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 to make minor changes if 22** 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** @(#) $Id: sqlite.h.in,v 1.433 2009/02/18 18:37:59 drh Exp $ 34*/ 35#ifndef _SQLITE3_H_ 36#define _SQLITE3_H_ 37#include <stdarg.h> /* Needed for the definition of va_list */ 38 39/* 40** Make sure we can call this stuff from C++. 41*/ 42#ifdef __cplusplus 43extern "C" { 44#endif 45 46 47/* 48** Add the ability to override 'extern' 49*/ 50#ifndef SQLITE_EXTERN 51# define SQLITE_EXTERN extern 52#endif 53 54/* 55** These no-op macros are used in front of interfaces to mark those 56** interfaces as either deprecated or experimental. New applications 57** should not use deprecated intrfaces - they are support for backwards 58** compatibility only. Application writers should be aware that 59** experimental interfaces are subject to change in point releases. 60** 61** These macros used to resolve to various kinds of compiler magic that 62** would generate warning messages when they were used. But that 63** compiler magic ended up generating such a flurry of bug reports 64** that we have taken it all out and gone back to using simple 65** noop macros. 66*/ 67#define SQLITE_DEPRECATED 68#define SQLITE_EXPERIMENTAL 69 70/* 71** Ensure these symbols were not defined by some previous header file. 72*/ 73#ifdef SQLITE_VERSION 74# undef SQLITE_VERSION 75#endif 76#ifdef SQLITE_VERSION_NUMBER 77# undef SQLITE_VERSION_NUMBER 78#endif 79 80/* 81** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100> 82** 83** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in 84** the sqlite3.h file specify the version of SQLite with which 85** that header file is associated. 86** 87** The "version" of SQLite is a string of the form "X.Y.Z". 88** The phrase "alpha" or "beta" might be appended after the Z. 89** The X value is major version number always 3 in SQLite3. 90** The X value only changes when backwards compatibility is 91** broken and we intend to never break backwards compatibility. 92** The Y value is the minor version number and only changes when 93** there are major feature enhancements that are forwards compatible 94** but not backwards compatible. 95** The Z value is the release number and is incremented with 96** each release but resets back to 0 whenever Y is incremented. 97** 98** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. 99** 100** Requirements: [H10011] [H10014] 101*/ 102#define SQLITE_VERSION "--VERS--" 103#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 104 105/* 106** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> 107** KEYWORDS: sqlite3_version 108** 109** These features provide the same information as the [SQLITE_VERSION] 110** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated 111** with the library instead of the header file. Cautious programmers might 112** include a check in their application to verify that 113** sqlite3_libversion_number() always returns the value 114** [SQLITE_VERSION_NUMBER]. 115** 116** The sqlite3_libversion() function returns the same information as is 117** in the sqlite3_version[] string constant. The function is provided 118** for use in DLLs since DLL users usually do not have direct access to string 119** constants within the DLL. 120** 121** Requirements: [H10021] [H10022] [H10023] 122*/ 123SQLITE_EXTERN const char sqlite3_version[]; 124const char *sqlite3_libversion(void); 125int sqlite3_libversion_number(void); 126 127/* 128** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> 129** 130** SQLite can be compiled with or without mutexes. When 131** the [SQLITE_THREADSAFE] C preprocessor macro 1 or 2, mutexes 132** are enabled and SQLite is threadsafe. When the 133** [SQLITE_THREADSAFE] macro is 0, 134** the mutexes are omitted. Without the mutexes, it is not safe 135** to use SQLite concurrently from more than one thread. 136** 137** Enabling mutexes incurs a measurable performance penalty. 138** So if speed is of utmost importance, it makes sense to disable 139** the mutexes. But for maximum safety, mutexes should be enabled. 140** The default behavior is for mutexes to be enabled. 141** 142** This interface can be used by a program to make sure that the 143** version of SQLite that it is linking against was compiled with 144** the desired setting of the [SQLITE_THREADSAFE] macro. 145** 146** This interface only reports on the compile-time mutex setting 147** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 148** SQLITE_THREADSAFE=1 then mutexes are enabled by default but 149** can be fully or partially disabled using a call to [sqlite3_config()] 150** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 151** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows 152** only the default compile-time setting, not any run-time changes 153** to that setting. 154** 155** See the [threading mode] documentation for additional information. 156** 157** Requirements: [H10101] [H10102] 158*/ 159int sqlite3_threadsafe(void); 160 161/* 162** CAPI3REF: Database Connection Handle {H12000} <S40200> 163** KEYWORDS: {database connection} {database connections} 164** 165** Each open SQLite database is represented by a pointer to an instance of 166** the opaque structure named "sqlite3". It is useful to think of an sqlite3 167** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 168** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 169** is its destructor. There are many other interfaces (such as 170** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 171** [sqlite3_busy_timeout()] to name but three) that are methods on an 172** sqlite3 object. 173*/ 174typedef struct sqlite3 sqlite3; 175 176/* 177** CAPI3REF: 64-Bit Integer Types {H10200} <S10110> 178** KEYWORDS: sqlite_int64 sqlite_uint64 179** 180** Because there is no cross-platform way to specify 64-bit integer types 181** SQLite includes typedefs for 64-bit signed and unsigned integers. 182** 183** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 184** The sqlite_int64 and sqlite_uint64 types are supported for backwards 185** compatibility only. 186** 187** Requirements: [H10201] [H10202] 188*/ 189#ifdef SQLITE_INT64_TYPE 190 typedef SQLITE_INT64_TYPE sqlite_int64; 191 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 192#elif defined(_MSC_VER) || defined(__BORLANDC__) 193 typedef __int64 sqlite_int64; 194 typedef unsigned __int64 sqlite_uint64; 195#else 196 typedef long long int sqlite_int64; 197 typedef unsigned long long int sqlite_uint64; 198#endif 199typedef sqlite_int64 sqlite3_int64; 200typedef sqlite_uint64 sqlite3_uint64; 201 202/* 203** If compiling for a processor that lacks floating point support, 204** substitute integer for floating-point. 205*/ 206#ifdef SQLITE_OMIT_FLOATING_POINT 207# define double sqlite3_int64 208#endif 209 210/* 211** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200> 212** 213** This routine is the destructor for the [sqlite3] object. 214** 215** Applications should [sqlite3_finalize | finalize] all [prepared statements] 216** and [sqlite3_blob_close | close] all [BLOB handles] associated with 217** the [sqlite3] object prior to attempting to close the object. 218** The [sqlite3_next_stmt()] interface can be used to locate all 219** [prepared statements] associated with a [database connection] if desired. 220** Typical code might look like this: 221** 222** <blockquote><pre> 223** sqlite3_stmt *pStmt; 224** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){ 225** sqlite3_finalize(pStmt); 226** } 227** </pre></blockquote> 228** 229** If [sqlite3_close()] is invoked while a transaction is open, 230** the transaction is automatically rolled back. 231** 232** The C parameter to [sqlite3_close(C)] must be either a NULL 233** pointer or an [sqlite3] object pointer obtained 234** from [sqlite3_open()], [sqlite3_open16()], or 235** [sqlite3_open_v2()], and not previously closed. 236** 237** Requirements: 238** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019] 239*/ 240int sqlite3_close(sqlite3 *); 241 242/* 243** The type for a callback function. 244** This is legacy and deprecated. It is included for historical 245** compatibility and is not documented. 246*/ 247typedef int (*sqlite3_callback)(void*,int,char**, char**); 248 249/* 250** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000> 251** 252** The sqlite3_exec() interface is a convenient way of running one or more 253** SQL statements without having to write a lot of C code. The UTF-8 encoded 254** SQL statements are passed in as the second parameter to sqlite3_exec(). 255** The statements are evaluated one by one until either an error or 256** an interrupt is encountered, or until they are all done. The 3rd parameter 257** is an optional callback that is invoked once for each row of any query 258** results produced by the SQL statements. The 5th parameter tells where 259** to write any error messages. 260** 261** The error message passed back through the 5th parameter is held 262** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, 263** the calling application should call [sqlite3_free()] on any error 264** message returned through the 5th parameter when it has finished using 265** the error message. 266** 267** If the SQL statement in the 2nd parameter is NULL or an empty string 268** or a string containing only whitespace and comments, then no SQL 269** statements are evaluated and the database is not changed. 270** 271** The sqlite3_exec() interface is implemented in terms of 272** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 273** The sqlite3_exec() routine does nothing to the database that cannot be done 274** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 275** 276** The first parameter to [sqlite3_exec()] must be an valid and open 277** [database connection]. 278** 279** The database connection must not be closed while 280** [sqlite3_exec()] is running. 281** 282** The calling function should use [sqlite3_free()] to free 283** the memory that *errmsg is left pointing at once the error 284** message is no longer needed. 285** 286** The SQL statement text in the 2nd parameter to [sqlite3_exec()] 287** must remain unchanged while [sqlite3_exec()] is running. 288** 289** Requirements: 290** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116] 291** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138] 292*/ 293int sqlite3_exec( 294 sqlite3*, /* An open database */ 295 const char *sql, /* SQL to be evaluated */ 296 int (*callback)(void*,int,char**,char**), /* Callback function */ 297 void *, /* 1st argument to callback */ 298 char **errmsg /* Error msg written here */ 299); 300 301/* 302** CAPI3REF: Result Codes {H10210} <S10700> 303** KEYWORDS: SQLITE_OK {error code} {error codes} 304** KEYWORDS: {result code} {result codes} 305** 306** Many SQLite functions return an integer result code from the set shown 307** here in order to indicates success or failure. 308** 309** New error codes may be added in future versions of SQLite. 310** 311** See also: [SQLITE_IOERR_READ | extended result codes] 312*/ 313#define SQLITE_OK 0 /* Successful result */ 314/* beginning-of-error-codes */ 315#define SQLITE_ERROR 1 /* SQL error or missing database */ 316#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 317#define SQLITE_PERM 3 /* Access permission denied */ 318#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 319#define SQLITE_BUSY 5 /* The database file is locked */ 320#define SQLITE_LOCKED 6 /* A table in the database is locked */ 321#define SQLITE_NOMEM 7 /* A malloc() failed */ 322#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 323#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 324#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 325#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 326#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 327#define SQLITE_FULL 13 /* Insertion failed because database is full */ 328#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 329#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 330#define SQLITE_EMPTY 16 /* Database is empty */ 331#define SQLITE_SCHEMA 17 /* The database schema changed */ 332#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 333#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 334#define SQLITE_MISMATCH 20 /* Data type mismatch */ 335#define SQLITE_MISUSE 21 /* Library used incorrectly */ 336#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 337#define SQLITE_AUTH 23 /* Authorization denied */ 338#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 339#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 340#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 341#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 342#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 343/* end-of-error-codes */ 344 345/* 346** CAPI3REF: Extended Result Codes {H10220} <S10700> 347** KEYWORDS: {extended error code} {extended error codes} 348** KEYWORDS: {extended result code} {extended result codes} 349** 350** In its default configuration, SQLite API routines return one of 26 integer 351** [SQLITE_OK | result codes]. However, experience has shown that many of 352** these result codes are too coarse-grained. They do not provide as 353** much information about problems as programmers might like. In an effort to 354** address this, newer versions of SQLite (version 3.3.8 and later) include 355** support for additional result codes that provide more detailed information 356** about errors. The extended result codes are enabled or disabled 357** on a per database connection basis using the 358** [sqlite3_extended_result_codes()] API. 359** 360** Some of the available extended result codes are listed here. 361** One may expect the number of extended result codes will be expand 362** over time. Software that uses extended result codes should expect 363** to see new result codes in future releases of SQLite. 364** 365** The SQLITE_OK result code will never be extended. It will always 366** be exactly zero. 367*/ 368#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 369#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 370#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 371#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 372#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 373#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 374#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 375#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 376#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 377#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 378#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 379#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 380#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 381#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 382#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 383#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 384#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 385 386/* 387** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> 388** 389** These bit values are intended for use in the 390** 3rd parameter to the [sqlite3_open_v2()] interface and 391** in the 4th parameter to the xOpen method of the 392** [sqlite3_vfs] object. 393*/ 394#define SQLITE_OPEN_READONLY 0x00000001 395#define SQLITE_OPEN_READWRITE 0x00000002 396#define SQLITE_OPEN_CREATE 0x00000004 397#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 398#define SQLITE_OPEN_EXCLUSIVE 0x00000010 399#define SQLITE_OPEN_MAIN_DB 0x00000100 400#define SQLITE_OPEN_TEMP_DB 0x00000200 401#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 402#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 403#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 404#define SQLITE_OPEN_SUBJOURNAL 0x00002000 405#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 406#define SQLITE_OPEN_NOMUTEX 0x00008000 407#define SQLITE_OPEN_FULLMUTEX 0x00010000 408 409/* 410** CAPI3REF: Device Characteristics {H10240} <H11120> 411** 412** The xDeviceCapabilities method of the [sqlite3_io_methods] 413** object returns an integer which is a vector of the these 414** bit values expressing I/O characteristics of the mass storage 415** device that holds the file that the [sqlite3_io_methods] 416** refers to. 417** 418** The SQLITE_IOCAP_ATOMIC property means that all writes of 419** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 420** mean that writes of blocks that are nnn bytes in size and 421** are aligned to an address which is an integer multiple of 422** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 423** that when data is appended to a file, the data is appended 424** first then the size of the file is extended, never the other 425** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 426** information is written to disk in the same order as calls 427** to xWrite(). 428*/ 429#define SQLITE_IOCAP_ATOMIC 0x00000001 430#define SQLITE_IOCAP_ATOMIC512 0x00000002 431#define SQLITE_IOCAP_ATOMIC1K 0x00000004 432#define SQLITE_IOCAP_ATOMIC2K 0x00000008 433#define SQLITE_IOCAP_ATOMIC4K 0x00000010 434#define SQLITE_IOCAP_ATOMIC8K 0x00000020 435#define SQLITE_IOCAP_ATOMIC16K 0x00000040 436#define SQLITE_IOCAP_ATOMIC32K 0x00000080 437#define SQLITE_IOCAP_ATOMIC64K 0x00000100 438#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 439#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 440 441/* 442** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> 443** 444** SQLite uses one of these integer values as the second 445** argument to calls it makes to the xLock() and xUnlock() methods 446** of an [sqlite3_io_methods] object. 447*/ 448#define SQLITE_LOCK_NONE 0 449#define SQLITE_LOCK_SHARED 1 450#define SQLITE_LOCK_RESERVED 2 451#define SQLITE_LOCK_PENDING 3 452#define SQLITE_LOCK_EXCLUSIVE 4 453 454/* 455** CAPI3REF: Synchronization Type Flags {H10260} <H11120> 456** 457** When SQLite invokes the xSync() method of an 458** [sqlite3_io_methods] object it uses a combination of 459** these integer values as the second argument. 460** 461** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 462** sync operation only needs to flush data to mass storage. Inode 463** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 464** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 465** to use Mac OS X style fullsync instead of fsync(). 466*/ 467#define SQLITE_SYNC_NORMAL 0x00002 468#define SQLITE_SYNC_FULL 0x00003 469#define SQLITE_SYNC_DATAONLY 0x00010 470 471/* 472** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> 473** 474** An [sqlite3_file] object represents an open file in the OS 475** interface layer. Individual OS interface implementations will 476** want to subclass this object by appending additional fields 477** for their own use. The pMethods entry is a pointer to an 478** [sqlite3_io_methods] object that defines methods for performing 479** I/O operations on the open file. 480*/ 481typedef struct sqlite3_file sqlite3_file; 482struct sqlite3_file { 483 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 484}; 485 486/* 487** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> 488** 489** Every file opened by the [sqlite3_vfs] xOpen method populates an 490** [sqlite3_file] object (or, more commonly, a subclass of the 491** [sqlite3_file] object) with a pointer to an instance of this object. 492** This object defines the methods used to perform various operations 493** against the open file represented by the [sqlite3_file] object. 494** 495** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 496** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 497** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 498** flag may be ORed in to indicate that only the data of the file 499** and not its inode needs to be synced. 500** 501** The integer values to xLock() and xUnlock() are one of 502** <ul> 503** <li> [SQLITE_LOCK_NONE], 504** <li> [SQLITE_LOCK_SHARED], 505** <li> [SQLITE_LOCK_RESERVED], 506** <li> [SQLITE_LOCK_PENDING], or 507** <li> [SQLITE_LOCK_EXCLUSIVE]. 508** </ul> 509** xLock() increases the lock. xUnlock() decreases the lock. 510** The xCheckReservedLock() method checks whether any database connection, 511** either in this process or in some other process, is holding a RESERVED, 512** PENDING, or EXCLUSIVE lock on the file. It returns true 513** if such a lock exists and false otherwise. 514** 515** The xFileControl() method is a generic interface that allows custom 516** VFS implementations to directly control an open file using the 517** [sqlite3_file_control()] interface. The second "op" argument is an 518** integer opcode. The third argument is a generic pointer intended to 519** point to a structure that may contain arguments or space in which to 520** write return values. Potential uses for xFileControl() might be 521** functions to enable blocking locks with timeouts, to change the 522** locking strategy (for example to use dot-file locks), to inquire 523** about the status of a lock, or to break stale locks. The SQLite 524** core reserves all opcodes less than 100 for its own use. 525** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 526** Applications that define a custom xFileControl method should use opcodes 527** greater than 100 to avoid conflicts. 528** 529** The xSectorSize() method returns the sector size of the 530** device that underlies the file. The sector size is the 531** minimum write that can be performed without disturbing 532** other bytes in the file. The xDeviceCharacteristics() 533** method returns a bit vector describing behaviors of the 534** underlying device: 535** 536** <ul> 537** <li> [SQLITE_IOCAP_ATOMIC] 538** <li> [SQLITE_IOCAP_ATOMIC512] 539** <li> [SQLITE_IOCAP_ATOMIC1K] 540** <li> [SQLITE_IOCAP_ATOMIC2K] 541** <li> [SQLITE_IOCAP_ATOMIC4K] 542** <li> [SQLITE_IOCAP_ATOMIC8K] 543** <li> [SQLITE_IOCAP_ATOMIC16K] 544** <li> [SQLITE_IOCAP_ATOMIC32K] 545** <li> [SQLITE_IOCAP_ATOMIC64K] 546** <li> [SQLITE_IOCAP_SAFE_APPEND] 547** <li> [SQLITE_IOCAP_SEQUENTIAL] 548** </ul> 549** 550** The SQLITE_IOCAP_ATOMIC property means that all writes of 551** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 552** mean that writes of blocks that are nnn bytes in size and 553** are aligned to an address which is an integer multiple of 554** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 555** that when data is appended to a file, the data is appended 556** first then the size of the file is extended, never the other 557** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 558** information is written to disk in the same order as calls 559** to xWrite(). 560** 561** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 562** in the unread portions of the buffer with zeros. A VFS that 563** fails to zero-fill short reads might seem to work. However, 564** failure to zero-fill short reads will eventually lead to 565** database corruption. 566*/ 567typedef struct sqlite3_io_methods sqlite3_io_methods; 568struct sqlite3_io_methods { 569 int iVersion; 570 int (*xClose)(sqlite3_file*); 571 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 572 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 573 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 574 int (*xSync)(sqlite3_file*, int flags); 575 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 576 int (*xLock)(sqlite3_file*, int); 577 int (*xUnlock)(sqlite3_file*, int); 578 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 579 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 580 int (*xSectorSize)(sqlite3_file*); 581 int (*xDeviceCharacteristics)(sqlite3_file*); 582 /* Additional methods may be added in future releases */ 583}; 584 585/* 586** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> 587** 588** These integer constants are opcodes for the xFileControl method 589** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 590** interface. 