQLITE_FCNTL_TRACE] file control provides advisory information 929** to the VFS about what the higher layers of the SQLite stack are doing. 930** This file control is used by some VFS activity tracing [shims]. 931** The argument is a zero-terminated string. Higher layers in the 932** SQLite stack may generate instances of this file control if 933** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 934** 935** <li>[[SQLITE_FCNTL_HAS_MOVED]] 936** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 937** pointer to an integer and it writes a boolean into that integer depending 938** on whether or not the file has been renamed, moved, or deleted since it 939** was first opened. 940** 941** </ul> 942*/ 943#define SQLITE_FCNTL_LOCKSTATE 1 944#define SQLITE_GET_LOCKPROXYFILE 2 945#define SQLITE_SET_LOCKPROXYFILE 3 946#define SQLITE_LAST_ERRNO 4 947#define SQLITE_FCNTL_SIZE_HINT 5 948#define SQLITE_FCNTL_CHUNK_SIZE 6 949#define SQLITE_FCNTL_FILE_POINTER 7 950#define SQLITE_FCNTL_SYNC_OMITTED 8 951#define SQLITE_FCNTL_WIN32_AV_RETRY 9 952#define SQLITE_FCNTL_PERSIST_WAL 10 953#define SQLITE_FCNTL_OVERWRITE 11 954#define SQLITE_FCNTL_VFSNAME 12 955#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 956#define SQLITE_FCNTL_PRAGMA 14 957#define SQLITE_FCNTL_BUSYHANDLER 15 958#define SQLITE_FCNTL_TEMPFILENAME 16 959#define SQLITE_FCNTL_MMAP_SIZE 18 960#define SQLITE_FCNTL_TRACE 19 961#define SQLITE_FCNTL_HAS_MOVED 20 962#define SQLITE_FCNTL_SYNC 21 963#define SQLITE_FCNTL_COMMIT_PHASETWO 22 964 965/* 966** CAPI3REF: Mutex Handle 967** 968** The mutex module within SQLite defines [sqlite3_mutex] to be an 969** abstract type for a mutex object. The SQLite core never looks 970** at the internal representation of an [sqlite3_mutex]. It only 971** deals with pointers to the [sqlite3_mutex] object. 972** 973** Mutexes are created using [sqlite3_mutex_alloc()]. 974*/ 975typedef struct sqlite3_mutex sqlite3_mutex; 976 977/* 978** CAPI3REF: OS Interface Object 979** 980** An instance of the sqlite3_vfs object defines the interface between 981** the SQLite core and the underlying operating system. The "vfs" 982** in the name of the object stands for "virtual file system". See 983** the [VFS | VFS documentation] for further information. 984** 985** The value of the iVersion field is initially 1 but may be larger in 986** future versions of SQLite. Additional fields may be appended to this 987** object when the iVersion value is increased. Note that the structure 988** of the sqlite3_vfs object changes in the transaction between 989** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 990** modified. 991** 992** The szOsFile field is the size of the subclassed [sqlite3_file] 993** structure used by this VFS. mxPathname is the maximum length of 994** a pathname in this VFS. 995** 996** Registered sqlite3_vfs objects are kept on a linked list formed by 997** the pNext pointer. The [sqlite3_vfs_register()] 998** and [sqlite3_vfs_unregister()] interfaces manage this list 999** in a thread-safe way. The [sqlite3_vfs_find()] interface 1000** searches the list. Neither the application code nor the VFS 1001** implementation should use the pNext pointer. 1002** 1003** The pNext field is the only field in the sqlite3_vfs 1004** structure that SQLite will ever modify. SQLite will only access 1005** or modify this field while holding a particular static mutex. 1006** The application should never modify anything within the sqlite3_vfs 1007** object once the object has been registered. 1008** 1009** The zName field holds the name of the VFS module. The name must 1010** be unique across all VFS modules. 1011** 1012** [[sqlite3_vfs.xOpen]] 1013** ^SQLite guarantees that the zFilename parameter to xOpen 1014** is either a NULL pointer or string obtained 1015** from xFullPathname() with an optional suffix added. 1016** ^If a suffix is added to the zFilename parameter, it will 1017** consist of a single "-" character followed by no more than 1018** 11 alphanumeric and/or "-" characters. 1019** ^SQLite further guarantees that 1020** the string will be valid and unchanged until xClose() is 1021** called. Because of the previous sentence, 1022** the [sqlite3_file] can safely store a pointer to the 1023** filename if it needs to remember the filename for some reason. 1024** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1025** must invent its own temporary name for the file. ^Whenever the 1026** xFilename parameter is NULL it will also be the case that the 1027** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1028** 1029** The flags argument to xOpen() includes all bits set in 1030** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1031** or [sqlite3_open16()] is used, then flags includes at least 1032** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1033** If xOpen() opens a file read-only then it sets *pOutFlags to 1034** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1035** 1036** ^(SQLite will also add one of the following flags to the xOpen() 1037** call, depending on the object being opened: 1038** 1039** <ul> 1040** <li> [SQLITE_OPEN_MAIN_DB] 1041** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1042** <li> [SQLITE_OPEN_TEMP_DB] 1043** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1044** <li> [SQLITE_OPEN_TRANSIENT_DB] 1045** <li> [SQLITE_OPEN_SUBJOURNAL] 1046** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1047** <li> [SQLITE_OPEN_WAL] 1048** </ul>)^ 1049** 1050** The file I/O implementation can use the object type flags to 1051** change the way it deals with files. For example, an application 1052** that does not care about crash recovery or rollback might make 1053** the open of a journal file a no-op. Writes to this journal would 1054** also be no-ops, and any attempt to read the journal would return 1055** SQLITE_IOERR. Or the implementation might recognize that a database 1056** file will be doing page-aligned sector reads and writes in a random 1057** order and set up its I/O subsystem accordingly. 1058** 1059** SQLite might also add one of the following flags to the xOpen method: 1060** 1061** <ul> 1062** <li> [SQLITE_OPEN_DELETEONCLOSE] 1063** <li> [SQLITE_OPEN_EXCLUSIVE] 1064** </ul> 1065** 1066** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1067** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1068** will be set for TEMP databases and their journals, transient 1069** databases, and subjournals. 1070** 1071** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1072** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1073** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1074** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1075** SQLITE_OPEN_CREATE, is used to indicate that file should always 1076** be created, and that it is an error if it already exists. 1077** It is <i>not</i> used to indicate the file should be opened 1078** for exclusive access. 1079** 1080** ^At least szOsFile bytes of memory are allocated by SQLite 1081** to hold the [sqlite3_file] structure passed as the third 1082** argument to xOpen. The xOpen method does not have to 1083** allocate the structure; it should just fill it in. Note that 1084** the xOpen method must set the sqlite3_file.pMethods to either 1085** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1086** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1087** element will be valid after xOpen returns regardless of the success 1088** or failure of the xOpen call. 1089** 1090** [[sqlite3_vfs.xAccess]] 1091** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1092** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1093** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1094** to test whether a file is at least readable. The file can be a 1095** directory. 1096** 1097** ^SQLite will always allocate at least mxPathname+1 bytes for the 1098** output buffer xFullPathname. The exact size of the output buffer 1099** is also passed as a parameter to both methods. If the output buffer 1100** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1101** handled as a fatal error by SQLite, vfs implementations should endeavor 1102** to prevent this by setting mxPathname to a sufficiently large value. 1103** 1104** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1105** interfaces are not strictly a part of the filesystem, but they are 1106** included in the VFS structure for completeness. 1107** The xRandomness() function attempts to return nBytes bytes 1108** of good-quality randomness into zOut. The return value is 1109** the actual number of bytes of randomness obtained. 1110** The xSleep() method causes the calling thread to sleep for at 1111** least the number of microseconds given. ^The xCurrentTime() 1112** method returns a Julian Day Number for the current date and time as 1113** a floating point value. 1114** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1115** Day Number multiplied by 86400000 (the number of milliseconds in 1116** a 24-hour day). 1117** ^SQLite will use the xCurrentTimeInt64() method to get the current 1118** date and time if that method is available (if iVersion is 2 or 1119** greater and the function pointer is not NULL) and will fall back 1120** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1121** 1122** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1123** are not used by the SQLite core. These optional interfaces are provided 1124** by some VFSes to facilitate testing of the VFS code. By overriding 1125** system calls with functions under its control, a test program can 1126** simulate faults and error conditions that would otherwise be difficult 1127** or impossible to induce. The set of system calls that can be overridden 1128** varies from one VFS to another, and from one version of the same VFS to the 1129** next. Applications that use these interfaces must be prepared for any 1130** or all of these interfaces to be NULL or for their behavior to change 1131** from one release to the next. Applications must not attempt to access 1132** any of these methods if the iVersion of the VFS is less than 3. 1133*/ 1134typedef struct sqlite3_vfs sqlite3_vfs; 1135typedef void (*sqlite3_syscall_ptr)(void); 1136struct sqlite3_vfs { 1137 int iVersion; /* Structure version number (currently 3) */ 1138 int szOsFile; /* Size of subclassed sqlite3_file */ 1139 int mxPathname; /* Maximum file pathname length */ 1140 sqlite3_vfs *pNext; /* Next registered VFS */ 1141 const char *zName; /* Name of this virtual file system */ 1142 void *pAppData; /* Pointer to application-specific data */ 1143 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1144 int flags, int *pOutFlags); 1145 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1146 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1147 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1148 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1149 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1150 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1151 void (*xDlClose)(sqlite3_vfs*, void*); 1152 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1153 int (*xSleep)(sqlite3_vfs*, int microseconds); 1154 int (*xCurrentTime)(sqlite3_vfs*, double*); 1155 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1156 /* 1157 ** The methods above are in version 1 of the sqlite_vfs object 1158 ** definition. Those that follow are added in version 2 or later 1159 */ 1160 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1161 /* 1162 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1163 ** Those below are for version 3 and greater. 1164 */ 1165 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1166 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1167 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1168 /* 1169 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1170 ** New fields may be appended in figure versions. The iVersion 1171 ** value will increment whenever this happens. 1172 */ 1173}; 1174 1175/* 1176** CAPI3REF: Flags for the xAccess VFS method 1177** 1178** These integer constants can be used as the third parameter to 1179** the xAccess method of an [sqlite3_vfs] object. They determine 1180** what kind of permissions the xAccess method is looking for. 1181** With SQLITE_ACCESS_EXISTS, the xAccess method 1182** simply checks whether the file exists. 1183** With SQLITE_ACCESS_READWRITE, the xAccess method 1184** checks whether the named directory is both readable and writable 1185** (in other words, if files can be added, removed, and renamed within 1186** the directory). 1187** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1188** [temp_store_directory pragma], though this could change in a future 1189** release of SQLite. 1190** With SQLITE_ACCESS_READ, the xAccess method 1191** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1192** currently unused, though it might be used in a future release of 1193** SQLite. 1194*/ 1195#define SQLITE_ACCESS_EXISTS 0 1196#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1197#define SQLITE_ACCESS_READ 2 /* Unused */ 1198 1199/* 1200** CAPI3REF: Flags for the xShmLock VFS method 1201** 1202** These integer constants define the various locking operations 1203** allowed by the xShmLock method of [sqlite3_io_methods]. The 1204** following are the only legal combinations of flags to the 1205** xShmLock method: 1206** 1207** <ul> 1208** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1209** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1210** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1211** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1212** </ul> 1213** 1214** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1215** was given no the corresponding lock. 1216** 1217** The xShmLock method can transition between unlocked and SHARED or 1218** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1219** and EXCLUSIVE. 1220*/ 1221#define SQLITE_SHM_UNLOCK 1 1222#define SQLITE_SHM_LOCK 2 1223#define SQLITE_SHM_SHARED 4 1224#define SQLITE_SHM_EXCLUSIVE 8 1225 1226/* 1227** CAPI3REF: Maximum xShmLock index 1228** 1229** The xShmLock method on [sqlite3_io_methods] may use values 1230** between 0 and this upper bound as its "offset" argument. 1231** The SQLite core will never attempt to acquire or release a 1232** lock outside of this range 1233*/ 1234#define SQLITE_SHM_NLOCK 8 1235 1236 1237/* 1238** CAPI3REF: Initialize The SQLite Library 1239** 1240** ^The sqlite3_initialize() routine initializes the 1241** SQLite library. ^The sqlite3_shutdown() routine 1242** deallocates any resources that were allocated by sqlite3_initialize(). 1243** These routines are designed to aid in process initialization and 1244** shutdown on embedded systems. Workstation applications using 1245** SQLite normally do not need to invoke either of these routines. 1246** 1247** A call to sqlite3_initialize() is an "effective" call if it is 1248** the first time sqlite3_initialize() is invoked during the lifetime of 1249** the process, or if it is the first time sqlite3_initialize() is invoked 1250** following a call to sqlite3_shutdown(). ^(Only an effective call 1251** of sqlite3_initialize() does any initialization. All other calls 1252** are harmless no-ops.)^ 1253** 1254** A call to sqlite3_shutdown() is an "effective" call if it is the first 1255** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1256** an effective call to sqlite3_shutdown() does any deinitialization. 1257** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1258** 1259** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1260** is not. The sqlite3_shutdown() interface must only be called from a 1261** single thread. All open [database connections] must be closed and all 1262** other SQLite resources must be deallocated prior to invoking 1263** sqlite3_shutdown(). 1264** 1265** Among other things, ^sqlite3_initialize() will invoke 1266** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1267** will invoke sqlite3_os_end(). 1268** 1269** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1270** ^If for some reason, sqlite3_initialize() is unable to initialize 1271** the library (perhaps it is unable to allocate a needed resource such 1272** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1273** 1274** ^The sqlite3_initialize() routine is called internally by many other 1275** SQLite interfaces so that an application usually does not need to 1276** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1277** calls sqlite3_initialize() so the SQLite library will be automatically 1278** initialized when [sqlite3_open()] is called if it has not be initialized 1279** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1280** compile-time option, then the automatic calls to sqlite3_initialize() 1281** are omitted and the application must call sqlite3_initialize() directly 1282** prior to using any other SQLite interface. For maximum portability, 1283** it is recommended that applications always invoke sqlite3_initialize() 1284** directly prior to using any other SQLite interface. Future releases 1285** of SQLite may require this. In other words, the behavior exhibited 1286** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1287** default behavior in some future release of SQLite. 1288** 1289** The sqlite3_os_init() routine does operating-system specific 1290** initialization of the SQLite library. The sqlite3_os_end() 1291** routine undoes the effect of sqlite3_os_init(). Typical tasks 1292** performed by these routines include allocation or deallocation 1293** of static resources, initialization of global variables, 1294** setting up a default [sqlite3_vfs] module, or setting up 1295** a default configuration using [sqlite3_config()]. 1296** 1297** The application should never invoke either sqlite3_os_init() 1298** or sqlite3_os_end() directly. The application should only invoke 1299** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1300** interface is called automatically by sqlite3_initialize() and 1301** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1302** implementations for sqlite3_os_init() and sqlite3_os_end() 1303** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1304** When [custom builds | built for other platforms] 1305** (using the [SQLITE_OS_OTHER=1] compile-time 1306** option) the application must supply a suitable implementation for 1307** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1308** implementation of sqlite3_os_init() or sqlite3_os_end() 1309** must return [SQLITE_OK] on success and some other [error code] upon 1310** failure. 1311*/ 1312int sqlite3_initialize(void); 1313int sqlite3_shutdown(void); 1314int sqlite3_os_init(void); 1315int sqlite3_os_end(void); 1316 1317/* 1318** CAPI3REF: Configuring The SQLite Library 1319** 1320** The sqlite3_config() interface is used to make global configuration 1321** changes to SQLite in order to tune SQLite to the specific needs of 1322** the application. The default configuration is recommended for most 1323** applications and so this routine is usually not necessary. It is 1324** provided to support rare applications with unusual needs. 1325** 1326** The sqlite3_config() interface is not threadsafe. The application 1327** must insure that no other SQLite interfaces are invoked by other 1328** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1329** may only be invoked prior to library initialization using 1330** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1331** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1332** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1333** Note, however, that ^sqlite3_config() can be called as part of the 1334** implementation of an application-defined [sqlite3_os_init()]. 1335** 1336** The first argument to sqlite3_config() is an integer 1337** [configuration option] that determines 1338** what property of SQLite is to be configured. Subsequent arguments 1339** vary depending on the [configuration option] 1340** in the first argument. 1341** 1342** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1343** ^If the option is unknown or SQLite is unable to set the option 1344** then this routine returns a non-zero [error code]. 1345*/ 1346int sqlite3_config(int, ...); 1347 1348/* 1349** CAPI3REF: Configure database connections 1350** 1351** The sqlite3_db_config() interface is used to make configuration 1352** changes to a [database connection]. The interface is similar to 1353** [sqlite3_config()] except that the changes apply to a single 1354** [database connection] (specified in the first argument). 1355** 1356** The second argument to sqlite3_db_config(D,V,...) is the 1357** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1358** that indicates what aspect of the [database connection] is being configured. 1359** Subsequent arguments vary depending on the configuration verb. 1360** 1361** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1362** the call is considered successful. 1363*/ 1364int sqlite3_db_config(sqlite3*, int op, ...); 1365 1366/* 1367** CAPI3REF: Memory Allocation Routines 1368** 1369** An instance of this object defines the interface between SQLite 1370** and low-level memory allocation routines. 1371** 1372** This object is used in only one place in the SQLite interface. 1373** A pointer to an instance of this object is the argument to 1374** [sqlite3_config()] when the configuration option is 1375** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1376** By creating an instance of this object 1377** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1378** during configuration, an application can specify an alternative 1379** memory allocation subsystem for SQLite to use for all of its 1380** dynamic memory needs. 1381** 1382** Note that SQLite comes with several [built-in memory allocators] 1383** that are perfectly adequate for the overwhelming majority of applications 1384** and that this object is only useful to a tiny minority of applications 1385** with specialized memory allocation requirements. This object is 1386** also used during testing of SQLite in order to specify an alternative 1387** memory allocator that simulates memory out-of-memory conditions in 1388** order to verify that SQLite recovers gracefully from such 1389** conditions. 1390** 1391** The xMalloc, xRealloc, and xFree methods must work like the 1392** malloc(), realloc() and free() functions from the standard C library. 1393** ^SQLite guarantees that the second argument to 1394** xRealloc is always a value returned by a prior call to xRoundup. 1395** 1396** xSize should return the allocated size of a memory allocation 1397** previously obtained from xMalloc or xRealloc. The allocated size 1398** is always at least as big as the requested size but may be larger. 1399** 1400** The xRoundup method returns what would be the allocated size of 1401** a memory allocation given a particular requested size. Most memory 1402** allocators round up memory allocations at least to the next multiple 1403** of 8. Some allocators round up to a larger multiple or to a power of 2. 1404** Every memory allocation request coming in through [sqlite3_malloc()] 1405** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1406** that causes the corresponding memory allocation to fail. 1407** 1408** The xInit method initializes the memory allocator. For example, 1409** it might allocate any require mutexes or initialize internal data 1410** structures. The xShutdown method is invoked (indirectly) by 1411** [sqlite3_shutdown()] and should deallocate any resources acquired 1412** by xInit. The pAppData pointer is used as the only parameter to 1413** xInit and xShutdown. 1414** 1415** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1416** the xInit method, so the xInit method need not be threadsafe. The 1417** xShutdown method is only called from [sqlite3_shutdown()] so it does 1418** not need to be threadsafe either. For all other methods, SQLite 1419** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1420** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1421** it is by default) and so the methods are automatically serialized. 1422** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1423** methods must be threadsafe or else make their own arrangements for 1424** serialization. 1425** 1426** SQLite will never invoke xInit() more than once without an intervening 1427** call to xShutdown(). 1428*/ 1429typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1430struct sqlite3_mem_methods { 1431 void *(*xMalloc)(int); /* Memory allocation function */ 1432 void (*xFree)(void*); /* Free a prior allocation */ 1433 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1434 int (*xSize)(void*); /* Return the size of an allocation */ 1435 int (*xRoundup)(int); /* Round up request size to allocation size */ 1436 int (*xInit)(void*); /* Initialize the memory allocator */ 1437 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1438 void *pAppData; /* Argument to xInit() and xShutdown() */ 1439}; 1440 1441/* 1442** CAPI3REF: Configuration Options 1443** KEYWORDS: {configuration option} 1444** 1445** These constants are the available integer configuration options that 1446** can be passed as the first argument to the [sqlite3_config()] interface. 1447** 1448** New configuration options may be added in future releases of SQLite. 1449** Existing configuration options might be discontinued. Applications 1450** should check the return code from [sqlite3_config()] to make sure that 1451** the call worked. The [sqlite3_config()] interface will return a 1452** non-zero [error code] if a discontinued or unsupported configuration option 1453** is invoked. 1454** 1455** <dl> 1456** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1457** <dd>There are no arguments to this option. ^This option sets the 1458** [threading mode] to Single-thread. In other words, it disables 1459** all mutexing and puts SQLite into a mode where it can only be used 1460** by a single thread. ^If SQLite is compiled with 1461** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1462** it is not possible to change the [threading mode] from its default 1463** value of Single-thread and so [sqlite3_config()] will return 1464** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1465** configuration option.</dd> 1466** 1467** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1468** <dd>There are no arguments to this option. ^This option sets the 1469** [threading mode] to Multi-thread. In other words, it disables 1470** mutexing on [database connection] and [prepared statement] objects. 1471** The application is responsible for serializing access to 1472** [database connections] and [prepared statements]. But other mutexes 1473** are enabled so that SQLite will be safe to use in a multi-threaded 1474** environment as long as no two threads attempt to use the same 1475** [database connection] at the same time. ^If SQLite is compiled with 1476** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1477** it is not possible to set the Multi-thread [threading mode] and 1478** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1479** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1480** 1481** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1482** <dd>There are no arguments to this option. ^This option sets the 1483** [threading mode] to Serialized. In other words, this option enables 1484** all mutexes including the recursive 1485** mutexes on [database connection] and [prepared statement] objects. 1486** In this mode (which is the default when SQLite is compiled with 1487** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1488** to [database connections] and [prepared statements] so that the 1489** application is free to use the same [database connection] or the 1490** same [prepared statement] in different threads at the same time. 1491** ^If SQLite is compiled with 1492** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1493** it is not possible to set the Serialized [threading mode] and 1494** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1495** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1496** 1497** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1498** <dd> ^(This option takes a single argument which is a pointer to an 1499** instance of the [sqlite3_mem_methods] structure. The argument specifies 1500** alternative low-level memory allocation routines to be used in place of 1501** the memory allocation routines built into SQLite.)^ ^SQLite makes 1502** its own private copy of the content of the [sqlite3_mem_methods] structure 1503** before the [sqlite3_config()] call returns.</dd> 1504** 1505** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1506** <dd> ^(This option takes a single argument which is a pointer to an 1507** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1508** structure is filled with the currently defined memory allocation routines.)^ 1509** This option can be used to overload the default memory allocation 1510** routines with a wrapper that simulations memory allocation failure or 1511** tracks memory usage, for example. </dd> 1512** 1513** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1514** <dd> ^This option takes single argument of type int, interpreted as a 1515** boolean, which enables or disables the collection of memory allocation 1516** statistics. ^(When memory allocation statistics are disabled, the 1517** following SQLite interfaces become non-operational: 1518** <ul> 1519** <li> [sqlite3_memory_used()] 1520** <li> [sqlite3_memory_highwater()] 1521** <li> [sqlite3_soft_heap_limit64()] 1522** <li> [sqlite3_status()] 1523** </ul>)^ 1524** ^Memory allocation statistics are enabled by default unless SQLite is 1525** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1526** allocation statistics are disabled by default. 1527** </dd> 1528** 1529** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1530** <dd> ^This option specifies a static memory buffer that SQLite can use for 1531** scratch memory. There are three arguments: A pointer an 8-byte 1532** aligned memory buffer from which the scratch allocations will be 1533** drawn, the size of each scratch allocation (sz), 1534** and the maximum number of scratch allocations (N). The sz 1535** argument must be a multiple of 16. 1536** The first argument must be a pointer to an 8-byte aligned buffer 1537** of at least sz*N bytes of memory. 1538** ^SQLite will use no more than two scratch buffers per thread. So 1539** N should be set to twice the expected maximum number of threads. 1540** ^SQLite will never require a scratch buffer that is more than 6 1541** times the database page size. ^If SQLite needs needs additional 1542** scratch memory beyond what is provided by this configuration option, then 1543** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1544** 1545** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1546** <dd> ^This option specifies a static memory buffer that SQLite can use for 1547** the database page cache with the default page cache implementation. 1548** This configuration should not be used if an application-define page 1549** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1550** There are three arguments to this option: A pointer to 8-byte aligned 1551** memory, the size of each page buffer (sz), and the number of pages (N). 1552** The sz argument should be the size of the largest database page 1553** (a power of two between 512 and 32768) plus a little extra for each 1554** page header. ^The page header size is 20 to 40 bytes depending on 1555** the host architecture. ^It is harmless, apart from the wasted memory, 1556** to make sz a little too large. The first 1557** argument should point to an allocation of at least sz*N bytes of memory. 1558** ^SQLite will use the memory provided by the first argument to satisfy its 1559** memory needs for the first N pages that it adds to cache. ^If additional 1560** page cache memory is needed beyond what is provided by this option, then 1561** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1562** The pointer in the first argument must 1563** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1564** will be undefined.</dd> 1565** 1566** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1567** <dd> ^This option specifies a static memory buffer that SQLite will use 1568** for all of its dynamic memory allocation needs beyond those provided 1569** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1570** There are three arguments: An 8-byte aligned pointer to the memory, 1571** the number of bytes in the memory buffer, and the minimum allocation size. 1572** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1573** to using its default memory allocator (the system malloc() implementation), 1574** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1575** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1576** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1577** allocator is engaged to handle all of SQLites memory allocation needs. 1578** The first pointer (the memory pointer) must be aligned to an 8-byte 1579** boundary or subsequent behavior of SQLite will be undefined. 1580** The minimum allocation size is capped at 2**12. Reasonable values 1581** for the minimum allocation size are 2**5 through 2**8.</dd> 1582** 1583** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1584** <dd> ^(This option takes a single argument which is a pointer to an 1585** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1586** alternative low-level mutex routines to be used in place 1587** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1588** content of the [sqlite3_mutex_methods] structure before the call to 1589** [sqlite3_config()] returns. ^If SQLite is compiled with 1590** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1591** the entire mutexing subsystem is omitted from the build and hence calls to 1592** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1593** return [SQLITE_ERROR].</dd> 1594** 1595** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1596** <dd> ^(This option takes a single argument which is a pointer to an 1597** instance of the [sqlite3_mutex_methods] structure. The 1598** [sqlite3_mutex_methods] 1599** structure is filled with the currently defined mutex routines.)^ 1600** This option can be used to overload the default mutex allocation 1601** routines with a wrapper used to track mutex usage for performance 1602** profiling or testing, for example. ^If SQLite is compiled with 1603** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1604** the entire mutexing subsystem is omitted from the build and hence calls to 1605** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1606** return [SQLITE_ERROR].</dd> 1607** 1608** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1609** <dd> ^(This option takes two arguments that determine the default 1610** memory allocation for the lookaside memory allocator on each 1611** [database connection]. The first argument is the 1612** size of each lookaside buffer slot and the second is the number of 1613** slots allocated to each database connection.)^ ^(This option sets the 1614** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1615** verb to [sqlite3_db_config()] can be used to change the lookaside 1616** configuration on individual connections.)^ </dd> 1617** 1618** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1619** <dd> ^(This option takes a single argument which is a pointer to 1620** an [sqlite3_pcache_methods2] object. This object specifies the interface 1621** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1622** object and uses it for page cache memory allocations.</dd> 1623** 1624** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1625** <dd> ^(This option takes a single argument which is a pointer to an 1626** [sqlite3_pcache_methods2] object. SQLite copies of the current 1627** page cache implementation into that object.)^ </dd> 1628** 1629** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1630** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1631** global [error log]. 1632** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1633** function with a call signature of void(*)(void*,int,const char*), 1634** and a pointer to void. ^If the function pointer is not NULL, it is 1635** invoked by [sqlite3_log()] to process each logging event. ^If the 1636** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1637** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1638** passed through as the first parameter to the application-defined logger 1639** function whenever that function is invoked. ^The second parameter to 1640** the logger function is a copy of the first parameter to the corresponding 1641** [sqlite3_log()] call and is intended to be a [result code] or an 1642** [extended result code]. ^The third parameter passed to the logger is 1643** log message after formatting via [sqlite3_snprintf()]. 1644** The SQLite logging interface is not reentrant; the logger function 1645** supplied by the application must not invoke any SQLite interface. 1646** In a multi-threaded application, the application-defined logger 1647** function must be threadsafe. </dd> 1648** 1649** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1650** <dd>^(This option takes a single argument of type int. If non-zero, then 1651** URI handling is globally enabled. If the parameter is zero, then URI handling 1652** is globally disabled.)^ ^If URI handling is globally enabled, all filenames 1653** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1654** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1655** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1656** connection is opened. ^If it is globally disabled, filenames are 1657** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1658** database connection is opened. ^(By default, URI handling is globally 1659** disabled. The default value may be changed by compiling with the 1660** [SQLITE_USE_URI] symbol defined.)^ 1661** 1662** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1663** <dd>^This option takes a single integer argument which is interpreted as 1664** a boolean in order to enable or disable the use of covering indices for 1665** full table scans in the query optimizer. ^The default setting is determined 1666** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1667** if that compile-time option is omitted. 1668** The ability to disable the use of covering indices for full table scans 1669** is because some incorrectly coded legacy applications might malfunction 1670** when the optimization is enabled. Providing the ability to 1671** disable the optimization allows the older, buggy application code to work 1672** without change even with newer versions of SQLite. 