591** 592** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 593** opcode causes the xFileControl method to write the current state of 594** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 595** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 596** into an integer that the pArg argument points to. This capability 597** is used during testing and only needs to be supported when SQLITE_TEST 598** is defined. 599*/ 600#define SQLITE_FCNTL_LOCKSTATE 1 601#define SQLITE_GET_LOCKPROXYFILE 2 602#define SQLITE_SET_LOCKPROXYFILE 3 603#define SQLITE_LAST_ERRNO 4 604 605/* 606** CAPI3REF: Mutex Handle {H17110} <S20130> 607** 608** The mutex module within SQLite defines [sqlite3_mutex] to be an 609** abstract type for a mutex object. The SQLite core never looks 610** at the internal representation of an [sqlite3_mutex]. It only 611** deals with pointers to the [sqlite3_mutex] object. 612** 613** Mutexes are created using [sqlite3_mutex_alloc()]. 614*/ 615typedef struct sqlite3_mutex sqlite3_mutex; 616 617/* 618** CAPI3REF: OS Interface Object {H11140} <S20100> 619** 620** An instance of the sqlite3_vfs object defines the interface between 621** the SQLite core and the underlying operating system. The "vfs" 622** in the name of the object stands for "virtual file system". 623** 624** The value of the iVersion field is initially 1 but may be larger in 625** future versions of SQLite. Additional fields may be appended to this 626** object when the iVersion value is increased. Note that the structure 627** of the sqlite3_vfs object changes in the transaction between 628** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 629** modified. 630** 631** The szOsFile field is the size of the subclassed [sqlite3_file] 632** structure used by this VFS. mxPathname is the maximum length of 633** a pathname in this VFS. 634** 635** Registered sqlite3_vfs objects are kept on a linked list formed by 636** the pNext pointer. The [sqlite3_vfs_register()] 637** and [sqlite3_vfs_unregister()] interfaces manage this list 638** in a thread-safe way. The [sqlite3_vfs_find()] interface 639** searches the list. Neither the application code nor the VFS 640** implementation should use the pNext pointer. 641** 642** The pNext field is the only field in the sqlite3_vfs 643** structure that SQLite will ever modify. SQLite will only access 644** or modify this field while holding a particular static mutex. 645** The application should never modify anything within the sqlite3_vfs 646** object once the object has been registered. 647** 648** The zName field holds the name of the VFS module. The name must 649** be unique across all VFS modules. 650** 651** SQLite will guarantee that the zFilename parameter to xOpen 652** is either a NULL pointer or string obtained 653** from xFullPathname(). SQLite further guarantees that 654** the string will be valid and unchanged until xClose() is 655** called. Because of the previous sentense, 656** the [sqlite3_file] can safely store a pointer to the 657** filename if it needs to remember the filename for some reason. 658** If the zFilename parameter is xOpen is a NULL pointer then xOpen 659** must invite its own temporary name for the file. Whenever the 660** xFilename parameter is NULL it will also be the case that the 661** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 662** 663** The flags argument to xOpen() includes all bits set in 664** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 665** or [sqlite3_open16()] is used, then flags includes at least 666** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 667** If xOpen() opens a file read-only then it sets *pOutFlags to 668** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 669** 670** SQLite will also add one of the following flags to the xOpen() 671** call, depending on the object being opened: 672** 673** <ul> 674** <li> [SQLITE_OPEN_MAIN_DB] 675** <li> [SQLITE_OPEN_MAIN_JOURNAL] 676** <li> [SQLITE_OPEN_TEMP_DB] 677** <li> [SQLITE_OPEN_TEMP_JOURNAL] 678** <li> [SQLITE_OPEN_TRANSIENT_DB] 679** <li> [SQLITE_OPEN_SUBJOURNAL] 680** <li> [SQLITE_OPEN_MASTER_JOURNAL] 681** </ul> 682** 683** The file I/O implementation can use the object type flags to 684** change the way it deals with files. For example, an application 685** that does not care about crash recovery or rollback might make 686** the open of a journal file a no-op. Writes to this journal would 687** also be no-ops, and any attempt to read the journal would return 688** SQLITE_IOERR. Or the implementation might recognize that a database 689** file will be doing page-aligned sector reads and writes in a random 690** order and set up its I/O subsystem accordingly. 691** 692** SQLite might also add one of the following flags to the xOpen method: 693** 694** <ul> 695** <li> [SQLITE_OPEN_DELETEONCLOSE] 696** <li> [SQLITE_OPEN_EXCLUSIVE] 697** </ul> 698** 699** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 700** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] 701** will be set for TEMP databases, journals and for subjournals. 702** 703** The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 704** for exclusive access. This flag is set for all files except 705** for the main database file. 706** 707** At least szOsFile bytes of memory are allocated by SQLite 708** to hold the [sqlite3_file] structure passed as the third 709** argument to xOpen. The xOpen method does not have to 710** allocate the structure; it should just fill it in. 711** 712** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 713** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 714** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 715** to test whether a file is at least readable. The file can be a 716** directory. 717** 718** SQLite will always allocate at least mxPathname+1 bytes for the 719** output buffer xFullPathname. The exact size of the output buffer 720** is also passed as a parameter to both methods. If the output buffer 721** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 722** handled as a fatal error by SQLite, vfs implementations should endeavor 723** to prevent this by setting mxPathname to a sufficiently large value. 724** 725** The xRandomness(), xSleep(), and xCurrentTime() interfaces 726** are not strictly a part of the filesystem, but they are 727** included in the VFS structure for completeness. 728** The xRandomness() function attempts to return nBytes bytes 729** of good-quality randomness into zOut. The return value is 730** the actual number of bytes of randomness obtained. 731** The xSleep() method causes the calling thread to sleep for at 732** least the number of microseconds given. The xCurrentTime() 733** method returns a Julian Day Number for the current date and time. 734** 735*/ 736typedef struct sqlite3_vfs sqlite3_vfs; 737struct sqlite3_vfs { 738 int iVersion; /* Structure version number */ 739 int szOsFile; /* Size of subclassed sqlite3_file */ 740 int mxPathname; /* Maximum file pathname length */ 741 sqlite3_vfs *pNext; /* Next registered VFS */ 742 const char *zName; /* Name of this virtual file system */ 743 void *pAppData; /* Pointer to application-specific data */ 744 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 745 int flags, int *pOutFlags); 746 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 747 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 748 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 749 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 750 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 751 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 752 void (*xDlClose)(sqlite3_vfs*, void*); 753 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 754 int (*xSleep)(sqlite3_vfs*, int microseconds); 755 int (*xCurrentTime)(sqlite3_vfs*, double*); 756 int (*xGetLastError)(sqlite3_vfs*, int, char *); 757 /* New fields may be appended in figure versions. The iVersion 758 ** value will increment whenever this happens. */ 759}; 760 761/* 762** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> 763** 764** These integer constants can be used as the third parameter to 765** the xAccess method of an [sqlite3_vfs] object. {END} They determine 766** what kind of permissions the xAccess method is looking for. 767** With SQLITE_ACCESS_EXISTS, the xAccess method 768** simply checks whether the file exists. 769** With SQLITE_ACCESS_READWRITE, the xAccess method 770** checks whether the file is both readable and writable. 771** With SQLITE_ACCESS_READ, the xAccess method 772** checks whether the file is readable. 773*/ 774#define SQLITE_ACCESS_EXISTS 0 775#define SQLITE_ACCESS_READWRITE 1 776#define SQLITE_ACCESS_READ 2 777 778/* 779** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> 780** 781** The sqlite3_initialize() routine initializes the 782** SQLite library. The sqlite3_shutdown() routine 783** deallocates any resources that were allocated by sqlite3_initialize(). 784** 785** A call to sqlite3_initialize() is an "effective" call if it is 786** the first time sqlite3_initialize() is invoked during the lifetime of 787** the process, or if it is the first time sqlite3_initialize() is invoked 788** following a call to sqlite3_shutdown(). Only an effective call 789** of sqlite3_initialize() does any initialization. All other calls 790** are harmless no-ops. 791** 792** Among other things, sqlite3_initialize() shall invoke 793** sqlite3_os_init(). Similarly, sqlite3_shutdown() 794** shall invoke sqlite3_os_end(). 795** 796** The sqlite3_initialize() routine returns [SQLITE_OK] on success. 797** If for some reason, sqlite3_initialize() is unable to initialize 798** the library (perhaps it is unable to allocate a needed resource such 799** as a mutex) it returns an [error code] other than [SQLITE_OK]. 800** 801** The sqlite3_initialize() routine is called internally by many other 802** SQLite interfaces so that an application usually does not need to 803** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 804** calls sqlite3_initialize() so the SQLite library will be automatically 805** initialized when [sqlite3_open()] is called if it has not be initialized 806** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 807** compile-time option, then the automatic calls to sqlite3_initialize() 808** are omitted and the application must call sqlite3_initialize() directly 809** prior to using any other SQLite interface. For maximum portability, 810** it is recommended that applications always invoke sqlite3_initialize() 811** directly prior to using any other SQLite interface. Future releases 812** of SQLite may require this. In other words, the behavior exhibited 813** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 814** default behavior in some future release of SQLite. 815** 816** The sqlite3_os_init() routine does operating-system specific 817** initialization of the SQLite library. The sqlite3_os_end() 818** routine undoes the effect of sqlite3_os_init(). Typical tasks 819** performed by these routines include allocation or deallocation 820** of static resources, initialization of global variables, 821** setting up a default [sqlite3_vfs] module, or setting up 822** a default configuration using [sqlite3_config()]. 823** 824** The application should never invoke either sqlite3_os_init() 825** or sqlite3_os_end() directly. The application should only invoke 826** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 827** interface is called automatically by sqlite3_initialize() and 828** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 829** implementations for sqlite3_os_init() and sqlite3_os_end() 830** are built into SQLite when it is compiled for unix, windows, or os/2. 831** When built for other platforms (using the [SQLITE_OS_OTHER=1] compile-time 832** option) the application must supply a suitable implementation for 833** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 834** implementation of sqlite3_os_init() or sqlite3_os_end() 835** must return [SQLITE_OK] on success and some other [error code] upon 836** failure. 837*/ 838int sqlite3_initialize(void); 839int sqlite3_shutdown(void); 840int sqlite3_os_init(void); 841int sqlite3_os_end(void); 842 843/* 844** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> 845** EXPERIMENTAL 846** 847** The sqlite3_config() interface is used to make global configuration 848** changes to SQLite in order to tune SQLite to the specific needs of 849** the application. The default configuration is recommended for most 850** applications and so this routine is usually not necessary. It is 851** provided to support rare applications with unusual needs. 852** 853** The sqlite3_config() interface is not threadsafe. The application 854** must insure that no other SQLite interfaces are invoked by other 855** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 856** may only be invoked prior to library initialization using 857** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 858** Note, however, that sqlite3_config() can be called as part of the 859** implementation of an application-defined [sqlite3_os_init()]. 860** 861** The first argument to sqlite3_config() is an integer 862** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines 863** what property of SQLite is to be configured. Subsequent arguments 864** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] 865** in the first argument. 866** 867** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 868** If the option is unknown or SQLite is unable to set the option 869** then this routine returns a non-zero [error code]. 870** 871** Requirements: 872** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] 873** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] 874** [H14162] [H14165] [H14168] 875*/ 876SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); 877 878/* 879** CAPI3REF: Configure database connections {H14200} <S20000> 880** EXPERIMENTAL 881** 882** The sqlite3_db_config() interface is used to make configuration 883** changes to a [database connection]. The interface is similar to 884** [sqlite3_config()] except that the changes apply to a single 885** [database connection] (specified in the first argument). The 886** sqlite3_db_config() interface can only be used immediately after 887** the database connection is created using [sqlite3_open()], 888** [sqlite3_open16()], or [sqlite3_open_v2()]. 889** 890** The second argument to sqlite3_db_config(D,V,...) is the 891** configuration verb - an integer code that indicates what 892** aspect of the [database connection] is being configured. 893** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. 894** New verbs are likely to be added in future releases of SQLite. 895** Additional arguments depend on the verb. 896** 897** Requirements: 898** [H14203] [H14206] [H14209] [H14212] [H14215] 899*/ 900SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); 901 902/* 903** CAPI3REF: Memory Allocation Routines {H10155} <S20120> 904** EXPERIMENTAL 905** 906** An instance of this object defines the interface between SQLite 907** and low-level memory allocation routines. 908** 909** This object is used in only one place in the SQLite interface. 910** A pointer to an instance of this object is the argument to 911** [sqlite3_config()] when the configuration option is 912** [SQLITE_CONFIG_MALLOC]. By creating an instance of this object 913** and passing it to [sqlite3_config()] during configuration, an 914** application can specify an alternative memory allocation subsystem 915** for SQLite to use for all of its dynamic memory needs. 916** 917** Note that SQLite comes with a built-in memory allocator that is 918** perfectly adequate for the overwhelming majority of applications 919** and that this object is only useful to a tiny minority of applications 920** with specialized memory allocation requirements. This object is 921** also used during testing of SQLite in order to specify an alternative 922** memory allocator that simulates memory out-of-memory conditions in 923** order to verify that SQLite recovers gracefully from such 924** conditions. 925** 926** The xMalloc, xFree, and xRealloc methods must work like the 927** malloc(), free(), and realloc() functions from the standard library. 928** 929** xSize should return the allocated size of a memory allocation 930** previously obtained from xMalloc or xRealloc. The allocated size 931** is always at least as big as the requested size but may be larger. 932** 933** The xRoundup method returns what would be the allocated size of 934** a memory allocation given a particular requested size. Most memory 935** allocators round up memory allocations at least to the next multiple 936** of 8. Some allocators round up to a larger multiple or to a power of 2. 937** 938** The xInit method initializes the memory allocator. (For example, 939** it might allocate any require mutexes or initialize internal data 940** structures. The xShutdown method is invoked (indirectly) by 941** [sqlite3_shutdown()] and should deallocate any resources acquired 942** by xInit. The pAppData pointer is used as the only parameter to 943** xInit and xShutdown. 944*/ 945typedef struct sqlite3_mem_methods sqlite3_mem_methods; 946struct sqlite3_mem_methods { 947 void *(*xMalloc)(int); /* Memory allocation function */ 948 void (*xFree)(void*); /* Free a prior allocation */ 949 void *(*xRealloc)(void*,int); /* Resize an allocation */ 950 int (*xSize)(void*); /* Return the size of an allocation */ 951 int (*xRoundup)(int); /* Round up request size to allocation size */ 952 int (*xInit)(void*); /* Initialize the memory allocator */ 953 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 954 void *pAppData; /* Argument to xInit() and xShutdown() */ 955}; 956 957/* 958** CAPI3REF: Configuration Options {H10160} <S20000> 959** EXPERIMENTAL 960** 961** These constants are the available integer configuration options that 962** can be passed as the first argument to the [sqlite3_config()] interface. 963** 964** New configuration options may be added in future releases of SQLite. 965** Existing configuration options might be discontinued. Applications 966** should check the return code from [sqlite3_config()] to make sure that 967** the call worked. The [sqlite3_config()] interface will return a 968** non-zero [error code] if a discontinued or unsupported configuration option 969** is invoked. 970** 971** <dl> 972** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 973** <dd>There are no arguments to this option. This option disables 974** all mutexing and puts SQLite into a mode where it can only be used 975** by a single thread.</dd> 976** 977** <dt>SQLITE_CONFIG_MULTITHREAD</dt> 978** <dd>There are no arguments to this option. This option disables 979** mutexing on [database connection] and [prepared statement] objects. 980** The application is responsible for serializing access to 981** [database connections] and [prepared statements]. But other mutexes 982** are enabled so that SQLite will be safe to use in a multi-threaded 983** environment as long as no two threads attempt to use the same 984** [database connection] at the same time. See the [threading mode] 985** documentation for additional information.</dd> 986** 987** <dt>SQLITE_CONFIG_SERIALIZED</dt> 988** <dd>There are no arguments to this option. This option enables 989** all mutexes including the recursive 990** mutexes on [database connection] and [prepared statement] objects. 991** In this mode (which is the default when SQLite is compiled with 992** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 993** to [database connections] and [prepared statements] so that the 994** application is free to use the same [database connection] or the 995** same [prepared statement] in different threads at the same time. 996** See the [threading mode] documentation for additional information.</dd> 997** 998** <dt>SQLITE_CONFIG_MALLOC</dt> 999** <dd>This option takes a single argument which is a pointer to an 1000** instance of the [sqlite3_mem_methods] structure. The argument specifies 1001** alternative low-level memory allocation routines to be used in place of 1002** the memory allocation routines built into SQLite.</dd> 1003** 1004** <dt>SQLITE_CONFIG_GETMALLOC</dt> 1005** <dd>This option takes a single argument which is a pointer to an 1006** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1007** structure is filled with the currently defined memory allocation routines. 1008** This option can be used to overload the default memory allocation 1009** routines with a wrapper that simulations memory allocation failure or 1010** tracks memory usage, for example.</dd> 1011** 1012** <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1013** <dd>This option takes single argument of type int, interpreted as a 1014** boolean, which enables or disables the collection of memory allocation 1015** statistics. When disabled, the following SQLite interfaces become 1016** non-operational: 1017** <ul> 1018** <li> [sqlite3_memory_used()] 1019** <li> [sqlite3_memory_highwater()] 1020** <li> [sqlite3_soft_heap_limit()] 1021** <li> [sqlite3_status()] 1022** </ul> 1023** </dd> 1024** 1025** <dt>SQLITE_CONFIG_SCRATCH</dt> 1026** <dd>This option specifies a static memory buffer that SQLite can use for 1027** scratch memory. There are three arguments: A pointer to the memory, the 1028** size of each scratch buffer (sz), and the number of buffers (N). The sz 1029** argument must be a multiple of 16. The sz parameter should be a few bytes 1030** larger than the actual scratch space required due internal overhead. 1031** The first 1032** argument should point to an allocation of at least sz*N bytes of memory. 1033** SQLite will use no more than one scratch buffer at once per thread, so 1034** N should be set to the expected maximum number of threads. The sz 1035** parameter should be 6 times the size of the largest database page size. 1036** Scratch buffers are used as part of the btree balance operation. If 1037** The btree balancer needs additional memory beyond what is provided by 1038** scratch buffers or if no scratch buffer space is specified, then SQLite 1039** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> 1040** 1041** <dt>SQLITE_CONFIG_PAGECACHE</dt> 1042** <dd>This option specifies a static memory buffer that SQLite can use for 1043** the database page cache with the default page cache implemenation. 1044** This configuration should not be used if an application-define page 1045** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. 1046** There are three arguments to this option: A pointer to the 1047** memory, the size of each page buffer (sz), and the number of pages (N). 1048** The sz argument must be a power of two between 512 and 32768. The first 1049** argument should point to an allocation of at least sz*N bytes of memory. 1050** SQLite will use the memory provided by the first argument to satisfy its 1051** memory needs for the first N pages that it adds to cache. If additional 1052** page cache memory is needed beyond what is provided by this option, then 1053** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1054** The implementation might use one or more of the N buffers to hold 1055** memory accounting information. </dd> 1056** 1057** <dt>SQLITE_CONFIG_HEAP</dt> 1058** <dd>This option specifies a static memory buffer that SQLite will use 1059** for all of its dynamic memory allocation needs beyond those provided 1060** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1061** There are three arguments: A pointer to the memory, the number of 1062** bytes in the memory buffer, and the minimum allocation size. If 1063** the first pointer (the memory pointer) is NULL, then SQLite reverts 1064** to using its default memory allocator (the system malloc() implementation), 1065** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the 1066** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1067** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1068** allocator is engaged to handle all of SQLites memory allocation needs.</dd> 1069** 1070** <dt>SQLITE_CONFIG_MUTEX</dt> 1071** <dd>This option takes a single argument which is a pointer to an 1072** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1073** alternative low-level mutex routines to be used in place 1074** the mutex routines built into SQLite.</dd> 1075** 1076** <dt>SQLITE_CONFIG_GETMUTEX</dt> 1077** <dd>This option takes a single argument which is a pointer to an 1078** instance of the [sqlite3_mutex_methods] structure. The 1079** [sqlite3_mutex_methods] 1080** structure is filled with the currently defined mutex routines. 1081** This option can be used to overload the default mutex allocation 1082** routines with a wrapper used to track mutex usage for performance 1083** profiling or testing, for example.</dd> 1084** 1085** <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1086** <dd>This option takes two arguments that determine the default 1087** memory allcation lookaside optimization. The first argument is the 1088** size of each lookaside buffer slot and the second is the number of 1089** slots allocated to each database connection.</dd> 1090** 1091** <dt>SQLITE_CONFIG_PCACHE</dt> 1092** <dd>This option takes a single argument which is a pointer to 1093** an [sqlite3_pcache_methods] object. This object specifies the interface 1094** to a custom page cache implementation. SQLite makes a copy of the 1095** object and uses it for page cache memory allocations.</dd> 1096** 1097** <dt>SQLITE_CONFIG_GETPCACHE</dt> 1098** <dd>This option takes a single argument which is a pointer to an 1099** [sqlite3_pcache_methods] object. SQLite copies of the current 1100** page cache implementation into that object.</dd> 1101** 1102** </dl> 1103*/ 1104#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1105#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1106#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1107#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1108#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1109#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1110#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1111#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1112#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1113#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1114#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1115/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1116#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1117#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ 1118#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ 1119 1120/* 1121** CAPI3REF: Configuration Options {H10170} <S20000> 1122** EXPERIMENTAL 1123** 1124** These constants are the available integer configuration options that 1125** can be passed as the second argument to the [sqlite3_db_config()] interface. 1126** 1127** New configuration options may be added in future releases of SQLite. 1128** Existing configuration options might be discontinued. Applications 1129** should check the return code from [sqlite3_db_config()] to make sure that 1130** the call worked. The [sqlite3_db_config()] interface will return a 1131** non-zero [error code] if a discontinued or unsupported configuration option 1132** is invoked. 1133** 1134** <dl> 1135** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1136** <dd>This option takes three additional arguments that determine the 1137** [lookaside memory allocator] configuration for the [database connection]. 1138** The first argument (the third parameter to [sqlite3_db_config()] is a 1139** pointer to a memory buffer to use for lookaside memory. The first 1140** argument may be NULL in which case SQLite will allocate the lookaside 1141** buffer itself using [sqlite3_malloc()]. The second argument is the 1142** size of each lookaside buffer slot and the third argument is the number of 1143** slots. The size of the buffer in the first argument must be greater than 1144** or equal to the product of the second and third arguments.</dd> 1145** 1146** </dl> 1147*/ 1148#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1149 1150 1151/* 1152** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> 1153** 1154** The sqlite3_extended_result_codes() routine enables or disables the 1155** [extended result codes] feature of SQLite. The extended result 1156** codes are disabled by default for historical compatibility considerations. 1157** 1158** Requirements: 1159** [H12201] [H12202] 1160*/ 1161int sqlite3_extended_result_codes(sqlite3*, int onoff); 1162 1163/* 1164** CAPI3REF: Last Insert Rowid {H12220} <S10700> 1165** 1166** Each entry in an SQLite table has a unique 64-bit signed 1167** integer key called the [ROWID | "rowid"]. The rowid is always available 1168** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1169** names are not also used by explicitly declared columns. If 1170** the table has a column of type [INTEGER PRIMARY KEY] then that column 1171** is another alias for the rowid. 1172** 1173** This routine returns the [rowid] of the most recent 1174** successful [INSERT] into the database from the [database connection] 1175** in the first argument. If no successful [INSERT]s 1176** have ever occurred on that database connection, zero is returned. 1177** 1178** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted 1179** row is returned by this routine as long as the trigger is running. 1180** But once the trigger terminates, the value returned by this routine 1181** reverts to the last value inserted before the trigger fired. 1182** 1183** An [INSERT] that fails due to a constraint violation is not a 1184** successful [INSERT] and does not change the value returned by this 1185** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1186** and INSERT OR ABORT make no changes to the return value of this 1187** routine when their insertion fails. When INSERT OR REPLACE 1188** encounters a constraint violation, it does not fail. The 1189** INSERT continues to completion after deleting rows that caused 1190** the constraint problem so INSERT OR REPLACE will always change 1191** the return value of this interface. 1192** 1193** For the purposes of this routine, an [INSERT] is considered to 1194** be successful even if it is subsequently rolled back. 1195** 1196** Requirements: 1197** [H12221] [H12223] 1198** 1199** If a separate thread performs a new [INSERT] on the same 1200** database connection while the [sqlite3_last_insert_rowid()] 1201** function is running and thus changes the last insert [rowid], 1202** then the value returned by [sqlite3_last_insert_rowid()] is 1203** unpredictable and might not equal either the old or the new 1204** last insert [rowid]. 1205*/ 1206sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1207 1208/* 1209** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> 1210** 1211** This function returns the number of database rows that were changed 1212** or inserted or deleted by the most recently completed SQL statement 1213** on the [database connection] specified by the first parameter. 1214** Only changes that are directly specified by the [INSERT], [UPDATE], 1215** or [DELETE] statement are counted. Auxiliary changes caused by 1216** triggers are not counted. Use the [sqlite3_total_changes()] function 1217** to find the total number of changes including changes caused by triggers. 1218** 1219** A "row change" is a change to a single row of a single table 1220** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1221** are changed as side effects of REPLACE constraint resolution, 1222** rollback, ABORT processing, DROP TABLE, or by any other 1223** mechanisms do not count as direct row changes. 1224** 1225** A "trigger context" is a scope of execution that begins and 1226** ends with the script of a trigger. Most SQL statements are 1227** evaluated outside of any trigger. This is the "top level" 1228** trigger context. If a trigger fires from the top level, a 1229** new trigger context is entered for the duration of that one 1230** trigger. Subtriggers create subcontexts for their duration. 1231** 1232** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1233** not create a new trigger context. 1234** 1235** This function returns the number of direct row changes in the 1236** most recent INSERT, UPDATE, or DELETE statement within the same 1237** trigger context. 1238** 1239** Thus, when called from the top level, this function returns the 1240** number of changes in the most recent INSERT, UPDATE, or DELETE 1241** that also occurred at the top level. Within the body of a trigger, 1242** the sqlite3_changes() interface can be called to find the number of 1243** changes in the most recently completed INSERT, UPDATE, or DELETE 1244** statement within the body of the same trigger. 1245** However, the number returned does not include changes 1246** caused by subtriggers since those have their own context. 1247** 1248** SQLite implements the command "DELETE FROM table" without a WHERE clause 1249** by dropping and recreating the table. Doing so is much faster than going 1250** through and deleting individual elements from the table. Because of this 1251** optimization, the deletions in "DELETE FROM table" are not row changes and 1252** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1253** functions, regardless of the number of elements that were originally 1254** in the table. To get an accurate count of the number of rows deleted, use 1255** "DELETE FROM table WHERE 1" instead. Or recompile using the 1256** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the 1257** optimization on all queries. 1258** 1259** Requirements: 1260** [H12241] [H12243] 1261** 1262** If a separate thread makes changes on the same database connection 1263** while [sqlite3_changes()] is running then the value returned 1264** is unpredictable and not meaningful. 1265*/ 1266int sqlite3_changes(sqlite3*); 1267 1268/* 1269** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> 1270** 1271** This function returns the number of row changes caused by INSERT, 1272** UPDATE or DELETE statements since the [database connection] was opened. 1273** The count includes all changes from all trigger contexts. However, 1274** the count does not include changes used to implement REPLACE constraints, 1275** do rollbacks or ABORT processing, or DROP table processing. 1276** The changes are counted as soon as the statement that makes them is 1277** completed (when the statement handle is passed to [sqlite3_reset()] or 1278** [sqlite3_finalize()]). 1279** 1280** SQLite implements the command "DELETE FROM table" without a WHERE clause 1281** by dropping and recreating the table. (This is much faster than going 1282** through and deleting individual elements from the table.) Because of this 1283** optimization, the deletions in "DELETE FROM table" are not row changes and 1284** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] 1285** functions, regardless of the number of elements that were originally 1286** in the table. To get an accurate count of the number of rows deleted, use 1287** "DELETE FROM table WHERE 1" instead. Or recompile using the 1288** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the 1289** optimization on all queries. 1290** 1291** See also the [sqlite3_changes()] interface. 1292** 1293** Requirements: 1294** [H12261] [H12263] 1295** 1296** If a separate thread makes changes on the same database connection 1297** while [sqlite3_total_changes()] is running then the value 1298** returned is unpredictable and not meaningful. 1299*/ 1300int sqlite3_total_changes(sqlite3*); 1301 1302/* 1303** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> 1304** 1305** This function causes any pending database operation to abort and 1306** return at its earliest opportunity. This routine is typically 1307** called in response to a user action such as pressing "Cancel" 1308** or Ctrl-C where the user wants a long query operation to halt 1309** immediately. 1310** 1311** It is safe to call this routine from a thread different from the 1312** thread that is currently running the database operation. But it 1313** is not safe to call this routine with a [database connection] that 1314** is closed or might close before sqlite3_interrupt() returns. 1315** 1316** If an SQL operation is very nearly finished at the time when 1317** sqlite3_interrupt() is called, then it might not have an opportunity 1318** to be interrupted and might continue to completion. 1319** 1320** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1321** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1322** that is inside an explicit transaction, then the entire transaction 1323** will be rolled back automatically. 1324** 1325** A call to sqlite3_interrupt() has no effect on SQL statements 1326** that are started after sqlite3_interrupt() returns. 1327** 1328** Requirements: 1329** [H12271] [H12272] 1330** 1331** If the database connection closes while [sqlite3_interrupt()] 1332** is running then bad things will likely happen. 1333*/ 1334void sqlite3_interrupt(sqlite3*); 1335 1336/* 1337** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> 1338** 1339** These routines are useful for command-line input to determine if the 1340** currently entered text seems to form complete a SQL statement or 1341** if additional input is needed before sending the text into 1342** SQLite for parsing. These routines return true if the input string 1343** appears to be a complete SQL statement. A statement is judged to be 1344** complete if it ends with a semicolon token and is not a fragment of a 1345** CREATE TRIGGER statement. Semicolons that are embedded within 1346** string literals or quoted identifier names or comments are not 1347** independent tokens (they are part of the token in which they are 1348** embedded) and thus do not count as a statement terminator. 1349** 1350** These routines do not parse the SQL statements thus 1351** will not detect syntactically incorrect SQL. 1352** 1353** Requirements: [H10511] [H10512] 1354** 1355** The input to [sqlite3_complete()] must be a zero-terminated 1356** UTF-8 string. 1357** 1358** The input to [sqlite3_complete16()] must be a zero-terminated 1359** UTF-16 string in native byte order. 1360*/ 1361int sqlite3_complete(const char *sql); 1362int sqlite3_complete16(const void *sql); 1363 1364/* 1365** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> 1366** 1367** This routine sets a callback function that might be invoked whenever 1368** an attempt is made to open a database table that another thread 1369** or process has locked. 1370** 1371** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1372** is returned immediately upon encountering the lock. If the busy callback 1373** is not NULL, then the callback will be invoked with two arguments. 1374** 1375** The first argument to the handler is a copy of the void* pointer which 1376** is the third argument to sqlite3_busy_handler(). The second argument to 1377** the handler callback is the number of times that the busy handler has 1378** been invoked for this locking event. If the 1379** busy callback returns 0, then no additional attempts are made to 1380** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1381** If the callback returns non-zero, then another attempt 1382** is made to open the database for reading and the cycle repeats. 1383** 1384** The presence of a busy handler does not guarantee that it will be invoked 1385** when there is lock contention. If SQLite determines that invoking the busy 1386** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1387** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1388** Consider a scenario where one process is holding a read lock that 1389** it is trying to promote to a reserved lock and 1390** a second process is holding a reserved lock that it is trying 1391** to promote to an exclusive lock. The first process cannot proceed 1392** because it is blocked by the second and the second process cannot 1393** proceed because it is blocked by the first. If both processes 1394** invoke the busy handlers, neither will make any progress. Therefore, 1395** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1396** will induce the first process to release its read lock and allow 1397** the second process to proceed. 1398** 1399** The default busy callback is NULL. 1400** 1401** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1402** when SQLite is in the middle of a large transaction where all the 1403** changes will not fit into the in-memory cache. SQLite will 1404** already hold a RESERVED lock on the database file, but it needs 1405** to promote this lock to EXCLUSIVE so that it can spill cache 1406** pages into the database file without harm to concurrent 1407** readers. If it is unable to promote the lock, then the in-memory 1408** cache will be left in an inconsistent state and so the error 1409** code is promoted from the relatively benign [SQLITE_BUSY] to 1410** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1411** forces an automatic rollback of the changes. See the 1412** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1413** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1414** this is important. 1415** 1416** There can only be a single busy handler defined for each 1417** [database connection]. Setting a new busy handler clears any 1418** previously set handler. Note that calling [sqlite3_busy_timeout()] 1419** will also set or clear the busy handler. 1420** 1421** The busy callback should not take any actions which modify the 1422** database connection that invoked the busy handler. Any such actions 1423** result in undefined behavior. 1424** 1425** Requirements: 1426** [H12311] [H12312] [H12314] [H12316] [H12318] 1427** 1428** A busy handler must not close the database connection 1429** or [prepared statement] that invoked the busy handler. 1430*/ 1431int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1432 1433/* 1434** CAPI3REF: Set A Busy Timeout {H12340} <S40410> 1435** 1436** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1437** for a specified amount of time when a table is locked. The handler 1438** will sleep multiple times until at least "ms" milliseconds of sleeping 1439** have accumulated. {H12343} After "ms" milliseconds of sleeping, 1440** the handler returns 0 which causes [sqlite3_step()] to return 1441** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1442** 1443** Calling this routine with an argument less than or equal to zero 1444** turns off all busy handlers. 1445** 1446** There can only be a single busy handler for a particular 1447** [database connection] any any given moment. If another busy handler 1448** was defined (using [sqlite3_busy_handler()]) prior to calling 1449** this routine, that other busy handler is cleared. 1450** 1451** Requirements: 1452** [H12341] [H12343] [H12344] 1453*/ 1454int sqlite3_busy_timeout(sqlite3*, int ms); 1455 1456/* 1457** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> 1458** 1459** Definition: A <b>result table</b> is memory data structure created by the 1460** [sqlite3_get_table()] interface. A result table records the 1461** complete query results from one or more queries. 1462** 1463** The table conceptually has a number of rows and columns. But 1464** these numbers are not part of the result table itself. These 1465** numbers are obtained separately. Let N be the number of rows 1466** and M be the number of columns. 1467** 1468** A result table is an array of pointers to zero-terminated UTF-8 strings. 1469** There are (N+1)*M elements in the array. The first M pointers point 1470** to zero-terminated strings that contain the names of the columns. 1471** The remaining entries all point to query results. NULL values result 1472** in NULL pointers. All other values are in their UTF-8 zero-terminated 1473** string representation as returned by [sqlite3_column_text()]. 1474** 1475** A result table might consist of one or more memory allocations. 1476** It is not safe to pass a result table directly to [sqlite3_free()]. 1477** A result table should be deallocated using [sqlite3_free_table()]. 1478** 1479** As an example of the result table format, suppose a query result 1480** is as follows: 1481** 1482** <blockquote><pre> 1483** Name | Age 1484** ----------------------- 1485** Alice | 43 1486** Bob | 28 1487** Cindy | 21 1488** </pre></blockquote> 1489** 1490** There are two column (M==2) and three rows (N==3). Thus the 1491** result table has 8 entries. Suppose the result table is stored 1492** in an array names azResult. Then azResult holds this content: 1493** 1494** <blockquote><pre> 1495** azResult[0] = "Name"; 1496** azResult[1] = "Age"; 1497** azResult[2] = "Alice"; 1498** azResult[3] = "43"; 1499** azResult[4] = "Bob"; 1500** azResult[5] = "28"; 1501** azResult[6] = "Cindy"; 1502** azResult[7] = "21"; 1503** </pre></blockquote> 1504** 1505** The sqlite3_get_table() function evaluates one or more 1506** semicolon-separated SQL statements in the zero-terminated UTF-8 1507** string of its 2nd parameter. It returns a result table to the 1508** pointer given in its 3rd parameter. 1509** 1510** After the calling function has finished using the result, it should 1511** pass the pointer to the result table to sqlite3_free_table() in order to 1512** release the memory that was malloced. Because of the way the 1513** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1514** function must not try to call [sqlite3_free()] directly. Only 1515** [sqlite3_free_table()] is able to release the memory properly and safely. 1516** 1517** The sqlite3_get_table() interface is implemented as a wrapper around 1518** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1519** to any internal data structures of SQLite. It uses only the public 1520** interface defined here. As a consequence, errors that occur in the 1521** wrapper layer outside of the internal [sqlite3_exec()] call are not 1522** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. 1523** 1524** Requirements: 1525** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] 1526*/ 1527int sqlite3_get_table( 1528 sqlite3 *db, /* An open database */ 1529 const char *zSql, /* SQL to be evaluated */ 1530 char ***pazResult, /* Results of the query */ 1531 int *pnRow, /* Number of result rows written here */ 1532 int *pnColumn, /* Number of result columns written here */ 1533 char **pzErrmsg /* Error msg written here */ 1534); 1535void sqlite3_free_table(char **result); 1536 1537/* 1538** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> 1539** 1540** These routines are workalikes of the "printf()" family of functions 1541** from the standard C library. 1542** 1543** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1544** results into memory obtained from [sqlite3_malloc()]. 