1673** 1674** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1675** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1676** <dd> These options are obsolete and should not be used by new code. 1677** They are retained for backwards compatibility but are now no-ops. 1678** </dd> 1679** 1680** [[SQLITE_CONFIG_SQLLOG]] 1681** <dt>SQLITE_CONFIG_SQLLOG 1682** <dd>This option is only available if sqlite is compiled with the 1683** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1684** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1685** The second should be of type (void*). The callback is invoked by the library 1686** in three separate circumstances, identified by the value passed as the 1687** fourth parameter. If the fourth parameter is 0, then the database connection 1688** passed as the second argument has just been opened. The third argument 1689** points to a buffer containing the name of the main database file. If the 1690** fourth parameter is 1, then the SQL statement that the third parameter 1691** points to has just been executed. Or, if the fourth parameter is 2, then 1692** the connection being passed as the second parameter is being closed. The 1693** third parameter is passed NULL In this case. An example of using this 1694** configuration option can be seen in the "test_sqllog.c" source file in 1695** the canonical SQLite source tree.</dd> 1696** 1697** [[SQLITE_CONFIG_MMAP_SIZE]] 1698** <dt>SQLITE_CONFIG_MMAP_SIZE 1699** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1700** that are the default mmap size limit (the default setting for 1701** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1702** ^The default setting can be overridden by each database connection using 1703** either the [PRAGMA mmap_size] command, or by using the 1704** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1705** cannot be changed at run-time. Nor may the maximum allowed mmap size 1706** exceed the compile-time maximum mmap size set by the 1707** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1708** ^If either argument to this option is negative, then that argument is 1709** changed to its compile-time default. 1710** 1711** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1712** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1713** <dd>^This option is only available if SQLite is compiled for Windows 1714** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. 1715** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1716** that specifies the maximum size of the created heap. 1717** </dl> 1718*/ 1719#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1720#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1721#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1722#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1723#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1724#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1725#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1726#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1727#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1728#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1729#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1730/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1731#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1732#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1733#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1734#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1735#define SQLITE_CONFIG_URI 17 /* int */ 1736#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1737#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1738#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1739#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1740#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1741#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1742 1743/* 1744** CAPI3REF: Database Connection Configuration Options 1745** 1746** These constants are the available integer configuration options that 1747** can be passed as the second argument to the [sqlite3_db_config()] interface. 1748** 1749** New configuration options may be added in future releases of SQLite. 1750** Existing configuration options might be discontinued. Applications 1751** should check the return code from [sqlite3_db_config()] to make sure that 1752** the call worked. ^The [sqlite3_db_config()] interface will return a 1753** non-zero [error code] if a discontinued or unsupported configuration option 1754** is invoked. 1755** 1756** <dl> 1757** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1758** <dd> ^This option takes three additional arguments that determine the 1759** [lookaside memory allocator] configuration for the [database connection]. 1760** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1761** pointer to a memory buffer to use for lookaside memory. 1762** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1763** may be NULL in which case SQLite will allocate the 1764** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1765** size of each lookaside buffer slot. ^The third argument is the number of 1766** slots. The size of the buffer in the first argument must be greater than 1767** or equal to the product of the second and third arguments. The buffer 1768** must be aligned to an 8-byte boundary. ^If the second argument to 1769** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1770** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1771** configuration for a database connection can only be changed when that 1772** connection is not currently using lookaside memory, or in other words 1773** when the "current value" returned by 1774** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1775** Any attempt to change the lookaside memory configuration when lookaside 1776** memory is in use leaves the configuration unchanged and returns 1777** [SQLITE_BUSY].)^</dd> 1778** 1779** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1780** <dd> ^This option is used to enable or disable the enforcement of 1781** [foreign key constraints]. There should be two additional arguments. 1782** The first argument is an integer which is 0 to disable FK enforcement, 1783** positive to enable FK enforcement or negative to leave FK enforcement 1784** unchanged. The second parameter is a pointer to an integer into which 1785** is written 0 or 1 to indicate whether FK enforcement is off or on 1786** following this call. The second parameter may be a NULL pointer, in 1787** which case the FK enforcement setting is not reported back. </dd> 1788** 1789** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1790** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1791** There should be two additional arguments. 1792** The first argument is an integer which is 0 to disable triggers, 1793** positive to enable triggers or negative to leave the setting unchanged. 1794** The second parameter is a pointer to an integer into which 1795** is written 0 or 1 to indicate whether triggers are disabled or enabled 1796** following this call. The second parameter may be a NULL pointer, in 1797** which case the trigger setting is not reported back. </dd> 1798** 1799** </dl> 1800*/ 1801#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1802#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1803#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1804 1805 1806/* 1807** CAPI3REF: Enable Or Disable Extended Result Codes 1808** 1809** ^The sqlite3_extended_result_codes() routine enables or disables the 1810** [extended result codes] feature of SQLite. ^The extended result 1811** codes are disabled by default for historical compatibility. 1812*/ 1813int sqlite3_extended_result_codes(sqlite3*, int onoff); 1814 1815/* 1816** CAPI3REF: Last Insert Rowid 1817** 1818** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1819** has a unique 64-bit signed 1820** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1821** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1822** names are not also used by explicitly declared columns. ^If 1823** the table has a column of type [INTEGER PRIMARY KEY] then that column 1824** is another alias for the rowid. 1825** 1826** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1827** most recent successful [INSERT] into a rowid table or [virtual table] 1828** on database connection D. 1829** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1830** ^If no successful [INSERT]s into rowid tables 1831** have ever occurred on the database connection D, 1832** then sqlite3_last_insert_rowid(D) returns zero. 1833** 1834** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1835** method, then this routine will return the [rowid] of the inserted 1836** row as long as the trigger or virtual table method is running. 1837** But once the trigger or virtual table method ends, the value returned 1838** by this routine reverts to what it was before the trigger or virtual 1839** table method began.)^ 1840** 1841** ^An [INSERT] that fails due to a constraint violation is not a 1842** successful [INSERT] and does not change the value returned by this 1843** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1844** and INSERT OR ABORT make no changes to the return value of this 1845** routine when their insertion fails. ^(When INSERT OR REPLACE 1846** encounters a constraint violation, it does not fail. The 1847** INSERT continues to completion after deleting rows that caused 1848** the constraint problem so INSERT OR REPLACE will always change 1849** the return value of this interface.)^ 1850** 1851** ^For the purposes of this routine, an [INSERT] is considered to 1852** be successful even if it is subsequently rolled back. 1853** 1854** This function is accessible to SQL statements via the 1855** [last_insert_rowid() SQL function]. 1856** 1857** If a separate thread performs a new [INSERT] on the same 1858** database connection while the [sqlite3_last_insert_rowid()] 1859** function is running and thus changes the last insert [rowid], 1860** then the value returned by [sqlite3_last_insert_rowid()] is 1861** unpredictable and might not equal either the old or the new 1862** last insert [rowid]. 1863*/ 1864sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1865 1866/* 1867** CAPI3REF: Count The Number Of Rows Modified 1868** 1869** ^This function returns the number of database rows that were changed 1870** or inserted or deleted by the most recently completed SQL statement 1871** on the [database connection] specified by the first parameter. 1872** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1873** or [DELETE] statement are counted. Auxiliary changes caused by 1874** triggers or [foreign key actions] are not counted.)^ Use the 1875** [sqlite3_total_changes()] function to find the total number of changes 1876** including changes caused by triggers and foreign key actions. 1877** 1878** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1879** are not counted. Only real table changes are counted. 1880** 1881** ^(A "row change" is a change to a single row of a single table 1882** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1883** are changed as side effects of [REPLACE] constraint resolution, 1884** rollback, ABORT processing, [DROP TABLE], or by any other 1885** mechanisms do not count as direct row changes.)^ 1886** 1887** A "trigger context" is a scope of execution that begins and 1888** ends with the script of a [CREATE TRIGGER | trigger]. 1889** Most SQL statements are 1890** evaluated outside of any trigger. This is the "top level" 1891** trigger context. If a trigger fires from the top level, a 1892** new trigger context is entered for the duration of that one 1893** trigger. Subtriggers create subcontexts for their duration. 1894** 1895** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1896** not create a new trigger context. 1897** 1898** ^This function returns the number of direct row changes in the 1899** most recent INSERT, UPDATE, or DELETE statement within the same 1900** trigger context. 1901** 1902** ^Thus, when called from the top level, this function returns the 1903** number of changes in the most recent INSERT, UPDATE, or DELETE 1904** that also occurred at the top level. ^(Within the body of a trigger, 1905** the sqlite3_changes() interface can be called to find the number of 1906** changes in the most recently completed INSERT, UPDATE, or DELETE 1907** statement within the body of the same trigger. 1908** However, the number returned does not include changes 1909** caused by subtriggers since those have their own context.)^ 1910** 1911** See also the [sqlite3_total_changes()] interface, the 1912** [count_changes pragma], and the [changes() SQL function]. 1913** 1914** If a separate thread makes changes on the same database connection 1915** while [sqlite3_changes()] is running then the value returned 1916** is unpredictable and not meaningful. 1917*/ 1918int sqlite3_changes(sqlite3*); 1919 1920/* 1921** CAPI3REF: Total Number Of Rows Modified 1922** 1923** ^This function returns the number of row changes caused by [INSERT], 1924** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1925** ^(The count returned by sqlite3_total_changes() includes all changes 1926** from all [CREATE TRIGGER | trigger] contexts and changes made by 1927** [foreign key actions]. However, 1928** the count does not include changes used to implement [REPLACE] constraints, 1929** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1930** count does not include rows of views that fire an [INSTEAD OF trigger], 1931** though if the INSTEAD OF trigger makes changes of its own, those changes 1932** are counted.)^ 1933** ^The sqlite3_total_changes() function counts the changes as soon as 1934** the statement that makes them is completed (when the statement handle 1935** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1936** 1937** See also the [sqlite3_changes()] interface, the 1938** [count_changes pragma], and the [total_changes() SQL function]. 1939** 1940** If a separate thread makes changes on the same database connection 1941** while [sqlite3_total_changes()] is running then the value 1942** returned is unpredictable and not meaningful. 1943*/ 1944int sqlite3_total_changes(sqlite3*); 1945 1946/* 1947** CAPI3REF: Interrupt A Long-Running Query 1948** 1949** ^This function causes any pending database operation to abort and 1950** return at its earliest opportunity. This routine is typically 1951** called in response to a user action such as pressing "Cancel" 1952** or Ctrl-C where the user wants a long query operation to halt 1953** immediately. 1954** 1955** ^It is safe to call this routine from a thread different from the 1956** thread that is currently running the database operation. But it 1957** is not safe to call this routine with a [database connection] that 1958** is closed or might close before sqlite3_interrupt() returns. 1959** 1960** ^If an SQL operation is very nearly finished at the time when 1961** sqlite3_interrupt() is called, then it might not have an opportunity 1962** to be interrupted and might continue to completion. 1963** 1964** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1965** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1966** that is inside an explicit transaction, then the entire transaction 1967** will be rolled back automatically. 1968** 1969** ^The sqlite3_interrupt(D) call is in effect until all currently running 1970** SQL statements on [database connection] D complete. ^Any new SQL statements 1971** that are started after the sqlite3_interrupt() call and before the 1972** running statements reaches zero are interrupted as if they had been 1973** running prior to the sqlite3_interrupt() call. ^New SQL statements 1974** that are started after the running statement count reaches zero are 1975** not effected by the sqlite3_interrupt(). 1976** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1977** SQL statements is a no-op and has no effect on SQL statements 1978** that are started after the sqlite3_interrupt() call returns. 1979** 1980** If the database connection closes while [sqlite3_interrupt()] 1981** is running then bad things will likely happen. 1982*/ 1983void sqlite3_interrupt(sqlite3*); 1984 1985/* 1986** CAPI3REF: Determine If An SQL Statement Is Complete 1987** 1988** These routines are useful during command-line input to determine if the 1989** currently entered text seems to form a complete SQL statement or 1990** if additional input is needed before sending the text into 1991** SQLite for parsing. ^These routines return 1 if the input string 1992** appears to be a complete SQL statement. ^A statement is judged to be 1993** complete if it ends with a semicolon token and is not a prefix of a 1994** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1995** string literals or quoted identifier names or comments are not 1996** independent tokens (they are part of the token in which they are 1997** embedded) and thus do not count as a statement terminator. ^Whitespace 1998** and comments that follow the final semicolon are ignored. 1999** 2000** ^These routines return 0 if the statement is incomplete. ^If a 2001** memory allocation fails, then SQLITE_NOMEM is returned. 2002** 2003** ^These routines do not parse the SQL statements thus 2004** will not detect syntactically incorrect SQL. 2005** 2006** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2007** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2008** automatically by sqlite3_complete16(). If that initialization fails, 2009** then the return value from sqlite3_complete16() will be non-zero 2010** regardless of whether or not the input SQL is complete.)^ 2011** 2012** The input to [sqlite3_complete()] must be a zero-terminated 2013** UTF-8 string. 2014** 2015** The input to [sqlite3_complete16()] must be a zero-terminated 2016** UTF-16 string in native byte order. 2017*/ 2018int sqlite3_complete(const char *sql); 2019int sqlite3_complete16(const void *sql); 2020 2021/* 2022** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2023** 2024** ^This routine sets a callback function that might be invoked whenever 2025** an attempt is made to open a database table that another thread 2026** or process has locked. 2027** 2028** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 2029** is returned immediately upon encountering the lock. ^If the busy callback 2030** is not NULL, then the callback might be invoked with two arguments. 2031** 2032** ^The first argument to the busy handler is a copy of the void* pointer which 2033** is the third argument to sqlite3_busy_handler(). ^The second argument to 2034** the busy handler callback is the number of times that the busy handler has 2035** been invoked for this locking event. ^If the 2036** busy callback returns 0, then no additional attempts are made to 2037** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 2038** ^If the callback returns non-zero, then another attempt 2039** is made to open the database for reading and the cycle repeats. 2040** 2041** The presence of a busy handler does not guarantee that it will be invoked 2042** when there is lock contention. ^If SQLite determines that invoking the busy 2043** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2044** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 2045** Consider a scenario where one process is holding a read lock that 2046** it is trying to promote to a reserved lock and 2047** a second process is holding a reserved lock that it is trying 2048** to promote to an exclusive lock. The first process cannot proceed 2049** because it is blocked by the second and the second process cannot 2050** proceed because it is blocked by the first. If both processes 2051** invoke the busy handlers, neither will make any progress. Therefore, 2052** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2053** will induce the first process to release its read lock and allow 2054** the second process to proceed. 2055** 2056** ^The default busy callback is NULL. 2057** 2058** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 2059** when SQLite is in the middle of a large transaction where all the 2060** changes will not fit into the in-memory cache. SQLite will 2061** already hold a RESERVED lock on the database file, but it needs 2062** to promote this lock to EXCLUSIVE so that it can spill cache 2063** pages into the database file without harm to concurrent 2064** readers. ^If it is unable to promote the lock, then the in-memory 2065** cache will be left in an inconsistent state and so the error 2066** code is promoted from the relatively benign [SQLITE_BUSY] to 2067** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 2068** forces an automatic rollback of the changes. See the 2069** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 2070** CorruptionFollowingBusyError</a> wiki page for a discussion of why 2071** this is important. 2072** 2073** ^(There can only be a single busy handler defined for each 2074** [database connection]. Setting a new busy handler clears any 2075** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2076** will also set or clear the busy handler. 2077** 2078** The busy callback should not take any actions which modify the 2079** database connection that invoked the busy handler. Any such actions 2080** result in undefined behavior. 2081** 2082** A busy handler must not close the database connection 2083** or [prepared statement] that invoked the busy handler. 2084*/ 2085int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2086 2087/* 2088** CAPI3REF: Set A Busy Timeout 2089** 2090** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2091** for a specified amount of time when a table is locked. ^The handler 2092** will sleep multiple times until at least "ms" milliseconds of sleeping 2093** have accumulated. ^After at least "ms" milliseconds of sleeping, 2094** the handler returns 0 which causes [sqlite3_step()] to return 2095** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 2096** 2097** ^Calling this routine with an argument less than or equal to zero 2098** turns off all busy handlers. 2099** 2100** ^(There can only be a single busy handler for a particular 2101** [database connection] any any given moment. If another busy handler 2102** was defined (using [sqlite3_busy_handler()]) prior to calling 2103** this routine, that other busy handler is cleared.)^ 2104*/ 2105int sqlite3_busy_timeout(sqlite3*, int ms); 2106 2107/* 2108** CAPI3REF: Convenience Routines For Running Queries 2109** 2110** This is a legacy interface that is preserved for backwards compatibility. 2111** Use of this interface is not recommended. 2112** 2113** Definition: A <b>result table</b> is memory data structure created by the 2114** [sqlite3_get_table()] interface. A result table records the 2115** complete query results from one or more queries. 2116** 2117** The table conceptually has a number of rows and columns. But 2118** these numbers are not part of the result table itself. These 2119** numbers are obtained separately. Let N be the number of rows 2120** and M be the number of columns. 2121** 2122** A result table is an array of pointers to zero-terminated UTF-8 strings. 2123** There are (N+1)*M elements in the array. The first M pointers point 2124** to zero-terminated strings that contain the names of the columns. 2125** The remaining entries all point to query results. NULL values result 2126** in NULL pointers. All other values are in their UTF-8 zero-terminated 2127** string representation as returned by [sqlite3_column_text()]. 2128** 2129** A result table might consist of one or more memory allocations. 2130** It is not safe to pass a result table directly to [sqlite3_free()]. 2131** A result table should be deallocated using [sqlite3_free_table()]. 2132** 2133** ^(As an example of the result table format, suppose a query result 2134** is as follows: 2135** 2136** <blockquote><pre> 2137** Name | Age 2138** ----------------------- 2139** Alice | 43 2140** Bob | 28 2141** Cindy | 21 2142** </pre></blockquote> 2143** 2144** There are two column (M==2) and three rows (N==3). Thus the 2145** result table has 8 entries. Suppose the result table is stored 2146** in an array names azResult. Then azResult holds this content: 2147** 2148** <blockquote><pre> 2149** azResult[0] = "Name"; 2150** azResult[1] = "Age"; 2151** azResult[2] = "Alice"; 2152** azResult[3] = "43"; 2153** azResult[4] = "Bob"; 2154** azResult[5] = "28"; 2155** azResult[6] = "Cindy"; 2156** azResult[7] = "21"; 2157** </pre></blockquote>)^ 2158** 2159** ^The sqlite3_get_table() function evaluates one or more 2160** semicolon-separated SQL statements in the zero-terminated UTF-8 2161** string of its 2nd parameter and returns a result table to the 2162** pointer given in its 3rd parameter. 2163** 2164** After the application has finished with the result from sqlite3_get_table(), 2165** it must pass the result table pointer to sqlite3_free_table() in order to 2166** release the memory that was malloced. Because of the way the 2167** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2168** function must not try to call [sqlite3_free()] directly. Only 2169** [sqlite3_free_table()] is able to release the memory properly and safely. 2170** 2171** The sqlite3_get_table() interface is implemented as a wrapper around 2172** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2173** to any internal data structures of SQLite. It uses only the public 2174** interface defined here. As a consequence, errors that occur in the 2175** wrapper layer outside of the internal [sqlite3_exec()] call are not 2176** reflected in subsequent calls to [sqlite3_errcode()] or 2177** [sqlite3_errmsg()]. 2178*/ 2179int sqlite3_get_table( 2180 sqlite3 *db, /* An open database */ 2181 const char *zSql, /* SQL to be evaluated */ 2182 char ***pazResult, /* Results of the query */ 2183 int *pnRow, /* Number of result rows written here */ 2184 int *pnColumn, /* Number of result columns written here */ 2185 char **pzErrmsg /* Error msg written here */ 2186); 2187void sqlite3_free_table(char **result); 2188 2189/* 2190** CAPI3REF: Formatted String Printing Functions 2191** 2192** These routines are work-alikes of the "printf()" family of functions 2193** from the standard C library. 2194** 2195** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2196** results into memory obtained from [sqlite3_malloc()]. 2197** The strings returned by these two routines should be 2198** released by [sqlite3_free()]. ^Both routines return a 2199** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2200** memory to hold the resulting string. 2201** 2202** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2203** the standard C library. The result is written into the 2204** buffer supplied as the second parameter whose size is given by 2205** the first parameter. Note that the order of the 2206** first two parameters is reversed from snprintf().)^ This is an 2207** historical accident that cannot be fixed without breaking 2208** backwards compatibility. ^(Note also that sqlite3_snprintf() 2209** returns a pointer to its buffer instead of the number of 2210** characters actually written into the buffer.)^ We admit that 2211** the number of characters written would be a more useful return 2212** value but we cannot change the implementation of sqlite3_snprintf() 2213** now without breaking compatibility. 2214** 2215** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2216** guarantees that the buffer is always zero-terminated. ^The first 2217** parameter "n" is the total size of the buffer, including space for 2218** the zero terminator. So the longest string that can be completely 2219** written will be n-1 characters. 2220** 2221** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2222** 2223** These routines all implement some additional formatting 2224** options that are useful for constructing SQL statements. 2225** All of the usual printf() formatting options apply. In addition, there 2226** is are "%q", "%Q", and "%z" options. 2227** 2228** ^(The %q option works like %s in that it substitutes a nul-terminated 2229** string from the argument list. But %q also doubles every '\'' character. 2230** %q is designed for use inside a string literal.)^ By doubling each '\'' 2231** character it escapes that character and allows it to be inserted into 2232** the string. 2233** 2234** For example, assume the string variable zText contains text as follows: 2235** 2236** <blockquote><pre> 2237** char *zText = "It's a happy day!"; 2238** </pre></blockquote> 2239** 2240** One can use this text in an SQL statement as follows: 2241** 2242** <blockquote><pre> 2243** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2244** sqlite3_exec(db, zSQL, 0, 0, 0); 2245** sqlite3_free(zSQL); 2246** </pre></blockquote> 2247** 2248** Because the %q format string is used, the '\'' character in zText 2249** is escaped and the SQL generated is as follows: 2250** 2251** <blockquote><pre> 2252** INSERT INTO table1 VALUES('It''s a happy day!') 2253** </pre></blockquote> 2254** 2255** This is correct. Had we used %s instead of %q, the generated SQL 2256** would have looked like this: 2257** 2258** <blockquote><pre> 2259** INSERT INTO table1 VALUES('It's a happy day!'); 2260** </pre></blockquote> 2261** 2262** This second example is an SQL syntax error. As a general rule you should 2263** always use %q instead of %s when inserting text into a string literal. 2264** 2265** ^(The %Q option works like %q except it also adds single quotes around 2266** the outside of the total string. Additionally, if the parameter in the 2267** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2268** single quotes).)^ So, for example, one could say: 2269** 2270** <blockquote><pre> 2271** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2272** sqlite3_exec(db, zSQL, 0, 0, 0); 2273** sqlite3_free(zSQL); 2274** </pre></blockquote> 2275** 2276** The code above will render a correct SQL statement in the zSQL 2277** variable even if the zText variable is a NULL pointer. 2278** 2279** ^(The "%z" formatting option works like "%s" but with the 2280** addition that after the string has been read and copied into 2281** the result, [sqlite3_free()] is called on the input string.)^ 2282*/ 2283char *sqlite3_mprintf(const char*,...); 2284char *sqlite3_vmprintf(const char*, va_list); 2285char *sqlite3_snprintf(int,char*,const char*, ...); 2286char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2287 2288/* 2289** CAPI3REF: Memory Allocation Subsystem 2290** 2291** The SQLite core uses these three routines for all of its own 2292** internal memory allocation needs. "Core" in the previous sentence 2293** does not include operating-system specific VFS implementation. The 2294** Windows VFS uses native malloc() and free() for some operations. 2295** 2296** ^The sqlite3_malloc() routine returns a pointer to a block 2297** of memory at least N bytes in length, where N is the parameter. 2298** ^If sqlite3_malloc() is unable to obtain sufficient free 2299** memory, it returns a NULL pointer. ^If the parameter N to 2300** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2301** a NULL pointer. 2302** 2303** ^Calling sqlite3_free() with a pointer previously returned 2304** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2305** that it might be reused. ^The sqlite3_free() routine is 2306** a no-op if is called with a NULL pointer. Passing a NULL pointer 2307** to sqlite3_free() is harmless. After being freed, memory 2308** should neither be read nor written. Even reading previously freed 2309** memory might result in a segmentation fault or other severe error. 2310** Memory corruption, a segmentation fault, or other severe error 2311** might result if sqlite3_free() is called with a non-NULL pointer that 2312** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2313** 2314** ^(The sqlite3_realloc() interface attempts to resize a 2315** prior memory allocation to be at least N bytes, where N is the 2316** second parameter. The memory allocation to be resized is the first 2317** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2318** is a NULL pointer then its behavior is identical to calling 2319** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2320** ^If the second parameter to sqlite3_realloc() is zero or 2321** negative then the behavior is exactly the same as calling 2322** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2323** ^sqlite3_realloc() returns a pointer to a memory allocation 2324** of at least N bytes in size or NULL if sufficient memory is unavailable. 2325** ^If M is the size of the prior allocation, then min(N,M) bytes 2326** of the prior allocation are copied into the beginning of buffer returned 2327** by sqlite3_realloc() and the prior allocation is freed. 2328** ^If sqlite3_realloc() returns NULL, then the prior allocation 2329** is not freed. 2330** 2331** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2332** is always aligned to at least an 8 byte boundary, or to a 2333** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2334** option is used. 2335** 2336** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2337** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2338** implementation of these routines to be omitted. That capability 2339** is no longer provided. Only built-in memory allocators can be used. 2340** 2341** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2342** the system malloc() and free() directly when converting 2343** filenames between the UTF-8 encoding used by SQLite 2344** and whatever filename encoding is used by the particular Windows 2345** installation. Memory allocation errors were detected, but 2346** they were reported back as [SQLITE_CANTOPEN] or 2347** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2348** 2349** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2350** must be either NULL or else pointers obtained from a prior 2351** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2352** not yet been released. 2353** 2354** The application must not read or write any part of 2355** a block of memory after it has been released using 2356** [sqlite3_free()] or [sqlite3_realloc()]. 2357*/ 2358void *sqlite3_malloc(int); 2359void *sqlite3_realloc(void*, int); 2360void sqlite3_free(void*); 2361 2362/* 2363** CAPI3REF: Memory Allocator Statistics 2364** 2365** SQLite provides these two interfaces for reporting on the status 2366** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2367** routines, which form the built-in memory allocation subsystem. 2368** 2369** ^The [sqlite3_memory_used()] routine returns the number of bytes 2370** of memory currently outstanding (malloced but not freed). 2371** ^The [sqlite3_memory_highwater()] routine returns the maximum 2372** value of [sqlite3_memory_used()] since the high-water mark 2373** was last reset. ^The values returned by [sqlite3_memory_used()] and 2374** [sqlite3_memory_highwater()] include any overhead 2375** added by SQLite in its implementation of [sqlite3_malloc()], 2376** but not overhead added by the any underlying system library 2377** routines that [sqlite3_malloc()] may call. 2378** 2379** ^The memory high-water mark is reset to the current value of 2380** [sqlite3_memory_used()] if and only if the parameter to 2381** [sqlite3_memory_highwater()] is true. ^The value returned 2382** by [sqlite3_memory_highwater(1)] is the high-water mark 2383** prior to the reset. 2384*/ 2385sqlite3_int64 sqlite3_memory_used(void); 2386sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2387 2388/* 2389** CAPI3REF: Pseudo-Random Number Generator 2390** 2391** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2392** select random [ROWID | ROWIDs] when inserting new records into a table that 2393** already uses the largest possible [ROWID]. The PRNG is also used for 2394** the build-in random() and randomblob() SQL functions. This interface allows 2395** applications to access the same PRNG for other purposes. 2396** 2397** ^A call to this routine stores N bytes of randomness into buffer P. 2398** ^If N is less than one, then P can be a NULL pointer. 2399** 2400** ^If this routine has not been previously called or if the previous 2401** call had N less than one, then the PRNG is seeded using randomness 2402** obtained from the xRandomness method of the default [sqlite3_vfs] object. 2403** ^If the previous call to this routine had an N of 1 or more then 2404** the pseudo-randomness is generated 2405** internally and without recourse to the [sqlite3_vfs] xRandomness 2406** method. 2407*/ 2408void sqlite3_randomness(int N, void *P); 2409 2410/* 2411** CAPI3REF: Compile-Time Authorization Callbacks 2412** 2413** ^This routine registers an authorizer callback with a particular 2414** [database connection], supplied in the first argument. 2415** ^The authorizer callback is invoked as SQL statements are being compiled 2416** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2417** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2418** points during the compilation process, as logic is being created 2419** to perform various actions, the authorizer callback is invoked to 2420** see if those actions are allowed. ^The authorizer callback should 2421** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2422** specific action but allow the SQL statement to continue to be 2423** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2424** rejected with an error. ^If the authorizer callback returns 2425** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2426** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2427** the authorizer will fail with an error message. 2428** 2429** When the callback returns [SQLITE_OK], that means the operation 2430** requested is ok. ^When the callback returns [SQLITE_DENY], the 2431** [sqlite3_prepare_v2()] or equivalent call that triggered the 2432** authorizer will fail with an error message explaining that 2433** access is denied. 2434** 2435** ^The first parameter to the authorizer callback is a copy of the third 2436** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2437** to the callback is an integer [SQLITE_COPY | action code] that specifies 2438** the particular action to be authorized. ^The third through sixth parameters 2439** to the callback are zero-terminated strings that contain additional 2440** details about the action to be authorized. 2441** 2442** ^If the action code is [SQLITE_READ] 2443** and the callback returns [SQLITE_IGNORE] then the 2444** [prepared statement] statement is constructed to substitute 2445** a NULL value in place of the table column that would have 2446** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2447** return can be used to deny an untrusted user access to individual 2448** columns of a table. 2449** ^If the action code is [SQLITE_DELETE] and the callback returns 2450** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2451** [truncate optimization] is disabled and all rows are deleted individually. 