1545** The strings returned by these two routines should be 1546** released by [sqlite3_free()]. Both routines return a 1547** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1548** memory to hold the resulting string. 1549** 1550** In sqlite3_snprintf() routine is similar to "snprintf()" from 1551** the standard C library. The result is written into the 1552** buffer supplied as the second parameter whose size is given by 1553** the first parameter. Note that the order of the 1554** first two parameters is reversed from snprintf(). This is an 1555** historical accident that cannot be fixed without breaking 1556** backwards compatibility. Note also that sqlite3_snprintf() 1557** returns a pointer to its buffer instead of the number of 1558** characters actually written into the buffer. We admit that 1559** the number of characters written would be a more useful return 1560** value but we cannot change the implementation of sqlite3_snprintf() 1561** now without breaking compatibility. 1562** 1563** As long as the buffer size is greater than zero, sqlite3_snprintf() 1564** guarantees that the buffer is always zero-terminated. The first 1565** parameter "n" is the total size of the buffer, including space for 1566** the zero terminator. So the longest string that can be completely 1567** written will be n-1 characters. 1568** 1569** These routines all implement some additional formatting 1570** options that are useful for constructing SQL statements. 1571** All of the usual printf() formatting options apply. In addition, there 1572** is are "%q", "%Q", and "%z" options. 1573** 1574** The %q option works like %s in that it substitutes a null-terminated 1575** string from the argument list. But %q also doubles every '\'' character. 1576** %q is designed for use inside a string literal. By doubling each '\'' 1577** character it escapes that character and allows it to be inserted into 1578** the string. 1579** 1580** For example, assume the string variable zText contains text as follows: 1581** 1582** <blockquote><pre> 1583** char *zText = "It's a happy day!"; 1584** </pre></blockquote> 1585** 1586** One can use this text in an SQL statement as follows: 1587** 1588** <blockquote><pre> 1589** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1590** sqlite3_exec(db, zSQL, 0, 0, 0); 1591** sqlite3_free(zSQL); 1592** </pre></blockquote> 1593** 1594** Because the %q format string is used, the '\'' character in zText 1595** is escaped and the SQL generated is as follows: 1596** 1597** <blockquote><pre> 1598** INSERT INTO table1 VALUES('It''s a happy day!') 1599** </pre></blockquote> 1600** 1601** This is correct. Had we used %s instead of %q, the generated SQL 1602** would have looked like this: 1603** 1604** <blockquote><pre> 1605** INSERT INTO table1 VALUES('It's a happy day!'); 1606** </pre></blockquote> 1607** 1608** This second example is an SQL syntax error. As a general rule you should 1609** always use %q instead of %s when inserting text into a string literal. 1610** 1611** The %Q option works like %q except it also adds single quotes around 1612** the outside of the total string. Additionally, if the parameter in the 1613** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 1614** single quotes) in place of the %Q option. So, for example, one could say: 1615** 1616** <blockquote><pre> 1617** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1618** sqlite3_exec(db, zSQL, 0, 0, 0); 1619** sqlite3_free(zSQL); 1620** </pre></blockquote> 1621** 1622** The code above will render a correct SQL statement in the zSQL 1623** variable even if the zText variable is a NULL pointer. 1624** 1625** The "%z" formatting option works exactly like "%s" with the 1626** addition that after the string has been read and copied into 1627** the result, [sqlite3_free()] is called on the input string. {END} 1628** 1629** Requirements: 1630** [H17403] [H17406] [H17407] 1631*/ 1632char *sqlite3_mprintf(const char*,...); 1633char *sqlite3_vmprintf(const char*, va_list); 1634char *sqlite3_snprintf(int,char*,const char*, ...); 1635 1636/* 1637** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> 1638** 1639** The SQLite core uses these three routines for all of its own 1640** internal memory allocation needs. "Core" in the previous sentence 1641** does not include operating-system specific VFS implementation. The 1642** Windows VFS uses native malloc() and free() for some operations. 1643** 1644** The sqlite3_malloc() routine returns a pointer to a block 1645** of memory at least N bytes in length, where N is the parameter. 1646** If sqlite3_malloc() is unable to obtain sufficient free 1647** memory, it returns a NULL pointer. If the parameter N to 1648** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1649** a NULL pointer. 1650** 1651** Calling sqlite3_free() with a pointer previously returned 1652** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1653** that it might be reused. The sqlite3_free() routine is 1654** a no-op if is called with a NULL pointer. Passing a NULL pointer 1655** to sqlite3_free() is harmless. After being freed, memory 1656** should neither be read nor written. Even reading previously freed 1657** memory might result in a segmentation fault or other severe error. 1658** Memory corruption, a segmentation fault, or other severe error 1659** might result if sqlite3_free() is called with a non-NULL pointer that 1660** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 1661** 1662** The sqlite3_realloc() interface attempts to resize a 1663** prior memory allocation to be at least N bytes, where N is the 1664** second parameter. The memory allocation to be resized is the first 1665** parameter. If the first parameter to sqlite3_realloc() 1666** is a NULL pointer then its behavior is identical to calling 1667** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1668** If the second parameter to sqlite3_realloc() is zero or 1669** negative then the behavior is exactly the same as calling 1670** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1671** sqlite3_realloc() returns a pointer to a memory allocation 1672** of at least N bytes in size or NULL if sufficient memory is unavailable. 1673** If M is the size of the prior allocation, then min(N,M) bytes 1674** of the prior allocation are copied into the beginning of buffer returned 1675** by sqlite3_realloc() and the prior allocation is freed. 1676** If sqlite3_realloc() returns NULL, then the prior allocation 1677** is not freed. 1678** 1679** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1680** is always aligned to at least an 8 byte boundary. {END} 1681** 1682** The default implementation of the memory allocation subsystem uses 1683** the malloc(), realloc() and free() provided by the standard C library. 1684** {H17382} However, if SQLite is compiled with the 1685** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> 1686** is an integer), then SQLite create a static array of at least 1687** <i>NNN</i> bytes in size and uses that array for all of its dynamic 1688** memory allocation needs. {END} Additional memory allocator options 1689** may be added in future releases. 1690** 1691** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1692** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1693** implementation of these routines to be omitted. That capability 1694** is no longer provided. Only built-in memory allocators can be used. 1695** 1696** The Windows OS interface layer calls 1697** the system malloc() and free() directly when converting 1698** filenames between the UTF-8 encoding used by SQLite 1699** and whatever filename encoding is used by the particular Windows 1700** installation. Memory allocation errors are detected, but 1701** they are reported back as [SQLITE_CANTOPEN] or 1702** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1703** 1704** Requirements: 1705** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] 1706** [H17321] [H17322] [H17323] 1707** 1708** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1709** must be either NULL or else pointers obtained from a prior 1710** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 1711** not yet been released. 1712** 1713** The application must not read or write any part of 1714** a block of memory after it has been released using 1715** [sqlite3_free()] or [sqlite3_realloc()]. 1716*/ 1717void *sqlite3_malloc(int); 1718void *sqlite3_realloc(void*, int); 1719void sqlite3_free(void*); 1720 1721/* 1722** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> 1723** 1724** SQLite provides these two interfaces for reporting on the status 1725** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1726** routines, which form the built-in memory allocation subsystem. 1727** 1728** Requirements: 1729** [H17371] [H17373] [H17374] [H17375] 1730*/ 1731sqlite3_int64 sqlite3_memory_used(void); 1732sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1733 1734/* 1735** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> 1736** 1737** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1738** select random [ROWID | ROWIDs] when inserting new records into a table that 1739** already uses the largest possible [ROWID]. The PRNG is also used for 1740** the build-in random() and randomblob() SQL functions. This interface allows 1741** applications to access the same PRNG for other purposes. 1742** 1743** A call to this routine stores N bytes of randomness into buffer P. 1744** 1745** The first time this routine is invoked (either internally or by 1746** the application) the PRNG is seeded using randomness obtained 1747** from the xRandomness method of the default [sqlite3_vfs] object. 1748** On all subsequent invocations, the pseudo-randomness is generated 1749** internally and without recourse to the [sqlite3_vfs] xRandomness 1750** method. 1751** 1752** Requirements: 1753** [H17392] 1754*/ 1755void sqlite3_randomness(int N, void *P); 1756 1757/* 1758** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> 1759** 1760** This routine registers a authorizer callback with a particular 1761** [database connection], supplied in the first argument. 1762** The authorizer callback is invoked as SQL statements are being compiled 1763** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1764** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1765** points during the compilation process, as logic is being created 1766** to perform various actions, the authorizer callback is invoked to 1767** see if those actions are allowed. The authorizer callback should 1768** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1769** specific action but allow the SQL statement to continue to be 1770** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1771** rejected with an error. If the authorizer callback returns 1772** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1773** then the [sqlite3_prepare_v2()] or equivalent call that triggered 1774** the authorizer will fail with an error message. 1775** 1776** When the callback returns [SQLITE_OK], that means the operation 1777** requested is ok. When the callback returns [SQLITE_DENY], the 1778** [sqlite3_prepare_v2()] or equivalent call that triggered the 1779** authorizer will fail with an error message explaining that 1780** access is denied. If the authorizer code is [SQLITE_READ] 1781** and the callback returns [SQLITE_IGNORE] then the 1782** [prepared statement] statement is constructed to substitute 1783** a NULL value in place of the table column that would have 1784** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1785** return can be used to deny an untrusted user access to individual 1786** columns of a table. 1787** 1788** The first parameter to the authorizer callback is a copy of the third 1789** parameter to the sqlite3_set_authorizer() interface. The second parameter 1790** to the callback is an integer [SQLITE_COPY | action code] that specifies 1791** the particular action to be authorized. The third through sixth parameters 1792** to the callback are zero-terminated strings that contain additional 1793** details about the action to be authorized. 1794** 1795** An authorizer is used when [sqlite3_prepare | preparing] 1796** SQL statements from an untrusted source, to ensure that the SQL statements 1797** do not try to access data they are not allowed to see, or that they do not 1798** try to execute malicious statements that damage the database. For 1799** example, an application may allow a user to enter arbitrary 1800** SQL queries for evaluation by a database. But the application does 1801** not want the user to be able to make arbitrary changes to the 1802** database. An authorizer could then be put in place while the 1803** user-entered SQL is being [sqlite3_prepare | prepared] that 1804** disallows everything except [SELECT] statements. 1805** 1806** Applications that need to process SQL from untrusted sources 1807** might also consider lowering resource limits using [sqlite3_limit()] 1808** and limiting database size using the [max_page_count] [PRAGMA] 1809** in addition to using an authorizer. 1810** 1811** Only a single authorizer can be in place on a database connection 1812** at a time. Each call to sqlite3_set_authorizer overrides the 1813** previous call. Disable the authorizer by installing a NULL callback. 1814** The authorizer is disabled by default. 1815** 1816** The authorizer callback must not do anything that will modify 1817** the database connection that invoked the authorizer callback. 1818** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1819** database connections for the meaning of "modify" in this paragraph. 1820** 1821** When [sqlite3_prepare_v2()] is used to prepare a statement, the 1822** statement might be reprepared during [sqlite3_step()] due to a 1823** schema change. Hence, the application should ensure that the 1824** correct authorizer callback remains in place during the [sqlite3_step()]. 1825** 1826** Note that the authorizer callback is invoked only during 1827** [sqlite3_prepare()] or its variants. Authorization is not 1828** performed during statement evaluation in [sqlite3_step()]. 1829** 1830** Requirements: 1831** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] 1832** [H12511] [H12512] [H12520] [H12521] [H12522] 1833*/ 1834int sqlite3_set_authorizer( 1835 sqlite3*, 1836 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1837 void *pUserData 1838); 1839 1840/* 1841** CAPI3REF: Authorizer Return Codes {H12590} <H12500> 1842** 1843** The [sqlite3_set_authorizer | authorizer callback function] must 1844** return either [SQLITE_OK] or one of these two constants in order 1845** to signal SQLite whether or not the action is permitted. See the 1846** [sqlite3_set_authorizer | authorizer documentation] for additional 1847** information. 1848*/ 1849#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1850#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1851 1852/* 1853** CAPI3REF: Authorizer Action Codes {H12550} <H12500> 1854** 1855** The [sqlite3_set_authorizer()] interface registers a callback function 1856** that is invoked to authorize certain SQL statement actions. The 1857** second parameter to the callback is an integer code that specifies 1858** what action is being authorized. These are the integer action codes that 1859** the authorizer callback may be passed. 1860** 1861** These action code values signify what kind of operation is to be 1862** authorized. The 3rd and 4th parameters to the authorization 1863** callback function will be parameters or NULL depending on which of these 1864** codes is used as the second parameter. The 5th parameter to the 1865** authorizer callback is the name of the database ("main", "temp", 1866** etc.) if applicable. The 6th parameter to the authorizer callback 1867** is the name of the inner-most trigger or view that is responsible for 1868** the access attempt or NULL if this access attempt is directly from 1869** top-level SQL code. 1870** 1871** Requirements: 1872** [H12551] [H12552] [H12553] [H12554] 1873*/ 1874/******************************************* 3rd ************ 4th ***********/ 1875#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1876#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1877#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1878#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1879#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1880#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1881#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1882#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1883#define SQLITE_DELETE 9 /* Table Name NULL */ 1884#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1885#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1886#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1887#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1888#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1889#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1890#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1891#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1892#define SQLITE_INSERT 18 /* Table Name NULL */ 1893#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 1894#define SQLITE_READ 20 /* Table Name Column Name */ 1895#define SQLITE_SELECT 21 /* NULL NULL */ 1896#define SQLITE_TRANSACTION 22 /* Operation NULL */ 1897#define SQLITE_UPDATE 23 /* Table Name Column Name */ 1898#define SQLITE_ATTACH 24 /* Filename NULL */ 1899#define SQLITE_DETACH 25 /* Database Name NULL */ 1900#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 1901#define SQLITE_REINDEX 27 /* Index Name NULL */ 1902#define SQLITE_ANALYZE 28 /* Table Name NULL */ 1903#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 1904#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 1905#define SQLITE_FUNCTION 31 /* NULL Function Name */ 1906#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 1907#define SQLITE_COPY 0 /* No longer used */ 1908 1909/* 1910** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> 1911** EXPERIMENTAL 1912** 1913** These routines register callback functions that can be used for 1914** tracing and profiling the execution of SQL statements. 1915** 1916** The callback function registered by sqlite3_trace() is invoked at 1917** various times when an SQL statement is being run by [sqlite3_step()]. 1918** The callback returns a UTF-8 rendering of the SQL statement text 1919** as the statement first begins executing. Additional callbacks occur 1920** as each triggered subprogram is entered. The callbacks for triggers 1921** contain a UTF-8 SQL comment that identifies the trigger. 1922** 1923** The callback function registered by sqlite3_profile() is invoked 1924** as each SQL statement finishes. The profile callback contains 1925** the original statement text and an estimate of wall-clock time 1926** of how long that statement took to run. 1927** 1928** Requirements: 1929** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] 1930** [H12290] 1931*/ 1932SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 1933SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 1934 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 1935 1936/* 1937** CAPI3REF: Query Progress Callbacks {H12910} <S60400> 1938** 1939** This routine configures a callback function - the 1940** progress callback - that is invoked periodically during long 1941** running calls to [sqlite3_exec()], [sqlite3_step()] and 1942** [sqlite3_get_table()]. An example use for this 1943** interface is to keep a GUI updated during a large query. 1944** 1945** If the progress callback returns non-zero, the operation is 1946** interrupted. This feature can be used to implement a 1947** "Cancel" button on a GUI progress dialog box. 1948** 1949** The progress handler must not do anything that will modify 1950** the database connection that invoked the progress handler. 1951** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 1952** database connections for the meaning of "modify" in this paragraph. 1953** 1954** Requirements: 1955** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] 1956** 1957*/ 1958void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 1959 1960/* 1961** CAPI3REF: Opening A New Database Connection {H12700} <S40200> 1962** 1963** These routines open an SQLite database file whose name is given by the 1964** filename argument. The filename argument is interpreted as UTF-8 for 1965** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 1966** order for sqlite3_open16(). A [database connection] handle is usually 1967** returned in *ppDb, even if an error occurs. The only exception is that 1968** if SQLite is unable to allocate memory to hold the [sqlite3] object, 1969** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 1970** object. If the database is opened (and/or created) successfully, then 1971** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The 1972** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 1973** an English language description of the error. 1974** 1975** The default encoding for the database will be UTF-8 if 1976** sqlite3_open() or sqlite3_open_v2() is called and 1977** UTF-16 in the native byte order if sqlite3_open16() is used. 1978** 1979** Whether or not an error occurs when it is opened, resources 1980** associated with the [database connection] handle should be released by 1981** passing it to [sqlite3_close()] when it is no longer required. 1982** 1983** The sqlite3_open_v2() interface works like sqlite3_open() 1984** except that it accepts two additional parameters for additional control 1985** over the new database connection. The flags parameter can take one of 1986** the following three values, optionally combined with the 1987** [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags: 1988** 1989** <dl> 1990** <dt>[SQLITE_OPEN_READONLY]</dt> 1991** <dd>The database is opened in read-only mode. If the database does not 1992** already exist, an error is returned.</dd> 1993** 1994** <dt>[SQLITE_OPEN_READWRITE]</dt> 1995** <dd>The database is opened for reading and writing if possible, or reading 1996** only if the file is write protected by the operating system. In either 1997** case the database must already exist, otherwise an error is returned.</dd> 1998** 1999** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2000** <dd>The database is opened for reading and writing, and is creates it if 2001** it does not already exist. This is the behavior that is always used for 2002** sqlite3_open() and sqlite3_open16().</dd> 2003** </dl> 2004** 2005** If the 3rd parameter to sqlite3_open_v2() is not one of the 2006** combinations shown above or one of the combinations shown above combined 2007** with the [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags, 2008** then the behavior is undefined. 2009** 2010** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2011** opens in the multi-thread [threading mode] as long as the single-thread 2012** mode has not been set at compile-time or start-time. If the 2013** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2014** in the serialized [threading mode] unless single-thread was 2015** previously selected at compile-time or start-time. 2016** 2017** If the filename is ":memory:", then a private, temporary in-memory database 2018** is created for the connection. This in-memory database will vanish when 2019** the database connection is closed. Future versions of SQLite might 2020** make use of additional special filenames that begin with the ":" character. 2021** It is recommended that when a database filename actually does begin with 2022** a ":" character you should prefix the filename with a pathname such as 2023** "./" to avoid ambiguity. 2024** 2025** If the filename is an empty string, then a private, temporary 2026** on-disk database will be created. This private database will be 2027** automatically deleted as soon as the database connection is closed. 2028** 2029** The fourth parameter to sqlite3_open_v2() is the name of the 2030** [sqlite3_vfs] object that defines the operating system interface that 2031** the new database connection should use. If the fourth parameter is 2032** a NULL pointer then the default [sqlite3_vfs] object is used. 2033** 2034** <b>Note to Windows users:</b> The encoding used for the filename argument 2035** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2036** codepage is currently defined. Filenames containing international 2037** characters must be converted to UTF-8 prior to passing them into 2038** sqlite3_open() or sqlite3_open_v2(). 2039** 2040** Requirements: 2041** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] 2042** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] 2043*/ 2044int sqlite3_open( 2045 const char *filename, /* Database filename (UTF-8) */ 2046 sqlite3 **ppDb /* OUT: SQLite db handle */ 2047); 2048int sqlite3_open16( 2049 const void *filename, /* Database filename (UTF-16) */ 2050 sqlite3 **ppDb /* OUT: SQLite db handle */ 2051); 2052int sqlite3_open_v2( 2053 const char *filename, /* Database filename (UTF-8) */ 2054 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2055 int flags, /* Flags */ 2056 const char *zVfs /* Name of VFS module to use */ 2057); 2058 2059/* 2060** CAPI3REF: Error Codes And Messages {H12800} <S60200> 2061** 2062** The sqlite3_errcode() interface returns the numeric [result code] or 2063** [extended result code] for the most recent failed sqlite3_* API call 2064** associated with a [database connection]. If a prior API call failed 2065** but the most recent API call succeeded, the return value from 2066** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() 2067** interface is the same except that it always returns the 2068** [extended result code] even when extended result codes are 2069** disabled. 2070** 2071** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2072** text that describes the error, as either UTF-8 or UTF-16 respectively. 2073** Memory to hold the error message string is managed internally. 2074** The application does not need to worry about freeing the result. 2075** However, the error string might be overwritten or deallocated by 2076** subsequent calls to other SQLite interface functions. 2077** 2078** When the serialized [threading mode] is in use, it might be the 2079** case that a second error occurs on a separate thread in between 2080** the time of the first error and the call to these interfaces. 2081** When that happens, the second error will be reported since these 2082** interfaces always report the most recent result. To avoid 2083** this, each thread can obtain exclusive use of the [database connection] D 2084** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2085** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2086** all calls to the interfaces listed here are completed. 2087** 2088** If an interface fails with SQLITE_MISUSE, that means the interface 2089** was invoked incorrectly by the application. In that case, the 2090** error code and message may or may not be set. 2091** 2092** Requirements: 2093** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] 2094*/ 2095int sqlite3_errcode(sqlite3 *db); 2096int sqlite3_extended_errcode(sqlite3 *db); 2097const char *sqlite3_errmsg(sqlite3*); 2098const void *sqlite3_errmsg16(sqlite3*); 2099 2100/* 2101** CAPI3REF: SQL Statement Object {H13000} <H13010> 2102** KEYWORDS: {prepared statement} {prepared statements} 2103** 2104** An instance of this object represents a single SQL statement. 2105** This object is variously known as a "prepared statement" or a 2106** "compiled SQL statement" or simply as a "statement". 2107** 2108** The life of a statement object goes something like this: 2109** 2110** <ol> 2111** <li> Create the object using [sqlite3_prepare_v2()] or a related 2112** function. 2113** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2114** interfaces. 2115** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2116** <li> Reset the statement using [sqlite3_reset()] then go back 2117** to step 2. Do this zero or more times. 2118** <li> Destroy the object using [sqlite3_finalize()]. 2119** </ol> 2120** 2121** Refer to documentation on individual methods above for additional 2122** information. 2123*/ 2124typedef struct sqlite3_stmt sqlite3_stmt; 2125 2126/* 2127** CAPI3REF: Run-time Limits {H12760} <S20600> 2128** 2129** This interface allows the size of various constructs to be limited 2130** on a connection by connection basis. The first parameter is the 2131** [database connection] whose limit is to be set or queried. The 2132** second parameter is one of the [limit categories] that define a 2133** class of constructs to be size limited. The third parameter is the 2134** new limit for that construct. The function returns the old limit. 2135** 2136** If the new limit is a negative number, the limit is unchanged. 2137** For the limit category of SQLITE_LIMIT_XYZ there is a 2138** [limits | hard upper bound] 2139** set by a compile-time C preprocessor macro named 2140** [limits | SQLITE_MAX_XYZ]. 2141** (The "_LIMIT_" in the name is changed to "_MAX_".) 2142** Attempts to increase a limit above its hard upper bound are 2143** silently truncated to the hard upper limit. 2144** 2145** Run time limits are intended for use in applications that manage 2146** both their own internal database and also databases that are controlled 2147** by untrusted external sources. An example application might be a 2148** web browser that has its own databases for storing history and 2149** separate databases controlled by JavaScript applications downloaded 2150** off the Internet. The internal databases can be given the 2151** large, default limits. Databases managed by external sources can 2152** be given much smaller limits designed to prevent a denial of service 2153** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2154** interface to further control untrusted SQL. The size of the database 2155** created by an untrusted script can be contained using the 2156** [max_page_count] [PRAGMA]. 2157** 2158** New run-time limit categories may be added in future releases. 2159** 2160** Requirements: 2161** [H12762] [H12766] [H12769] 2162*/ 2163int sqlite3_limit(sqlite3*, int id, int newVal); 2164 2165/* 2166** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> 2167** KEYWORDS: {limit category} {limit categories} 2168** 2169** These constants define various performance limits 2170** that can be lowered at run-time using [sqlite3_limit()]. 2171** The synopsis of the meanings of the various limits is shown below. 2172** Additional information is available at [limits | Limits in SQLite]. 2173** 2174** <dl> 2175** <dt>SQLITE_LIMIT_LENGTH</dt> 2176** <dd>The maximum size of any string or BLOB or table row.<dd> 2177** 2178** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2179** <dd>The maximum length of an SQL statement.</dd> 2180** 2181** <dt>SQLITE_LIMIT_COLUMN</dt> 2182** <dd>The maximum number of columns in a table definition or in the 2183** result set of a [SELECT] or the maximum number of columns in an index 2184** or in an ORDER BY or GROUP BY clause.</dd> 2185** 2186** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2187** <dd>The maximum depth of the parse tree on any expression.</dd> 2188** 2189** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2190** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2191** 2192** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2193** <dd>The maximum number of instructions in a virtual machine program 2194** used to implement an SQL statement.</dd> 2195** 2196** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2197** <dd>The maximum number of arguments on a function.</dd> 2198** 2199** <dt>SQLITE_LIMIT_ATTACHED</dt> 2200** <dd>The maximum number of [ATTACH | attached databases].</dd> 2201** 2202** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2203** <dd>The maximum length of the pattern argument to the [LIKE] or 2204** [GLOB] operators.</dd> 2205** 2206** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2207** <dd>The maximum number of variables in an SQL statement that can 2208** be bound.</dd> 2209** </dl> 2210*/ 2211#define SQLITE_LIMIT_LENGTH 0 2212#define SQLITE_LIMIT_SQL_LENGTH 1 2213#define SQLITE_LIMIT_COLUMN 2 2214#define SQLITE_LIMIT_EXPR_DEPTH 3 2215#define SQLITE_LIMIT_COMPOUND_SELECT 4 2216#define SQLITE_LIMIT_VDBE_OP 5 2217#define SQLITE_LIMIT_FUNCTION_ARG 6 2218#define SQLITE_LIMIT_ATTACHED 7 2219#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2220#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2221 2222/* 2223** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> 2224** KEYWORDS: {SQL statement compiler} 2225** 2226** To execute an SQL query, it must first be compiled into a byte-code 2227** program using one of these routines. 2228** 2229** The first argument, "db", is a [database connection] obtained from a 2230** prior call to [sqlite3_open()], [sqlite3_open_v2()] or [sqlite3_open16()]. 2231** 2232** The second argument, "zSql", is the statement to be compiled, encoded 2233** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2234** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2235** use UTF-16. 2236** 2237** If the nByte argument is less than zero, then zSql is read up to the 2238** first zero terminator. If nByte is non-negative, then it is the maximum 2239** number of bytes read from zSql. When nByte is non-negative, the 2240** zSql string ends at either the first '\000' or '\u0000' character or 2241** the nByte-th byte, whichever comes first. If the caller knows 2242** that the supplied string is nul-terminated, then there is a small 2243** performance advantage to be gained by passing an nByte parameter that 2244** is equal to the number of bytes in the input string <i>including</i> 2245** the nul-terminator bytes. 2246** 2247** *pzTail is made to point to the first byte past the end of the 2248** first SQL statement in zSql. These routines only compile the first 2249** statement in zSql, so *pzTail is left pointing to what remains 2250** uncompiled. 2251** 2252** *ppStmt is left pointing to a compiled [prepared statement] that can be 2253** executed using [sqlite3_step()]. If there is an error, *ppStmt is set 2254** to NULL. If the input text contains no SQL (if the input is an empty 2255** string or a comment) then *ppStmt is set to NULL. 2256** {A13018} The calling procedure is responsible for deleting the compiled 2257** SQL statement using [sqlite3_finalize()] after it has finished with it. 2258** 2259** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. 2260** 2261** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2262** recommended for all new programs. The two older interfaces are retained 2263** for backwards compatibility, but their use is discouraged. 2264** In the "v2" interfaces, the prepared statement 2265** that is returned (the [sqlite3_stmt] object) contains a copy of the 2266** original SQL text. This causes the [sqlite3_step()] interface to 2267** behave a differently in two ways: 2268** 2269** <ol> 2270** <li> 2271** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2272** always used to do, [sqlite3_step()] will automatically recompile the SQL 2273** statement and try to run it again. If the schema has changed in 2274** a way that makes the statement no longer valid, [sqlite3_step()] will still 2275** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is 2276** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the 2277** error go away. Note: use [sqlite3_errmsg()] to find the text 2278** of the parsing error that results in an [SQLITE_SCHEMA] return. 2279** </li> 2280** 2281** <li> 2282** When an error occurs, [sqlite3_step()] will return one of the detailed 2283** [error codes] or [extended error codes]. The legacy behavior was that 2284** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 2285** and you would have to make a second call to [sqlite3_reset()] in order 2286** to find the underlying cause of the problem. With the "v2" prepare 2287** interfaces, the underlying reason for the error is returned immediately. 2288** </li> 2289** </ol> 2290** 2291** Requirements: 2292** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] 2293** 2294*/ 2295int sqlite3_prepare( 2296 sqlite3 *db, /* Database handle */ 2297 const char *zSql, /* SQL statement, UTF-8 encoded */ 2298 int nByte, /* Maximum length of zSql in bytes. */ 2299 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2300 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2301); 2302int sqlite3_prepare_v2( 2303 sqlite3 *db, /* Database handle */ 2304 const char *zSql, /* SQL statement, UTF-8 encoded */ 2305 int nByte, /* Maximum length of zSql in bytes. */ 2306 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2307 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2308); 2309int sqlite3_prepare16( 2310 sqlite3 *db, /* Database handle */ 2311 const void *zSql, /* SQL statement, UTF-16 encoded */ 2312 int nByte, /* Maximum length of zSql in bytes. */ 2313 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2314 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2315); 2316int sqlite3_prepare16_v2( 2317 sqlite3 *db, /* Database handle */ 2318 const void *zSql, /* SQL statement, UTF-16 encoded */ 2319 int nByte, /* Maximum length of zSql in bytes. */ 2320 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2321 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2322); 2323 2324/* 2325** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> 2326** 2327** This interface can be used to retrieve a saved copy of the original 2328** SQL text used to create a [prepared statement] if that statement was 2329** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 2330** 2331** Requirements: 2332** [H13101] [H13102] [H13103] 2333*/ 2334const char *sqlite3_sql(sqlite3_stmt *pStmt); 2335 2336/* 2337** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> 2338** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2339** 2340** SQLite uses the sqlite3_value object to represent all values 2341** that can be stored in a database table. SQLite uses dynamic typing 2342** for the values it stores. Values stored in sqlite3_value objects 2343** can be integers, floating point values, strings, BLOBs, or NULL. 2344** 2345** An sqlite3_value object may be either "protected" or "unprotected". 2346** Some interfaces require a protected sqlite3_value. Other interfaces 2347** will accept either a protected or an unprotected sqlite3_value. 2348** Every interface that accepts sqlite3_value arguments specifies 2349** whether or not it requires a protected sqlite3_value. 2350** 2351** The terms "protected" and "unprotected" refer to whether or not 2352** a mutex is held. A internal mutex is held for a protected 2353** sqlite3_value object but no mutex is held for an unprotected 2354** sqlite3_value object. If SQLite is compiled to be single-threaded 2355** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 2356** or if SQLite is run in one of reduced mutex modes 2357** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 2358** then there is no distinction between protected and unprotected 2359** sqlite3_value objects and they can be used interchangeably. However, 2360** for maximum code portability it is recommended that applications 2361** still make the distinction between between protected and unprotected 2362** sqlite3_value objects even when not strictly required. 2363** 2364** The sqlite3_value objects that are passed as parameters into the 2365** implementation of [application-defined SQL functions] are protected. 2366** The sqlite3_value object returned by 2367** [sqlite3_column_value()] is unprotected. 2368** Unprotected sqlite3_value objects may only be used with 2369** [sqlite3_result_value()] and [sqlite3_bind_value()]. 2370** The [sqlite3_value_blob | sqlite3_value_type()] family of 2371** interfaces require protected sqlite3_value objects. 2372*/ 2373typedef struct Mem sqlite3_value; 2374 2375/* 2376** CAPI3REF: SQL Function Context Object {H16001} <S20200> 2377** 2378** The context in which an SQL function executes is stored in an 2379** sqlite3_context object. A pointer to an sqlite3_context object 2380** is always first parameter to [application-defined SQL functions]. 2381** The application-defined SQL function implementation will pass this 2382** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 2383** [sqlite3_aggregate_context()], [sqlite3_user_data()], 2384** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 2385** and/or [sqlite3_set_auxdata()]. 2386*/ 2387typedef struct sqlite3_context sqlite3_context; 2388 2389/* 2390** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> 2391** KEYWORDS: {host parameter} {host parameters} {host parameter name} 2392** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 2393** 2394** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, 2395** literals may be replaced by a [parameter] in one of these forms: 2396** 2397** <ul> 2398** <li> ? 2399** <li> ?NNN 2400** <li> :VVV 2401** <li> @VVV 2402** <li> $VVV 2403** </ul> 2404** 2405** In the parameter forms shown above NNN is an integer literal, 2406** and VVV is an alpha-numeric parameter name. The values of these 2407** parameters (also called "host parameter names" or "SQL parameters") 2408** can be set using the sqlite3_bind_*() routines defined here. 2409** 2410** The first argument to the sqlite3_bind_*() routines is always 2411** a pointer to the [sqlite3_stmt] object returned from 2412** [sqlite3_prepare_v2()] or its variants. 2413** 2414** The second argument is the index of the SQL parameter to be set. 2415** The leftmost SQL parameter has an index of 1. When the same named 2416** SQL parameter is used more than once, second and subsequent 2417** occurrences have the same index as the first occurrence. 2418** The index for named parameters can be looked up using the 2419** [sqlite3_bind_parameter_index()] API if desired. The index 2420** for "?NNN" parameters is the value of NNN. 2421** The NNN value must be between 1 and the [sqlite3_limit()] 2422** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 2423** 2424** The third argument is the value to bind to the parameter. 2425** 2426** In those routines that have a fourth argument, its value is the 2427** number of bytes in the parameter. To be clear: the value is the 2428** number of <u>bytes</u> in the value, not the number of characters. 2429** If the fourth parameter is negative, the length of the string is 2430** the number of bytes up to the first zero terminator. 2431** 2432** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2433** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2434** string after SQLite has finished with it. If the fifth argument is 2435** the special value [SQLITE_STATIC], then SQLite assumes that the 2436** information is in static, unmanaged space and does not need to be freed. 2437** If the fifth argument has the value [SQLITE_TRANSIENT], then 2438** SQLite makes its own private copy of the data immediately, before 2439** the sqlite3_bind_*() routine returns. 2440** 2441** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2442** is filled with zeroes. A zeroblob uses a fixed amount of memory 2443** (just an integer to hold its size) while it is being processed. 2444** Zeroblobs are intended to serve as placeholders for BLOBs whose 2445** content is later written using 2446** [sqlite3_blob_open | incremental BLOB I/O] routines. 2447** A negative value for the zeroblob results in a zero-length BLOB. 2448** 2449** The sqlite3_bind_*() routines must be called after 2450** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2451** before [sqlite3_step()]. 2452** Bindings are not cleared by the [sqlite3_reset()] routine. 2453** Unbound parameters are interpreted as NULL. 2454** 2455** These routines return [SQLITE_OK] on success or an error code if 2456** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2457** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. 2458** [SQLITE_MISUSE] might be returned if these routines are called on a 2459** virtual machine that is the wrong state or which has already been finalized. 2460** Detection of misuse is unreliable. Applications should not depend 2461** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2462** a logic error in the application. Future versions of SQLite might 2463** panic rather than return SQLITE_MISUSE. 2464** 2465** See also: [sqlite3_bind_parameter_count()], 2466** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 2467** 2468** Requirements: 2469** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] 2470** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] 2471** 2472*/ 2473int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2474int sqlite3_bind_double(sqlite3_stmt*, int, double); 2475int sqlite3_bind_int(sqlite3_stmt*, int, int); 2476int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2477int sqlite3_bind_null(sqlite3_stmt*, int); 2478int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2479int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2480int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2481int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2482 2483/* 2484** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> 2485** 2486** This routine can be used to find the number of [SQL parameters] 2487** in a [prepared statement]. SQL parameters are tokens of the 2488** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2489** placeholders for values that are [sqlite3_bind_blob | bound] 2490** to the parameters at a later time. 2491** 2492** This routine actually returns the index of the largest (rightmost) 2493** parameter. For all forms except ?NNN, this will correspond to the 2494** number of unique parameters. If parameters of the ?NNN are used, 2495** there may be gaps in the list. 2496** 2497** See also: [sqlite3_bind_blob|sqlite3_bind()], 2498** [sqlite3_bind_parameter_name()], and 2499** [sqlite3_bind_parameter_index()]. 2500** 2501** Requirements: 2502** [H13601] 2503*/ 2504int sqlite3_bind_parameter_count(sqlite3_stmt*); 2505 2506/* 2507** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> 2508** 2509** This routine returns a pointer to the name of the n-th 2510** [SQL parameter] in a [prepared statement]. 2511** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2512** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2513** respectively. 2514** In other words, the initial ":" or "$" or "@" or "?" 2515** is included as part of the name. 2516** Parameters of the form "?" without a following integer have no name 2517** and are also referred to as "anonymous parameters". 2518** 2519** The first host parameter has an index of 1, not 0. 2520** 2521** If the value n is out of range or if the n-th parameter is 2522** nameless, then NULL is returned. The returned string is 2523** always in UTF-8 encoding even if the named parameter was 2524** originally specified as UTF-16 in [sqlite3_prepare16()] or 2525** [sqlite3_prepare16_v2()]. 2526** 2527** See also: [sqlite3_bind_blob|sqlite3_bind()], 2528** [sqlite3_bind_parameter_count()], and 2529** [sqlite3_bind_parameter_index()]. 