2452** 2453** An authorizer is used when [sqlite3_prepare | preparing] 2454** SQL statements from an untrusted source, to ensure that the SQL statements 2455** do not try to access data they are not allowed to see, or that they do not 2456** try to execute malicious statements that damage the database. For 2457** example, an application may allow a user to enter arbitrary 2458** SQL queries for evaluation by a database. But the application does 2459** not want the user to be able to make arbitrary changes to the 2460** database. An authorizer could then be put in place while the 2461** user-entered SQL is being [sqlite3_prepare | prepared] that 2462** disallows everything except [SELECT] statements. 2463** 2464** Applications that need to process SQL from untrusted sources 2465** might also consider lowering resource limits using [sqlite3_limit()] 2466** and limiting database size using the [max_page_count] [PRAGMA] 2467** in addition to using an authorizer. 2468** 2469** ^(Only a single authorizer can be in place on a database connection 2470** at a time. Each call to sqlite3_set_authorizer overrides the 2471** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2472** The authorizer is disabled by default. 2473** 2474** The authorizer callback must not do anything that will modify 2475** the database connection that invoked the authorizer callback. 2476** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2477** database connections for the meaning of "modify" in this paragraph. 2478** 2479** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2480** statement might be re-prepared during [sqlite3_step()] due to a 2481** schema change. Hence, the application should ensure that the 2482** correct authorizer callback remains in place during the [sqlite3_step()]. 2483** 2484** ^Note that the authorizer callback is invoked only during 2485** [sqlite3_prepare()] or its variants. Authorization is not 2486** performed during statement evaluation in [sqlite3_step()], unless 2487** as stated in the previous paragraph, sqlite3_step() invokes 2488** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2489*/ 2490int sqlite3_set_authorizer( 2491 sqlite3*, 2492 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2493 void *pUserData 2494); 2495 2496/* 2497** CAPI3REF: Authorizer Return Codes 2498** 2499** The [sqlite3_set_authorizer | authorizer callback function] must 2500** return either [SQLITE_OK] or one of these two constants in order 2501** to signal SQLite whether or not the action is permitted. See the 2502** [sqlite3_set_authorizer | authorizer documentation] for additional 2503** information. 2504** 2505** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2506** from the [sqlite3_vtab_on_conflict()] interface. 2507*/ 2508#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2509#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2510 2511/* 2512** CAPI3REF: Authorizer Action Codes 2513** 2514** The [sqlite3_set_authorizer()] interface registers a callback function 2515** that is invoked to authorize certain SQL statement actions. The 2516** second parameter to the callback is an integer code that specifies 2517** what action is being authorized. These are the integer action codes that 2518** the authorizer callback may be passed. 2519** 2520** These action code values signify what kind of operation is to be 2521** authorized. The 3rd and 4th parameters to the authorization 2522** callback function will be parameters or NULL depending on which of these 2523** codes is used as the second parameter. ^(The 5th parameter to the 2524** authorizer callback is the name of the database ("main", "temp", 2525** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2526** is the name of the inner-most trigger or view that is responsible for 2527** the access attempt or NULL if this access attempt is directly from 2528** top-level SQL code. 2529*/ 2530/******************************************* 3rd ************ 4th ***********/ 2531#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2532#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2533#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2534#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2535#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2536#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2537#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2538#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2539#define SQLITE_DELETE 9 /* Table Name NULL */ 2540#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2541#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2542#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2543#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2544#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2545#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2546#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2547#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2548#define SQLITE_INSERT 18 /* Table Name NULL */ 2549#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2550#define SQLITE_READ 20 /* Table Name Column Name */ 2551#define SQLITE_SELECT 21 /* NULL NULL */ 2552#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2553#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2554#define SQLITE_ATTACH 24 /* Filename NULL */ 2555#define SQLITE_DETACH 25 /* Database Name NULL */ 2556#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2557#define SQLITE_REINDEX 27 /* Index Name NULL */ 2558#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2559#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2560#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2561#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2562#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2563#define SQLITE_COPY 0 /* No longer used */ 2564#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2565 2566/* 2567** CAPI3REF: Tracing And Profiling Functions 2568** 2569** These routines register callback functions that can be used for 2570** tracing and profiling the execution of SQL statements. 2571** 2572** ^The callback function registered by sqlite3_trace() is invoked at 2573** various times when an SQL statement is being run by [sqlite3_step()]. 2574** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2575** SQL statement text as the statement first begins executing. 2576** ^(Additional sqlite3_trace() callbacks might occur 2577** as each triggered subprogram is entered. The callbacks for triggers 2578** contain a UTF-8 SQL comment that identifies the trigger.)^ 2579** 2580** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2581** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2582** 2583** ^The callback function registered by sqlite3_profile() is invoked 2584** as each SQL statement finishes. ^The profile callback contains 2585** the original statement text and an estimate of wall-clock time 2586** of how long that statement took to run. ^The profile callback 2587** time is in units of nanoseconds, however the current implementation 2588** is only capable of millisecond resolution so the six least significant 2589** digits in the time are meaningless. Future versions of SQLite 2590** might provide greater resolution on the profiler callback. The 2591** sqlite3_profile() function is considered experimental and is 2592** subject to change in future versions of SQLite. 2593*/ 2594void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2595SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2596 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2597 2598/* 2599** CAPI3REF: Query Progress Callbacks 2600** 2601** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2602** function X to be invoked periodically during long running calls to 2603** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2604** database connection D. An example use for this 2605** interface is to keep a GUI updated during a large query. 2606** 2607** ^The parameter P is passed through as the only parameter to the 2608** callback function X. ^The parameter N is the approximate number of 2609** [virtual machine instructions] that are evaluated between successive 2610** invocations of the callback X. ^If N is less than one then the progress 2611** handler is disabled. 2612** 2613** ^Only a single progress handler may be defined at one time per 2614** [database connection]; setting a new progress handler cancels the 2615** old one. ^Setting parameter X to NULL disables the progress handler. 2616** ^The progress handler is also disabled by setting N to a value less 2617** than 1. 2618** 2619** ^If the progress callback returns non-zero, the operation is 2620** interrupted. This feature can be used to implement a 2621** "Cancel" button on a GUI progress dialog box. 2622** 2623** The progress handler callback must not do anything that will modify 2624** the database connection that invoked the progress handler. 2625** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2626** database connections for the meaning of "modify" in this paragraph. 2627** 2628*/ 2629void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2630 2631/* 2632** CAPI3REF: Opening A New Database Connection 2633** 2634** ^These routines open an SQLite database file as specified by the 2635** filename argument. ^The filename argument is interpreted as UTF-8 for 2636** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2637** order for sqlite3_open16(). ^(A [database connection] handle is usually 2638** returned in *ppDb, even if an error occurs. The only exception is that 2639** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2640** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2641** object.)^ ^(If the database is opened (and/or created) successfully, then 2642** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2643** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2644** an English language description of the error following a failure of any 2645** of the sqlite3_open() routines. 2646** 2647** ^The default encoding for the database will be UTF-8 if 2648** sqlite3_open() or sqlite3_open_v2() is called and 2649** UTF-16 in the native byte order if sqlite3_open16() is used. 2650** 2651** Whether or not an error occurs when it is opened, resources 2652** associated with the [database connection] handle should be released by 2653** passing it to [sqlite3_close()] when it is no longer required. 2654** 2655** The sqlite3_open_v2() interface works like sqlite3_open() 2656** except that it accepts two additional parameters for additional control 2657** over the new database connection. ^(The flags parameter to 2658** sqlite3_open_v2() can take one of 2659** the following three values, optionally combined with the 2660** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2661** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2662** 2663** <dl> 2664** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2665** <dd>The database is opened in read-only mode. If the database does not 2666** already exist, an error is returned.</dd>)^ 2667** 2668** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2669** <dd>The database is opened for reading and writing if possible, or reading 2670** only if the file is write protected by the operating system. In either 2671** case the database must already exist, otherwise an error is returned.</dd>)^ 2672** 2673** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2674** <dd>The database is opened for reading and writing, and is created if 2675** it does not already exist. This is the behavior that is always used for 2676** sqlite3_open() and sqlite3_open16().</dd>)^ 2677** </dl> 2678** 2679** If the 3rd parameter to sqlite3_open_v2() is not one of the 2680** combinations shown above optionally combined with other 2681** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2682** then the behavior is undefined. 2683** 2684** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2685** opens in the multi-thread [threading mode] as long as the single-thread 2686** mode has not been set at compile-time or start-time. ^If the 2687** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2688** in the serialized [threading mode] unless single-thread was 2689** previously selected at compile-time or start-time. 2690** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2691** eligible to use [shared cache mode], regardless of whether or not shared 2692** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2693** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2694** participate in [shared cache mode] even if it is enabled. 2695** 2696** ^The fourth parameter to sqlite3_open_v2() is the name of the 2697** [sqlite3_vfs] object that defines the operating system interface that 2698** the new database connection should use. ^If the fourth parameter is 2699** a NULL pointer then the default [sqlite3_vfs] object is used. 2700** 2701** ^If the filename is ":memory:", then a private, temporary in-memory database 2702** is created for the connection. ^This in-memory database will vanish when 2703** the database connection is closed. Future versions of SQLite might 2704** make use of additional special filenames that begin with the ":" character. 2705** It is recommended that when a database filename actually does begin with 2706** a ":" character you should prefix the filename with a pathname such as 2707** "./" to avoid ambiguity. 2708** 2709** ^If the filename is an empty string, then a private, temporary 2710** on-disk database will be created. ^This private database will be 2711** automatically deleted as soon as the database connection is closed. 2712** 2713** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2714** 2715** ^If [URI filename] interpretation is enabled, and the filename argument 2716** begins with "file:", then the filename is interpreted as a URI. ^URI 2717** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2718** set in the fourth argument to sqlite3_open_v2(), or if it has 2719** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2720** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2721** As of SQLite version 3.7.7, URI filename interpretation is turned off 2722** by default, but future releases of SQLite might enable URI filename 2723** interpretation by default. See "[URI filenames]" for additional 2724** information. 2725** 2726** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2727** authority, then it must be either an empty string or the string 2728** "localhost". ^If the authority is not an empty string or "localhost", an 2729** error is returned to the caller. ^The fragment component of a URI, if 2730** present, is ignored. 2731** 2732** ^SQLite uses the path component of the URI as the name of the disk file 2733** which contains the database. ^If the path begins with a '/' character, 2734** then it is interpreted as an absolute path. ^If the path does not begin 2735** with a '/' (meaning that the authority section is omitted from the URI) 2736** then the path is interpreted as a relative path. 2737** ^On windows, the first component of an absolute path 2738** is a drive specification (e.g. "C:"). 2739** 2740** [[core URI query parameters]] 2741** The query component of a URI may contain parameters that are interpreted 2742** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2743** SQLite interprets the following three query parameters: 2744** 2745** <ul> 2746** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2747** a VFS object that provides the operating system interface that should 2748** be used to access the database file on disk. ^If this option is set to 2749** an empty string the default VFS object is used. ^Specifying an unknown 2750** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2751** present, then the VFS specified by the option takes precedence over 2752** the value passed as the fourth parameter to sqlite3_open_v2(). 2753** 2754** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2755** "rwc", or "memory". Attempting to set it to any other value is 2756** an error)^. 2757** ^If "ro" is specified, then the database is opened for read-only 2758** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2759** third argument to sqlite3_open_v2(). ^If the mode option is set to 2760** "rw", then the database is opened for read-write (but not create) 2761** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2762** been set. ^Value "rwc" is equivalent to setting both 2763** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2764** set to "memory" then a pure [in-memory database] that never reads 2765** or writes from disk is used. ^It is an error to specify a value for 2766** the mode parameter that is less restrictive than that specified by 2767** the flags passed in the third parameter to sqlite3_open_v2(). 2768** 2769** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2770** "private". ^Setting it to "shared" is equivalent to setting the 2771** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2772** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2773** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2774** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2775** a URI filename, its value overrides any behavior requested by setting 2776** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2777** </ul> 2778** 2779** ^Specifying an unknown parameter in the query component of a URI is not an 2780** error. Future versions of SQLite might understand additional query 2781** parameters. See "[query parameters with special meaning to SQLite]" for 2782** additional information. 2783** 2784** [[URI filename examples]] <h3>URI filename examples</h3> 2785** 2786** <table border="1" align=center cellpadding=5> 2787** <tr><th> URI filenames <th> Results 2788** <tr><td> file:data.db <td> 2789** Open the file "data.db" in the current directory. 2790** <tr><td> file:/home/fred/data.db<br> 2791** file:///home/fred/data.db <br> 2792** file://localhost/home/fred/data.db <br> <td> 2793** Open the database file "/home/fred/data.db". 2794** <tr><td> file://darkstar/home/fred/data.db <td> 2795** An error. "darkstar" is not a recognized authority. 2796** <tr><td style="white-space:nowrap"> 2797** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2798** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2799** C:. Note that the %20 escaping in this example is not strictly 2800** necessary - space characters can be used literally 2801** in URI filenames. 2802** <tr><td> file:data.db?mode=ro&cache=private <td> 2803** Open file "data.db" in the current directory for read-only access. 2804** Regardless of whether or not shared-cache mode is enabled by 2805** default, use a private cache. 2806** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2807** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2808** <tr><td> file:data.db?mode=readonly <td> 2809** An error. "readonly" is not a valid option for the "mode" parameter. 2810** </table> 2811** 2812** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2813** query components of a URI. A hexadecimal escape sequence consists of a 2814** percent sign - "%" - followed by exactly two hexadecimal digits 2815** specifying an octet value. ^Before the path or query components of a 2816** URI filename are interpreted, they are encoded using UTF-8 and all 2817** hexadecimal escape sequences replaced by a single byte containing the 2818** corresponding octet. If this process generates an invalid UTF-8 encoding, 2819** the results are undefined. 2820** 2821** <b>Note to Windows users:</b> The encoding used for the filename argument 2822** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2823** codepage is currently defined. Filenames containing international 2824** characters must be converted to UTF-8 prior to passing them into 2825** sqlite3_open() or sqlite3_open_v2(). 2826** 2827** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2828** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2829** features that require the use of temporary files may fail. 2830** 2831** See also: [sqlite3_temp_directory] 2832*/ 2833int sqlite3_open( 2834 const char *filename, /* Database filename (UTF-8) */ 2835 sqlite3 **ppDb /* OUT: SQLite db handle */ 2836); 2837int sqlite3_open16( 2838 const void *filename, /* Database filename (UTF-16) */ 2839 sqlite3 **ppDb /* OUT: SQLite db handle */ 2840); 2841int sqlite3_open_v2( 2842 const char *filename, /* Database filename (UTF-8) */ 2843 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2844 int flags, /* Flags */ 2845 const char *zVfs /* Name of VFS module to use */ 2846); 2847 2848/* 2849** CAPI3REF: Obtain Values For URI Parameters 2850** 2851** These are utility routines, useful to VFS implementations, that check 2852** to see if a database file was a URI that contained a specific query 2853** parameter, and if so obtains the value of that query parameter. 2854** 2855** If F is the database filename pointer passed into the xOpen() method of 2856** a VFS implementation when the flags parameter to xOpen() has one or 2857** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2858** P is the name of the query parameter, then 2859** sqlite3_uri_parameter(F,P) returns the value of the P 2860** parameter if it exists or a NULL pointer if P does not appear as a 2861** query parameter on F. If P is a query parameter of F 2862** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2863** a pointer to an empty string. 2864** 2865** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2866** parameter and returns true (1) or false (0) according to the value 2867** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2868** value of query parameter P is one of "yes", "true", or "on" in any 2869** case or if the value begins with a non-zero number. The 2870** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2871** query parameter P is one of "no", "false", or "off" in any case or 2872** if the value begins with a numeric zero. If P is not a query 2873** parameter on F or if the value of P is does not match any of the 2874** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2875** 2876** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2877** 64-bit signed integer and returns that integer, or D if P does not 2878** exist. If the value of P is something other than an integer, then 2879** zero is returned. 2880** 2881** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2882** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2883** is not a database file pathname pointer that SQLite passed into the xOpen 2884** VFS method, then the behavior of this routine is undefined and probably 2885** undesirable. 2886*/ 2887const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2888int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2889sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2890 2891 2892/* 2893** CAPI3REF: Error Codes And Messages 2894** 2895** ^The sqlite3_errcode() interface returns the numeric [result code] or 2896** [extended result code] for the most recent failed sqlite3_* API call 2897** associated with a [database connection]. If a prior API call failed 2898** but the most recent API call succeeded, the return value from 2899** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2900** interface is the same except that it always returns the 2901** [extended result code] even when extended result codes are 2902** disabled. 2903** 2904** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2905** text that describes the error, as either UTF-8 or UTF-16 respectively. 2906** ^(Memory to hold the error message string is managed internally. 2907** The application does not need to worry about freeing the result. 2908** However, the error string might be overwritten or deallocated by 2909** subsequent calls to other SQLite interface functions.)^ 2910** 2911** ^The sqlite3_errstr() interface returns the English-language text 2912** that describes the [result code], as UTF-8. 2913** ^(Memory to hold the error message string is managed internally 2914** and must not be freed by the application)^. 2915** 2916** When the serialized [threading mode] is in use, it might be the 2917** case that a second error occurs on a separate thread in between 2918** the time of the first error and the call to these interfaces. 2919** When that happens, the second error will be reported since these 2920** interfaces always report the most recent result. To avoid 2921** this, each thread can obtain exclusive use of the [database connection] D 2922** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2923** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2924** all calls to the interfaces listed here are completed. 2925** 2926** If an interface fails with SQLITE_MISUSE, that means the interface 2927** was invoked incorrectly by the application. In that case, the 2928** error code and message may or may not be set. 2929*/ 2930int sqlite3_errcode(sqlite3 *db); 2931int sqlite3_extended_errcode(sqlite3 *db); 2932const char *sqlite3_errmsg(sqlite3*); 2933const void *sqlite3_errmsg16(sqlite3*); 2934const char *sqlite3_errstr(int); 2935 2936/* 2937** CAPI3REF: SQL Statement Object 2938** KEYWORDS: {prepared statement} {prepared statements} 2939** 2940** An instance of this object represents a single SQL statement. 2941** This object is variously known as a "prepared statement" or a 2942** "compiled SQL statement" or simply as a "statement". 2943** 2944** The life of a statement object goes something like this: 2945** 2946** <ol> 2947** <li> Create the object using [sqlite3_prepare_v2()] or a related 2948** function. 2949** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2950** interfaces. 2951** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2952** <li> Reset the statement using [sqlite3_reset()] then go back 2953** to step 2. Do this zero or more times. 2954** <li> Destroy the object using [sqlite3_finalize()]. 2955** </ol> 2956** 2957** Refer to documentation on individual methods above for additional 2958** information. 2959*/ 2960typedef struct sqlite3_stmt sqlite3_stmt; 2961 2962/* 2963** CAPI3REF: Run-time Limits 2964** 2965** ^(This interface allows the size of various constructs to be limited 2966** on a connection by connection basis. The first parameter is the 2967** [database connection] whose limit is to be set or queried. The 2968** second parameter is one of the [limit categories] that define a 2969** class of constructs to be size limited. The third parameter is the 2970** new limit for that construct.)^ 2971** 2972** ^If the new limit is a negative number, the limit is unchanged. 2973** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2974** [limits | hard upper bound] 2975** set at compile-time by a C preprocessor macro called 2976** [limits | SQLITE_MAX_<i>NAME</i>]. 2977** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2978** ^Attempts to increase a limit above its hard upper bound are 2979** silently truncated to the hard upper bound. 2980** 2981** ^Regardless of whether or not the limit was changed, the 2982** [sqlite3_limit()] interface returns the prior value of the limit. 2983** ^Hence, to find the current value of a limit without changing it, 2984** simply invoke this interface with the third parameter set to -1. 2985** 2986** Run-time limits are intended for use in applications that manage 2987** both their own internal database and also databases that are controlled 2988** by untrusted external sources. An example application might be a 2989** web browser that has its own databases for storing history and 2990** separate databases controlled by JavaScript applications downloaded 2991** off the Internet. The internal databases can be given the 2992** large, default limits. Databases managed by external sources can 2993** be given much smaller limits designed to prevent a denial of service 2994** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2995** interface to further control untrusted SQL. The size of the database 2996** created by an untrusted script can be contained using the 2997** [max_page_count] [PRAGMA]. 2998** 2999** New run-time limit categories may be added in future releases. 3000*/ 3001int sqlite3_limit(sqlite3*, int id, int newVal); 3002 3003/* 3004** CAPI3REF: Run-Time Limit Categories 3005** KEYWORDS: {limit category} {*limit categories} 3006** 3007** These constants define various performance limits 3008** that can be lowered at run-time using [sqlite3_limit()]. 3009** The synopsis of the meanings of the various limits is shown below. 3010** Additional information is available at [limits | Limits in SQLite]. 3011** 3012** <dl> 3013** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3014** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3015** 3016** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3017** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3018** 3019** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3020** <dd>The maximum number of columns in a table definition or in the 3021** result set of a [SELECT] or the maximum number of columns in an index 3022** or in an ORDER BY or GROUP BY clause.</dd>)^ 3023** 3024** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3025** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3026** 3027** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3028** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3029** 3030** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3031** <dd>The maximum number of instructions in a virtual machine program 3032** used to implement an SQL statement. This limit is not currently 3033** enforced, though that might be added in some future release of 3034** SQLite.</dd>)^ 3035** 3036** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3037** <dd>The maximum number of arguments on a function.</dd>)^ 3038** 3039** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3040** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3041** 3042** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3043** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3044** <dd>The maximum length of the pattern argument to the [LIKE] or 3045** [GLOB] operators.</dd>)^ 3046** 3047** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3048** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3049** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3050** 3051** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3052** <dd>The maximum depth of recursion for triggers.</dd>)^ 3053** </dl> 3054*/ 3055#define SQLITE_LIMIT_LENGTH 0 3056#define SQLITE_LIMIT_SQL_LENGTH 1 3057#define SQLITE_LIMIT_COLUMN 2 3058#define SQLITE_LIMIT_EXPR_DEPTH 3 3059#define SQLITE_LIMIT_COMPOUND_SELECT 4 3060#define SQLITE_LIMIT_VDBE_OP 5 3061#define SQLITE_LIMIT_FUNCTION_ARG 6 3062#define SQLITE_LIMIT_ATTACHED 7 3063#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3064#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3065#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3066 3067/* 3068** CAPI3REF: Compiling An SQL Statement 3069** KEYWORDS: {SQL statement compiler} 3070** 3071** To execute an SQL query, it must first be compiled into a byte-code 3072** program using one of these routines. 3073** 3074** The first argument, "db", is a [database connection] obtained from a 3075** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3076** [sqlite3_open16()]. The database connection must not have been closed. 3077** 3078** The second argument, "zSql", is the statement to be compiled, encoded 3079** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3080** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3081** use UTF-16. 3082** 3083** ^If the nByte argument is less than zero, then zSql is read up to the 3084** first zero terminator. ^If nByte is non-negative, then it is the maximum 3085** number of bytes read from zSql. ^When nByte is non-negative, the 3086** zSql string ends at either the first '\000' or '\u0000' character or 3087** the nByte-th byte, whichever comes first. If the caller knows 3088** that the supplied string is nul-terminated, then there is a small 3089** performance advantage to be gained by passing an nByte parameter that 3090** is equal to the number of bytes in the input string <i>including</i> 3091** the nul-terminator bytes as this saves SQLite from having to 3092** make a copy of the input string. 3093** 3094** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3095** past the end of the first SQL statement in zSql. These routines only 3096** compile the first statement in zSql, so *pzTail is left pointing to 3097** what remains uncompiled. 3098** 3099** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3100** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3101** to NULL. ^If the input text contains no SQL (if the input is an empty 3102** string or a comment) then *ppStmt is set to NULL. 3103** The calling procedure is responsible for deleting the compiled 3104** SQL statement using [sqlite3_finalize()] after it has finished with it. 3105** ppStmt may not be NULL. 3106** 3107** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3108** otherwise an [error code] is returned. 3109** 3110** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3111** recommended for all new programs. The two older interfaces are retained 3112** for backwards compatibility, but their use is discouraged. 3113** ^In the "v2" interfaces, the prepared statement 3114** that is returned (the [sqlite3_stmt] object) contains a copy of the 3115** original SQL text. This causes the [sqlite3_step()] interface to 3116** behave differently in three ways: 3117** 3118** <ol> 3119** <li> 3120** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3121** always used to do, [sqlite3_step()] will automatically recompile the SQL 3122** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3123** retries will occur before sqlite3_step() gives up and returns an error. 3124** </li> 3125** 3126** <li> 3127** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3128** [error codes] or [extended error codes]. ^The legacy behavior was that 3129** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3130** and the application would have to make a second call to [sqlite3_reset()] 3131** in order to find the underlying cause of the problem. With the "v2" prepare 3132** interfaces, the underlying reason for the error is returned immediately. 3133** </li> 3134** 3135** <li> 3136** ^If the specific value bound to [parameter | host parameter] in the 3137** WHERE clause might influence the choice of query plan for a statement, 3138** then the statement will be automatically recompiled, as if there had been 3139** a schema change, on the first [sqlite3_step()] call following any change 3140** to the [sqlite3_bind_text | bindings] of that [parameter]. 3141** ^The specific value of WHERE-clause [parameter] might influence the 3142** choice of query plan if the parameter is the left-hand side of a [LIKE] 3143** or [GLOB] operator or if the parameter is compared to an indexed column 3144** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3145** </li> 3146** </ol> 3147*/ 3148int sqlite3_prepare( 3149 sqlite3 *db, /* Database handle */ 3150 const char *zSql, /* SQL statement, UTF-8 encoded */ 3151 int nByte, /* Maximum length of zSql in bytes. */ 3152 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3153 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3154); 3155int sqlite3_prepare_v2( 3156 sqlite3 *db, /* Database handle */ 3157 const char *zSql, /* SQL statement, UTF-8 encoded */ 3158 int nByte, /* Maximum length of zSql in bytes. */ 3159 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3160 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3161); 3162int sqlite3_prepare16( 3163 sqlite3 *db, /* Database handle */ 3164 const void *zSql, /* SQL statement, UTF-16 encoded */ 3165 int nByte, /* Maximum length of zSql in bytes. */ 3166 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3167 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3168); 3169int sqlite3_prepare16_v2( 3170 sqlite3 *db, /* Database handle */ 3171 const void *zSql, /* SQL statement, UTF-16 encoded */ 3172 int nByte, /* Maximum length of zSql in bytes. */ 3173 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3174 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3175); 3176 3177/* 3178** CAPI3REF: Retrieving Statement SQL 3179** 3180** ^This interface can be used to retrieve a saved copy of the original 3181** SQL text used to create a [prepared statement] if that statement was 3182** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3183*/ 3184const char *sqlite3_sql(sqlite3_stmt *pStmt); 3185 3186/* 3187** CAPI3REF: Determine If An SQL Statement Writes The Database 3188** 3189** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3190** and only if the [prepared statement] X makes no direct changes to 3191** the content of the database file. 3192** 3193** Note that [application-defined SQL functions] or 3194** [virtual tables] might change the database indirectly as a side effect. 3195** ^(For example, if an application defines a function "eval()" that 3196** calls [sqlite3_exec()], then the following SQL statement would 3197** change the database file through side-effects: 3198** 3199** <blockquote><pre> 3200** SELECT eval('DELETE FROM t1') FROM t2; 3201** </pre></blockquote> 3202** 3203** But because the [SELECT] statement does not change the database file 3204** directly, sqlite3_stmt_readonly() would still return true.)^ 3205** 3206** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3207** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3208** since the statements themselves do not actually modify the database but 3209** rather they control the timing of when other statements modify the 3210** database. ^The [ATTACH] and [DETACH] statements also cause 3211** sqlite3_stmt_readonly() to return true since, while those statements 3212** change the configuration of a database connection, they do not make 3213** changes to the content of the database files on disk. 3214*/ 3215int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3216 3217/* 3218** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3219** 3220** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3221** [prepared statement] S has been stepped at least once using 3222** [sqlite3_step(S)] but has not run to completion and/or has not 3223** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3224** interface returns false if S is a NULL pointer. If S is not a 3225** NULL pointer and is not a pointer to a valid [prepared statement] 3226** object, then the behavior is undefined and probably undesirable. 