2530** 2531** Requirements: 2532** [H13621] 2533*/ 2534const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2535 2536/* 2537** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> 2538** 2539** Return the index of an SQL parameter given its name. The 2540** index value returned is suitable for use as the second 2541** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 2542** is returned if no matching parameter is found. The parameter 2543** name must be given in UTF-8 even if the original statement 2544** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2545** 2546** See also: [sqlite3_bind_blob|sqlite3_bind()], 2547** [sqlite3_bind_parameter_count()], and 2548** [sqlite3_bind_parameter_index()]. 2549** 2550** Requirements: 2551** [H13641] 2552*/ 2553int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2554 2555/* 2556** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> 2557** 2558** Contrary to the intuition of many, [sqlite3_reset()] does not reset 2559** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 2560** Use this routine to reset all host parameters to NULL. 2561** 2562** Requirements: 2563** [H13661] 2564*/ 2565int sqlite3_clear_bindings(sqlite3_stmt*); 2566 2567/* 2568** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> 2569** 2570** Return the number of columns in the result set returned by the 2571** [prepared statement]. This routine returns 0 if pStmt is an SQL 2572** statement that does not return data (for example an [UPDATE]). 2573** 2574** Requirements: 2575** [H13711] 2576*/ 2577int sqlite3_column_count(sqlite3_stmt *pStmt); 2578 2579/* 2580** CAPI3REF: Column Names In A Result Set {H13720} <S10700> 2581** 2582** These routines return the name assigned to a particular column 2583** in the result set of a [SELECT] statement. The sqlite3_column_name() 2584** interface returns a pointer to a zero-terminated UTF-8 string 2585** and sqlite3_column_name16() returns a pointer to a zero-terminated 2586** UTF-16 string. The first parameter is the [prepared statement] 2587** that implements the [SELECT] statement. The second parameter is the 2588** column number. The leftmost column is number 0. 2589** 2590** The returned string pointer is valid until either the [prepared statement] 2591** is destroyed by [sqlite3_finalize()] or until the next call to 2592** sqlite3_column_name() or sqlite3_column_name16() on the same column. 2593** 2594** If sqlite3_malloc() fails during the processing of either routine 2595** (for example during a conversion from UTF-8 to UTF-16) then a 2596** NULL pointer is returned. 2597** 2598** The name of a result column is the value of the "AS" clause for 2599** that column, if there is an AS clause. If there is no AS clause 2600** then the name of the column is unspecified and may change from 2601** one release of SQLite to the next. 2602** 2603** Requirements: 2604** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] 2605*/ 2606const char *sqlite3_column_name(sqlite3_stmt*, int N); 2607const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2608 2609/* 2610** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> 2611** 2612** These routines provide a means to determine what column of what 2613** table in which database a result of a [SELECT] statement comes from. 2614** The name of the database or table or column can be returned as 2615** either a UTF-8 or UTF-16 string. The _database_ routines return 2616** the database name, the _table_ routines return the table name, and 2617** the origin_ routines return the column name. 2618** The returned string is valid until the [prepared statement] is destroyed 2619** using [sqlite3_finalize()] or until the same information is requested 2620** again in a different encoding. 2621** 2622** The names returned are the original un-aliased names of the 2623** database, table, and column. 2624** 2625** The first argument to the following calls is a [prepared statement]. 2626** These functions return information about the Nth column returned by 2627** the statement, where N is the second function argument. 2628** 2629** If the Nth column returned by the statement is an expression or 2630** subquery and is not a column value, then all of these functions return 2631** NULL. These routine might also return NULL if a memory allocation error 2632** occurs. Otherwise, they return the name of the attached database, table 2633** and column that query result column was extracted from. 2634** 2635** As with all other SQLite APIs, those postfixed with "16" return 2636** UTF-16 encoded strings, the other functions return UTF-8. {END} 2637** 2638** These APIs are only available if the library was compiled with the 2639** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 2640** 2641** {A13751} 2642** If two or more threads call one or more of these routines against the same 2643** prepared statement and column at the same time then the results are 2644** undefined. 2645** 2646** Requirements: 2647** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] 2648** 2649** If two or more threads call one or more 2650** [sqlite3_column_database_name | column metadata interfaces] 2651** for the same [prepared statement] and result column 2652** at the same time then the results are undefined. 2653*/ 2654const char *sqlite3_column_database_name(sqlite3_stmt*,int); 2655const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 2656const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2657const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2658const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2659const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2660 2661/* 2662** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> 2663** 2664** The first parameter is a [prepared statement]. 2665** If this statement is a [SELECT] statement and the Nth column of the 2666** returned result set of that [SELECT] is a table column (not an 2667** expression or subquery) then the declared type of the table 2668** column is returned. If the Nth column of the result set is an 2669** expression or subquery, then a NULL pointer is returned. 2670** The returned string is always UTF-8 encoded. {END} 2671** 2672** For example, given the database schema: 2673** 2674** CREATE TABLE t1(c1 VARIANT); 2675** 2676** and the following statement to be compiled: 2677** 2678** SELECT c1 + 1, c1 FROM t1; 2679** 2680** this routine would return the string "VARIANT" for the second result 2681** column (i==1), and a NULL pointer for the first result column (i==0). 2682** 2683** SQLite uses dynamic run-time typing. So just because a column 2684** is declared to contain a particular type does not mean that the 2685** data stored in that column is of the declared type. SQLite is 2686** strongly typed, but the typing is dynamic not static. Type 2687** is associated with individual values, not with the containers 2688** used to hold those values. 2689** 2690** Requirements: 2691** [H13761] [H13762] [H13763] 2692*/ 2693const char *sqlite3_column_decltype(sqlite3_stmt*,int); 2694const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2695 2696/* 2697** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> 2698** 2699** After a [prepared statement] has been prepared using either 2700** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 2701** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 2702** must be called one or more times to evaluate the statement. 2703** 2704** The details of the behavior of the sqlite3_step() interface depend 2705** on whether the statement was prepared using the newer "v2" interface 2706** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 2707** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 2708** new "v2" interface is recommended for new applications but the legacy 2709** interface will continue to be supported. 2710** 2711** In the legacy interface, the return value will be either [SQLITE_BUSY], 2712** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 2713** With the "v2" interface, any of the other [result codes] or 2714** [extended result codes] might be returned as well. 2715** 2716** [SQLITE_BUSY] means that the database engine was unable to acquire the 2717** database locks it needs to do its job. If the statement is a [COMMIT] 2718** or occurs outside of an explicit transaction, then you can retry the 2719** statement. If the statement is not a [COMMIT] and occurs within a 2720** explicit transaction then you should rollback the transaction before 2721** continuing. 2722** 2723** [SQLITE_DONE] means that the statement has finished executing 2724** successfully. sqlite3_step() should not be called again on this virtual 2725** machine without first calling [sqlite3_reset()] to reset the virtual 2726** machine back to its initial state. 2727** 2728** If the SQL statement being executed returns any data, then [SQLITE_ROW] 2729** is returned each time a new row of data is ready for processing by the 2730** caller. The values may be accessed using the [column access functions]. 2731** sqlite3_step() is called again to retrieve the next row of data. 2732** 2733** [SQLITE_ERROR] means that a run-time error (such as a constraint 2734** violation) has occurred. sqlite3_step() should not be called again on 2735** the VM. More information may be found by calling [sqlite3_errmsg()]. 2736** With the legacy interface, a more specific error code (for example, 2737** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 2738** can be obtained by calling [sqlite3_reset()] on the 2739** [prepared statement]. In the "v2" interface, 2740** the more specific error code is returned directly by sqlite3_step(). 2741** 2742** [SQLITE_MISUSE] means that the this routine was called inappropriately. 2743** Perhaps it was called on a [prepared statement] that has 2744** already been [sqlite3_finalize | finalized] or on one that had 2745** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 2746** be the case that the same database connection is being used by two or 2747** more threads at the same moment in time. 2748** 2749** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 2750** API always returns a generic error code, [SQLITE_ERROR], following any 2751** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 2752** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 2753** specific [error codes] that better describes the error. 2754** We admit that this is a goofy design. The problem has been fixed 2755** with the "v2" interface. If you prepare all of your SQL statements 2756** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 2757** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 2758** then the more specific [error codes] are returned directly 2759** by sqlite3_step(). The use of the "v2" interface is recommended. 2760** 2761** Requirements: 2762** [H13202] [H15304] [H15306] [H15308] [H15310] 2763*/ 2764int sqlite3_step(sqlite3_stmt*); 2765 2766/* 2767** CAPI3REF: Number of columns in a result set {H13770} <S10700> 2768** 2769** Returns the number of values in the current row of the result set. 2770** 2771** Requirements: 2772** [H13771] [H13772] 2773*/ 2774int sqlite3_data_count(sqlite3_stmt *pStmt); 2775 2776/* 2777** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> 2778** KEYWORDS: SQLITE_TEXT 2779** 2780** {H10266} Every value in SQLite has one of five fundamental datatypes: 2781** 2782** <ul> 2783** <li> 64-bit signed integer 2784** <li> 64-bit IEEE floating point number 2785** <li> string 2786** <li> BLOB 2787** <li> NULL 2788** </ul> {END} 2789** 2790** These constants are codes for each of those types. 2791** 2792** Note that the SQLITE_TEXT constant was also used in SQLite version 2 2793** for a completely different meaning. Software that links against both 2794** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 2795** SQLITE_TEXT. 2796*/ 2797#define SQLITE_INTEGER 1 2798#define SQLITE_FLOAT 2 2799#define SQLITE_BLOB 4 2800#define SQLITE_NULL 5 2801#ifdef SQLITE_TEXT 2802# undef SQLITE_TEXT 2803#else 2804# define SQLITE_TEXT 3 2805#endif 2806#define SQLITE3_TEXT 3 2807 2808/* 2809** CAPI3REF: Result Values From A Query {H13800} <S10700> 2810** KEYWORDS: {column access functions} 2811** 2812** These routines form the "result set query" interface. 2813** 2814** These routines return information about a single column of the current 2815** result row of a query. In every case the first argument is a pointer 2816** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 2817** that was returned from [sqlite3_prepare_v2()] or one of its variants) 2818** and the second argument is the index of the column for which information 2819** should be returned. The leftmost column of the result set has the index 0. 2820** 2821** If the SQL statement does not currently point to a valid row, or if the 2822** column index is out of range, the result is undefined. 2823** These routines may only be called when the most recent call to 2824** [sqlite3_step()] has returned [SQLITE_ROW] and neither 2825** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 2826** If any of these routines are called after [sqlite3_reset()] or 2827** [sqlite3_finalize()] or after [sqlite3_step()] has returned 2828** something other than [SQLITE_ROW], the results are undefined. 2829** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 2830** are called from a different thread while any of these routines 2831** are pending, then the results are undefined. 2832** 2833** The sqlite3_column_type() routine returns the 2834** [SQLITE_INTEGER | datatype code] for the initial data type 2835** of the result column. The returned value is one of [SQLITE_INTEGER], 2836** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 2837** returned by sqlite3_column_type() is only meaningful if no type 2838** conversions have occurred as described below. After a type conversion, 2839** the value returned by sqlite3_column_type() is undefined. Future 2840** versions of SQLite may change the behavior of sqlite3_column_type() 2841** following a type conversion. 2842** 2843** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 2844** routine returns the number of bytes in that BLOB or string. 2845** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 2846** the string to UTF-8 and then returns the number of bytes. 2847** If the result is a numeric value then sqlite3_column_bytes() uses 2848** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 2849** the number of bytes in that string. 2850** The value returned does not include the zero terminator at the end 2851** of the string. For clarity: the value returned is the number of 2852** bytes in the string, not the number of characters. 2853** 2854** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 2855** even empty strings, are always zero terminated. The return 2856** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary 2857** pointer, possibly even a NULL pointer. 2858** 2859** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 2860** but leaves the result in UTF-16 in native byte order instead of UTF-8. 2861** The zero terminator is not included in this count. 2862** 2863** The object returned by [sqlite3_column_value()] is an 2864** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 2865** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 2866** If the [unprotected sqlite3_value] object returned by 2867** [sqlite3_column_value()] is used in any other way, including calls 2868** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 2869** or [sqlite3_value_bytes()], then the behavior is undefined. 2870** 2871** These routines attempt to convert the value where appropriate. For 2872** example, if the internal representation is FLOAT and a text result 2873** is requested, [sqlite3_snprintf()] is used internally to perform the 2874** conversion automatically. The following table details the conversions 2875** that are applied: 2876** 2877** <blockquote> 2878** <table border="1"> 2879** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 2880** 2881** <tr><td> NULL <td> INTEGER <td> Result is 0 2882** <tr><td> NULL <td> FLOAT <td> Result is 0.0 2883** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 2884** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 2885** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 2886** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 2887** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 2888** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 2889** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 2890** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 2891** <tr><td> TEXT <td> INTEGER <td> Use atoi() 2892** <tr><td> TEXT <td> FLOAT <td> Use atof() 2893** <tr><td> TEXT <td> BLOB <td> No change 2894** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 2895** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 2896** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 2897** </table> 2898** </blockquote> 2899** 2900** The table above makes reference to standard C library functions atoi() 2901** and atof(). SQLite does not really use these functions. It has its 2902** own equivalent internal routines. The atoi() and atof() names are 2903** used in the table for brevity and because they are familiar to most 2904** C programmers. 2905** 2906** Note that when type conversions occur, pointers returned by prior 2907** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 2908** sqlite3_column_text16() may be invalidated. 2909** Type conversions and pointer invalidations might occur 2910** in the following cases: 2911** 2912** <ul> 2913** <li> The initial content is a BLOB and sqlite3_column_text() or 2914** sqlite3_column_text16() is called. A zero-terminator might 2915** need to be added to the string.</li> 2916** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 2917** sqlite3_column_text16() is called. The content must be converted 2918** to UTF-16.</li> 2919** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 2920** sqlite3_column_text() is called. The content must be converted 2921** to UTF-8.</li> 2922** </ul> 2923** 2924** Conversions between UTF-16be and UTF-16le are always done in place and do 2925** not invalidate a prior pointer, though of course the content of the buffer 2926** that the prior pointer points to will have been modified. Other kinds 2927** of conversion are done in place when it is possible, but sometimes they 2928** are not possible and in those cases prior pointers are invalidated. 2929** 2930** The safest and easiest to remember policy is to invoke these routines 2931** in one of the following ways: 2932** 2933** <ul> 2934** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 2935** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 2936** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 2937** </ul> 2938** 2939** In other words, you should call sqlite3_column_text(), 2940** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 2941** into the desired format, then invoke sqlite3_column_bytes() or 2942** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 2943** to sqlite3_column_text() or sqlite3_column_blob() with calls to 2944** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 2945** with calls to sqlite3_column_bytes(). 2946** 2947** The pointers returned are valid until a type conversion occurs as 2948** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 2949** [sqlite3_finalize()] is called. The memory space used to hold strings 2950** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 2951** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 2952** [sqlite3_free()]. 2953** 2954** If a memory allocation error occurs during the evaluation of any 2955** of these routines, a default value is returned. The default value 2956** is either the integer 0, the floating point number 0.0, or a NULL 2957** pointer. Subsequent calls to [sqlite3_errcode()] will return 2958** [SQLITE_NOMEM]. 2959** 2960** Requirements: 2961** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] 2962** [H13827] [H13830] 2963*/ 2964const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 2965int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 2966int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 2967double sqlite3_column_double(sqlite3_stmt*, int iCol); 2968int sqlite3_column_int(sqlite3_stmt*, int iCol); 2969sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 2970const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 2971const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 2972int sqlite3_column_type(sqlite3_stmt*, int iCol); 2973sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 2974 2975/* 2976** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> 2977** 2978** The sqlite3_finalize() function is called to delete a [prepared statement]. 2979** If the statement was executed successfully or not executed at all, then 2980** SQLITE_OK is returned. If execution of the statement failed then an 2981** [error code] or [extended error code] is returned. 2982** 2983** This routine can be called at any point during the execution of the 2984** [prepared statement]. If the virtual machine has not 2985** completed execution when this routine is called, that is like 2986** encountering an error or an [sqlite3_interrupt | interrupt]. 2987** Incomplete updates may be rolled back and transactions canceled, 2988** depending on the circumstances, and the 2989** [error code] returned will be [SQLITE_ABORT]. 2990** 2991** Requirements: 2992** [H11302] [H11304] 2993*/ 2994int sqlite3_finalize(sqlite3_stmt *pStmt); 2995 2996/* 2997** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> 2998** 2999** The sqlite3_reset() function is called to reset a [prepared statement] 3000** object back to its initial state, ready to be re-executed. 3001** Any SQL statement variables that had values bound to them using 3002** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3003** Use [sqlite3_clear_bindings()] to reset the bindings. 3004** 3005** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3006** back to the beginning of its program. 3007** 3008** {H11334} If the most recent call to [sqlite3_step(S)] for the 3009** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3010** or if [sqlite3_step(S)] has never before been called on S, 3011** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3012** 3013** {H11336} If the most recent call to [sqlite3_step(S)] for the 3014** [prepared statement] S indicated an error, then 3015** [sqlite3_reset(S)] returns an appropriate [error code]. 3016** 3017** {H11338} The [sqlite3_reset(S)] interface does not change the values 3018** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3019*/ 3020int sqlite3_reset(sqlite3_stmt *pStmt); 3021 3022/* 3023** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> 3024** KEYWORDS: {function creation routines} 3025** KEYWORDS: {application-defined SQL function} 3026** KEYWORDS: {application-defined SQL functions} 3027** 3028** These two functions (collectively known as "function creation routines") 3029** are used to add SQL functions or aggregates or to redefine the behavior 3030** of existing SQL functions or aggregates. The only difference between the 3031** two is that the second parameter, the name of the (scalar) function or 3032** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 3033** for sqlite3_create_function16(). 3034** 3035** The first parameter is the [database connection] to which the SQL 3036** function is to be added. If a single program uses more than one database 3037** connection internally, then SQL functions must be added individually to 3038** each database connection. 3039** 3040** The second parameter is the name of the SQL function to be created or 3041** redefined. The length of the name is limited to 255 bytes, exclusive of 3042** the zero-terminator. Note that the name length limit is in bytes, not 3043** characters. Any attempt to create a function with a longer name 3044** will result in [SQLITE_ERROR] being returned. 3045** 3046** The third parameter (nArg) 3047** is the number of arguments that the SQL function or 3048** aggregate takes. If this parameter is negative, then the SQL function or 3049** aggregate may take any number of arguments. 3050** 3051** The fourth parameter, eTextRep, specifies what 3052** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3053** its parameters. Any SQL function implementation should be able to work 3054** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3055** more efficient with one encoding than another. It is allowed to 3056** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3057** times with the same function but with different values of eTextRep. 3058** When multiple implementations of the same function are available, SQLite 3059** will pick the one that involves the least amount of data conversion. 3060** If there is only a single implementation which does not care what text 3061** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3062** 3063** The fifth parameter is an arbitrary pointer. The implementation of the 3064** function can gain access to this pointer using [sqlite3_user_data()]. 3065** 3066** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3067** pointers to C-language functions that implement the SQL function or 3068** aggregate. A scalar SQL function requires an implementation of the xFunc 3069** callback only, NULL pointers should be passed as the xStep and xFinal 3070** parameters. An aggregate SQL function requires an implementation of xStep 3071** and xFinal and NULL should be passed for xFunc. To delete an existing 3072** SQL function or aggregate, pass NULL for all three function callbacks. 3073** 3074** It is permitted to register multiple implementations of the same 3075** functions with the same name but with either differing numbers of 3076** arguments or differing preferred text encodings. SQLite will use 3077** the implementation most closely matches the way in which the 3078** SQL function is used. A function implementation with a non-negative 3079** nArg parameter is a better match than a function implementation with 3080** a negative nArg. A function where the preferred text encoding 3081** matches the database encoding is a better 3082** match than a function where the encoding is different. 3083** A function where the encoding difference is between UTF16le and UTF16be 3084** is a closer match than a function where the encoding difference is 3085** between UTF8 and UTF16. 3086** 3087** Built-in functions may be overloaded by new application-defined functions. 3088** The first application-defined function with a given name overrides all 3089** built-in functions in the same [database connection] with the same name. 3090** Subsequent application-defined functions of the same name only override 3091** prior application-defined functions that are an exact match for the 3092** number of parameters and preferred encoding. 3093** 3094** An application-defined function is permitted to call other 3095** SQLite interfaces. However, such calls must not 3096** close the database connection nor finalize or reset the prepared 3097** statement in which the function is running. 3098** 3099** Requirements: 3100** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16124] [H16127] 3101** [H16130] [H16133] [H16136] [H16139] [H16142] 3102*/ 3103int sqlite3_create_function( 3104 sqlite3 *db, 3105 const char *zFunctionName, 3106 int nArg, 3107 int eTextRep, 3108 void *pApp, 3109 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3110 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3111 void (*xFinal)(sqlite3_context*) 3112); 3113int sqlite3_create_function16( 3114 sqlite3 *db, 3115 const void *zFunctionName, 3116 int nArg, 3117 int eTextRep, 3118 void *pApp, 3119 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3120 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3121 void (*xFinal)(sqlite3_context*) 3122); 3123 3124/* 3125** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> 3126** 3127** These constant define integer codes that represent the various 3128** text encodings supported by SQLite. 3129*/ 3130#define SQLITE_UTF8 1 3131#define SQLITE_UTF16LE 2 3132#define SQLITE_UTF16BE 3 3133#define SQLITE_UTF16 4 /* Use native byte order */ 3134#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3135#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3136 3137/* 3138** CAPI3REF: Deprecated Functions 3139** DEPRECATED 3140** 3141** These functions are [deprecated]. In order to maintain 3142** backwards compatibility with older code, these functions continue 3143** to be supported. However, new applications should avoid 3144** the use of these functions. To help encourage people to avoid 3145** using these functions, we are not going to tell you what they do. 3146*/ 3147#ifndef SQLITE_OMIT_DEPRECATED 3148SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3149SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3150SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3151SQLITE_DEPRECATED int sqlite3_global_recover(void); 3152SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3153SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3154#endif 3155 3156/* 3157** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> 3158** 3159** The C-language implementation of SQL functions and aggregates uses 3160** this set of interface routines to access the parameter values on 3161** the function or aggregate. 3162** 3163** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3164** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3165** define callbacks that implement the SQL functions and aggregates. 3166** The 4th parameter to these callbacks is an array of pointers to 3167** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3168** each parameter to the SQL function. These routines are used to 3169** extract values from the [sqlite3_value] objects. 3170** 3171** These routines work only with [protected sqlite3_value] objects. 3172** Any attempt to use these routines on an [unprotected sqlite3_value] 3173** object results in undefined behavior. 3174** 3175** These routines work just like the corresponding [column access functions] 3176** except that these routines take a single [protected sqlite3_value] object 3177** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 3178** 3179** The sqlite3_value_text16() interface extracts a UTF-16 string 3180** in the native byte-order of the host machine. The 3181** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3182** extract UTF-16 strings as big-endian and little-endian respectively. 3183** 3184** The sqlite3_value_numeric_type() interface attempts to apply 3185** numeric affinity to the value. This means that an attempt is 3186** made to convert the value to an integer or floating point. If 3187** such a conversion is possible without loss of information (in other 3188** words, if the value is a string that looks like a number) 3189** then the conversion is performed. Otherwise no conversion occurs. 3190** The [SQLITE_INTEGER | datatype] after conversion is returned. 3191** 3192** Please pay particular attention to the fact that the pointer returned 3193** from [sqlite3_value_blob()], [sqlite3_value_text()], or 3194** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3195** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3196** or [sqlite3_value_text16()]. 3197** 3198** These routines must be called from the same thread as 3199** the SQL function that supplied the [sqlite3_value*] parameters. 3200** 3201** Requirements: 3202** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] 3203** [H15127] [H15130] [H15133] [H15136] 3204*/ 3205const void *sqlite3_value_blob(sqlite3_value*); 3206int sqlite3_value_bytes(sqlite3_value*); 3207int sqlite3_value_bytes16(sqlite3_value*); 3208double sqlite3_value_double(sqlite3_value*); 3209int sqlite3_value_int(sqlite3_value*); 3210sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3211const unsigned char *sqlite3_value_text(sqlite3_value*); 3212const void *sqlite3_value_text16(sqlite3_value*); 3213const void *sqlite3_value_text16le(sqlite3_value*); 3214const void *sqlite3_value_text16be(sqlite3_value*); 3215int sqlite3_value_type(sqlite3_value*); 3216int sqlite3_value_numeric_type(sqlite3_value*); 3217 3218/* 3219** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> 3220** 3221** The implementation of aggregate SQL functions use this routine to allocate 3222** a structure for storing their state. 3223** 3224** The first time the sqlite3_aggregate_context() routine is called for a 3225** particular aggregate, SQLite allocates nBytes of memory, zeroes out that 3226** memory, and returns a pointer to it. On second and subsequent calls to 3227** sqlite3_aggregate_context() for the same aggregate function index, 3228** the same buffer is returned. The implementation of the aggregate can use 3229** the returned buffer to accumulate data. 3230** 3231** SQLite automatically frees the allocated buffer when the aggregate 3232** query concludes. 3233** 3234** The first parameter should be a copy of the 3235** [sqlite3_context | SQL function context] that is the first parameter 3236** to the callback routine that implements the aggregate function. 3237** 3238** This routine must be called from the same thread in which 3239** the aggregate SQL function is running. 3240** 3241** Requirements: 3242** [H16211] [H16213] [H16215] [H16217] 3243*/ 3244void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3245 3246/* 3247** CAPI3REF: User Data For Functions {H16240} <S20200> 3248** 3249** The sqlite3_user_data() interface returns a copy of 3250** the pointer that was the pUserData parameter (the 5th parameter) 3251** of the [sqlite3_create_function()] 3252** and [sqlite3_create_function16()] routines that originally 3253** registered the application defined function. {END} 3254** 3255** This routine must be called from the same thread in which 3256** the application-defined function is running. 3257** 3258** Requirements: 3259** [H16243] 3260*/ 3261void *sqlite3_user_data(sqlite3_context*); 3262 3263/* 3264** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> 3265** 3266** The sqlite3_context_db_handle() interface returns a copy of 3267** the pointer to the [database connection] (the 1st parameter) 3268** of the [sqlite3_create_function()] 3269** and [sqlite3_create_function16()] routines that originally 3270** registered the application defined function. 3271** 3272** Requirements: 3273** [H16253] 3274*/ 3275sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3276 3277/* 3278** CAPI3REF: Function Auxiliary Data {H16270} <S20200> 3279** 3280** The following two functions may be used by scalar SQL functions to 3281** associate metadata with argument values. If the same value is passed to 3282** multiple invocations of the same SQL function during query execution, under 3283** some circumstances the associated metadata may be preserved. This may 3284** be used, for example, to add a regular-expression matching scalar 3285** function. The compiled version of the regular expression is stored as 3286** metadata associated with the SQL value passed as the regular expression 3287** pattern. The compiled regular expression can be reused on multiple 3288** invocations of the same function so that the original pattern string 3289** does not need to be recompiled on each invocation. 3290** 3291** The sqlite3_get_auxdata() interface returns a pointer to the metadata 3292** associated by the sqlite3_set_auxdata() function with the Nth argument 3293** value to the application-defined function. If no metadata has been ever 3294** been set for the Nth argument of the function, or if the corresponding 3295** function parameter has changed since the meta-data was set, 3296** then sqlite3_get_auxdata() returns a NULL pointer. 3297** 3298** The sqlite3_set_auxdata() interface saves the metadata 3299** pointed to by its 3rd parameter as the metadata for the N-th 3300** argument of the application-defined function. Subsequent 3301** calls to sqlite3_get_auxdata() might return this data, if it has 3302** not been destroyed. 3303** If it is not NULL, SQLite will invoke the destructor 3304** function given by the 4th parameter to sqlite3_set_auxdata() on 3305** the metadata when the corresponding function parameter changes 3306** or when the SQL statement completes, whichever comes first. 3307** 3308** SQLite is free to call the destructor and drop metadata on any 3309** parameter of any function at any time. The only guarantee is that 3310** the destructor will be called before the metadata is dropped. 3311** 3312** In practice, metadata is preserved between function calls for 3313** expressions that are constant at compile time. This includes literal 3314** values and SQL variables. 3315** 3316** These routines must be called from the same thread in which 3317** the SQL function is running. 3318** 3319** Requirements: 3320** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] 3321*/ 3322void *sqlite3_get_auxdata(sqlite3_context*, int N); 3323void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3324 3325 3326/* 3327** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> 3328** 3329** These are special values for the destructor that is passed in as the 3330** final argument to routines like [sqlite3_result_blob()]. If the destructor 3331** argument is SQLITE_STATIC, it means that the content pointer is constant 3332** and will never change. It does not need to be destroyed. The 3333** SQLITE_TRANSIENT value means that the content will likely change in 3334** the near future and that SQLite should make its own private copy of 3335** the content before returning. 3336** 3337** The typedef is necessary to work around problems in certain 3338** C++ compilers. See ticket #2191. 3339*/ 3340typedef void (*sqlite3_destructor_type)(void*); 3341#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3342#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3343 3344/* 3345** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> 3346** 3347** These routines are used by the xFunc or xFinal callbacks that 3348** implement SQL functions and aggregates. See 3349** [sqlite3_create_function()] and [sqlite3_create_function16()] 3350** for additional information. 3351** 3352** These functions work very much like the [parameter binding] family of 3353** functions used to bind values to host parameters in prepared statements. 3354** Refer to the [SQL parameter] documentation for additional information. 3355** 3356** The sqlite3_result_blob() interface sets the result from 3357** an application-defined function to be the BLOB whose content is pointed 3358** to by the second parameter and which is N bytes long where N is the 3359** third parameter. 3360** 3361** The sqlite3_result_zeroblob() interfaces set the result of 3362** the application-defined function to be a BLOB containing all zero 3363** bytes and N bytes in size, where N is the value of the 2nd parameter. 3364** 3365** The sqlite3_result_double() interface sets the result from 3366** an application-defined function to be a floating point value specified 3367** by its 2nd argument. 3368** 3369** The sqlite3_result_error() and sqlite3_result_error16() functions 3370** cause the implemented SQL function to throw an exception. 3371** SQLite uses the string pointed to by the 3372** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3373** as the text of an error message. SQLite interprets the error 3374** message string from sqlite3_result_error() as UTF-8. SQLite 3375** interprets the string from sqlite3_result_error16() as UTF-16 in native 3376** byte order. If the third parameter to sqlite3_result_error() 3377** or sqlite3_result_error16() is negative then SQLite takes as the error 3378** message all text up through the first zero character. 3379** If the third parameter to sqlite3_result_error() or 3380** sqlite3_result_error16() is non-negative then SQLite takes that many 3381** bytes (not characters) from the 2nd parameter as the error message. 3382** The sqlite3_result_error() and sqlite3_result_error16() 3383** routines make a private copy of the error message text before 3384** they return. Hence, the calling function can deallocate or 3385** modify the text after they return without harm. 3386** The sqlite3_result_error_code() function changes the error code 3387** returned by SQLite as a result of an error in a function. By default, 3388** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 3389** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3390** 3391** The sqlite3_result_toobig() interface causes SQLite to throw an error 3392** indicating that a string or BLOB is to long to represent. 3393** 3394** The sqlite3_result_nomem() interface causes SQLite to throw an error 3395** indicating that a memory allocation failed. 3396** 3397** The sqlite3_result_int() interface sets the return value 3398** of the application-defined function to be the 32-bit signed integer 3399** value given in the 2nd argument. 3400** The sqlite3_result_int64() interface sets the return value 3401** of the application-defined function to be the 64-bit signed integer 3402** value given in the 2nd argument. 3403** 3404** The sqlite3_result_null() interface sets the return value 3405** of the application-defined function to be NULL. 3406** 3407** The sqlite3_result_text(), sqlite3_result_text16(), 3408** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3409** set the return value of the application-defined function to be 3410** a text string which is represented as UTF-8, UTF-16 native byte order, 3411** UTF-16 little endian, or UTF-16 big endian, respectively. 3412** SQLite takes the text result from the application from 3413** the 2nd parameter of the sqlite3_result_text* interfaces. 3414** If the 3rd parameter to the sqlite3_result_text* interfaces 3415** is negative, then SQLite takes result text from the 2nd parameter 3416** through the first zero character. 3417** If the 3rd parameter to the sqlite3_result_text* interfaces 3418** is non-negative, then as many bytes (not characters) of the text 3419** pointed to by the 2nd parameter are taken as the application-defined 3420** function result. 3421** If the 4th parameter to the sqlite3_result_text* interfaces 3422** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3423** function as the destructor on the text or BLOB result when it has 3424** finished using that result. 3425** If the 4th parameter to the sqlite3_result_text* interfaces or 3426** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 3427** assumes that the text or BLOB result is in constant space and does not 3428** copy the it or call a destructor when it has finished using that result. 3429** If the 4th parameter to the sqlite3_result_text* interfaces 3430** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3431** then SQLite makes a copy of the result into space obtained from 3432** from [sqlite3_malloc()] before it returns. 3433** 3434** The sqlite3_result_value() interface sets the result of 3435** the application-defined function to be a copy the 3436** [unprotected sqlite3_value] object specified by the 2nd parameter. The 3437** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3438** so that the [sqlite3_value] specified in the parameter may change or 3439** be deallocated after sqlite3_result_value() returns without harm. 3440** A [protected sqlite3_value] object may always be used where an 3441** [unprotected sqlite3_value] object is required, so either 3442** kind of [sqlite3_value] object can be used with this interface. 3443** 3444** If these routines are called from within the different thread 3445** than the one containing the application-defined function that received 3446** the [sqlite3_context] pointer, the results are undefined. 3447** 3448** Requirements: 3449** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] 3450** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] 3451** [H16451] [H16454] [H16457] [H16460] [H16463] 3452*/ 3453void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 3454void sqlite3_result_double(sqlite3_context*, double); 3455void sqlite3_result_error(sqlite3_context*, const char*, int); 3456void sqlite3_result_error16(sqlite3_context*, const void*, int); 3457void sqlite3_result_error_toobig(sqlite3_context*); 3458void sqlite3_result_error_nomem(sqlite3_context*); 3459void sqlite3_result_error_code(sqlite3_context*, int); 3460void sqlite3_result_int(sqlite3_context*, int); 3461void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 3462void sqlite3_result_null(sqlite3_context*); 3463void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 3464void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 3465void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 3466void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 3467void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 3468void sqlite3_result_zeroblob(sqlite3_context*, int n); 3469 3470/* 3471** CAPI3REF: Define New Collating Sequences {H16600} <S20300> 3472** 3473** These functions are used to add new collation sequences to the 3474** [database connection] specified as the first argument. 3475** 3476** The name of the new collation sequence is specified as a UTF-8 string 3477** for sqlite3_create_collation() and sqlite3_create_collation_v2() 3478** and a UTF-16 string for sqlite3_create_collation16(). In all cases 3479** the name is passed as the second function argument. 3480** 3481** The third argument may be one of the constants [SQLITE_UTF8], 3482** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 3483** routine expects to be passed pointers to strings encoded using UTF-8, 3484** UTF-16 little-endian, or UTF-16 big-endian, respectively. The 3485** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 3486** the routine expects pointers to 16-bit word aligned strings 3487** of UTF-16 in the native byte order of the host computer. 3488** 3489** A pointer to the user supplied routine must be passed as the fifth 3490** argument. If it is NULL, this is the same as deleting the collation 3491** sequence (so that SQLite cannot call it anymore). 3492** Each time the application supplied function is invoked, it is passed 3493** as its first parameter a copy of the void* passed as the fourth argument 3494** to sqlite3_create_collation() or sqlite3_create_collation16(). 3495** 3496** The remaining arguments to the application-supplied routine are two strings, 3497** each represented by a (length, data) pair and encoded in the encoding 3498** that was passed as the third argument when the collation sequence was 3499** registered. {END} The application defined collation routine should 3500** return negative, zero or positive if the first string is less than, 3501** equal to, or greater than the second string. i.e. (STRING1 - STRING2). 3502** 3503** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 3504** except that it takes an extra argument which is a destructor for 3505** the collation. The destructor is called when the collation is 3506** destroyed and is passed a copy of the fourth parameter void* pointer 3507** of the sqlite3_create_collation_v2(). 