3227** 3228** This interface can be used in combination [sqlite3_next_stmt()] 3229** to locate all prepared statements associated with a database 3230** connection that are in need of being reset. This can be used, 3231** for example, in diagnostic routines to search for prepared 3232** statements that are holding a transaction open. 3233*/ 3234int sqlite3_stmt_busy(sqlite3_stmt*); 3235 3236/* 3237** CAPI3REF: Dynamically Typed Value Object 3238** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3239** 3240** SQLite uses the sqlite3_value object to represent all values 3241** that can be stored in a database table. SQLite uses dynamic typing 3242** for the values it stores. ^Values stored in sqlite3_value objects 3243** can be integers, floating point values, strings, BLOBs, or NULL. 3244** 3245** An sqlite3_value object may be either "protected" or "unprotected". 3246** Some interfaces require a protected sqlite3_value. Other interfaces 3247** will accept either a protected or an unprotected sqlite3_value. 3248** Every interface that accepts sqlite3_value arguments specifies 3249** whether or not it requires a protected sqlite3_value. 3250** 3251** The terms "protected" and "unprotected" refer to whether or not 3252** a mutex is held. An internal mutex is held for a protected 3253** sqlite3_value object but no mutex is held for an unprotected 3254** sqlite3_value object. If SQLite is compiled to be single-threaded 3255** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3256** or if SQLite is run in one of reduced mutex modes 3257** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3258** then there is no distinction between protected and unprotected 3259** sqlite3_value objects and they can be used interchangeably. However, 3260** for maximum code portability it is recommended that applications 3261** still make the distinction between protected and unprotected 3262** sqlite3_value objects even when not strictly required. 3263** 3264** ^The sqlite3_value objects that are passed as parameters into the 3265** implementation of [application-defined SQL functions] are protected. 3266** ^The sqlite3_value object returned by 3267** [sqlite3_column_value()] is unprotected. 3268** Unprotected sqlite3_value objects may only be used with 3269** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3270** The [sqlite3_value_blob | sqlite3_value_type()] family of 3271** interfaces require protected sqlite3_value objects. 3272*/ 3273typedef struct Mem sqlite3_value; 3274 3275/* 3276** CAPI3REF: SQL Function Context Object 3277** 3278** The context in which an SQL function executes is stored in an 3279** sqlite3_context object. ^A pointer to an sqlite3_context object 3280** is always first parameter to [application-defined SQL functions]. 3281** The application-defined SQL function implementation will pass this 3282** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3283** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3284** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3285** and/or [sqlite3_set_auxdata()]. 3286*/ 3287typedef struct sqlite3_context sqlite3_context; 3288 3289/* 3290** CAPI3REF: Binding Values To Prepared Statements 3291** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3292** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3293** 3294** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3295** literals may be replaced by a [parameter] that matches one of following 3296** templates: 3297** 3298** <ul> 3299** <li> ? 3300** <li> ?NNN 3301** <li> :VVV 3302** <li> @VVV 3303** <li> $VVV 3304** </ul> 3305** 3306** In the templates above, NNN represents an integer literal, 3307** and VVV represents an alphanumeric identifier.)^ ^The values of these 3308** parameters (also called "host parameter names" or "SQL parameters") 3309** can be set using the sqlite3_bind_*() routines defined here. 3310** 3311** ^The first argument to the sqlite3_bind_*() routines is always 3312** a pointer to the [sqlite3_stmt] object returned from 3313** [sqlite3_prepare_v2()] or its variants. 3314** 3315** ^The second argument is the index of the SQL parameter to be set. 3316** ^The leftmost SQL parameter has an index of 1. ^When the same named 3317** SQL parameter is used more than once, second and subsequent 3318** occurrences have the same index as the first occurrence. 3319** ^The index for named parameters can be looked up using the 3320** [sqlite3_bind_parameter_index()] API if desired. ^The index 3321** for "?NNN" parameters is the value of NNN. 3322** ^The NNN value must be between 1 and the [sqlite3_limit()] 3323** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3324** 3325** ^The third argument is the value to bind to the parameter. 3326** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3327** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3328** is ignored and the end result is the same as sqlite3_bind_null(). 3329** 3330** ^(In those routines that have a fourth argument, its value is the 3331** number of bytes in the parameter. To be clear: the value is the 3332** number of <u>bytes</u> in the value, not the number of characters.)^ 3333** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3334** is negative, then the length of the string is 3335** the number of bytes up to the first zero terminator. 3336** If the fourth parameter to sqlite3_bind_blob() is negative, then 3337** the behavior is undefined. 3338** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3339** or sqlite3_bind_text16() then that parameter must be the byte offset 3340** where the NUL terminator would occur assuming the string were NUL 3341** terminated. If any NUL characters occur at byte offsets less than 3342** the value of the fourth parameter then the resulting string value will 3343** contain embedded NULs. The result of expressions involving strings 3344** with embedded NULs is undefined. 3345** 3346** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3347** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3348** string after SQLite has finished with it. ^The destructor is called 3349** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3350** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3351** ^If the fifth argument is 3352** the special value [SQLITE_STATIC], then SQLite assumes that the 3353** information is in static, unmanaged space and does not need to be freed. 3354** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3355** SQLite makes its own private copy of the data immediately, before 3356** the sqlite3_bind_*() routine returns. 3357** 3358** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3359** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3360** (just an integer to hold its size) while it is being processed. 3361** Zeroblobs are intended to serve as placeholders for BLOBs whose 3362** content is later written using 3363** [sqlite3_blob_open | incremental BLOB I/O] routines. 3364** ^A negative value for the zeroblob results in a zero-length BLOB. 3365** 3366** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3367** for the [prepared statement] or with a prepared statement for which 3368** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3369** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3370** routine is passed a [prepared statement] that has been finalized, the 3371** result is undefined and probably harmful. 3372** 3373** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3374** ^Unbound parameters are interpreted as NULL. 3375** 3376** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3377** [error code] if anything goes wrong. 3378** ^[SQLITE_RANGE] is returned if the parameter 3379** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3380** 3381** See also: [sqlite3_bind_parameter_count()], 3382** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3383*/ 3384int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3385int sqlite3_bind_double(sqlite3_stmt*, int, double); 3386int sqlite3_bind_int(sqlite3_stmt*, int, int); 3387int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3388int sqlite3_bind_null(sqlite3_stmt*, int); 3389int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3390int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3391int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3392int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3393 3394/* 3395** CAPI3REF: Number Of SQL Parameters 3396** 3397** ^This routine can be used to find the number of [SQL parameters] 3398** in a [prepared statement]. SQL parameters are tokens of the 3399** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3400** placeholders for values that are [sqlite3_bind_blob | bound] 3401** to the parameters at a later time. 3402** 3403** ^(This routine actually returns the index of the largest (rightmost) 3404** parameter. For all forms except ?NNN, this will correspond to the 3405** number of unique parameters. If parameters of the ?NNN form are used, 3406** there may be gaps in the list.)^ 3407** 3408** See also: [sqlite3_bind_blob|sqlite3_bind()], 3409** [sqlite3_bind_parameter_name()], and 3410** [sqlite3_bind_parameter_index()]. 3411*/ 3412int sqlite3_bind_parameter_count(sqlite3_stmt*); 3413 3414/* 3415** CAPI3REF: Name Of A Host Parameter 3416** 3417** ^The sqlite3_bind_parameter_name(P,N) interface returns 3418** the name of the N-th [SQL parameter] in the [prepared statement] P. 3419** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3420** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3421** respectively. 3422** In other words, the initial ":" or "$" or "@" or "?" 3423** is included as part of the name.)^ 3424** ^Parameters of the form "?" without a following integer have no name 3425** and are referred to as "nameless" or "anonymous parameters". 3426** 3427** ^The first host parameter has an index of 1, not 0. 3428** 3429** ^If the value N is out of range or if the N-th parameter is 3430** nameless, then NULL is returned. ^The returned string is 3431** always in UTF-8 encoding even if the named parameter was 3432** originally specified as UTF-16 in [sqlite3_prepare16()] or 3433** [sqlite3_prepare16_v2()]. 3434** 3435** See also: [sqlite3_bind_blob|sqlite3_bind()], 3436** [sqlite3_bind_parameter_count()], and 3437** [sqlite3_bind_parameter_index()]. 3438*/ 3439const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3440 3441/* 3442** CAPI3REF: Index Of A Parameter With A Given Name 3443** 3444** ^Return the index of an SQL parameter given its name. ^The 3445** index value returned is suitable for use as the second 3446** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3447** is returned if no matching parameter is found. ^The parameter 3448** name must be given in UTF-8 even if the original statement 3449** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3450** 3451** See also: [sqlite3_bind_blob|sqlite3_bind()], 3452** [sqlite3_bind_parameter_count()], and 3453** [sqlite3_bind_parameter_index()]. 3454*/ 3455int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3456 3457/* 3458** CAPI3REF: Reset All Bindings On A Prepared Statement 3459** 3460** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3461** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3462** ^Use this routine to reset all host parameters to NULL. 3463*/ 3464int sqlite3_clear_bindings(sqlite3_stmt*); 3465 3466/* 3467** CAPI3REF: Number Of Columns In A Result Set 3468** 3469** ^Return the number of columns in the result set returned by the 3470** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3471** statement that does not return data (for example an [UPDATE]). 3472** 3473** See also: [sqlite3_data_count()] 3474*/ 3475int sqlite3_column_count(sqlite3_stmt *pStmt); 3476 3477/* 3478** CAPI3REF: Column Names In A Result Set 3479** 3480** ^These routines return the name assigned to a particular column 3481** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3482** interface returns a pointer to a zero-terminated UTF-8 string 3483** and sqlite3_column_name16() returns a pointer to a zero-terminated 3484** UTF-16 string. ^The first parameter is the [prepared statement] 3485** that implements the [SELECT] statement. ^The second parameter is the 3486** column number. ^The leftmost column is number 0. 3487** 3488** ^The returned string pointer is valid until either the [prepared statement] 3489** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3490** reprepared by the first call to [sqlite3_step()] for a particular run 3491** or until the next call to 3492** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3493** 3494** ^If sqlite3_malloc() fails during the processing of either routine 3495** (for example during a conversion from UTF-8 to UTF-16) then a 3496** NULL pointer is returned. 3497** 3498** ^The name of a result column is the value of the "AS" clause for 3499** that column, if there is an AS clause. If there is no AS clause 3500** then the name of the column is unspecified and may change from 3501** one release of SQLite to the next. 3502*/ 3503const char *sqlite3_column_name(sqlite3_stmt*, int N); 3504const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3505 3506/* 3507** CAPI3REF: Source Of Data In A Query Result 3508** 3509** ^These routines provide a means to determine the database, table, and 3510** table column that is the origin of a particular result column in 3511** [SELECT] statement. 3512** ^The name of the database or table or column can be returned as 3513** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3514** the database name, the _table_ routines return the table name, and 3515** the origin_ routines return the column name. 3516** ^The returned string is valid until the [prepared statement] is destroyed 3517** using [sqlite3_finalize()] or until the statement is automatically 3518** reprepared by the first call to [sqlite3_step()] for a particular run 3519** or until the same information is requested 3520** again in a different encoding. 3521** 3522** ^The names returned are the original un-aliased names of the 3523** database, table, and column. 3524** 3525** ^The first argument to these interfaces is a [prepared statement]. 3526** ^These functions return information about the Nth result column returned by 3527** the statement, where N is the second function argument. 3528** ^The left-most column is column 0 for these routines. 3529** 3530** ^If the Nth column returned by the statement is an expression or 3531** subquery and is not a column value, then all of these functions return 3532** NULL. ^These routine might also return NULL if a memory allocation error 3533** occurs. ^Otherwise, they return the name of the attached database, table, 3534** or column that query result column was extracted from. 3535** 3536** ^As with all other SQLite APIs, those whose names end with "16" return 3537** UTF-16 encoded strings and the other functions return UTF-8. 3538** 3539** ^These APIs are only available if the library was compiled with the 3540** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3541** 3542** If two or more threads call one or more of these routines against the same 3543** prepared statement and column at the same time then the results are 3544** undefined. 3545** 3546** If two or more threads call one or more 3547** [sqlite3_column_database_name | column metadata interfaces] 3548** for the same [prepared statement] and result column 3549** at the same time then the results are undefined. 3550*/ 3551const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3552const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3553const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3554const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3555const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3556const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3557 3558/* 3559** CAPI3REF: Declared Datatype Of A Query Result 3560** 3561** ^(The first parameter is a [prepared statement]. 3562** If this statement is a [SELECT] statement and the Nth column of the 3563** returned result set of that [SELECT] is a table column (not an 3564** expression or subquery) then the declared type of the table 3565** column is returned.)^ ^If the Nth column of the result set is an 3566** expression or subquery, then a NULL pointer is returned. 3567** ^The returned string is always UTF-8 encoded. 3568** 3569** ^(For example, given the database schema: 3570** 3571** CREATE TABLE t1(c1 VARIANT); 3572** 3573** and the following statement to be compiled: 3574** 3575** SELECT c1 + 1, c1 FROM t1; 3576** 3577** this routine would return the string "VARIANT" for the second result 3578** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3579** 3580** ^SQLite uses dynamic run-time typing. ^So just because a column 3581** is declared to contain a particular type does not mean that the 3582** data stored in that column is of the declared type. SQLite is 3583** strongly typed, but the typing is dynamic not static. ^Type 3584** is associated with individual values, not with the containers 3585** used to hold those values. 3586*/ 3587const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3588const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3589 3590/* 3591** CAPI3REF: Evaluate An SQL Statement 3592** 3593** After a [prepared statement] has been prepared using either 3594** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3595** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3596** must be called one or more times to evaluate the statement. 3597** 3598** The details of the behavior of the sqlite3_step() interface depend 3599** on whether the statement was prepared using the newer "v2" interface 3600** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3601** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3602** new "v2" interface is recommended for new applications but the legacy 3603** interface will continue to be supported. 3604** 3605** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3606** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3607** ^With the "v2" interface, any of the other [result codes] or 3608** [extended result codes] might be returned as well. 3609** 3610** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3611** database locks it needs to do its job. ^If the statement is a [COMMIT] 3612** or occurs outside of an explicit transaction, then you can retry the 3613** statement. If the statement is not a [COMMIT] and occurs within an 3614** explicit transaction then you should rollback the transaction before 3615** continuing. 3616** 3617** ^[SQLITE_DONE] means that the statement has finished executing 3618** successfully. sqlite3_step() should not be called again on this virtual 3619** machine without first calling [sqlite3_reset()] to reset the virtual 3620** machine back to its initial state. 3621** 3622** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3623** is returned each time a new row of data is ready for processing by the 3624** caller. The values may be accessed using the [column access functions]. 3625** sqlite3_step() is called again to retrieve the next row of data. 3626** 3627** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3628** violation) has occurred. sqlite3_step() should not be called again on 3629** the VM. More information may be found by calling [sqlite3_errmsg()]. 3630** ^With the legacy interface, a more specific error code (for example, 3631** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3632** can be obtained by calling [sqlite3_reset()] on the 3633** [prepared statement]. ^In the "v2" interface, 3634** the more specific error code is returned directly by sqlite3_step(). 3635** 3636** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3637** Perhaps it was called on a [prepared statement] that has 3638** already been [sqlite3_finalize | finalized] or on one that had 3639** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3640** be the case that the same database connection is being used by two or 3641** more threads at the same moment in time. 3642** 3643** For all versions of SQLite up to and including 3.6.23.1, a call to 3644** [sqlite3_reset()] was required after sqlite3_step() returned anything 3645** other than [SQLITE_ROW] before any subsequent invocation of 3646** sqlite3_step(). Failure to reset the prepared statement using 3647** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3648** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3649** calling [sqlite3_reset()] automatically in this circumstance rather 3650** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3651** break because any application that ever receives an SQLITE_MISUSE error 3652** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3653** can be used to restore the legacy behavior. 3654** 3655** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3656** API always returns a generic error code, [SQLITE_ERROR], following any 3657** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3658** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3659** specific [error codes] that better describes the error. 3660** We admit that this is a goofy design. The problem has been fixed 3661** with the "v2" interface. If you prepare all of your SQL statements 3662** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3663** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3664** then the more specific [error codes] are returned directly 3665** by sqlite3_step(). The use of the "v2" interface is recommended. 3666*/ 3667int sqlite3_step(sqlite3_stmt*); 3668 3669/* 3670** CAPI3REF: Number of columns in a result set 3671** 3672** ^The sqlite3_data_count(P) interface returns the number of columns in the 3673** current row of the result set of [prepared statement] P. 3674** ^If prepared statement P does not have results ready to return 3675** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3676** interfaces) then sqlite3_data_count(P) returns 0. 3677** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3678** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3679** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3680** will return non-zero if previous call to [sqlite3_step](P) returned 3681** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3682** where it always returns zero since each step of that multi-step 3683** pragma returns 0 columns of data. 3684** 3685** See also: [sqlite3_column_count()] 3686*/ 3687int sqlite3_data_count(sqlite3_stmt *pStmt); 3688 3689/* 3690** CAPI3REF: Fundamental Datatypes 3691** KEYWORDS: SQLITE_TEXT 3692** 3693** ^(Every value in SQLite has one of five fundamental datatypes: 3694** 3695** <ul> 3696** <li> 64-bit signed integer 3697** <li> 64-bit IEEE floating point number 3698** <li> string 3699** <li> BLOB 3700** <li> NULL 3701** </ul>)^ 3702** 3703** These constants are codes for each of those types. 3704** 3705** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3706** for a completely different meaning. Software that links against both 3707** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3708** SQLITE_TEXT. 3709*/ 3710#define SQLITE_INTEGER 1 3711#define SQLITE_FLOAT 2 3712#define SQLITE_BLOB 4 3713#define SQLITE_NULL 5 3714#ifdef SQLITE_TEXT 3715# undef SQLITE_TEXT 3716#else 3717# define SQLITE_TEXT 3 3718#endif 3719#define SQLITE3_TEXT 3 3720 3721/* 3722** CAPI3REF: Result Values From A Query 3723** KEYWORDS: {column access functions} 3724** 3725** These routines form the "result set" interface. 3726** 3727** ^These routines return information about a single column of the current 3728** result row of a query. ^In every case the first argument is a pointer 3729** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3730** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3731** and the second argument is the index of the column for which information 3732** should be returned. ^The leftmost column of the result set has the index 0. 3733** ^The number of columns in the result can be determined using 3734** [sqlite3_column_count()]. 3735** 3736** If the SQL statement does not currently point to a valid row, or if the 3737** column index is out of range, the result is undefined. 3738** These routines may only be called when the most recent call to 3739** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3740** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3741** If any of these routines are called after [sqlite3_reset()] or 3742** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3743** something other than [SQLITE_ROW], the results are undefined. 3744** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3745** are called from a different thread while any of these routines 3746** are pending, then the results are undefined. 3747** 3748** ^The sqlite3_column_type() routine returns the 3749** [SQLITE_INTEGER | datatype code] for the initial data type 3750** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3751** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3752** returned by sqlite3_column_type() is only meaningful if no type 3753** conversions have occurred as described below. After a type conversion, 3754** the value returned by sqlite3_column_type() is undefined. Future 3755** versions of SQLite may change the behavior of sqlite3_column_type() 3756** following a type conversion. 3757** 3758** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3759** routine returns the number of bytes in that BLOB or string. 3760** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3761** the string to UTF-8 and then returns the number of bytes. 3762** ^If the result is a numeric value then sqlite3_column_bytes() uses 3763** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3764** the number of bytes in that string. 3765** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3766** 3767** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3768** routine returns the number of bytes in that BLOB or string. 3769** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3770** the string to UTF-16 and then returns the number of bytes. 3771** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3772** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3773** the number of bytes in that string. 3774** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3775** 3776** ^The values returned by [sqlite3_column_bytes()] and 3777** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3778** of the string. ^For clarity: the values returned by 3779** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3780** bytes in the string, not the number of characters. 3781** 3782** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3783** even empty strings, are always zero-terminated. ^The return 3784** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3785** 3786** ^The object returned by [sqlite3_column_value()] is an 3787** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3788** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3789** If the [unprotected sqlite3_value] object returned by 3790** [sqlite3_column_value()] is used in any other way, including calls 3791** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3792** or [sqlite3_value_bytes()], then the behavior is undefined. 3793** 3794** These routines attempt to convert the value where appropriate. ^For 3795** example, if the internal representation is FLOAT and a text result 3796** is requested, [sqlite3_snprintf()] is used internally to perform the 3797** conversion automatically. ^(The following table details the conversions 3798** that are applied: 3799** 3800** <blockquote> 3801** <table border="1"> 3802** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3803** 3804** <tr><td> NULL <td> INTEGER <td> Result is 0 3805** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3806** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3807** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3808** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3809** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3810** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3811** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3812** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3813** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3814** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3815** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3816** <tr><td> TEXT <td> BLOB <td> No change 3817** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3818** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3819** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3820** </table> 3821** </blockquote>)^ 3822** 3823** The table above makes reference to standard C library functions atoi() 3824** and atof(). SQLite does not really use these functions. It has its 3825** own equivalent internal routines. The atoi() and atof() names are 3826** used in the table for brevity and because they are familiar to most 3827** C programmers. 3828** 3829** Note that when type conversions occur, pointers returned by prior 3830** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3831** sqlite3_column_text16() may be invalidated. 3832** Type conversions and pointer invalidations might occur 3833** in the following cases: 3834** 3835** <ul> 3836** <li> The initial content is a BLOB and sqlite3_column_text() or 3837** sqlite3_column_text16() is called. A zero-terminator might 3838** need to be added to the string.</li> 3839** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3840** sqlite3_column_text16() is called. The content must be converted 3841** to UTF-16.</li> 3842** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3843** sqlite3_column_text() is called. The content must be converted 3844** to UTF-8.</li> 3845** </ul> 3846** 3847** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3848** not invalidate a prior pointer, though of course the content of the buffer 3849** that the prior pointer references will have been modified. Other kinds 3850** of conversion are done in place when it is possible, but sometimes they 3851** are not possible and in those cases prior pointers are invalidated. 3852** 3853** The safest and easiest to remember policy is to invoke these routines 3854** in one of the following ways: 3855** 3856** <ul> 3857** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3858** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3859** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3860** </ul> 3861** 3862** In other words, you should call sqlite3_column_text(), 3863** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3864** into the desired format, then invoke sqlite3_column_bytes() or 3865** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3866** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3867** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3868** with calls to sqlite3_column_bytes(). 3869** 3870** ^The pointers returned are valid until a type conversion occurs as 3871** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3872** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3873** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3874** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3875** [sqlite3_free()]. 3876** 3877** ^(If a memory allocation error occurs during the evaluation of any 3878** of these routines, a default value is returned. The default value 3879** is either the integer 0, the floating point number 0.0, or a NULL 3880** pointer. Subsequent calls to [sqlite3_errcode()] will return 3881** [SQLITE_NOMEM].)^ 3882*/ 3883const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3884int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3885int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3886double sqlite3_column_double(sqlite3_stmt*, int iCol); 3887int sqlite3_column_int(sqlite3_stmt*, int iCol); 3888sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3889const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3890const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3891int sqlite3_column_type(sqlite3_stmt*, int iCol); 3892sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3893 3894/* 3895** CAPI3REF: Destroy A Prepared Statement Object 3896** 3897** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3898** ^If the most recent evaluation of the statement encountered no errors 3899** or if the statement is never been evaluated, then sqlite3_finalize() returns 3900** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3901** sqlite3_finalize(S) returns the appropriate [error code] or 3902** [extended error code]. 3903** 3904** ^The sqlite3_finalize(S) routine can be called at any point during 3905** the life cycle of [prepared statement] S: 3906** before statement S is ever evaluated, after 3907** one or more calls to [sqlite3_reset()], or after any call 3908** to [sqlite3_step()] regardless of whether or not the statement has 3909** completed execution. 3910** 3911** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3912** 3913** The application must finalize every [prepared statement] in order to avoid 3914** resource leaks. It is a grievous error for the application to try to use 3915** a prepared statement after it has been finalized. Any use of a prepared 3916** statement after it has been finalized can result in undefined and 3917** undesirable behavior such as segfaults and heap corruption. 3918*/ 3919int sqlite3_finalize(sqlite3_stmt *pStmt); 3920 3921/* 3922** CAPI3REF: Reset A Prepared Statement Object 3923** 3924** The sqlite3_reset() function is called to reset a [prepared statement] 3925** object back to its initial state, ready to be re-executed. 3926** ^Any SQL statement variables that had values bound to them using 3927** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3928** Use [sqlite3_clear_bindings()] to reset the bindings. 3929** 3930** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3931** back to the beginning of its program. 3932** 3933** ^If the most recent call to [sqlite3_step(S)] for the 3934** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3935** or if [sqlite3_step(S)] has never before been called on S, 3936** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3937** 3938** ^If the most recent call to [sqlite3_step(S)] for the 3939** [prepared statement] S indicated an error, then 3940** [sqlite3_reset(S)] returns an appropriate [error code]. 3941** 3942** ^The [sqlite3_reset(S)] interface does not change the values 3943** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3944*/ 3945int sqlite3_reset(sqlite3_stmt *pStmt); 3946 3947/* 3948** CAPI3REF: Create Or Redefine SQL Functions 3949** KEYWORDS: {function creation routines} 3950** KEYWORDS: {application-defined SQL function} 3951** KEYWORDS: {application-defined SQL functions} 3952** 3953** ^These functions (collectively known as "function creation routines") 3954** are used to add SQL functions or aggregates or to redefine the behavior 3955** of existing SQL functions or aggregates. The only differences between 3956** these routines are the text encoding expected for 3957** the second parameter (the name of the function being created) 3958** and the presence or absence of a destructor callback for 3959** the application data pointer. 3960** 3961** ^The first parameter is the [database connection] to which the SQL 3962** function is to be added. ^If an application uses more than one database 3963** connection then application-defined SQL functions must be added 3964** to each database connection separately. 3965** 3966** ^The second parameter is the name of the SQL function to be created or 3967** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3968** representation, exclusive of the zero-terminator. ^Note that the name 3969** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3970** ^Any attempt to create a function with a longer name 3971** will result in [SQLITE_MISUSE] being returned. 3972** 3973** ^The third parameter (nArg) 3974** is the number of arguments that the SQL function or 3975** aggregate takes. ^If this parameter is -1, then the SQL function or 3976** aggregate may take any number of arguments between 0 and the limit 3977** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3978** parameter is less than -1 or greater than 127 then the behavior is 3979** undefined. 3980** 3981** ^The fourth parameter, eTextRep, specifies what 3982** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3983** its parameters. The application should set this parameter to 3984** [SQLITE_UTF16LE] if the function implementation invokes 3985** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 3986** implementation invokes [sqlite3_value_text16be()] on an input, or 3987** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 3988** otherwise. ^The same SQL function may be registered multiple times using 3989** different preferred text encodings, with different implementations for 3990** each encoding. 3991** ^When multiple implementations of the same function are available, SQLite 3992** will pick the one that involves the least amount of data conversion. 3993** 3994** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 3995** to signal that the function will always return the same result given 3996** the same inputs within a single SQL statement. Most SQL functions are 3997** deterministic. The built-in [random()] SQL function is an example of a 3998** function that is not deterministic. The SQLite query planner is able to 3999** perform additional optimizations on deterministic functions, so use 4000** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4001** 4002** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4003** function can gain access to this pointer using [sqlite3_user_data()].)^ 4004** 4005** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4006** pointers to C-language functions that implement the SQL function or 4007** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4008** callback only; NULL pointers must be passed as the xStep and xFinal 4009** parameters. ^An aggregate SQL function requires an implementation of xStep 4010** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4011** SQL function or aggregate, pass NULL pointers for all three function 4012** callbacks. 4013** 4014** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4015** then it is destructor for the application data pointer. 4016** The destructor is invoked when the function is deleted, either by being 4017** overloaded or when the database connection closes.)^ 4018** ^The destructor is also invoked if the call to 4019** sqlite3_create_function_v2() fails. 4020** ^When the destructor callback of the tenth parameter is invoked, it 4021** is passed a single argument which is a copy of the application data 4022** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4023** 4024** ^It is permitted to register multiple implementations of the same 4025** functions with the same name but with either differing numbers of 4026** arguments or differing preferred text encodings. ^SQLite will use 4027** the implementation that most closely matches the way in which the 4028** SQL function is used. ^A function implementation with a non-negative 4029** nArg parameter is a better match than a function implementation with 4030** a negative nArg. ^A function where the preferred text encoding 4031** matches the database encoding is a better 4032** match than a function where the encoding is different. 4033** ^A function where the encoding difference is between UTF16le and UTF16be 4034** is a closer match than a function where the encoding difference is 4035** between UTF8 and UTF16. 4036** 4037** ^Built-in functions may be overloaded by new application-defined functions. 4038** 4039** ^An application-defined function is permitted to call other 4040** SQLite interfaces. However, such calls must not 4041** close the database connection nor finalize or reset the prepared 4042** statement in which the function is running. 4043*/ 4044int sqlite3_create_function( 4045 sqlite3 *db, 4046 const char *zFunctionName, 4047 int nArg, 4048 int eTextRep, 4049 void *pApp, 4050 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4051 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4052 void (*xFinal)(sqlite3_context*) 4053); 4054int sqlite3_create_function16( 4055 sqlite3 *db, 4056 const void *zFunctionName, 4057 int nArg, 4058 int eTextRep, 4059 void *pApp, 4060 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4061 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4062 void (*xFinal)(sqlite3_context*) 4063); 4064int sqlite3_create_function_v2( 4065 sqlite3 *db, 4066 const char *zFunctionName, 4067 int nArg, 4068 int eTextRep, 4069 void *pApp, 4070 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4071 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4072 void (*xFinal)(sqlite3_context*), 4073 void(*xDestroy)(void*) 4074); 4075 4076/* 4077** CAPI3REF: Text Encodings 4078** 4079** These constant define integer codes that represent the various 4080** text encodings supported by SQLite. 4081*/ 4082#define SQLITE_UTF8 1 4083#define SQLITE_UTF16LE 2 4084#define SQLITE_UTF16BE 3 4085#define SQLITE_UTF16 4 /* Use native byte order */ 4086#define SQLITE_ANY 5 /* Deprecated */ 4087#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4088 4089/* 4090** CAPI3REF: Function Flags 4091** 4092** These constants may be ORed together with the 4093** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4094** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4095** [sqlite3_create_function_v2()]. 4096*/ 4097#define SQLITE_DETERMINISTIC 0x800 4098 4099/* 4100** CAPI3REF: Deprecated Functions 4101** DEPRECATED 4102** 4103** These functions are [deprecated]. In order to maintain 4104** backwards compatibility with older code, these functions continue 4105** to be supported. However, new applications should avoid 4106** the use of these functions. To help encourage people to avoid 4107** using these functions, we are not going to tell you what they do. 4108*/ 4109#ifndef SQLITE_OMIT_DEPRECATED 4110SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4111SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4112SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4113SQLITE_DEPRECATED int sqlite3_global_recover(void); 4114SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4115SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4116 void*,sqlite3_int64); 4117#endif 4118 4119/* 4120** CAPI3REF: Obtaining SQL Function Parameter Values 4121** 4122** The C-language implementation of SQL functions and aggregates uses 4123** this set of interface routines to access the parameter values on 4124** the function or aggregate. 4125** 4126** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4127** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4128** define callbacks that implement the SQL functions and aggregates. 4129** The 3rd parameter to these callbacks is an array of pointers to 4130** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4131** each parameter to the SQL function. These routines are used to 4132** extract values from the [sqlite3_value] objects. 4133** 4134** These routines work only with [protected sqlite3_value] objects. 4135** Any attempt to use these routines on an [unprotected sqlite3_value] 4136** object results in undefined behavior. 4137** 4138** ^These routines work just like the corresponding [column access functions] 4139** except that these routines take a single [protected sqlite3_value] object 4140** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4141** 4142** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4143** in the native byte-order of the host machine. ^The 4144** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4145** extract UTF-16 strings as big-endian and little-endian respectively. 4146** 4147** ^(The sqlite3_value_numeric_type() interface attempts to apply 4148** numeric affinity to the value. This means that an attempt is 4149** made to convert the value to an integer or floating point. If 4150** such a conversion is possible without loss of information (in other 4151** words, if the value is a string that looks like a number) 4152** then the conversion is performed. Otherwise no conversion occurs. 4153** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4154** 4155** Please pay particular attention to the fact that the pointer returned 4156** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4157** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4158** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4159** or [sqlite3_value_text16()]. 4160** 4161** These routines must be called from the same thread as 4162** the SQL function that supplied the [sqlite3_value*] parameters. 4163*/ 4164const void *sqlite3_value_blob(sqlite3_value*); 4165int sqlite3_value_bytes(sqlite3_value*); 4166int sqlite3_value_bytes16(sqlite3_value*); 4167double sqlite3_value_double(sqlite3_value*); 4168int sqlite3_value_int(sqlite3_value*); 4169sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4170const unsigned char *sqlite3_value_text(sqlite3_value*); 4171const void *sqlite3_value_text16(sqlite3_value*); 4172const void *sqlite3_value_text16le(sqlite3_value*); 4173const void *sqlite3_value_text16be(sqlite3_value*); 4174int sqlite3_value_type(sqlite3_value*); 4175int sqlite3_value_numeric_type(sqlite3_value*); 4176 4177/* 4178** CAPI3REF: Obtain Aggregate Function Context 4179** 4180** Implementations of aggregate SQL functions use this 4181** routine to allocate memory for storing their state. 4182** 4183** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4184** for a particular aggregate function, SQLite 4185** allocates N of memory, zeroes out that memory, and returns a pointer 4186** to the new memory. ^On second and subsequent calls to 4187** sqlite3_aggregate_context() for the same aggregate function instance, 4188** the same buffer is returned. Sqlite3_aggregate_context() is normally 4189** called once for each invocation of the xStep callback and then one 4190** last time when the xFinal callback is invoked. ^(When no rows match 4191** an aggregate query, the xStep() callback of the aggregate function 4192** implementation is never called and xFinal() is called exactly once. 4193** In those cases, sqlite3_aggregate_context() might be called for the 4194** first time from within xFinal().)^ 4195** 4196** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4197** when first called if N is less than or equal to zero or if a memory 4198** allocate error occurs. 4199** 4200** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4201** determined by the N parameter on first successful call. Changing the 4202** value of N in subsequent call to sqlite3_aggregate_context() within 4203** the same aggregate function instance will not resize the memory 4204** allocation.)^ Within the xFinal callback, it is customary to set 4205** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4206** pointless memory allocations occur. 4207** 4208** ^SQLite automatically frees the memory allocated by 4209** sqlite3_aggregate_context() when the aggregate query concludes. 4210** 4211** The first parameter must be a copy of the 4212** [sqlite3_context | SQL function context] that is the first parameter 4213** to the xStep or xFinal callback routine that implements the aggregate 4214** function. 4215** 4216** This routine must be called from the same thread in which 4217** the aggregate SQL function is running. 4218*/ 4219void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4220 4221/* 4222** CAPI3REF: User Data For Functions 4223** 4224** ^The sqlite3_user_data() interface returns a copy of 4225** the pointer that was the pUserData parameter (the 5th parameter) 4226** of the [sqlite3_create_function()] 4227** and [sqlite3_create_function16()] routines that originally 4228** registered the application defined function. 4229** 4230** This routine must be called from the same thread in which 4231** the application-defined function is running. 4232*/ 4233void *sqlite3_user_data(sqlite3_context*); 4234 4235/* 4236** CAPI3REF: Database Connection For Functions 4237** 4238** ^The sqlite3_context_db_handle() interface returns a copy of 4239** the pointer to the [database connection] (the 1st parameter) 4240** of the [sqlite3_create_function()] 4241** and [sqlite3_create_function16()] routines that originally 4242** registered the application defined function. 4243*/ 4244sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4245 4246/* 4247** CAPI3REF: Function Auxiliary Data 4248** 4249** These functions may be used by (non-aggregate) SQL functions to 4250** associate metadata with argument values. If the same value is passed to 4251** multiple invocations of the same SQL function during query execution, under 4252** some circumstances the associated metadata may be preserved. An example 4253** of where this might be useful is in a regular-expression matching 4254** function. The compiled version of the regular expression can be stored as 4255** metadata associated with the pattern string. 4256** Then as long as the pattern string remains the same, 4257** the compiled regular expression can be reused on multiple 4258** invocations of the same function. 4259** 4260** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4261** associated by the sqlite3_set_auxdata() function with the Nth argument 4262** value to the application-defined function. ^If there is no metadata 4263** associated with the function argument, this sqlite3_get_auxdata() interface 4264** returns a NULL pointer. 4265** 4266** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4267** argument of the application-defined function. ^Subsequent 4268** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4269** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4270** NULL if the metadata has been discarded. 4271** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4272** SQLite will invoke the destructor function X with parameter P exactly 4273** once, when the metadata is discarded. 4274** SQLite is free to discard the metadata at any time, including: <ul> 4275** <li> when the corresponding function parameter changes, or 4276** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4277** SQL statement, or 4278** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4279** <li> during the original sqlite3_set_auxdata() call when a memory 4280** allocation error occurs. </ul>)^ 4281** 4282** Note the last bullet in particular. The destructor X in 4283** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4284** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4285** should be called near the end of the function implementation and the 4286** function implementation should not make any use of P after 4287** sqlite3_set_auxdata() has been called. 4288** 4289** ^(In practice, metadata is preserved between function calls for 4290** function parameters that are compile-time constants, including literal 4291** values and [parameters] and expressions composed from the same.)^ 4292** 4293** These routines must be called from the same thread in which 4294** the SQL function is running. 4295*/ 4296void *sqlite3_get_auxdata(sqlite3_context*, int N); 4297void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4298 4299 4300/* 4301** CAPI3REF: Constants Defining Special Destructor Behavior 4302** 4303** These are special values for the destructor that is passed in as the 4304** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4305** argument is SQLITE_STATIC, it means that the content pointer is constant 4306** and will never change. It does not need to be destroyed. ^The 4307** SQLITE_TRANSIENT value means that the content will likely change in 4308** the near future and that SQLite should make its own private copy of 4309** the content before returning. 4310** 4311** The typedef is necessary to work around problems in certain 4312** C++ compilers. 4313*/ 4314typedef void (*sqlite3_destructor_type)(void*); 4315#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4316#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4317 4318/* 4319** CAPI3REF: Setting The Result Of An SQL Function 4320** 4321** These routines are used by the xFunc or xFinal callbacks that 4322** implement SQL functions and aggregates. See 4323** [sqlite3_create_function()] and [sqlite3_create_function16()] 4324** for additional information. 4325** 4326** These functions work very much like the [parameter binding] family of 4327** functions used to bind values to host parameters in prepared statements. 4328** Refer to the [SQL parameter] documentation for additional information. 4329** 4330** ^The sqlite3_result_blob() interface sets the result from 4331** an application-defined function to be the BLOB whose content is pointed 4332** to by the second parameter and which is N bytes long where N is the 4333** third parameter. 4334** 4335** ^The sqlite3_result_zeroblob() interfaces set the result of 4336** the application-defined function to be a BLOB containing all zero 4337** bytes and N bytes in size, where N is the value of the 2nd parameter. 4338** 4339** ^The sqlite3_result_double() interface sets the result from 4340** an application-defined function to be a floating point value specified 4341** by its 2nd argument. 4342** 4343** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4344** cause the implemented SQL function to throw an exception. 4345** ^SQLite uses the string pointed to by the 4346** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4347** as the text of an error message. ^SQLite interprets the error 4348** message string from sqlite3_result_error() as UTF-8. ^SQLite 4349** interprets the string from sqlite3_result_error16() as UTF-16 in native 4350** byte order. ^If the third parameter to sqlite3_result_error() 4351** or sqlite3_result_error16() is negative then SQLite takes as the error 4352** message all text up through the first zero character. 4353** ^If the third parameter to sqlite3_result_error() or 4354** sqlite3_result_error16() is non-negative then SQLite takes that many 4355** bytes (not characters) from the 2nd parameter as the error message. 4356** ^The sqlite3_result_error() and sqlite3_result_error16() 4357** routines make a private copy of the error message text before 4358** they return. Hence, the calling function can deallocate or 4359** modify the text after they return without harm. 4360** ^The sqlite3_result_error_code() function changes the error code 4361** returned by SQLite as a result of an error in a function. ^By default, 4362** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4363** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4364** 4365** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4366** error indicating that a string or BLOB is too long to represent. 4367** 4368** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4369** error indicating that a memory allocation failed. 4370** 4371** ^The sqlite3_result_int() interface sets the return value 4372** of the application-defined function to be the 32-bit signed integer 4373** value given in the 2nd argument. 4374** ^The sqlite3_result_int64() interface sets the return value 4375** of the application-defined function to be the 64-bit signed integer 4376** value given in the 2nd argument. 4377** 4378** ^The sqlite3_result_null() interface sets the return value 4379** of the application-defined function to be NULL. 4380** 4381** ^The sqlite3_result_text(), sqlite3_result_text16(), 4382** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4383** set the return value of the application-defined function to be 4384** a text string which is represented as UTF-8, UTF-16 native byte order, 4385** UTF-16 little endian, or UTF-16 big endian, respectively. 4386** ^SQLite takes the text result from the application from 4387** the 2nd parameter of the sqlite3_result_text* interfaces. 4388** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4389** is negative, then SQLite takes result text from the 2nd parameter 4390** through the first zero character. 4391** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4392** is non-negative, then as many bytes (not characters) of the text 4393** pointed to by the 2nd parameter are taken as the application-defined 4394** function result. If the 3rd parameter is non-negative, then it 4395** must be the byte offset into the string where the NUL terminator would 4396** appear if the string where NUL terminated. If any NUL characters occur 4397** in the string at a byte offset that is less than the value of the 3rd 4398** parameter, then the resulting string will contain embedded NULs and the 4399** result of expressions operating on strings with embedded NULs is undefined. 4400** ^If the 4th parameter to the sqlite3_result_text* interfaces 4401** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4402** function as the destructor on the text or BLOB result when it has 4403** finished using that result. 4404** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4405** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4406** assumes that the text or BLOB result is in constant space and does not 4407** copy the content of the parameter nor call a destructor on the content 4408** when it has finished using that result. 4409** ^If the 4th parameter to the sqlite3_result_text* interfaces 4410** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4411** then SQLite makes a copy of the result into space obtained from 4412** from [sqlite3_malloc()] before it returns. 4413** 4414** ^The sqlite3_result_value() interface sets the result of 4415** the application-defined function to be a copy the 4416** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4417** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4418** so that the [sqlite3_value] specified in the parameter may change or 4419** be deallocated after sqlite3_result_value() returns without harm. 4420** ^A [protected sqlite3_value] object may always be used where an 4421** [unprotected sqlite3_value] object is required, so either 4422** kind of [sqlite3_value] object can be used with this interface. 4423** 4424** If these routines are called from within the different thread 4425** than the one containing the application-defined function that received 4426** the [sqlite3_context] pointer, the results are undefined. 4427*/ 4428void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4429void sqlite3_result_double(sqlite3_context*, double); 4430void sqlite3_result_error(sqlite3_context*, const char*, int); 4431void sqlite3_result_error16(sqlite3_context*, const void*, int); 4432void sqlite3_result_error_toobig(sqlite3_context*); 4433void sqlite3_result_error_nomem(sqlite3_context*); 4434void sqlite3_result_error_code(sqlite3_context*, int); 4435void sqlite3_result_int(sqlite3_context*, int); 4436void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4437void sqlite3_result_null(sqlite3_context*); 4438void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4439void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4440void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4441void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4442void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4443void sqlite3_result_zeroblob(sqlite3_context*, int n); 4444 4445/* 4446** CAPI3REF: Define New Collating Sequences 4447** 4448** ^These functions add, remove, or modify a [collation] associated 4449** with the [database connection] specified as the first argument. 4450** 4451** ^The name of the collation is a UTF-8 string 4452** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4453** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4454** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4455** considered to be the same name. 4456** 4457** ^(The third argument (eTextRep) must be one of the constants: 4458** <ul> 4459** <li> [SQLITE_UTF8], 4460** <li> [SQLITE_UTF16LE], 4461** <li> [SQLITE_UTF16BE], 4462** <li> [SQLITE_UTF16], or 4463** <li> [SQLITE_UTF16_ALIGNED]. 4464** </ul>)^ 4465** ^The eTextRep argument determines the encoding of strings passed 4466** to the collating function callback, xCallback. 4467** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4468** force strings to be UTF16 with native byte order. 4469** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4470** on an even byte address. 4471** 4472** ^The fourth argument, pArg, is an application data pointer that is passed 4473** through as the first argument to the collating function callback. 4474** 4475** ^The fifth argument, xCallback, is a pointer to the collating function. 4476** ^Multiple collating functions can be registered using the same name but 4477** with different eTextRep parameters and SQLite will use whichever 4478** function requires the least amount of data transformation. 4479** ^If the xCallback argument is NULL then the collating function is 4480** deleted. ^When all collating functions having the same name are deleted, 4481** that collation is no longer usable. 4482** 4483** ^The collating function callback is invoked with a copy of the pArg 4484** application data pointer and with two strings in the encoding specified 4485** by the eTextRep argument. The collating function must return an 4486** integer that is negative, zero, or positive 4487** if the first string is less than, equal to, or greater than the second, 4488** respectively. A collating function must always return the same answer 4489** given the same inputs. If two or more collating functions are registered 4490** to the same collation name (using different eTextRep values) then all 4491** must give an equivalent answer when invoked with equivalent strings. 4492** The collating function must obey the following properties for all 4493** strings A, B, and C: 4494** 4495** <ol> 4496** <li> If A==B then B==A. 4497** <li> If A==B and B==C then A==C. 4498** <li> If A<B THEN B>A. 4499** <li> If A<B and B<C then A<C. 4500** </ol> 4501** 4502** If a collating function fails any of the above constraints and that 4503** collating function is registered and used, then the behavior of SQLite 4504** is undefined. 4505** 4506** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4507** with the addition that the xDestroy callback is invoked on pArg when 4508** the collating function is deleted. 4509** ^Collating functions are deleted when they are overridden by later 4510** calls to the collation creation functions or when the 4511** [database connection] is closed using [sqlite3_close()]. 4512** 4513** ^The xDestroy callback is <u>not</u> called if the 4514** sqlite3_create_collation_v2() function fails. Applications that invoke 4515** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4516** check the return code and dispose of the application data pointer 4517** themselves rather than expecting SQLite to deal with it for them. 4518** This is different from every other SQLite interface. The inconsistency 4519** is unfortunate but cannot be changed without breaking backwards 4520** compatibility. 4521** 4522** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4523*/ 4524int sqlite3_create_collation( 4525 sqlite3*, 4526 const char *zName, 4527 int eTextRep, 4528 void *pArg, 4529 int(*xCompare)(void*,int,const void*,int,const void*) 4530); 4531int sqlite3_create_collation_v2( 4532 sqlite3*, 4533 const char *zName, 4534 int eTextRep, 4535 void *pArg, 4536 int(*xCompare)(void*,int,const void*,int,const void*), 4537 void(*xDestroy)(void*) 4538); 4539int sqlite3_create_collation16( 4540 sqlite3*, 4541 const void *zName, 4542 int eTextRep, 4543 void *pArg, 4544 int(*xCompare)(void*,int,const void*,int,const void*) 4545); 4546 4547/* 4548** CAPI3REF: Collation Needed Callbacks 4549** 4550** ^To avoid having to register all collation sequences before a database 4551** can be used, a single callback function may be registered with the 4552** [database connection] to be invoked whenever an undefined collation 4553** sequence is required. 4554** 4555** ^If the function is registered using the sqlite3_collation_needed() API, 4556** then it is passed the names of undefined collation sequences as strings 4557** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4558** the names are passed as UTF-16 in machine native byte order. 4559** ^A call to either function replaces the existing collation-needed callback. 4560** 4561** ^(When the callback is invoked, the first argument passed is a copy 4562** of the second argument to sqlite3_collation_needed() or 4563** sqlite3_collation_needed16(). The second argument is the database 4564** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4565** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4566** sequence function required. The fourth parameter is the name of the 4567** required collation sequence.)^ 4568** 4569** The callback function should register the desired collation using 4570** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4571** [sqlite3_create_collation_v2()]. 4572*/ 4573int sqlite3_collation_needed( 4574 sqlite3*, 4575 void*, 4576 void(*)(void*,sqlite3*,int eTextRep,const char*) 4577); 4578int sqlite3_collation_needed16( 4579 sqlite3*, 4580 void*, 4581 void(*)(void*,sqlite3*,int eTextRep,const void*) 4582); 4583 4584#ifdef SQLITE_HAS_CODEC 4585/* 4586** Specify the key for an encrypted database. This routine should be 4587** called right after sqlite3_open(). 4588** 4589** The code to implement this API is not available in the public release 4590** of SQLite. 4591*/ 4592int sqlite3_key( 4593 sqlite3 *db, /* Database to be rekeyed */ 4594 const void *pKey, int nKey /* The key */ 4595); 4596int sqlite3_key_v2( 4597 sqlite3 *db, /* Database to be rekeyed */ 4598 const char *zDbName, /* Name of the database */ 4599 const void *pKey, int nKey /* The key */ 4600); 4601 4602/* 4603** Change the key on an open database. If the current database is not 4604** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4605** database is decrypted. 4606** 4607** The code to implement this API is not available in the public release 4608** of SQLite. 4609*/ 4610int sqlite3_rekey( 4611 sqlite3 *db, /* Database to be rekeyed */ 4612 const void *pKey, int nKey /* The new key */ 4613); 4614int sqlite3_rekey_v2( 4615 sqlite3 *db, /* Database to be rekeyed */ 4616 const char *zDbName, /* Name of the database */ 4617 const void *pKey, int nKey /* The new key */ 4618); 4619 4620/* 4621** Specify the activation key for a SEE database. Unless 4622** activated, none of the SEE routines will work. 4623*/ 4624void sqlite3_activate_see( 4625 const char *zPassPhrase /* Activation phrase */ 4626); 4627#endif 4628 4629#ifdef SQLITE_ENABLE_CEROD 4630/* 4631** Specify the activation key for a CEROD database. Unless 4632** activated, none of the CEROD routines will work. 4633*/ 4634void sqlite3_activate_cerod( 4635 const char *zPassPhrase /* Activation phrase */ 4636); 4637#endif 4638 4639/* 4640** CAPI3REF: Suspend Execution For A Short Time 4641** 4642** The sqlite3_sleep() function causes the current thread to suspend execution 4643** for at least a number of milliseconds specified in its parameter. 4644** 4645** If the operating system does not support sleep requests with 4646** millisecond time resolution, then the time will be rounded up to 4647** the nearest second. The number of milliseconds of sleep actually 4648** requested from the operating system is returned. 4649** 4650** ^SQLite implements this interface by calling the xSleep() 4651** method of the default [sqlite3_vfs] object. If the xSleep() method 4652** of the default VFS is not implemented correctly, or not implemented at 4653** all, then the behavior of sqlite3_sleep() may deviate from the description 4654** in the previous paragraphs. 4655*/ 4656int sqlite3_sleep(int); 4657 4658/* 4659** CAPI3REF: Name Of The Folder Holding Temporary Files 4660** 4661** ^(If this global variable is made to point to a string which is 4662** the name of a folder (a.k.a. directory), then all temporary files 4663** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4664** will be placed in that directory.)^ ^If this variable 4665** is a NULL pointer, then SQLite performs a search for an appropriate 4666** temporary file directory. 4667** 4668** It is not safe to read or modify this variable in more than one 4669** thread at a time. It is not safe to read or modify this variable 4670** if a [database connection] is being used at the same time in a separate 4671** thread. 4672** It is intended that this variable be set once 4673** as part of process initialization and before any SQLite interface 4674** routines have been called and that this variable remain unchanged 4675** thereafter. 4676** 4677** ^The [temp_store_directory pragma] may modify this variable and cause 4678** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4679** the [temp_store_directory pragma] always assumes that any string 4680** that this variable points to is held in memory obtained from 4681** [sqlite3_malloc] and the pragma may attempt to free that memory 4682** using [sqlite3_free]. 4683** Hence, if this variable is modified directly, either it should be 4684** made NULL or made to point to memory obtained from [sqlite3_malloc] 4685** or else the use of the [temp_store_directory pragma] should be avoided. 4686** 4687** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4688** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4689** features that require the use of temporary files may fail. Here is an 4690** example of how to do this using C++ with the Windows Runtime: 4691** 4692** <blockquote><pre> 4693** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4694** TemporaryFolder->Path->Data(); 4695** char zPathBuf[MAX_PATH + 1]; 4696** memset(zPathBuf, 0, sizeof(zPathBuf)); 4697** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4698** NULL, NULL); 4699** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4700** </pre></blockquote> 4701*/ 4702SQLITE_EXTERN char *sqlite3_temp_directory; 4703 4704/* 4705** CAPI3REF: Name Of The Folder Holding Database Files 4706** 4707** ^(If this global variable is made to point to a string which is 4708** the name of a folder (a.k.a. directory), then all database files 4709** specified with a relative pathname and created or accessed by 4710** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4711** to be relative to that directory.)^ ^If this variable is a NULL 4712** pointer, then SQLite assumes that all database files specified 4713** with a relative pathname are relative to the current directory 4714** for the process. Only the windows VFS makes use of this global 4715** variable; it is ignored by the unix VFS. 4716** 4717** Changing the value of this variable while a database connection is 4718** open can result in a corrupt database. 4719** 4720** It is not safe to read or modify this variable in more than one 4721** thread at a time. It is not safe to read or modify this variable 4722** if a [database connection] is being used at the same time in a separate 4723** thread. 4724** It is intended that this variable be set once 4725** as part of process initialization and before any SQLite interface 4726** routines have been called and that this variable remain unchanged 4727** thereafter. 4728** 4729** ^The [data_store_directory pragma] may modify this variable and cause 4730** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4731** the [data_store_directory pragma] always assumes that any string 4732** that this variable points to is held in memory obtained from 4733** [sqlite3_malloc] and the pragma may attempt to free that memory 4734** using [sqlite3_free]. 4735** Hence, if this variable is modified directly, either it should be 4736** made NULL or made to point to memory obtained from [sqlite3_malloc] 4737** or else the use of the [data_store_directory pragma] should be avoided. 4738*/ 4739SQLITE_EXTERN char *sqlite3_data_directory; 4740 4741/* 4742** CAPI3REF: Test For Auto-Commit Mode 4743** KEYWORDS: {autocommit mode} 4744** 4745** ^The sqlite3_get_autocommit() interface returns non-zero or 4746** zero if the given database connection is or is not in autocommit mode, 4747** respectively. ^Autocommit mode is on by default. 4748** ^Autocommit mode is disabled by a [BEGIN] statement. 4749** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4750** 4751** If certain kinds of errors occur on a statement within a multi-statement 4752** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4753** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4754** transaction might be rolled back automatically. The only way to 4755** find out whether SQLite automatically rolled back the transaction after 4756** an error is to use this function. 4757** 4758** If another thread changes the autocommit status of the database 4759** connection while this routine is running, then the return value 4760** is undefined. 4761*/ 4762int sqlite3_get_autocommit(sqlite3*); 4763 4764/* 4765** CAPI3REF: Find The Database Handle Of A Prepared Statement 4766** 4767** ^The sqlite3_db_handle interface returns the [database connection] handle 4768** to which a [prepared statement] belongs. ^The [database connection] 4769** returned by sqlite3_db_handle is the same [database connection] 4770** that was the first argument 4771** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4772** create the statement in the first place. 4773*/ 4774sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4775 4776/* 4777** CAPI3REF: Return The Filename For A Database Connection 4778** 4779** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4780** associated with database N of connection D. ^The main database file 4781** has the name "main". If there is no attached database N on the database 4782** connection D, or if database N is a temporary or in-memory database, then 4783** a NULL pointer is returned. 4784** 4785** ^The filename returned by this function is the output of the 4786** xFullPathname method of the [VFS]. ^In other words, the filename 4787** will be an absolute pathname, even if the filename used 4788** to open the database originally was a URI or relative pathname. 4789*/ 4790const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4791 4792/* 4793** CAPI3REF: Determine if a database is read-only 4794** 4795** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4796** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4797** the name of a database on connection D. 4798*/ 4799int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4800 4801/* 4802** CAPI3REF: Find the next prepared statement 4803** 4804** ^This interface returns a pointer to the next [prepared statement] after 4805** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4806** then this interface returns a pointer to the first prepared statement 4807** associated with the database connection pDb. ^If no prepared statement 4808** satisfies the conditions of this routine, it returns NULL. 4809** 4810** The [database connection] pointer D in a call to 4811** [sqlite3_next_stmt(D,S)] must refer to an open database 4812** connection and in particular must not be a NULL pointer. 4813*/ 4814sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4815 4816/* 4817** CAPI3REF: Commit And Rollback Notification Callbacks 4818** 4819** ^The sqlite3_commit_hook() interface registers a callback 4820** function to be invoked whenever a transaction is [COMMIT | committed]. 4821** ^Any callback set by a previous call to sqlite3_commit_hook() 4822** for the same database connection is overridden. 4823** ^The sqlite3_rollback_hook() interface registers a callback 4824** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4825** ^Any callback set by a previous call to sqlite3_rollback_hook() 4826** for the same database connection is overridden. 4827** ^The pArg argument is passed through to the callback. 4828** ^If the callback on a commit hook function returns non-zero, 4829** then the commit is converted into a rollback. 4830** 4831** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4832** return the P argument from the previous call of the same function 4833** on the same [database connection] D, or NULL for 4834** the first call for each function on D. 4835** 4836** The commit and rollback hook callbacks are not reentrant. 4837** The callback implementation must not do anything that will modify 4838** the database connection that invoked the callback. Any actions 4839** to modify the database connection must be deferred until after the 4840** completion of the [sqlite3_step()] call that triggered the commit 4841** or rollback hook in the first place. 4842** Note that running any other SQL statements, including SELECT statements, 4843** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4844** the database connections for the meaning of "modify" in this paragraph. 4845** 4846** ^Registering a NULL function disables the callback. 4847** 4848** ^When the commit hook callback routine returns zero, the [COMMIT] 4849** operation is allowed to continue normally. ^If the commit hook 4850** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4851** ^The rollback hook is invoked on a rollback that results from a commit 4852** hook returning non-zero, just as it would be with any other rollback. 4853** 4854** ^For the purposes of this API, a transaction is said to have been 4855** rolled back if an explicit "ROLLBACK" statement is executed, or 4856** an error or constraint causes an implicit rollback to occur. 4857** ^The rollback callback is not invoked if a transaction is 4858** automatically rolled back because the database connection is closed. 4859** 4860** See also the [sqlite3_update_hook()] interface. 4861*/ 4862void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4863void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4864 4865/* 4866** CAPI3REF: Data Change Notification Callbacks 4867** 4868** ^The sqlite3_update_hook() interface registers a callback function 4869** with the [database connection] identified by the first argument 4870** to be invoked whenever a row is updated, inserted or deleted in 4871** a rowid table. 4872** ^Any callback set by a previous call to this function 4873** for the same database connection is overridden. 4874** 4875** ^The second argument is a pointer to the function to invoke when a 4876** row is updated, inserted or deleted in a rowid table. 4877** ^The first argument to the callback is a copy of the third argument 4878** to sqlite3_update_hook(). 4879** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4880** or [SQLITE_UPDATE], depending on the operation that caused the callback 4881** to be invoked. 4882** ^The third and fourth arguments to the callback contain pointers to the 4883** database and table name containing the affected row. 4884** ^The final callback parameter is the [rowid] of the row. 4885** ^In the case of an update, this is the [rowid] after the update takes place. 4886** 4887** ^(The update hook is not invoked when internal system tables are 4888** modified (i.e. sqlite_master and sqlite_sequence).)^ 4889** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 4890** 4891** ^In the current implementation, the update hook 4892** is not invoked when duplication rows are deleted because of an 4893** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4894** invoked when rows are deleted using the [truncate optimization]. 4895** The exceptions defined in this paragraph might change in a future 4896** release of SQLite. 4897** 4898** The update hook implementation must not do anything that will modify 4899** the database connection that invoked the update hook. Any actions 4900** to modify the database connection must be deferred until after the 4901** completion of the [sqlite3_step()] call that triggered the update hook. 4902** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4903** database connections for the meaning of "modify" in this paragraph. 4904** 4905** ^The sqlite3_update_hook(D,C,P) function 4906** returns the P argument from the previous call 4907** on the same [database connection] D, or NULL for 4908** the first call on D. 4909** 4910** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4911** interfaces. 4912*/ 4913void *sqlite3_update_hook( 4914 sqlite3*, 4915 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4916 void* 4917); 4918 4919/* 4920** CAPI3REF: Enable Or Disable Shared Pager Cache 4921** 4922** ^(This routine enables or disables the sharing of the database cache 4923** and schema data structures between [database connection | connections] 4924** to the same database. Sharing is enabled if the argument is true 4925** and disabled if the argument is false.)^ 4926** 4927** ^Cache sharing is enabled and disabled for an entire process. 4928** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4929** sharing was enabled or disabled for each thread separately. 4930** 4931** ^(The cache sharing mode set by this interface effects all subsequent 4932** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4933** Existing database connections continue use the sharing mode 4934** that was in effect at the time they were opened.)^ 4935** 4936** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4937** successfully. An [error code] is returned otherwise.)^ 4938** 4939** ^Shared cache is disabled by default. But this might change in 4940** future releases of SQLite. Applications that care about shared 4941** cache setting should set it explicitly. 4942** 4943** This interface is threadsafe on processors where writing a 4944** 32-bit integer is atomic. 4945** 4946** See Also: [SQLite Shared-Cache Mode] 4947*/ 4948int sqlite3_enable_shared_cache(int); 4949 4950/* 4951** CAPI3REF: Attempt To Free Heap Memory 4952** 4953** ^The sqlite3_release_memory() interface attempts to free N bytes 4954** of heap memory by deallocating non-essential memory allocations 4955** held by the database library. Memory used to cache database 4956** pages to improve performance is an example of non-essential memory. 4957** ^sqlite3_release_memory() returns the number of bytes actually freed, 4958** which might be more or less than the amount requested. 4959** ^The sqlite3_release_memory() routine is a no-op returning zero 4960** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4961** 4962** See also: [sqlite3_db_release_memory()] 4963*/ 4964int sqlite3_release_memory(int); 4965 4966/* 4967** CAPI3REF: Free Memory Used By A Database Connection 4968** 4969** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4970** memory as possible from database connection D. Unlike the 4971** [sqlite3_release_memory()] interface, this interface is in effect even 4972** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4973** omitted. 4974** 4975** See also: [sqlite3_release_memory()] 4976*/ 4977int sqlite3_db_release_memory(sqlite3*); 4978 4979/* 4980** CAPI3REF: Impose A Limit On Heap Size 4981** 4982** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4983** soft limit on the amount of heap memory that may be allocated by SQLite. 4984** ^SQLite strives to keep heap memory utilization below the soft heap 4985** limit by reducing the number of pages held in the page cache 4986** as heap memory usages approaches the limit. 4987** ^The soft heap limit is "soft" because even though SQLite strives to stay 4988** below the limit, it will exceed the limit rather than generate 4989** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4990** is advisory only. 4991** 4992** ^The return value from sqlite3_soft_heap_limit64() is the size of 4993** the soft heap limit prior to the call, or negative in the case of an 4994** error. ^If the argument N is negative 4995** then no change is made to the soft heap limit. Hence, the current 4996** size of the soft heap limit can be determined by invoking 4997** sqlite3_soft_heap_limit64() with a negative argument. 4998** 4999** ^If the argument N is zero then the soft heap limit is disabled. 5000** 5001** ^(The soft heap limit is not enforced in the current implementation 5002** if one or more of following conditions are true: 5003** 5004** <ul> 5005** <li> The soft heap limit is set to zero. 5006** <li> Memory accounting is disabled using a combination of the 5007** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5008** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5009** <li> An alternative page cache implementation is specified using 5010** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5011** <li> The page cache allocates from its own memory pool supplied 5012** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5013** from the heap. 5014** </ul>)^ 5015** 5016** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5017** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5018** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5019** the soft heap limit is enforced on every memory allocation. Without 5020** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5021** when memory is allocated by the page cache. Testing suggests that because 5022** the page cache is the predominate memory user in SQLite, most 5023** applications will achieve adequate soft heap limit enforcement without 5024** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5025** 5026** The circumstances under which SQLite will enforce the soft heap limit may 5027** changes in future releases of SQLite. 5028*/ 5029sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5030 5031/* 5032** CAPI3REF: Deprecated Soft Heap Limit Interface 5033** DEPRECATED 5034** 5035** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5036** interface. This routine is provided for historical compatibility 5037** only. All new applications should use the 5038** [sqlite3_soft_heap_limit64()] interface rather than this one. 5039*/ 5040SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5041 5042 5043/* 5044** CAPI3REF: Extract Metadata About A Column Of A Table 5045** 5046** ^This routine returns metadata about a specific column of a specific 5047** database table accessible using the [database connection] handle 5048** passed as the first function argument. 5049** 5050** ^The column is identified by the second, third and fourth parameters to 5051** this function. ^The second parameter is either the name of the database 5052** (i.e. "main", "temp", or an attached database) containing the specified 5053** table or NULL. ^If it is NULL, then all attached databases are searched 5054** for the table using the same algorithm used by the database engine to 5055** resolve unqualified table references. 5056** 5057** ^The third and fourth parameters to this function are the table and column 5058** name of the desired column, respectively. Neither of these parameters 5059** may be NULL. 5060** 5061** ^Metadata is returned by writing to the memory locations passed as the 5th 5062** and subsequent parameters to this function. ^Any of these arguments may be 5063** NULL, in which case the corresponding element of metadata is omitted. 5064** 5065** ^(<blockquote> 5066** <table border="1"> 5067** <tr><th> Parameter <th> Output<br>Type <th> Description 5068** 5069** <tr><td> 5th <td> const char* <td> Data type 5070** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5071** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5072** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5073** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5074** </table> 5075** </blockquote>)^ 5076** 5077** ^The memory pointed to by the character pointers returned for the 5078** declaration type and collation sequence is valid only until the next 5079** call to any SQLite API function. 5080** 5081** ^If the specified table is actually a view, an [error code] is returned. 5082** 5083** ^If the specified column is "rowid", "oid" or "_rowid_" and an 5084** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5085** parameters are set for the explicitly declared column. ^(If there is no 5086** explicitly declared [INTEGER PRIMARY KEY] column, then the output 5087** parameters are set as follows: 5088** 5089** <pre> 5090** data type: "INTEGER" 5091** collation sequence: "BINARY" 5092** not null: 0 5093** primary key: 1 5094** auto increment: 0 5095** </pre>)^ 5096** 5097** ^(This function may load one or more schemas from database files. If an 5098** error occurs during this process, or if the requested table or column 5099** cannot be found, an [error code] is returned and an error message left 5100** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 5101** 5102** ^This API is only available if the library was compiled with the 5103** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5104*/ 5105int sqlite3_table_column_metadata( 5106 sqlite3 *db, /* Connection handle */ 5107 const char *zDbName, /* Database name or NULL */ 5108 const char *zTableName, /* Table name */ 5109 const char *zColumnName, /* Column name */ 5110 char const **pzDataType, /* OUTPUT: Declared data type */ 5111 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5112 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5113 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5114 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5115); 5116 5117/* 5118** CAPI3REF: Load An Extension 5119** 5120** ^This interface loads an SQLite extension library from the named file. 5121** 5122** ^The sqlite3_load_extension() interface attempts to load an 5123** [SQLite extension] library contained in the file zFile. If 5124** the file cannot be loaded directly, attempts are made to load 5125** with various operating-system specific extensions added. 5126** So for example, if "samplelib" cannot be loaded, then names like 5127** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5128** be tried also. 5129** 5130** ^The entry point is zProc. 5131** ^(zProc may be 0, in which case SQLite will try to come up with an 5132** entry point name on its own. It first tries "sqlite3_extension_init". 5133** If that does not work, it constructs a name "sqlite3_X_init" where the 5134** X is consists of the lower-case equivalent of all ASCII alphabetic 5135** characters in the filename from the last "/" to the first following 5136** "." and omitting any initial "lib".)^ 5137** ^The sqlite3_load_extension() interface returns 5138** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5139** ^If an error occurs and pzErrMsg is not 0, then the 5140** [sqlite3_load_extension()] interface shall attempt to 5141** fill *pzErrMsg with error message text stored in memory 5142** obtained from [sqlite3_malloc()]. The calling function 5143** should free this memory by calling [sqlite3_free()]. 5144** 5145** ^Extension loading must be enabled using 5146** [sqlite3_enable_load_extension()] prior to calling this API, 5147** otherwise an error will be returned. 5148** 5149** See also the [load_extension() SQL function]. 5150*/ 5151int sqlite3_load_extension( 5152 sqlite3 *db, /* Load the extension into this database connection */ 5153 const char *zFile, /* Name of the shared library containing extension */ 5154 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5155 char **pzErrMsg /* Put error message here if not 0 */ 5156); 5157 5158/* 5159** CAPI3REF: Enable Or Disable Extension Loading 5160** 5161** ^So as not to open security holes in older applications that are 5162** unprepared to deal with [extension loading], and as a means of disabling 5163** [extension loading] while evaluating user-entered SQL, the following API 5164** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5165** 5166** ^Extension loading is off by default. 5167** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5168** to turn extension loading on and call it with onoff==0 to turn 5169** it back off again. 5170*/ 5171int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5172 5173/* 5174** CAPI3REF: Automatically Load Statically Linked Extensions 5175** 5176** ^This interface causes the xEntryPoint() function to be invoked for 5177** each new [database connection] that is created. The idea here is that 5178** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5179** that is to be automatically loaded into all new database connections. 5180** 5181** ^(Even though the function prototype shows that xEntryPoint() takes 5182** no arguments and returns void, SQLite invokes xEntryPoint() with three 5183** arguments and expects and integer result as if the signature of the 5184** entry point where as follows: 5185** 5186** <blockquote><pre> 5187** int xEntryPoint( 5188** sqlite3 *db, 5189** const char **pzErrMsg, 5190** const struct sqlite3_api_routines *pThunk 5191** ); 5192** </pre></blockquote>)^ 5193** 5194** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5195** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5196** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5197** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5198** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5199** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5200** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5201** 5202** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5203** on the list of automatic extensions is a harmless no-op. ^No entry point 5204** will be called more than once for each database connection that is opened. 5205** 5206** See also: [sqlite3_reset_auto_extension()] 5207** and [sqlite3_cancel_auto_extension()] 5208*/ 5209int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5210 5211/* 5212** CAPI3REF: Cancel Automatic Extension Loading 5213** 5214** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5215** initialization routine X that was registered using a prior call to 5216** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5217** routine returns 1 if initialization routine X was successfully 5218** unregistered and it returns 0 if X was not on the list of initialization 5219** routines. 5220*/ 5221int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5222 5223/* 5224** CAPI3REF: Reset Automatic Extension Loading 5225** 5226** ^This interface disables all automatic extensions previously 5227** registered using [sqlite3_auto_extension()]. 5228*/ 5229void sqlite3_reset_auto_extension(void); 5230 5231/* 5232** The interface to the virtual-table mechanism is currently considered 5233** to be experimental. The interface might change in incompatible ways. 5234** If this is a problem for you, do not use the interface at this time. 5235** 5236** When the virtual-table mechanism stabilizes, we will declare the 5237** interface fixed, support it indefinitely, and remove this comment. 5238*/ 5239 5240/* 5241** Structures used by the virtual table interface 5242*/ 5243typedef struct sqlite3_vtab sqlite3_vtab; 5244typedef struct sqlite3_index_info sqlite3_index_info; 5245typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5246typedef struct sqlite3_module sqlite3_module; 5247 5248/* 5249** CAPI3REF: Virtual Table Object 5250** KEYWORDS: sqlite3_module {virtual table module} 5251** 5252** This structure, sometimes called a "virtual table module", 5253** defines the implementation of a [virtual tables]. 5254** This structure consists mostly of methods for the module. 5255** 5256** ^A virtual table module is created by filling in a persistent 5257** instance of this structure and passing a pointer to that instance 5258** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5259** ^The registration remains valid until it is replaced by a different 5260** module or until the [database connection] closes. The content 5261** of this structure must not change while it is registered with 5262** any database connection. 5263*/ 5264struct sqlite3_module { 5265 int iVersion; 5266 int (*xCreate)(sqlite3*, void *pAux, 5267 int argc, const char *const*argv, 5268 sqlite3_vtab **ppVTab, char**); 5269 int (*xConnect)(sqlite3*, void *pAux, 5270 int argc, const char *const*argv, 5271 sqlite3_vtab **ppVTab, char**); 5272 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5273 int (*xDisconnect)(sqlite3_vtab *pVTab); 5274 int (*xDestroy)(sqlite3_vtab *pVTab); 5275 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5276 int (*xClose)(sqlite3_vtab_cursor*); 5277 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5278 int argc, sqlite3_value **argv); 5279 int (*xNext)(sqlite3_vtab_cursor*); 5280 int (*xEof)(sqlite3_vtab_cursor*); 5281 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5282 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5283 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5284 int (*xBegin)(sqlite3_vtab *pVTab); 5285 int (*xSync)(sqlite3_vtab *pVTab); 5286 int (*xCommit)(sqlite3_vtab *pVTab); 5287 int (*xRollback)(sqlite3_vtab *pVTab); 5288 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5289 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5290 void **ppArg); 5291 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5292 /* The methods above are in version 1 of the sqlite_module object. Those 5293 ** below are for version 2 and greater. */ 5294 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5295 int (*xRelease)(sqlite3_vtab *pVTab, int); 5296 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5297}; 5298 5299/* 5300** CAPI3REF: Virtual Table Indexing Information 5301** KEYWORDS: sqlite3_index_info 5302** 5303** The sqlite3_index_info structure and its substructures is used as part 5304** of the [virtual table] interface to 5305** pass information into and receive the reply from the [xBestIndex] 5306** method of a [virtual table module]. The fields under **Inputs** are the 5307** inputs to xBestIndex and are read-only. xBestIndex inserts its 5308** results into the **Outputs** fields. 5309** 5310** ^(The aConstraint[] array records WHERE clause constraints of the form: 5311** 5312** <blockquote>column OP expr</blockquote> 5313** 5314** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5315** stored in aConstraint[].op using one of the 5316** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5317** ^(The index of the column is stored in 5318** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5319** expr on the right-hand side can be evaluated (and thus the constraint 5320** is usable) and false if it cannot.)^ 5321** 5322** ^The optimizer automatically inverts terms of the form "expr OP column" 5323** and makes other simplifications to the WHERE clause in an attempt to 5324** get as many WHERE clause terms into the form shown above as possible. 5325** ^The aConstraint[] array only reports WHERE clause terms that are 5326** relevant to the particular virtual table being queried. 5327** 5328** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5329** ^Each term of aOrderBy records a column of the ORDER BY clause. 5330** 5331** The [xBestIndex] method must fill aConstraintUsage[] with information 5332** about what parameters to pass to xFilter. ^If argvIndex>0 then 5333** the right-hand side of the corresponding aConstraint[] is evaluated 5334** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5335** is true, then the constraint is assumed to be fully handled by the 5336** virtual table and is not checked again by SQLite.)^ 5337** 5338** ^The idxNum and idxPtr values are recorded and passed into the 5339** [xFilter] method. 5340** ^[sqlite3_free()] is used to free idxPtr if and only if 5341** needToFreeIdxPtr is true. 5342** 5343** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5344** the correct order to satisfy the ORDER BY clause so that no separate 5345** sorting step is required. 5346** 5347** ^The estimatedCost value is an estimate of the cost of a particular 5348** strategy. A cost of N indicates that the cost of the strategy is similar 5349** to a linear scan of an SQLite table with N rows. A cost of log(N) 5350** indicates that the expense of the operation is similar to that of a 5351** binary search on a unique indexed field of an SQLite table with N rows. 5352** 5353** ^The estimatedRows value is an estimate of the number of rows that 5354** will be returned by the strategy. 5355** 5356** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5357** structure for SQLite version 3.8.2. If a virtual table extension is 5358** used with an SQLite version earlier than 3.8.2, the results of attempting 5359** to read or write the estimatedRows field are undefined (but are likely 5360** to included crashing the application). The estimatedRows field should 5361** therefore only be used if [sqlite3_libversion_number()] returns a 5362** value greater than or equal to 3008002. 5363*/ 5364struct sqlite3_index_info { 5365 /* Inputs */ 5366 int nConstraint; /* Number of entries in aConstraint */ 5367 struct sqlite3_index_constraint { 5368 int iColumn; /* Column on left-hand side of constraint */ 5369 unsigned char op; /* Constraint operator */ 5370 unsigned char usable; /* True if this constraint is usable */ 5371 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5372 } *aConstraint; /* Table of WHERE clause constraints */ 5373 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5374 struct sqlite3_index_orderby { 5375 int iColumn; /* Column number */ 5376 unsigned char desc; /* True for DESC. False for ASC. */ 5377 } *aOrderBy; /* The ORDER BY clause */ 5378 /* Outputs */ 5379 struct sqlite3_index_constraint_usage { 5380 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5381 unsigned char omit; /* Do not code a test for this constraint */ 5382 } *aConstraintUsage; 5383 int idxNum; /* Number used to identify the index */ 5384 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5385 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5386 int orderByConsumed; /* True if output is already ordered */ 5387 double estimatedCost; /* Estimated cost of using this index */ 5388 /* Fields below are only available in SQLite 3.8.2 and later */ 5389 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5390}; 5391 5392/* 5393** CAPI3REF: Virtual Table Constraint Operator Codes 5394** 5395** These macros defined the allowed values for the 5396** [sqlite3_index_info].aConstraint[].op field. Each value represents 5397** an operator that is part of a constraint term in the wHERE clause of 5398** a query that uses a [virtual table]. 5399*/ 5400#define SQLITE_INDEX_CONSTRAINT_EQ 2 5401#define SQLITE_INDEX_CONSTRAINT_GT 4 5402#define SQLITE_INDEX_CONSTRAINT_LE 8 5403#define SQLITE_INDEX_CONSTRAINT_LT 16 5404#define SQLITE_INDEX_CONSTRAINT_GE 32 5405#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5406 5407/* 5408** CAPI3REF: Register A Virtual Table Implementation 5409** 5410** ^These routines are used to register a new [virtual table module] name. 5411** ^Module names must be registered before 5412** creating a new [virtual table] using the module and before using a 5413** preexisting [virtual table] for the module. 5414** 5415** ^The module name is registered on the [database connection] specified 5416** by the first parameter. ^The name of the module is given by the 5417** second parameter. ^The third parameter is a pointer to 5418** the implementation of the [virtual table module]. ^The fourth 5419** parameter is an arbitrary client data pointer that is passed through 5420** into the [xCreate] and [xConnect] methods of the virtual table module 5421** when a new virtual table is be being created or reinitialized. 5422** 5423** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5424** is a pointer to a destructor for the pClientData. ^SQLite will 5425** invoke the destructor function (if it is not NULL) when SQLite 5426** no longer needs the pClientData pointer. ^The destructor will also 5427** be invoked if the call to sqlite3_create_module_v2() fails. 5428** ^The sqlite3_create_module() 5429** interface is equivalent to sqlite3_create_module_v2() with a NULL 5430** destructor. 5431*/ 5432int sqlite3_create_module( 5433 sqlite3 *db, /* SQLite connection to register module with */ 5434 const char *zName, /* Name of the module */ 5435 const sqlite3_module *p, /* Methods for the module */ 5436 void *pClientData /* Client data for xCreate/xConnect */ 5437); 5438int sqlite3_create_module_v2( 5439 sqlite3 *db, /* SQLite connection to register module with */ 5440 const char *zName, /* Name of the module */ 5441 const sqlite3_module *p, /* Methods for the module */ 5442 void *pClientData, /* Client data for xCreate/xConnect */ 5443 void(*xDestroy)(void*) /* Module destructor function */ 5444); 5445 5446/* 5447** CAPI3REF: Virtual Table Instance Object 5448** KEYWORDS: sqlite3_vtab 5449** 5450** Every [virtual table module] implementation uses a subclass 5451** of this object to describe a particular instance 5452** of the [virtual table]. Each subclass will 5453** be tailored to the specific needs of the module implementation. 5454** The purpose of this superclass is to define certain fields that are 5455** common to all module implementations. 5456** 5457** ^Virtual tables methods can set an error message by assigning a 5458** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5459** take care that any prior string is freed by a call to [sqlite3_free()] 5460** prior to assigning a new string to zErrMsg. ^After the error message 5461** is delivered up to the client application, the string will be automatically 5462** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5463*/ 5464struct sqlite3_vtab { 5465 const sqlite3_module *pModule; /* The module for this virtual table */ 5466 int nRef; /* NO LONGER USED */ 5467 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5468 /* Virtual table implementations will typically add additional fields */ 5469}; 5470 5471/* 5472** CAPI3REF: Virtual Table Cursor Object 5473** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5474** 5475** Every [virtual table module] implementation uses a subclass of the 5476** following structure to describe cursors that point into the 5477** [virtual table] and are used 5478** to loop through the virtual table. Cursors are created using the 5479** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5480** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5481** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5482** of the module. Each module implementation will define 5483** the content of a cursor structure to suit its own needs. 5484** 5485** This superclass exists in order to define fields of the cursor that 5486** are common to all implementations. 5487*/ 5488struct sqlite3_vtab_cursor { 5489 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5490 /* Virtual table implementations will typically add additional fields */ 5491}; 5492 5493/* 5494** CAPI3REF: Declare The Schema Of A Virtual Table 5495** 5496** ^The [xCreate] and [xConnect] methods of a 5497** [virtual table module] call this interface 5498** to declare the format (the names and datatypes of the columns) of 5499** the virtual tables they implement. 5500*/ 5501int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5502 5503/* 5504** CAPI3REF: Overload A Function For A Virtual Table 5505** 5506** ^(Virtual tables can provide alternative implementations of functions 5507** using the [xFindFunction] method of the [virtual table module]. 5508** But global versions of those functions 5509** must exist in order to be overloaded.)^ 5510** 5511** ^(This API makes sure a global version of a function with a particular 5512** name and number of parameters exists. If no such function exists 5513** before this API is called, a new function is created.)^ ^The implementation 5514** of the new function always causes an exception to be thrown. So 5515** the new function is not good for anything by itself. Its only 5516** purpose is to be a placeholder function that can be overloaded 5517** by a [virtual table]. 5518*/ 5519int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5520 5521/* 5522** The interface to the virtual-table mechanism defined above (back up 5523** to a comment remarkably similar to this one) is currently considered 5524** to be experimental. The interface might change in incompatible ways. 5525** If this is a problem for you, do not use the interface at this time. 5526** 5527** When the virtual-table mechanism stabilizes, we will declare the 5528** interface fixed, support it indefinitely, and remove this comment. 5529*/ 5530 5531/* 5532** CAPI3REF: A Handle To An Open BLOB 5533** KEYWORDS: {BLOB handle} {BLOB handles} 5534** 5535** An instance of this object represents an open BLOB on which 5536** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5537** ^Objects of this type are created by [sqlite3_blob_open()] 5538** and destroyed by [sqlite3_blob_close()]. 5539** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5540** can be used to read or write small subsections of the BLOB. 5541** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5542*/ 5543typedef struct sqlite3_blob sqlite3_blob; 5544 5545/* 5546** CAPI3REF: Open A BLOB For Incremental I/O 5547** 5548** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5549** in row iRow, column zColumn, table zTable in database zDb; 5550** in other words, the same BLOB that would be selected by: 5551** 5552** <pre> 5553** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5554** </pre>)^ 5555** 5556** ^If the flags parameter is non-zero, then the BLOB is opened for read 5557** and write access. ^If it is zero, the BLOB is opened for read access. 5558** ^It is not possible to open a column that is part of an index or primary 5559** key for writing. ^If [foreign key constraints] are enabled, it is 5560** not possible to open a column that is part of a [child key] for writing. 5561** 5562** ^Note that the database name is not the filename that contains 5563** the database but rather the symbolic name of the database that 5564** appears after the AS keyword when the database is connected using [ATTACH]. 5565** ^For the main database file, the database name is "main". 5566** ^For TEMP tables, the database name is "temp". 5567** 5568** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5569** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5570** to be a null pointer.)^ 5571** ^This function sets the [database connection] error code and message 5572** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5573** functions. ^Note that the *ppBlob variable is always initialized in a 5574** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5575** regardless of the success or failure of this routine. 5576** 5577** ^(If the row that a BLOB handle points to is modified by an 5578** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5579** then the BLOB handle is marked as "expired". 5580** This is true if any column of the row is changed, even a column 5581** other than the one the BLOB handle is open on.)^ 5582** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5583** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5584** ^(Changes written into a BLOB prior to the BLOB expiring are not 5585** rolled back by the expiration of the BLOB. Such changes will eventually 5586** commit if the transaction continues to completion.)^ 5587** 5588** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5589** the opened blob. ^The size of a blob may not be changed by this 5590** interface. Use the [UPDATE] SQL command to change the size of a 5591** blob. 5592** 5593** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] 5594** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. 5595** 5596** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5597** and the built-in [zeroblob] SQL function can be used, if desired, 5598** to create an empty, zero-filled blob in which to read or write using 5599** this interface. 5600** 5601** To avoid a resource leak, every open [BLOB handle] should eventually 5602** be released by a call to [sqlite3_blob_close()]. 5603*/ 5604int sqlite3_blob_open( 5605 sqlite3*, 5606 const char *zDb, 5607 const char *zTable, 5608 const char *zColumn, 5609 sqlite3_int64 iRow, 5610 int flags, 5611 sqlite3_blob **ppBlob 5612); 5613 5614/* 5615** CAPI3REF: Move a BLOB Handle to a New Row 5616** 5617** ^This function is used to move an existing blob handle so that it points 5618** to a different row of the same database table. ^The new row is identified 5619** by the rowid value passed as the second argument. Only the row can be 5620** changed. ^The database, table and column on which the blob handle is open 5621** remain the same. Moving an existing blob handle to a new row can be 5622** faster than closing the existing handle and opening a new one. 5623** 5624** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5625** it must exist and there must be either a blob or text value stored in 5626** the nominated column.)^ ^If the new row is not present in the table, or if 5627** it does not contain a blob or text value, or if another error occurs, an 5628** SQLite error code is returned and the blob handle is considered aborted. 5629** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5630** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5631** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5632** always returns zero. 5633** 5634** ^This function sets the database handle error code and message. 5635*/ 5636SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5637 5638/* 5639** CAPI3REF: Close A BLOB Handle 5640** 5641** ^Closes an open [BLOB handle]. 5642** 5643** ^Closing a BLOB shall cause the current transaction to commit 5644** if there are no other BLOBs, no pending prepared statements, and the 5645** database connection is in [autocommit mode]. 5646** ^If any writes were made to the BLOB, they might be held in cache 5647** until the close operation if they will fit. 5648** 5649** ^(Closing the BLOB often forces the changes 5650** out to disk and so if any I/O errors occur, they will likely occur 5651** at the time when the BLOB is closed. Any errors that occur during 5652** closing are reported as a non-zero return value.)^ 5653** 5654** ^(The BLOB is closed unconditionally. Even if this routine returns 5655** an error code, the BLOB is still closed.)^ 5656** 5657** ^Calling this routine with a null pointer (such as would be returned 5658** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5659*/ 5660int sqlite3_blob_close(sqlite3_blob *); 5661 5662/* 5663** CAPI3REF: Return The Size Of An Open BLOB 5664** 5665** ^Returns the size in bytes of the BLOB accessible via the 5666** successfully opened [BLOB handle] in its only argument. ^The 5667** incremental blob I/O routines can only read or overwriting existing 5668** blob content; they cannot change the size of a blob. 5669** 5670** This routine only works on a [BLOB handle] which has been created 5671** by a prior successful call to [sqlite3_blob_open()] and which has not 5672** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5673** to this routine results in undefined and probably undesirable behavior. 5674*/ 5675int sqlite3_blob_bytes(sqlite3_blob *); 5676 5677/* 5678** CAPI3REF: Read Data From A BLOB Incrementally 5679** 5680** ^(This function is used to read data from an open [BLOB handle] into a 5681** caller-supplied buffer. N bytes of data are copied into buffer Z 5682** from the open BLOB, starting at offset iOffset.)^ 5683** 5684** ^If offset iOffset is less than N bytes from the end of the BLOB, 5685** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5686** less than zero, [SQLITE_ERROR] is returned and no data is read. 5687** ^The size of the blob (and hence the maximum value of N+iOffset) 5688** can be determined using the [sqlite3_blob_bytes()] interface. 5689** 5690** ^An attempt to read from an expired [BLOB handle] fails with an 5691** error code of [SQLITE_ABORT]. 5692** 5693** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5694** Otherwise, an [error code] or an [extended error code] is returned.)^ 5695** 5696** This routine only works on a [BLOB handle] which has been created 5697** by a prior successful call to [sqlite3_blob_open()] and which has not 5698** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5699** to this routine results in undefined and probably undesirable behavior. 5700** 5701** See also: [sqlite3_blob_write()]. 5702*/ 5703int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5704 5705/* 5706** CAPI3REF: Write Data Into A BLOB Incrementally 5707** 5708** ^This function is used to write data into an open [BLOB handle] from a 5709** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5710** into the open BLOB, starting at offset iOffset. 5711** 5712** ^If the [BLOB handle] passed as the first argument was not opened for 5713** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5714** this function returns [SQLITE_READONLY]. 5715** 5716** ^This function may only modify the contents of the BLOB; it is 5717** not possible to increase the size of a BLOB using this API. 5718** ^If offset iOffset is less than N bytes from the end of the BLOB, 5719** [SQLITE_ERROR] is returned and no data is written. ^If N is 5720** less than zero [SQLITE_ERROR] is returned and no data is written. 5721** The size of the BLOB (and hence the maximum value of N+iOffset) 5722** can be determined using the [sqlite3_blob_bytes()] interface. 5723** 5724** ^An attempt to write to an expired [BLOB handle] fails with an 5725** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5726** before the [BLOB handle] expired are not rolled back by the 5727** expiration of the handle, though of course those changes might 5728** have been overwritten by the statement that expired the BLOB handle 5729** or by other independent statements. 5730** 5731** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5732** Otherwise, an [error code] or an [extended error code] is returned.)^ 5733** 5734** This routine only works on a [BLOB handle] which has been created 5735** by a prior successful call to [sqlite3_blob_open()] and which has not 5736** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5737** to this routine results in undefined and probably undesirable behavior. 5738** 5739** See also: [sqlite3_blob_read()]. 5740*/ 5741int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5742 5743/* 5744** CAPI3REF: Virtual File System Objects 5745** 5746** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5747** that SQLite uses to interact 5748** with the underlying operating system. Most SQLite builds come with a 5749** single default VFS that is appropriate for the host computer. 5750** New VFSes can be registered and existing VFSes can be unregistered. 5751** The following interfaces are provided. 5752** 5753** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5754** ^Names are case sensitive. 5755** ^Names are zero-terminated UTF-8 strings. 5756** ^If there is no match, a NULL pointer is returned. 5757** ^If zVfsName is NULL then the default VFS is returned. 5758** 5759** ^New VFSes are registered with sqlite3_vfs_register(). 5760** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5761** ^The same VFS can be registered multiple times without injury. 5762** ^To make an existing VFS into the default VFS, register it again 5763** with the makeDflt flag set. If two different VFSes with the 5764** same name are registered, the behavior is undefined. If a 5765** VFS is registered with a name that is NULL or an empty string, 5766** then the behavior is undefined. 5767** 5768** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5769** ^(If the default VFS is unregistered, another VFS is chosen as 5770** the default. The choice for the new VFS is arbitrary.)^ 5771*/ 5772sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5773int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5774int sqlite3_vfs_unregister(sqlite3_vfs*); 5775 5776/* 5777** CAPI3REF: Mutexes 5778** 5779** The SQLite core uses these routines for thread 5780** synchronization. Though they are intended for internal 5781** use by SQLite, code that links against SQLite is 5782** permitted to use any of these routines. 5783** 5784** The SQLite source code contains multiple implementations 5785** of these mutex routines. An appropriate implementation 5786** is selected automatically at compile-time. ^(The following 5787** implementations are available in the SQLite core: 5788** 5789** <ul> 5790** <li> SQLITE_MUTEX_PTHREADS 5791** <li> SQLITE_MUTEX_W32 5792** <li> SQLITE_MUTEX_NOOP 5793** </ul>)^ 5794** 5795** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5796** that does no real locking and is appropriate for use in 5797** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5798** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5799** and Windows. 5800** 5801** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5802** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5803** implementation is included with the library. In this case the 5804** application must supply a custom mutex implementation using the 5805** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5806** before calling sqlite3_initialize() or any other public sqlite3_ 5807** function that calls sqlite3_initialize().)^ 5808** 5809** ^The sqlite3_mutex_alloc() routine allocates a new 5810** mutex and returns a pointer to it. ^If it returns NULL 5811** that means that a mutex could not be allocated. ^SQLite 5812** will unwind its stack and return an error. ^(The argument 5813** to sqlite3_mutex_alloc() is one of these integer constants: 5814** 5815** <ul> 5816** <li> SQLITE_MUTEX_FAST 5817** <li> SQLITE_MUTEX_RECURSIVE 5818** <li> SQLITE_MUTEX_STATIC_MASTER 5819** <li> SQLITE_MUTEX_STATIC_MEM 5820** <li> SQLITE_MUTEX_STATIC_MEM2 5821** <li> SQLITE_MUTEX_STATIC_PRNG 5822** <li> SQLITE_MUTEX_STATIC_LRU 5823** <li> SQLITE_MUTEX_STATIC_LRU2 5824** </ul>)^ 5825** 5826** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5827** cause sqlite3_mutex_alloc() to create 5828** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5829** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5830** The mutex implementation does not need to make a distinction 5831** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5832** not want to. ^SQLite will only request a recursive mutex in 5833** cases where it really needs one. ^If a faster non-recursive mutex 5834** implementation is available on the host platform, the mutex subsystem 5835** might return such a mutex in response to SQLITE_MUTEX_FAST. 5836** 5837** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5838** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5839** a pointer to a static preexisting mutex. ^Six static mutexes are 5840** used by the current version of SQLite. Future versions of SQLite 5841** may add additional static mutexes. Static mutexes are for internal 5842** use by SQLite only. Applications that use SQLite mutexes should 5843** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5844** SQLITE_MUTEX_RECURSIVE. 5845** 5846** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5847** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5848** returns a different mutex on every call. ^But for the static 5849** mutex types, the same mutex is returned on every call that has 5850** the same type number. 5851** 5852** ^The sqlite3_mutex_free() routine deallocates a previously 5853** allocated dynamic mutex. ^SQLite is careful to deallocate every 5854** dynamic mutex that it allocates. The dynamic mutexes must not be in 5855** use when they are deallocated. Attempting to deallocate a static 5856** mutex results in undefined behavior. ^SQLite never deallocates 5857** a static mutex. 5858** 5859** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5860** to enter a mutex. ^If another thread is already within the mutex, 5861** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5862** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5863** upon successful entry. ^(Mutexes created using 5864** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5865** In such cases the, 5866** mutex must be exited an equal number of times before another thread 5867** can enter.)^ ^(If the same thread tries to enter any other 5868** kind of mutex more than once, the behavior is undefined. 5869** SQLite will never exhibit 5870** such behavior in its own use of mutexes.)^ 5871** 5872** ^(Some systems (for example, Windows 95) do not support the operation 5873** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5874** will always return SQLITE_BUSY. The SQLite core only ever uses 5875** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5876** 5877** ^The sqlite3_mutex_leave() routine exits a mutex that was 5878** previously entered by the same thread. ^(The behavior 5879** is undefined if the mutex is not currently entered by the 5880** calling thread or is not currently allocated. SQLite will 5881** never do either.)^ 5882** 5883** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5884** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5885** behave as no-ops. 5886** 5887** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5888*/ 5889sqlite3_mutex *sqlite3_mutex_alloc(int); 5890void sqlite3_mutex_free(sqlite3_mutex*); 5891void sqlite3_mutex_enter(sqlite3_mutex*); 5892int sqlite3_mutex_try(sqlite3_mutex*); 5893void sqlite3_mutex_leave(sqlite3_mutex*); 5894 5895/* 5896** CAPI3REF: Mutex Methods Object 5897** 5898** An instance of this structure defines the low-level routines 5899** used to allocate and use mutexes. 5900** 5901** Usually, the default mutex implementations provided by SQLite are 5902** sufficient, however the user has the option of substituting a custom 5903** implementation for specialized deployments or systems for which SQLite 5904** does not provide a suitable implementation. In this case, the user 5905** creates and populates an instance of this structure to pass 5906** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5907** Additionally, an instance of this structure can be used as an 5908** output variable when querying the system for the current mutex 5909** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5910** 5911** ^The xMutexInit method defined by this structure is invoked as 5912** part of system initialization by the sqlite3_initialize() function. 5913** ^The xMutexInit routine is called by SQLite exactly once for each 5914** effective call to [sqlite3_initialize()]. 5915** 5916** ^The xMutexEnd method defined by this structure is invoked as 5917** part of system shutdown by the sqlite3_shutdown() function. The 5918** implementation of this method is expected to release all outstanding 5919** resources obtained by the mutex methods implementation, especially 5920** those obtained by the xMutexInit method. ^The xMutexEnd() 5921** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5922** 5923** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5924** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5925** xMutexNotheld) implement the following interfaces (respectively): 5926** 5927** <ul> 5928** <li> [sqlite3_mutex_alloc()] </li> 5929** <li> [sqlite3_mutex_free()] </li> 5930** <li> [sqlite3_mutex_enter()] </li> 5931** <li> [sqlite3_mutex_try()] </li> 5932** <li> [sqlite3_mutex_leave()] </li> 5933** <li> [sqlite3_mutex_held()] </li> 5934** <li> [sqlite3_mutex_notheld()] </li> 5935** </ul>)^ 5936** 5937** The only difference is that the public sqlite3_XXX functions enumerated 5938** above silently ignore any invocations that pass a NULL pointer instead 5939** of a valid mutex handle. The implementations of the methods defined 5940** by this structure are not required to handle this case, the results 5941** of passing a NULL pointer instead of a valid mutex handle are undefined 5942** (i.e. it is acceptable to provide an implementation that segfaults if 5943** it is passed a NULL pointer). 5944** 5945** The xMutexInit() method must be threadsafe. ^It must be harmless to 5946** invoke xMutexInit() multiple times within the same process and without 5947** intervening calls to xMutexEnd(). Second and subsequent calls to 5948** xMutexInit() must be no-ops. 5949** 5950** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5951** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5952** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5953** memory allocation for a fast or recursive mutex. 5954** 5955** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5956** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5957** If xMutexInit fails in any way, it is expected to clean up after itself 5958** prior to returning. 5959*/ 5960typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5961struct sqlite3_mutex_methods { 5962 int (*xMutexInit)(void); 5963 int (*xMutexEnd)(void); 5964 sqlite3_mutex *(*xMutexAlloc)(int); 5965 void (*xMutexFree)(sqlite3_mutex *); 5966 void (*xMutexEnter)(sqlite3_mutex *); 5967 int (*xMutexTry)(sqlite3_mutex *); 5968 void (*xMutexLeave)(sqlite3_mutex *); 5969 int (*xMutexHeld)(sqlite3_mutex *); 5970 int (*xMutexNotheld)(sqlite3_mutex *); 5971}; 5972 5973/* 5974** CAPI3REF: Mutex Verification Routines 5975** 5976** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5977** are intended for use inside assert() statements. ^The SQLite core 5978** never uses these routines except inside an assert() and applications 5979** are advised to follow the lead of the core. ^The SQLite core only 5980** provides implementations for these routines when it is compiled 5981** with the SQLITE_DEBUG flag. ^External mutex implementations 5982** are only required to provide these routines if SQLITE_DEBUG is 5983** defined and if NDEBUG is not defined. 5984** 5985** ^These routines should return true if the mutex in their argument 5986** is held or not held, respectively, by the calling thread. 5987** 5988** ^The implementation is not required to provide versions of these 5989** routines that actually work. If the implementation does not provide working 5990** versions of these routines, it should at least provide stubs that always 5991** return true so that one does not get spurious assertion failures. 5992** 5993** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5994** the routine should return 1. This seems counter-intuitive since 5995** clearly the mutex cannot be held if it does not exist. But 5996** the reason the mutex does not exist is because the build is not 5997** using mutexes. And we do not want the assert() containing the 5998** call to sqlite3_mutex_held() to fail, so a non-zero return is 5999** the appropriate thing to do. ^The sqlite3_mutex_notheld() 6000** interface should also return 1 when given a NULL pointer. 6001*/ 6002#ifndef NDEBUG 6003int sqlite3_mutex_held(sqlite3_mutex*); 6004int sqlite3_mutex_notheld(sqlite3_mutex*); 6005#endif 6006 6007/* 6008** CAPI3REF: Mutex Types 6009** 6010** The [sqlite3_mutex_alloc()] interface takes a single argument 6011** which is one of these integer constants. 6012** 6013** The set of static mutexes may change from one SQLite release to the 6014** next. Applications that override the built-in mutex logic must be 6015** prepared to accommodate additional static mutexes. 6016*/ 6017#define SQLITE_MUTEX_FAST 0 6018#define SQLITE_MUTEX_RECURSIVE 1 6019#define SQLITE_MUTEX_STATIC_MASTER 2 6020#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6021#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6022#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6023#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6024#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6025#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6026#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6027 6028/* 6029** CAPI3REF: Retrieve the mutex for a database connection 6030** 6031** ^This interface returns a pointer the [sqlite3_mutex] object that 6032** serializes access to the [database connection] given in the argument 6033** when the [threading mode] is Serialized. 6034** ^If the [threading mode] is Single-thread or Multi-thread then this 6035** routine returns a NULL pointer. 6036*/ 6037sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6038 6039/* 6040** CAPI3REF: Low-Level Control Of Database Files 6041** 6042** ^The [sqlite3_file_control()] interface makes a direct call to the 6043** xFileControl method for the [sqlite3_io_methods] object associated 6044** with a particular database identified by the second argument. ^The 6045** name of the database is "main" for the main database or "temp" for the 6046** TEMP database, or the name that appears after the AS keyword for 6047** databases that are added using the [ATTACH] SQL command. 6048** ^A NULL pointer can be used in place of "main" to refer to the 6049** main database file. 6050** ^The third and fourth parameters to this routine 6051** are passed directly through to the second and third parameters of 6052** the xFileControl method. ^The return value of the xFileControl 6053** method becomes the return value of this routine. 6054** 6055** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6056** a pointer to the underlying [sqlite3_file] object to be written into 6057** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6058** case is a short-circuit path which does not actually invoke the 6059** underlying sqlite3_io_methods.xFileControl method. 6060** 6061** ^If the second parameter (zDbName) does not match the name of any 6062** open database file, then SQLITE_ERROR is returned. ^This error 6063** code is not remembered and will not be recalled by [sqlite3_errcode()] 6064** or [sqlite3_errmsg()]. The underlying xFileControl method might 6065** also return SQLITE_ERROR. There is no way to distinguish between 6066** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6067** xFileControl method. 6068** 6069** See also: [SQLITE_FCNTL_LOCKSTATE] 6070*/ 6071int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6072 6073/* 6074** CAPI3REF: Testing Interface 6075** 6076** ^The sqlite3_test_control() interface is used to read out internal 6077** state of SQLite and to inject faults into SQLite for testing 6078** purposes. ^The first parameter is an operation code that determines 6079** the number, meaning, and operation of all subsequent parameters. 6080** 6081** This interface is not for use by applications. It exists solely 6082** for verifying the correct operation of the SQLite library. Depending 6083** on how the SQLite library is compiled, this interface might not exist. 6084** 6085** The details of the operation codes, their meanings, the parameters 6086** they take, and what they do are all subject to change without notice. 6087** Unlike most of the SQLite API, this function is not guaranteed to 6088** operate consistently from one release to the next. 6089*/ 6090int sqlite3_test_control(int op, ...); 6091 6092/* 6093** CAPI3REF: Testing Interface Operation Codes 6094** 6095** These constants are the valid operation code parameters used 6096** as the first argument to [sqlite3_test_control()]. 6097** 6098** These parameters and their meanings are subject to change 6099** without notice. These values are for testing purposes only. 6100** Applications should not use any of these parameters or the 6101** [sqlite3_test_control()] interface. 6102*/ 6103#define SQLITE_TESTCTRL_FIRST 5 6104#define SQLITE_TESTCTRL_PRNG_SAVE 5 6105#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6106#define SQLITE_TESTCTRL_PRNG_RESET 7 6107#define SQLITE_TESTCTRL_BITVEC_TEST 8 6108#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6109#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6110#define SQLITE_TESTCTRL_PENDING_BYTE 11 6111#define SQLITE_TESTCTRL_ASSERT 12 6112#define SQLITE_TESTCTRL_ALWAYS 13 6113#define SQLITE_TESTCTRL_RESERVE 14 6114#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6115#define SQLITE_TESTCTRL_ISKEYWORD 16 6116#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6117#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6118#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 6119#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6120#define SQLITE_TESTCTRL_LAST 20 6121 6122/* 6123** CAPI3REF: SQLite Runtime Status 6124** 6125** ^This interface is used to retrieve runtime status information 6126** about the performance of SQLite, and optionally to reset various 6127** highwater marks. ^The first argument is an integer code for 6128** the specific parameter to measure. ^(Recognized integer codes 6129** are of the form [status parameters | SQLITE_STATUS_...].)^ 6130** ^The current value of the parameter is returned into *pCurrent. 6131** ^The highest recorded value is returned in *pHighwater. ^If the 6132** resetFlag is true, then the highest record value is reset after 6133** *pHighwater is written. ^(Some parameters do not record the highest 6134** value. For those parameters 6135** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6136** ^(Other parameters record only the highwater mark and not the current 6137** value. For these latter parameters nothing is written into *pCurrent.)^ 6138** 6139** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6140** non-zero [error code] on failure. 6141** 6142** This routine is threadsafe but is not atomic. This routine can be 6143** called while other threads are running the same or different SQLite 6144** interfaces. However the values returned in *pCurrent and 6145** *pHighwater reflect the status of SQLite at different points in time 6146** and it is possible that another thread might change the parameter 6147** in between the times when *pCurrent and *pHighwater are written. 6148** 6149** See also: [sqlite3_db_status()] 6150*/ 6151int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6152 6153 6154/* 6155** CAPI3REF: Status Parameters 6156** KEYWORDS: {status parameters} 6157** 6158** These integer constants designate various run-time status parameters 6159** that can be returned by [sqlite3_status()]. 6160** 6161** <dl> 6162** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6163** <dd>This parameter is the current amount of memory checked out 6164** using [sqlite3_malloc()], either directly or indirectly. The 6165** figure includes calls made to [sqlite3_malloc()] by the application 6166** and internal memory usage by the SQLite library. Scratch memory 6167** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6168** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6169** this parameter. The amount returned is the sum of the allocation 6170** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6171** 6172** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6173** <dd>This parameter records the largest memory allocation request 6174** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6175** internal equivalents). Only the value returned in the 6176** *pHighwater parameter to [sqlite3_status()] is of interest. 6177** The value written into the *pCurrent parameter is undefined.</dd>)^ 6178** 6179** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6180** <dd>This parameter records the number of separate memory allocations 6181** currently checked out.</dd>)^ 6182** 6183** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6184** <dd>This parameter returns the number of pages used out of the 6185** [pagecache memory allocator] that was configured using 6186** [SQLITE_CONFIG_PAGECACHE]. The 6187** value returned is in pages, not in bytes.</dd>)^ 6188** 6189** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6190** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6191** <dd>This parameter returns the number of bytes of page cache 6192** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6193** buffer and where forced to overflow to [sqlite3_malloc()]. The 6194** returned value includes allocations that overflowed because they 6195** where too large (they were larger than the "sz" parameter to 6196** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6197** no space was left in the page cache.</dd>)^ 6198** 6199** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6200** <dd>This parameter records the largest memory allocation request 6201** handed to [pagecache memory allocator]. Only the value returned in the 6202** *pHighwater parameter to [sqlite3_status()] is of interest. 6203** The value written into the *pCurrent parameter is undefined.</dd>)^ 6204** 6205** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6206** <dd>This parameter returns the number of allocations used out of the 6207** [scratch memory allocator] configured using 6208** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6209** in bytes. Since a single thread may only have one scratch allocation 6210** outstanding at time, this parameter also reports the number of threads 6211** using scratch memory at the same time.</dd>)^ 6212** 6213** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6214** <dd>This parameter returns the number of bytes of scratch memory 6215** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6216** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6217** returned include overflows because the requested allocation was too 6218** larger (that is, because the requested allocation was larger than the 6219** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6220** slots were available. 6221** </dd>)^ 6222** 6223** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6224** <dd>This parameter records the largest memory allocation request 6225** handed to [scratch memory allocator]. Only the value returned in the 6226** *pHighwater parameter to [sqlite3_status()] is of interest. 6227** The value written into the *pCurrent parameter is undefined.</dd>)^ 6228** 6229** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6230** <dd>This parameter records the deepest parser stack. It is only 6231** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6232** </dl> 6233** 6234** New status parameters may be added from time to time. 6235*/ 6236#define SQLITE_STATUS_MEMORY_USED 0 6237#define SQLITE_STATUS_PAGECACHE_USED 1 6238#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6239#define SQLITE_STATUS_SCRATCH_USED 3 6240#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6241#define SQLITE_STATUS_MALLOC_SIZE 5 6242#define SQLITE_STATUS_PARSER_STACK 6 6243#define SQLITE_STATUS_PAGECACHE_SIZE 7 6244#define SQLITE_STATUS_SCRATCH_SIZE 8 6245#define SQLITE_STATUS_MALLOC_COUNT 9 6246 6247/* 6248** CAPI3REF: Database Connection Status 6249** 6250** ^This interface is used to retrieve runtime status information 6251** about a single [database connection]. ^The first argument is the 6252** database connection object to be interrogated. ^The second argument 6253** is an integer constant, taken from the set of 6254** [SQLITE_DBSTATUS options], that 6255** determines the parameter to interrogate. The set of 6256** [SQLITE_DBSTATUS options] is likely 6257** to grow in future releases of SQLite. 6258** 6259** ^The current value of the requested parameter is written into *pCur 6260** and the highest instantaneous value is written into *pHiwtr. ^If 6261** the resetFlg is true, then the highest instantaneous value is 6262** reset back down to the current value. 6263** 6264** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6265** non-zero [error code] on failure. 6266** 6267** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6268*/ 6269int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6270 6271/* 6272** CAPI3REF: Status Parameters for database connections 6273** KEYWORDS: {SQLITE_DBSTATUS options} 6274** 6275** These constants are the available integer "verbs" that can be passed as 6276** the second argument to the [sqlite3_db_status()] interface. 6277** 6278** New verbs may be added in future releases of SQLite. Existing verbs 6279** might be discontinued. Applications should check the return code from 6280** [sqlite3_db_status()] to make sure that the call worked. 6281** The [sqlite3_db_status()] interface will return a non-zero error code 6282** if a discontinued or unsupported verb is invoked. 6283** 6284** <dl> 6285** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6286** <dd>This parameter returns the number of lookaside memory slots currently 6287** checked out.</dd>)^ 6288** 6289** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6290** <dd>This parameter returns the number malloc attempts that were 6291** satisfied using lookaside memory. Only the high-water value is meaningful; 6292** the current value is always zero.)^ 6293** 6294** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6295** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6296** <dd>This parameter returns the number malloc attempts that might have 6297** been satisfied using lookaside memory but failed due to the amount of 6298** memory requested being larger than the lookaside slot size. 6299** Only the high-water value is meaningful; 6300** the current value is always zero.)^ 6301** 6302** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6303** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6304** <dd>This parameter returns the number malloc attempts that might have 6305** been satisfied using lookaside memory but failed due to all lookaside 6306** memory already being in use. 6307** Only the high-water value is meaningful; 6308** the current value is always zero.)^ 6309** 6310** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6311** <dd>This parameter returns the approximate number of of bytes of heap 6312** memory used by all pager caches associated with the database connection.)^ 6313** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6314** 6315** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6316** <dd>This parameter returns the approximate number of of bytes of heap 6317** memory used to store the schema for all databases associated 6318** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6319** ^The full amount of memory used by the schemas is reported, even if the 6320** schema memory is shared with other database connections due to 6321** [shared cache mode] being enabled. 6322** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6323** 6324** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6325** <dd>This parameter returns the approximate number of of bytes of heap 6326** and lookaside memory used by all prepared statements associated with 6327** the database connection.)^ 6328** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6329** </dd> 6330** 6331** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6332** <dd>This parameter returns the number of pager cache hits that have 6333** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6334** is always 0. 6335** </dd> 6336** 6337** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6338** <dd>This parameter returns the number of pager cache misses that have 6339** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6340** is always 0. 6341** </dd> 6342** 6343** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6344** <dd>This parameter returns the number of dirty cache entries that have 6345** been written to disk. Specifically, the number of pages written to the 6346** wal file in wal mode databases, or the number of pages written to the 6347** database file in rollback mode databases. Any pages written as part of 6348** transaction rollback or database recovery operations are not included. 6349** If an IO or other error occurs while writing a page to disk, the effect 6350** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6351** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6352** </dd> 6353** 6354** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6355** <dd>This parameter returns zero for the current value if and only if 6356** all foreign key constraints (deferred or immediate) have been 6357** resolved.)^ ^The highwater mark is always 0. 6358** </dd> 6359** </dl> 6360*/ 6361#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6362#define SQLITE_DBSTATUS_CACHE_USED 1 6363#define SQLITE_DBSTATUS_SCHEMA_USED 2 6364#define SQLITE_DBSTATUS_STMT_USED 3 6365#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6366#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6367#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6368#define SQLITE_DBSTATUS_CACHE_HIT 7 6369#define SQLITE_DBSTATUS_CACHE_MISS 8 6370#define SQLITE_DBSTATUS_CACHE_WRITE 9 6371#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6372#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6373 6374 6375/* 6376** CAPI3REF: Prepared Statement Status 6377** 6378** ^(Each prepared statement maintains various 6379** [SQLITE_STMTSTATUS counters] that measure the number 6380** of times it has performed specific operations.)^ These counters can 6381** be used to monitor the performance characteristics of the prepared 6382** statements. For example, if the number of table steps greatly exceeds 6383** the number of table searches or result rows, that would tend to indicate 6384** that the prepared statement is using a full table scan rather than 6385** an index. 6386** 6387** ^(This interface is used to retrieve and reset counter values from 6388** a [prepared statement]. The first argument is the prepared statement 6389** object to be interrogated. The second argument 6390** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6391** to be interrogated.)^ 6392** ^The current value of the requested counter is returned. 6393** ^If the resetFlg is true, then the counter is reset to zero after this 6394** interface call returns. 6395** 6396** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6397*/ 6398int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6399 6400/* 6401** CAPI3REF: Status Parameters for prepared statements 6402** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6403** 6404** These preprocessor macros define integer codes that name counter 6405** values associated with the [sqlite3_stmt_status()] interface. 6406** The meanings of the various counters are as follows: 6407** 6408** <dl> 6409** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6410** <dd>^This is the number of times that SQLite has stepped forward in 6411** a table as part of a full table scan. Large numbers for this counter 6412** may indicate opportunities for performance improvement through 6413** careful use of indices.</dd> 6414** 6415** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6416** <dd>^This is the number of sort operations that have occurred. 6417** A non-zero value in this counter may indicate an opportunity to 6418** improvement performance through careful use of indices.</dd> 6419** 6420** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6421** <dd>^This is the number of rows inserted into transient indices that 6422** were created automatically in order to help joins run faster. 6423** A non-zero value in this counter may indicate an opportunity to 6424** improvement performance by adding permanent indices that do not 6425** need to be reinitialized each time the statement is run.</dd> 6426** 6427** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6428** <dd>^This is the number of virtual machine operations executed 6429** by the prepared statement if that number is less than or equal 6430** to 2147483647. The number of virtual machine operations can be 6431** used as a proxy for the total work done by the prepared statement. 6432** If the number of virtual machine operations exceeds 2147483647 6433** then the value returned by this statement status code is undefined. 6434** </dd> 6435** </dl> 6436*/ 6437#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6438#define SQLITE_STMTSTATUS_SORT 2 6439#define SQLITE_STMTSTATUS_AUTOINDEX 3 6440#define SQLITE_STMTSTATUS_VM_STEP 4 6441 6442/* 6443** CAPI3REF: Custom Page Cache Object 6444** 6445** The sqlite3_pcache type is opaque. It is implemented by 6446** the pluggable module. The SQLite core has no knowledge of 6447** its size or internal structure and never deals with the 6448** sqlite3_pcache object except by holding and passing pointers 6449** to the object. 6450** 6451** See [sqlite3_pcache_methods2] for additional information. 6452*/ 6453typedef struct sqlite3_pcache sqlite3_pcache; 6454 6455/* 6456** CAPI3REF: Custom Page Cache Object 6457** 6458** The sqlite3_pcache_page object represents a single page in the 6459** page cache. The page cache will allocate instances of this 6460** object. Various methods of the page cache use pointers to instances 6461** of this object as parameters or as their return value. 6462** 6463** See [sqlite3_pcache_methods2] for additional information. 6464*/ 6465typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6466struct sqlite3_pcache_page { 6467 void *pBuf; /* The content of the page */ 6468 void *pExtra; /* Extra information associated with the page */ 6469}; 6470 6471/* 6472** CAPI3REF: Application Defined Page Cache. 6473** KEYWORDS: {page cache} 6474** 6475** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6476** register an alternative page cache implementation by passing in an 6477** instance of the sqlite3_pcache_methods2 structure.)^ 6478** In many applications, most of the heap memory allocated by 6479** SQLite is used for the page cache. 6480** By implementing a 6481** custom page cache using this API, an application can better control 6482** the amount of memory consumed by SQLite, the way in which 6483** that memory is allocated and released, and the policies used to 6484** determine exactly which parts of a database file are cached and for 6485** how long. 6486** 6487** The alternative page cache mechanism is an 6488** extreme measure that is only needed by the most demanding applications. 6489** The built-in page cache is recommended for most uses. 6490** 6491** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6492** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6493** the application may discard the parameter after the call to 6494** [sqlite3_config()] returns.)^ 6495** 6496** [[the xInit() page cache method]] 6497** ^(The xInit() method is called once for each effective 6498** call to [sqlite3_initialize()])^ 6499** (usually only once during the lifetime of the process). ^(The xInit() 6500** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6501** The intent of the xInit() method is to set up global data structures 6502** required by the custom page cache implementation. 6503** ^(If the xInit() method is NULL, then the 6504** built-in default page cache is used instead of the application defined 6505** page cache.)^ 6506** 6507** [[the xShutdown() page cache method]] 6508** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6509** It can be used to clean up 6510** any outstanding resources before process shutdown, if required. 6511** ^The xShutdown() method may be NULL. 6512** 6513** ^SQLite automatically serializes calls to the xInit method, 6514** so the xInit method need not be threadsafe. ^The 6515** xShutdown method is only called from [sqlite3_shutdown()] so it does 6516** not need to be threadsafe either. All other methods must be threadsafe 6517** in multithreaded applications. 6518** 6519** ^SQLite will never invoke xInit() more than once without an intervening 6520** call to xShutdown(). 6521** 6522** [[the xCreate() page cache methods]] 6523** ^SQLite invokes the xCreate() method to construct a new cache instance. 6524** SQLite will typically create one cache instance for each open database file, 6525** though this is not guaranteed. ^The 6526** first parameter, szPage, is the size in bytes of the pages that must 6527** be allocated by the cache. ^szPage will always a power of two. ^The 6528** second parameter szExtra is a number of bytes of extra storage 6529** associated with each page cache entry. ^The szExtra parameter will 6530** a number less than 250. SQLite will use the 6531** extra szExtra bytes on each page to store metadata about the underlying 6532** database page on disk. The value passed into szExtra depends 6533** on the SQLite version, the target platform, and how SQLite was compiled. 6534** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6535** created will be used to cache database pages of a file stored on disk, or 6536** false if it is used for an in-memory database. The cache implementation 6537** does not have to do anything special based with the value of bPurgeable; 6538** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6539** never invoke xUnpin() except to deliberately delete a page. 6540** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6541** false will always have the "discard" flag set to true. 6542** ^Hence, a cache created with bPurgeable false will 6543** never contain any unpinned pages. 6544** 6545** [[the xCachesize() page cache method]] 6546** ^(The xCachesize() method may be called at any time by SQLite to set the 6547** suggested maximum cache-size (number of pages stored by) the cache 6548** instance passed as the first argument. This is the value configured using 6549** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6550** parameter, the implementation is not required to do anything with this 6551** value; it is advisory only. 6552** 6553** [[the xPagecount() page cache methods]] 6554** The xPagecount() method must return the number of pages currently 6555** stored in the cache, both pinned and unpinned. 6556** 6557** [[the xFetch() page cache methods]] 6558** The xFetch() method locates a page in the cache and returns a pointer to 6559** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6560** The pBuf element of the returned sqlite3_pcache_page object will be a 6561** pointer to a buffer of szPage bytes used to store the content of a 6562** single database page. The pExtra element of sqlite3_pcache_page will be 6563** a pointer to the szExtra bytes of extra storage that SQLite has requested 6564** for each entry in the page cache. 6565** 6566** The page to be fetched is determined by the key. ^The minimum key value 6567** is 1. After it has been retrieved using xFetch, the page is considered 6568** to be "pinned". 6569** 6570** If the requested page is already in the page cache, then the page cache 6571** implementation must return a pointer to the page buffer with its content 6572** intact. If the requested page is not already in the cache, then the 6573** cache implementation should use the value of the createFlag 6574** parameter to help it determined what action to take: 6575** 6576** <table border=1 width=85% align=center> 6577** <tr><th> createFlag <th> Behavior when page is not already in cache 6578** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6579** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6580** Otherwise return NULL. 6581** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6582** NULL if allocating a new page is effectively impossible. 6583** </table> 6584** 6585** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6586** will only use a createFlag of 2 after a prior call with a createFlag of 1 6587** failed.)^ In between the to xFetch() calls, SQLite may 6588** attempt to unpin one or more cache pages by spilling the content of 6589** pinned pages to disk and synching the operating system disk cache. 6590** 6591** [[the xUnpin() page cache method]] 6592** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6593** as its second argument. If the third parameter, discard, is non-zero, 6594** then the page must be evicted from the cache. 6595** ^If the discard parameter is 6596** zero, then the page may be discarded or retained at the discretion of 6597** page cache implementation. ^The page cache implementation 6598** may choose to evict unpinned pages at any time. 6599** 6600** The cache must not perform any reference counting. A single 6601** call to xUnpin() unpins the page regardless of the number of prior calls 6602** to xFetch(). 6603** 6604** [[the xRekey() page cache methods]] 6605** The xRekey() method is used to change the key value associated with the 6606** page passed as the second argument. If the cache 6607** previously contains an entry associated with newKey, it must be 6608** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6609** to be pinned. 6610** 6611** When SQLite calls the xTruncate() method, the cache must discard all 6612** existing cache entries with page numbers (keys) greater than or equal 6613** to the value of the iLimit parameter passed to xTruncate(). If any 6614** of these pages are pinned, they are implicitly unpinned, meaning that 6615** they can be safely discarded. 6616** 6617** [[the xDestroy() page cache method]] 6618** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6619** All resources associated with the specified cache should be freed. ^After 6620** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6621** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6622** functions. 6623** 6624** [[the xShrink() page cache method]] 6625** ^SQLite invokes the xShrink() method when it wants the page cache to 6626** free up as much of heap memory as possible. The page cache implementation 6627** is not obligated to free any memory, but well-behaved implementations should 6628** do their best. 6629*/ 6630typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6631struct sqlite3_pcache_methods2 { 6632 int iVersion; 6633 void *pArg; 6634 int (*xInit)(void*); 6635 void (*xShutdown)(void*); 6636 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6637 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6638 int (*xPagecount)(sqlite3_pcache*); 6639 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6640 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6641 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6642 unsigned oldKey, unsigned newKey); 6643 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6644 void (*xDestroy)(sqlite3_pcache*); 6645 void (*xShrink)(sqlite3_pcache*); 6646}; 6647 6648/* 6649** This is the obsolete pcache_methods object that has now been replaced 6650** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6651** retained in the header file for backwards compatibility only. 6652*/ 6653typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6654struct sqlite3_pcache_methods { 6655 void *pArg; 6656 int (*xInit)(void*); 6657 void (*xShutdown)(void*); 6658 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6659 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6660 int (*xPagecount)(sqlite3_pcache*); 6661 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6662 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6663 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6664 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6665 void (*xDestroy)(sqlite3_pcache*); 6666}; 6667 6668 6669/* 6670** CAPI3REF: Online Backup Object 6671** 6672** The sqlite3_backup object records state information about an ongoing 6673** online backup operation. ^The sqlite3_backup object is created by 6674** a call to [sqlite3_backup_init()] and is destroyed by a call to 6675** [sqlite3_backup_finish()]. 6676** 6677** See Also: [Using the SQLite Online Backup API] 6678*/ 6679typedef struct sqlite3_backup sqlite3_backup; 6680 6681/* 6682** CAPI3REF: Online Backup API. 6683** 6684** The backup API copies the content of one database into another. 6685** It is useful either for creating backups of databases or 6686** for copying in-memory databases to or from persistent files. 6687** 6688** See Also: [Using the SQLite Online Backup API] 6689** 6690** ^SQLite holds a write transaction open on the destination database file 6691** for the duration of the backup operation. 6692** ^The source database is read-locked only while it is being read; 6693** it is not locked continuously for the entire backup operation. 6694** ^Thus, the backup may be performed on a live source database without 6695** preventing other database connections from 6696** reading or writing to the source database while the backup is underway. 6697** 6698** ^(To perform a backup operation: 6699** <ol> 6700** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6701** backup, 6702** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6703** the data between the two databases, and finally 6704** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6705** associated with the backup operation. 6706** </ol>)^ 6707** There should be exactly one call to sqlite3_backup_finish() for each 6708** successful call to sqlite3_backup_init(). 6709** 6710** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6711** 6712** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6713** [database connection] associated with the destination database 6714** and the database name, respectively. 6715** ^The database name is "main" for the main database, "temp" for the 6716** temporary database, or the name specified after the AS keyword in 6717** an [ATTACH] statement for an attached database. 6718** ^The S and M arguments passed to 6719** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6720** and database name of the source database, respectively. 6721** ^The source and destination [database connections] (parameters S and D) 6722** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6723** an error. 6724** 6725** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6726** returned and an error code and error message are stored in the 6727** destination [database connection] D. 6728** ^The error code and message for the failed call to sqlite3_backup_init() 6729** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6730** [sqlite3_errmsg16()] functions. 6731** ^A successful call to sqlite3_backup_init() returns a pointer to an 6732** [sqlite3_backup] object. 6733** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6734** sqlite3_backup_finish() functions to perform the specified backup 6735** operation. 6736** 6737** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6738** 6739** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6740** the source and destination databases specified by [sqlite3_backup] object B. 6741** ^If N is negative, all remaining source pages are copied. 6742** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6743** are still more pages to be copied, then the function returns [SQLITE_OK]. 6744** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6745** from source to destination, then it returns [SQLITE_DONE]. 6746** ^If an error occurs while running sqlite3_backup_step(B,N), 6747** then an [error code] is returned. ^As well as [SQLITE_OK] and 6748** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6749** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6750** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6751** 6752** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6753** <ol> 6754** <li> the destination database was opened read-only, or 6755** <li> the destination database is using write-ahead-log journaling 6756** and the destination and source page sizes differ, or 6757** <li> the destination database is an in-memory database and the 6758** destination and source page sizes differ. 6759** </ol>)^ 6760** 6761** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6762** the [sqlite3_busy_handler | busy-handler function] 6763** is invoked (if one is specified). ^If the 6764** busy-handler returns non-zero before the lock is available, then 6765** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6766** sqlite3_backup_step() can be retried later. ^If the source 6767** [database connection] 6768** is being used to write to the source database when sqlite3_backup_step() 6769** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6770** case the call to sqlite3_backup_step() can be retried later on. ^(If 6771** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6772** [SQLITE_READONLY] is returned, then 6773** there is no point in retrying the call to sqlite3_backup_step(). These 6774** errors are considered fatal.)^ The application must accept 6775** that the backup operation has failed and pass the backup operation handle 6776** to the sqlite3_backup_finish() to release associated resources. 6777** 6778** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6779** on the destination file. ^The exclusive lock is not released until either 6780** sqlite3_backup_finish() is called or the backup operation is complete 6781** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6782** sqlite3_backup_step() obtains a [shared lock] on the source database that 6783** lasts for the duration of the sqlite3_backup_step() call. 6784** ^Because the source database is not locked between calls to 6785** sqlite3_backup_step(), the source database may be modified mid-way 6786** through the backup process. ^If the source database is modified by an 6787** external process or via a database connection other than the one being 6788** used by the backup operation, then the backup will be automatically 6789** restarted by the next call to sqlite3_backup_step(). ^If the source 6790** database is modified by the using the same database connection as is used 6791** by the backup operation, then the backup database is automatically 6792** updated at the same time. 6793** 6794** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6795** 6796** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6797** application wishes to abandon the backup operation, the application 6798** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6799** ^The sqlite3_backup_finish() interfaces releases all 6800** resources associated with the [sqlite3_backup] object. 6801** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6802** active write-transaction on the destination database is rolled back. 6803** The [sqlite3_backup] object is invalid 6804** and may not be used following a call to sqlite3_backup_finish(). 6805** 6806** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6807** sqlite3_backup_step() errors occurred, regardless or whether or not 6808** sqlite3_backup_step() completed. 6809** ^If an out-of-memory condition or IO error occurred during any prior 6810** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6811** sqlite3_backup_finish() returns the corresponding [error code]. 6812** 6813** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6814** is not a permanent error and does not affect the return value of 6815** sqlite3_backup_finish(). 6816** 6817** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6818** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6819** 6820** ^Each call to sqlite3_backup_step() sets two values inside 6821** the [sqlite3_backup] object: the number of pages still to be backed 6822** up and the total number of pages in the source database file. 6823** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6824** retrieve these two values, respectively. 6825** 6826** ^The values returned by these functions are only updated by 6827** sqlite3_backup_step(). ^If the source database is modified during a backup 6828** operation, then the values are not updated to account for any extra 6829** pages that need to be updated or the size of the source database file 6830** changing. 6831** 6832** <b>Concurrent Usage of Database Handles</b> 6833** 6834** ^The source [database connection] may be used by the application for other 6835** purposes while a backup operation is underway or being initialized. 6836** ^If SQLite is compiled and configured to support threadsafe database 6837** connections, then the source database connection may be used concurrently 6838** from within other threads. 6839** 6840** However, the application must guarantee that the destination 6841** [database connection] is not passed to any other API (by any thread) after 6842** sqlite3_backup_init() is called and before the corresponding call to 6843** sqlite3_backup_finish(). SQLite does not currently check to see 6844** if the application incorrectly accesses the destination [database connection] 6845** and so no error code is reported, but the operations may malfunction 6846** nevertheless. Use of the destination database connection while a 6847** backup is in progress might also also cause a mutex deadlock. 6848** 6849** If running in [shared cache mode], the application must 6850** guarantee that the shared cache used by the destination database 6851** is not accessed while the backup is running. In practice this means 6852** that the application must guarantee that the disk file being 6853** backed up to is not accessed by any connection within the process, 6854** not just the specific connection that was passed to sqlite3_backup_init(). 6855** 6856** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6857** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6858** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6859** APIs are not strictly speaking threadsafe. If they are invoked at the 6860** same time as another thread is invoking sqlite3_backup_step() it is 6861** possible that they return invalid values. 6862*/ 6863sqlite3_backup *sqlite3_backup_init( 6864 sqlite3 *pDest, /* Destination database handle */ 6865 const char *zDestName, /* Destination database name */ 6866 sqlite3 *pSource, /* Source database handle */ 6867 const char *zSourceName /* Source database name */ 6868); 6869int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6870int sqlite3_backup_finish(sqlite3_backup *p); 6871int sqlite3_backup_remaining(sqlite3_backup *p); 6872int sqlite3_backup_pagecount(sqlite3_backup *p); 6873 6874/* 6875** CAPI3REF: Unlock Notification 6876** 6877** ^When running in shared-cache mode, a database operation may fail with 6878** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6879** individual tables within the shared-cache cannot be obtained. See 6880** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6881** ^This API may be used to register a callback that SQLite will invoke 6882** when the connection currently holding the required lock relinquishes it. 6883** ^This API is only available if the library was compiled with the 6884** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6885** 6886** See Also: [Using the SQLite Unlock Notification Feature]. 6887** 6888** ^Shared-cache locks are released when a database connection concludes 6889** its current transaction, either by committing it or rolling it back. 6890** 6891** ^When a connection (known as the blocked connection) fails to obtain a 6892** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6893** identity of the database connection (the blocking connection) that 6894** has locked the required resource is stored internally. ^After an 6895** application receives an SQLITE_LOCKED error, it may call the 6896** sqlite3_unlock_notify() method with the blocked connection handle as 6897** the first argument to register for a callback that will be invoked 6898** when the blocking connections current transaction is concluded. ^The 6899** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6900** call that concludes the blocking connections transaction. 6901** 6902** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6903** there is a chance that the blocking connection will have already 6904** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6905** If this happens, then the specified callback is invoked immediately, 6906** from within the call to sqlite3_unlock_notify().)^ 6907** 6908** ^If the blocked connection is attempting to obtain a write-lock on a 6909** shared-cache table, and more than one other connection currently holds 6910** a read-lock on the same table, then SQLite arbitrarily selects one of 6911** the other connections to use as the blocking connection. 6912** 6913** ^(There may be at most one unlock-notify callback registered by a 6914** blocked connection. If sqlite3_unlock_notify() is called when the 6915** blocked connection already has a registered unlock-notify callback, 6916** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6917** called with a NULL pointer as its second argument, then any existing 6918** unlock-notify callback is canceled. ^The blocked connections 6919** unlock-notify callback may also be canceled by closing the blocked 6920** connection using [sqlite3_close()]. 6921** 6922** The unlock-notify callback is not reentrant. If an application invokes 6923** any sqlite3_xxx API functions from within an unlock-notify callback, a 6924** crash or deadlock may be the result. 6925** 6926** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6927** returns SQLITE_OK. 6928** 6929** <b>Callback Invocation Details</b> 6930** 6931** When an unlock-notify callback is registered, the application provides a 6932** single void* pointer that is passed to the callback when it is invoked. 6933** However, the signature of the callback function allows SQLite to pass 6934** it an array of void* context pointers. The first argument passed to 6935** an unlock-notify callback is a pointer to an array of void* pointers, 6936** and the second is the number of entries in the array. 6937** 6938** When a blocking connections transaction is concluded, there may be 6939** more than one blocked connection that has registered for an unlock-notify 6940** callback. ^If two or more such blocked connections have specified the 6941** same callback function, then instead of invoking the callback function 6942** multiple times, it is invoked once with the set of void* context pointers 6943** specified by the blocked connections bundled together into an array. 6944** This gives the application an opportunity to prioritize any actions 6945** related to the set of unblocked database connections. 6946** 6947** <b>Deadlock Detection</b> 6948** 6949** Assuming that after registering for an unlock-notify callback a 6950** database waits for the callback to be issued before taking any further 6951** action (a reasonable assumption), then using this API may cause the 6952** application to deadlock. For example, if connection X is waiting for 6953** connection Y's transaction to be concluded, and similarly connection 6954** Y is waiting on connection X's transaction, then neither connection 6955** will proceed and the system may remain deadlocked indefinitely. 6956** 6957** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6958** detection. ^If a given call to sqlite3_unlock_notify() would put the 6959** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6960** unlock-notify callback is registered. The system is said to be in 6961** a deadlocked state if connection A has registered for an unlock-notify 6962** callback on the conclusion of connection B's transaction, and connection 6963** B has itself registered for an unlock-notify callback when connection 6964** A's transaction is concluded. ^Indirect deadlock is also detected, so 6965** the system is also considered to be deadlocked if connection B has 6966** registered for an unlock-notify callback on the conclusion of connection 6967** C's transaction, where connection C is waiting on connection A. ^Any 6968** number of levels of indirection are allowed. 6969** 6970** <b>The "DROP TABLE" Exception</b> 6971** 6972** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6973** always appropriate to call sqlite3_unlock_notify(). There is however, 6974** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6975** SQLite checks if there are any currently executing SELECT statements 6976** that belong to the same connection. If there are, SQLITE_LOCKED is 6977** returned. In this case there is no "blocking connection", so invoking 6978** sqlite3_unlock_notify() results in the unlock-notify callback being 6979** invoked immediately. If the application then re-attempts the "DROP TABLE" 6980** or "DROP INDEX" query, an infinite loop might be the result. 6981** 6982** One way around this problem is to check the extended error code returned 6983** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6984** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6985** the special "DROP TABLE/INDEX" case, the extended error code is just 6986** SQLITE_LOCKED.)^ 6987*/ 6988int sqlite3_unlock_notify( 6989 sqlite3 *pBlocked, /* Waiting connection */ 6990 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6991 void *pNotifyArg /* Argument to pass to xNotify */ 6992); 6993 6994 6995/* 6996** CAPI3REF: String Comparison 6997** 6998** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 6999** and extensions to compare the contents of two buffers containing UTF-8 7000** strings in a case-independent fashion, using the same definition of "case 7001** independence" that SQLite uses internally when comparing identifiers. 7002*/ 7003int sqlite3_stricmp(const char *, const char *); 7004int sqlite3_strnicmp(const char *, const char *, int); 7005 7006/* 7007** CAPI3REF: String Globbing 7008* 7009** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7010** the glob pattern P, and it returns non-zero if string X does not match 7011** the glob pattern P. ^The definition of glob pattern matching used in 7012** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7013** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7014** sensitive. 7015** 7016** Note that this routine returns zero on a match and non-zero if the strings 7017** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7018*/ 7019int sqlite3_strglob(const char *zGlob, const char *zStr); 7020 7021/* 7022** CAPI3REF: Error Logging Interface 7023** 7024** ^The [sqlite3_log()] interface writes a message into the [error log] 7025** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7026** ^If logging is enabled, the zFormat string and subsequent arguments are 7027** used with [sqlite3_snprintf()] to generate the final output string. 7028** 7029** The sqlite3_log() interface is intended for use by extensions such as 7030** virtual tables, collating functions, and SQL functions. While there is 7031** nothing to prevent an application from calling sqlite3_log(), doing so 7032** is considered bad form. 7033** 7034** The zFormat string must not be NULL. 7035** 7036** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7037** will not use dynamically allocated memory. The log message is stored in 7038** a fixed-length buffer on the stack. If the log message is longer than 7039** a few hundred characters, it will be truncated to the length of the 7040** buffer. 7041*/ 7042void sqlite3_log(int iErrCode, const char *zFormat, ...); 7043 7044/* 7045** CAPI3REF: Write-Ahead Log Commit Hook 7046** 7047** ^The [sqlite3_wal_hook()] function is used to register a callback that 7048** will be invoked each time a database connection commits data to a 7049** [write-ahead log] (i.e. whenever a transaction is committed in 7050** [journal_mode | journal_mode=WAL mode]). 7051** 7052** ^The callback is invoked by SQLite after the commit has taken place and 7053** the associated write-lock on the database released, so the implementation 7054** may read, write or [checkpoint] the database as required. 7055** 7056** ^The first parameter passed to the callback function when it is invoked 7057** is a copy of the third parameter passed to sqlite3_wal_hook() when 7058** registering the callback. ^The second is a copy of the database handle. 7059** ^The third parameter is the name of the database that was written to - 7060** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7061** is the number of pages currently in the write-ahead log file, 7062** including those that were just committed. 7063** 7064** The callback function should normally return [SQLITE_OK]. ^If an error 7065** code is returned, that error will propagate back up through the 7066** SQLite code base to cause the statement that provoked the callback 7067** to report an error, though the commit will have still occurred. If the 7068** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7069** that does not correspond to any valid SQLite error code, the results 7070** are undefined. 7071** 7072** A single database handle may have at most a single write-ahead log callback 7073** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7074** previously registered write-ahead log callback. ^Note that the 7075** [sqlite3_wal_autocheckpoint()] interface and the 7076** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7077** those overwrite any prior [sqlite3_wal_hook()] settings. 7078*/ 7079void *sqlite3_wal_hook( 7080 sqlite3*, 7081 int(*)(void *,sqlite3*,const char*,int), 7082 void* 7083); 7084 7085/* 7086** CAPI3REF: Configure an auto-checkpoint 7087** 7088** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7089** [sqlite3_wal_hook()] that causes any database on [database connection] D 7090** to automatically [checkpoint] 7091** after committing a transaction if there are N or 7092** more frames in the [write-ahead log] file. ^Passing zero or 7093** a negative value as the nFrame parameter disables automatic 7094** checkpoints entirely. 7095** 7096** ^The callback registered by this function replaces any existing callback 7097** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7098** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7099** configured by this function. 7100** 7101** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7102** from SQL. 7103** 7104** ^Every new [database connection] defaults to having the auto-checkpoint 7105** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7106** pages. The use of this interface 7107** is only necessary if the default setting is found to be suboptimal 7108** for a particular application. 7109*/ 7110int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7111 7112/* 7113** CAPI3REF: Checkpoint a database 7114** 7115** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 7116** on [database connection] D to be [checkpointed]. ^If X is NULL or an 7117** empty string, then a checkpoint is run on all databases of 7118** connection D. ^If the database connection D is not in 7119** [WAL | write-ahead log mode] then this interface is a harmless no-op. 7120** 7121** ^The [wal_checkpoint pragma] can be used to invoke this interface 7122** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 7123** [wal_autocheckpoint pragma] can be used to cause this interface to be 7124** run whenever the WAL reaches a certain size threshold. 7125** 7126** See also: [sqlite3_wal_checkpoint_v2()] 7127*/ 7128int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7129 7130/* 7131** CAPI3REF: Checkpoint a database 7132** 7133** Run a checkpoint operation on WAL database zDb attached to database 7134** handle db. The specific operation is determined by the value of the 7135** eMode parameter: 7136** 7137** <dl> 7138** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7139** Checkpoint as many frames as possible without waiting for any database 7140** readers or writers to finish. Sync the db file if all frames in the log 7141** are checkpointed. This mode is the same as calling 7142** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 7143** 7144** <dt>SQLITE_CHECKPOINT_FULL<dd> 7145** This mode blocks (calls the busy-handler callback) until there is no 7146** database writer and all readers are reading from the most recent database 7147** snapshot. It then checkpoints all frames in the log file and syncs the 7148** database file. This call blocks database writers while it is running, 7149** but not database readers. 7150** 7151** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7152** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 7153** checkpointing the log file it blocks (calls the busy-handler callback) 7154** until all readers are reading from the database file only. This ensures 7155** that the next client to write to the database file restarts the log file 7156** from the beginning. This call blocks database writers while it is running, 7157** but not database readers. 7158** </dl> 7159** 7160** If pnLog is not NULL, then *pnLog is set to the total number of frames in 7161** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 7162** the total number of checkpointed frames (including any that were already 7163** checkpointed when this function is called). *pnLog and *pnCkpt may be 7164** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 7165** If no values are available because of an error, they are both set to -1 7166** before returning to communicate this to the caller. 7167** 7168** All calls obtain an exclusive "checkpoint" lock on the database file. If 7169** any other process is running a checkpoint operation at the same time, the 7170** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 7171** busy-handler configured, it will not be invoked in this case. 7172** 7173** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 7174** "writer" lock on the database file. If the writer lock cannot be obtained 7175** immediately, and a busy-handler is configured, it is invoked and the writer 7176** lock retried until either the busy-handler returns 0 or the lock is 7177** successfully obtained. The busy-handler is also invoked while waiting for 7178** database readers as described above. If the busy-handler returns 0 before 7179** the writer lock is obtained or while waiting for database readers, the 7180** checkpoint operation proceeds from that point in the same way as 7181** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7182** without blocking any further. SQLITE_BUSY is returned in this case. 7183** 7184** If parameter zDb is NULL or points to a zero length string, then the 7185** specified operation is attempted on all WAL databases. In this case the 7186** values written to output parameters *pnLog and *pnCkpt are undefined. If 7187** an SQLITE_BUSY error is encountered when processing one or more of the 7188** attached WAL databases, the operation is still attempted on any remaining 7189** attached databases and SQLITE_BUSY is returned to the caller. If any other 7190** error occurs while processing an attached database, processing is abandoned 7191** and the error code returned to the caller immediately. If no error 7192** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7193** databases, SQLITE_OK is returned. 7194** 7195** If database zDb is the name of an attached database that is not in WAL 7196** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 7197** zDb is not NULL (or a zero length string) and is not the name of any 7198** attached database, SQLITE_ERROR is returned to the caller. 7199*/ 7200int sqlite3_wal_checkpoint_v2( 7201 sqlite3 *db, /* Database handle */ 7202 const char *zDb, /* Name of attached database (or NULL) */ 7203 int eMode, /* SQLITE_CHECKPOINT_* value */ 7204 int *pnLog, /* OUT: Size of WAL log in frames */ 7205 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7206); 7207 7208/* 7209** CAPI3REF: Checkpoint operation parameters 7210** 7211** These constants can be used as the 3rd parameter to 7212** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 7213** documentation for additional information about the meaning and use of 7214** each of these values. 7215*/ 7216#define SQLITE_CHECKPOINT_PASSIVE 0 7217#define SQLITE_CHECKPOINT_FULL 1 7218#define SQLITE_CHECKPOINT_RESTART 2 7219 7220/* 7221** CAPI3REF: Virtual Table Interface Configuration 7222** 7223** This function may be called by either the [xConnect] or [xCreate] method 7224** of a [virtual table] implementation to configure 7225** various facets of the virtual table interface. 7226** 7227** If this interface is invoked outside the context of an xConnect or 7228** xCreate virtual table method then the behavior is undefined. 7229** 7230** At present, there is only one option that may be configured using 7231** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7232** may be added in the future. 7233*/ 7234int sqlite3_vtab_config(sqlite3*, int op, ...); 7235 7236/* 7237** CAPI3REF: Virtual Table Configuration Options 7238** 7239** These macros define the various options to the 7240** [sqlite3_vtab_config()] interface that [virtual table] implementations 7241** can use to customize and optimize their behavior. 7242** 7243** <dl> 7244** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7245** <dd>Calls of the form 7246** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7247** where X is an integer. If X is zero, then the [virtual table] whose 7248** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7249** support constraints. In this configuration (which is the default) if 7250** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7251** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7252** specified as part of the users SQL statement, regardless of the actual 7253** ON CONFLICT mode specified. 7254** 7255** If X is non-zero, then the virtual table implementation guarantees 7256** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7257** any modifications to internal or persistent data structures have been made. 7258** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7259** is able to roll back a statement or database transaction, and abandon 7260** or continue processing the current SQL statement as appropriate. 7261** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7262** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7263** had been ABORT. 7264** 7265** Virtual table implementations that are required to handle OR REPLACE 7266** must do so within the [xUpdate] method. If a call to the 7267** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7268** CONFLICT policy is REPLACE, the virtual table implementation should 7269** silently replace the appropriate rows within the xUpdate callback and 7270** return SQLITE_OK. Or, if this is not possible, it may return 7271** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7272** constraint handling. 7273** </dl> 7274*/ 7275#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7276 7277/* 7278** CAPI3REF: Determine The Virtual Table Conflict Policy 7279** 7280** This function may only be called from within a call to the [xUpdate] method 7281** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7282** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7283** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7284** of the SQL statement that triggered the call to the [xUpdate] method of the 7285** [virtual table]. 7286*/ 7287int sqlite3_vtab_on_conflict(sqlite3 *); 7288 7289/* 7290** CAPI3REF: Conflict resolution modes 7291** 7292** These constants are returned by [sqlite3_vtab_on_conflict()] to 7293** inform a [virtual table] implementation what the [ON CONFLICT] mode 7294** is for the SQL statement being evaluated. 7295** 7296** Note that the [SQLITE_IGNORE] constant is also used as a potential 7297** return value from the [sqlite3_set_authorizer()] callback and that 7298** [SQLITE_ABORT] is also a [result code]. 7299*/ 7300#define SQLITE_ROLLBACK 1 7301/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7302#define SQLITE_FAIL 3 7303/* #define SQLITE_ABORT 4 // Also an error code */ 7304#define SQLITE_REPLACE 5 7305 7306 7307 7308/* 7309** Undo the hack that converts floating point types to integer for 7310** builds on processors without floating point support. 7311*/ 7312#ifdef SQLITE_OMIT_FLOATING_POINT 7313# undef double 7314#endif 7315 7316#ifdef __cplusplus 7317} /* End of the 'extern "C"' block */ 7318#endif 7319#endif /* _SQLITE3_H_ */ 7320