3508** Collations are destroyed when they are overridden by later calls to the 3509** collation creation functions or when the [database connection] is closed 3510** using [sqlite3_close()]. 3511** 3512** Requirements: 3513** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] 3514** [H16624] [H16627] [H16630] 3515*/ 3516int sqlite3_create_collation( 3517 sqlite3*, 3518 const char *zName, 3519 int eTextRep, 3520 void*, 3521 int(*xCompare)(void*,int,const void*,int,const void*) 3522); 3523int sqlite3_create_collation_v2( 3524 sqlite3*, 3525 const char *zName, 3526 int eTextRep, 3527 void*, 3528 int(*xCompare)(void*,int,const void*,int,const void*), 3529 void(*xDestroy)(void*) 3530); 3531int sqlite3_create_collation16( 3532 sqlite3*, 3533 const void *zName, 3534 int eTextRep, 3535 void*, 3536 int(*xCompare)(void*,int,const void*,int,const void*) 3537); 3538 3539/* 3540** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> 3541** 3542** To avoid having to register all collation sequences before a database 3543** can be used, a single callback function may be registered with the 3544** [database connection] to be called whenever an undefined collation 3545** sequence is required. 3546** 3547** If the function is registered using the sqlite3_collation_needed() API, 3548** then it is passed the names of undefined collation sequences as strings 3549** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, 3550** the names are passed as UTF-16 in machine native byte order. 3551** A call to either function replaces any existing callback. 3552** 3553** When the callback is invoked, the first argument passed is a copy 3554** of the second argument to sqlite3_collation_needed() or 3555** sqlite3_collation_needed16(). The second argument is the database 3556** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 3557** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 3558** sequence function required. The fourth parameter is the name of the 3559** required collation sequence. 3560** 3561** The callback function should register the desired collation using 3562** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 3563** [sqlite3_create_collation_v2()]. 3564** 3565** Requirements: 3566** [H16702] [H16704] [H16706] 3567*/ 3568int sqlite3_collation_needed( 3569 sqlite3*, 3570 void*, 3571 void(*)(void*,sqlite3*,int eTextRep,const char*) 3572); 3573int sqlite3_collation_needed16( 3574 sqlite3*, 3575 void*, 3576 void(*)(void*,sqlite3*,int eTextRep,const void*) 3577); 3578 3579/* 3580** Specify the key for an encrypted database. This routine should be 3581** called right after sqlite3_open(). 3582** 3583** The code to implement this API is not available in the public release 3584** of SQLite. 3585*/ 3586int sqlite3_key( 3587 sqlite3 *db, /* Database to be rekeyed */ 3588 const void *pKey, int nKey /* The key */ 3589); 3590 3591/* 3592** Change the key on an open database. If the current database is not 3593** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 3594** database is decrypted. 3595** 3596** The code to implement this API is not available in the public release 3597** of SQLite. 3598*/ 3599int sqlite3_rekey( 3600 sqlite3 *db, /* Database to be rekeyed */ 3601 const void *pKey, int nKey /* The new key */ 3602); 3603 3604/* 3605** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> 3606** 3607** The sqlite3_sleep() function causes the current thread to suspend execution 3608** for at least a number of milliseconds specified in its parameter. 3609** 3610** If the operating system does not support sleep requests with 3611** millisecond time resolution, then the time will be rounded up to 3612** the nearest second. The number of milliseconds of sleep actually 3613** requested from the operating system is returned. 3614** 3615** SQLite implements this interface by calling the xSleep() 3616** method of the default [sqlite3_vfs] object. 3617** 3618** Requirements: [H10533] [H10536] 3619*/ 3620int sqlite3_sleep(int); 3621 3622/* 3623** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> 3624** 3625** If this global variable is made to point to a string which is 3626** the name of a folder (a.k.a. directory), then all temporary files 3627** created by SQLite will be placed in that directory. If this variable 3628** is a NULL pointer, then SQLite performs a search for an appropriate 3629** temporary file directory. 3630** 3631** It is not safe to modify this variable once a [database connection] 3632** has been opened. It is intended that this variable be set once 3633** as part of process initialization and before any SQLite interface 3634** routines have been call and remain unchanged thereafter. 3635*/ 3636SQLITE_EXTERN char *sqlite3_temp_directory; 3637 3638/* 3639** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> 3640** KEYWORDS: {autocommit mode} 3641** 3642** The sqlite3_get_autocommit() interface returns non-zero or 3643** zero if the given database connection is or is not in autocommit mode, 3644** respectively. Autocommit mode is on by default. 3645** Autocommit mode is disabled by a [BEGIN] statement. 3646** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 3647** 3648** If certain kinds of errors occur on a statement within a multi-statement 3649** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 3650** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 3651** transaction might be rolled back automatically. The only way to 3652** find out whether SQLite automatically rolled back the transaction after 3653** an error is to use this function. 3654** 3655** If another thread changes the autocommit status of the database 3656** connection while this routine is running, then the return value 3657** is undefined. 3658** 3659** Requirements: [H12931] [H12932] [H12933] [H12934] 3660*/ 3661int sqlite3_get_autocommit(sqlite3*); 3662 3663/* 3664** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> 3665** 3666** The sqlite3_db_handle interface returns the [database connection] handle 3667** to which a [prepared statement] belongs. The [database connection] 3668** returned by sqlite3_db_handle is the same [database connection] that was the first argument 3669** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 3670** create the statement in the first place. 3671** 3672** Requirements: [H13123] 3673*/ 3674sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 3675 3676/* 3677** CAPI3REF: Find the next prepared statement {H13140} <S60600> 3678** 3679** This interface returns a pointer to the next [prepared statement] after 3680** pStmt associated with the [database connection] pDb. If pStmt is NULL 3681** then this interface returns a pointer to the first prepared statement 3682** associated with the database connection pDb. If no prepared statement 3683** satisfies the conditions of this routine, it returns NULL. 3684** 3685** The [database connection] pointer D in a call to 3686** [sqlite3_next_stmt(D,S)] must refer to an open database 3687** connection and in particular must not be a NULL pointer. 3688** 3689** Requirements: [H13143] [H13146] [H13149] [H13152] 3690*/ 3691sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 3692 3693/* 3694** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> 3695** 3696** The sqlite3_commit_hook() interface registers a callback 3697** function to be invoked whenever a transaction is committed. 3698** Any callback set by a previous call to sqlite3_commit_hook() 3699** for the same database connection is overridden. 3700** The sqlite3_rollback_hook() interface registers a callback 3701** function to be invoked whenever a transaction is committed. 3702** Any callback set by a previous call to sqlite3_commit_hook() 3703** for the same database connection is overridden. 3704** The pArg argument is passed through to the callback. 3705** If the callback on a commit hook function returns non-zero, 3706** then the commit is converted into a rollback. 3707** 3708** If another function was previously registered, its 3709** pArg value is returned. Otherwise NULL is returned. 3710** 3711** The callback implementation must not do anything that will modify 3712** the database connection that invoked the callback. Any actions 3713** to modify the database connection must be deferred until after the 3714** completion of the [sqlite3_step()] call that triggered the commit 3715** or rollback hook in the first place. 3716** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3717** database connections for the meaning of "modify" in this paragraph. 3718** 3719** Registering a NULL function disables the callback. 3720** 3721** For the purposes of this API, a transaction is said to have been 3722** rolled back if an explicit "ROLLBACK" statement is executed, or 3723** an error or constraint causes an implicit rollback to occur. 3724** The rollback callback is not invoked if a transaction is 3725** automatically rolled back because the database connection is closed. 3726** The rollback callback is not invoked if a transaction is 3727** rolled back because a commit callback returned non-zero. 3728** <todo> Check on this </todo> 3729** 3730** Requirements: 3731** [H12951] [H12952] [H12953] [H12954] [H12955] 3732** [H12961] [H12962] [H12963] [H12964] 3733*/ 3734void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 3735void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 3736 3737/* 3738** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> 3739** 3740** The sqlite3_update_hook() interface registers a callback function 3741** with the [database connection] identified by the first argument 3742** to be invoked whenever a row is updated, inserted or deleted. 3743** Any callback set by a previous call to this function 3744** for the same database connection is overridden. 3745** 3746** The second argument is a pointer to the function to invoke when a 3747** row is updated, inserted or deleted. 3748** The first argument to the callback is a copy of the third argument 3749** to sqlite3_update_hook(). 3750** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 3751** or [SQLITE_UPDATE], depending on the operation that caused the callback 3752** to be invoked. 3753** The third and fourth arguments to the callback contain pointers to the 3754** database and table name containing the affected row. 3755** The final callback parameter is the [rowid] of the row. 3756** In the case of an update, this is the [rowid] after the update takes place. 3757** 3758** The update hook is not invoked when internal system tables are 3759** modified (i.e. sqlite_master and sqlite_sequence). 3760** 3761** The update hook implementation must not do anything that will modify 3762** the database connection that invoked the update hook. Any actions 3763** to modify the database connection must be deferred until after the 3764** completion of the [sqlite3_step()] call that triggered the update hook. 3765** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3766** database connections for the meaning of "modify" in this paragraph. 3767** 3768** If another function was previously registered, its pArg value 3769** is returned. Otherwise NULL is returned. 3770** 3771** Requirements: 3772** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] 3773*/ 3774void *sqlite3_update_hook( 3775 sqlite3*, 3776 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 3777 void* 3778); 3779 3780/* 3781** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> 3782** KEYWORDS: {shared cache} {shared cache mode} 3783** 3784** This routine enables or disables the sharing of the database cache 3785** and schema data structures between [database connection | connections] 3786** to the same database. Sharing is enabled if the argument is true 3787** and disabled if the argument is false. 3788** 3789** Cache sharing is enabled and disabled for an entire process. 3790** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 3791** sharing was enabled or disabled for each thread separately. 3792** 3793** The cache sharing mode set by this interface effects all subsequent 3794** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 3795** Existing database connections continue use the sharing mode 3796** that was in effect at the time they were opened. 3797** 3798** Virtual tables cannot be used with a shared cache. When shared 3799** cache is enabled, the [sqlite3_create_module()] API used to register 3800** virtual tables will always return an error. 3801** 3802** This routine returns [SQLITE_OK] if shared cache was enabled or disabled 3803** successfully. An [error code] is returned otherwise. 3804** 3805** Shared cache is disabled by default. But this might change in 3806** future releases of SQLite. Applications that care about shared 3807** cache setting should set it explicitly. 3808** 3809** See Also: [SQLite Shared-Cache Mode] 3810** 3811** Requirements: [H10331] [H10336] [H10337] [H10339] 3812*/ 3813int sqlite3_enable_shared_cache(int); 3814 3815/* 3816** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> 3817** 3818** The sqlite3_release_memory() interface attempts to free N bytes 3819** of heap memory by deallocating non-essential memory allocations 3820** held by the database library. {END} Memory used to cache database 3821** pages to improve performance is an example of non-essential memory. 3822** sqlite3_release_memory() returns the number of bytes actually freed, 3823** which might be more or less than the amount requested. 3824** 3825** Requirements: [H17341] [H17342] 3826*/ 3827int sqlite3_release_memory(int); 3828 3829/* 3830** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> 3831** 3832** The sqlite3_soft_heap_limit() interface places a "soft" limit 3833** on the amount of heap memory that may be allocated by SQLite. 3834** If an internal allocation is requested that would exceed the 3835** soft heap limit, [sqlite3_release_memory()] is invoked one or 3836** more times to free up some space before the allocation is performed. 3837** 3838** The limit is called "soft", because if [sqlite3_release_memory()] 3839** cannot free sufficient memory to prevent the limit from being exceeded, 3840** the memory is allocated anyway and the current operation proceeds. 3841** 3842** A negative or zero value for N means that there is no soft heap limit and 3843** [sqlite3_release_memory()] will only be called when memory is exhausted. 3844** The default value for the soft heap limit is zero. 3845** 3846** SQLite makes a best effort to honor the soft heap limit. 3847** But if the soft heap limit cannot be honored, execution will 3848** continue without error or notification. This is why the limit is 3849** called a "soft" limit. It is advisory only. 3850** 3851** Prior to SQLite version 3.5.0, this routine only constrained the memory 3852** allocated by a single thread - the same thread in which this routine 3853** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 3854** applied to all threads. The value specified for the soft heap limit 3855** is an upper bound on the total memory allocation for all threads. In 3856** version 3.5.0 there is no mechanism for limiting the heap usage for 3857** individual threads. 3858** 3859** Requirements: 3860** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] 3861*/ 3862void sqlite3_soft_heap_limit(int); 3863 3864/* 3865** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> 3866** 3867** This routine returns metadata about a specific column of a specific 3868** database table accessible using the [database connection] handle 3869** passed as the first function argument. 3870** 3871** The column is identified by the second, third and fourth parameters to 3872** this function. The second parameter is either the name of the database 3873** (i.e. "main", "temp" or an attached database) containing the specified 3874** table or NULL. If it is NULL, then all attached databases are searched 3875** for the table using the same algorithm used by the database engine to 3876** resolve unqualified table references. 3877** 3878** The third and fourth parameters to this function are the table and column 3879** name of the desired column, respectively. Neither of these parameters 3880** may be NULL. 3881** 3882** Metadata is returned by writing to the memory locations passed as the 5th 3883** and subsequent parameters to this function. Any of these arguments may be 3884** NULL, in which case the corresponding element of metadata is omitted. 3885** 3886** <blockquote> 3887** <table border="1"> 3888** <tr><th> Parameter <th> Output<br>Type <th> Description 3889** 3890** <tr><td> 5th <td> const char* <td> Data type 3891** <tr><td> 6th <td> const char* <td> Name of default collation sequence 3892** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 3893** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 3894** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 3895** </table> 3896** </blockquote> 3897** 3898** The memory pointed to by the character pointers returned for the 3899** declaration type and collation sequence is valid only until the next 3900** call to any SQLite API function. 3901** 3902** If the specified table is actually a view, an [error code] is returned. 3903** 3904** If the specified column is "rowid", "oid" or "_rowid_" and an 3905** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 3906** parameters are set for the explicitly declared column. If there is no 3907** explicitly declared [INTEGER PRIMARY KEY] column, then the output 3908** parameters are set as follows: 3909** 3910** <pre> 3911** data type: "INTEGER" 3912** collation sequence: "BINARY" 3913** not null: 0 3914** primary key: 1 3915** auto increment: 0 3916** </pre> 3917** 3918** This function may load one or more schemas from database files. If an 3919** error occurs during this process, or if the requested table or column 3920** cannot be found, an [error code] is returned and an error message left 3921** in the [database connection] (to be retrieved using sqlite3_errmsg()). 3922** 3923** This API is only available if the library was compiled with the 3924** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 3925*/ 3926int sqlite3_table_column_metadata( 3927 sqlite3 *db, /* Connection handle */ 3928 const char *zDbName, /* Database name or NULL */ 3929 const char *zTableName, /* Table name */ 3930 const char *zColumnName, /* Column name */ 3931 char const **pzDataType, /* OUTPUT: Declared data type */ 3932 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 3933 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 3934 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 3935 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 3936); 3937 3938/* 3939** CAPI3REF: Load An Extension {H12600} <S20500> 3940** 3941** This interface loads an SQLite extension library from the named file. 3942** 3943** {H12601} The sqlite3_load_extension() interface attempts to load an 3944** SQLite extension library contained in the file zFile. 3945** 3946** {H12602} The entry point is zProc. 3947** 3948** {H12603} zProc may be 0, in which case the name of the entry point 3949** defaults to "sqlite3_extension_init". 3950** 3951** {H12604} The sqlite3_load_extension() interface shall return 3952** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 3953** 3954** {H12605} If an error occurs and pzErrMsg is not 0, then the 3955** [sqlite3_load_extension()] interface shall attempt to 3956** fill *pzErrMsg with error message text stored in memory 3957** obtained from [sqlite3_malloc()]. {END} The calling function 3958** should free this memory by calling [sqlite3_free()]. 3959** 3960** {H12606} Extension loading must be enabled using 3961** [sqlite3_enable_load_extension()] prior to calling this API, 3962** otherwise an error will be returned. 3963*/ 3964int sqlite3_load_extension( 3965 sqlite3 *db, /* Load the extension into this database connection */ 3966 const char *zFile, /* Name of the shared library containing extension */ 3967 const char *zProc, /* Entry point. Derived from zFile if 0 */ 3968 char **pzErrMsg /* Put error message here if not 0 */ 3969); 3970 3971/* 3972** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> 3973** 3974** So as not to open security holes in older applications that are 3975** unprepared to deal with extension loading, and as a means of disabling 3976** extension loading while evaluating user-entered SQL, the following API 3977** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 3978** 3979** Extension loading is off by default. See ticket #1863. 3980** 3981** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 3982** to turn extension loading on and call it with onoff==0 to turn 3983** it back off again. 3984** 3985** {H12622} Extension loading is off by default. 3986*/ 3987int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 3988 3989/* 3990** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> 3991** 3992** This API can be invoked at program startup in order to register 3993** one or more statically linked extensions that will be available 3994** to all new [database connections]. {END} 3995** 3996** This routine stores a pointer to the extension in an array that is 3997** obtained from [sqlite3_malloc()]. If you run a memory leak checker 3998** on your program and it reports a leak because of this array, invoke 3999** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. 4000** 4001** {H12641} This function registers an extension entry point that is 4002** automatically invoked whenever a new [database connection] 4003** is opened using [sqlite3_open()], [sqlite3_open16()], 4004** or [sqlite3_open_v2()]. 4005** 4006** {H12642} Duplicate extensions are detected so calling this routine 4007** multiple times with the same extension is harmless. 4008** 4009** {H12643} This routine stores a pointer to the extension in an array 4010** that is obtained from [sqlite3_malloc()]. 4011** 4012** {H12644} Automatic extensions apply across all threads. 4013*/ 4014int sqlite3_auto_extension(void (*xEntryPoint)(void)); 4015 4016/* 4017** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> 4018** 4019** This function disables all previously registered automatic 4020** extensions. {END} It undoes the effect of all prior 4021** [sqlite3_auto_extension()] calls. 4022** 4023** {H12661} This function disables all previously registered 4024** automatic extensions. 4025** 4026** {H12662} This function disables automatic extensions in all threads. 4027*/ 4028void sqlite3_reset_auto_extension(void); 4029 4030/* 4031****** EXPERIMENTAL - subject to change without notice ************** 4032** 4033** The interface to the virtual-table mechanism is currently considered 4034** to be experimental. The interface might change in incompatible ways. 4035** If this is a problem for you, do not use the interface at this time. 4036** 4037** When the virtual-table mechanism stabilizes, we will declare the 4038** interface fixed, support it indefinitely, and remove this comment. 4039*/ 4040 4041/* 4042** Structures used by the virtual table interface 4043*/ 4044typedef struct sqlite3_vtab sqlite3_vtab; 4045typedef struct sqlite3_index_info sqlite3_index_info; 4046typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4047typedef struct sqlite3_module sqlite3_module; 4048 4049/* 4050** CAPI3REF: Virtual Table Object {H18000} <S20400> 4051** KEYWORDS: sqlite3_module 4052** EXPERIMENTAL 4053** 4054** A module is a class of virtual tables. Each module is defined 4055** by an instance of the following structure. This structure consists 4056** mostly of methods for the module. 4057** 4058** This interface is experimental and is subject to change or 4059** removal in future releases of SQLite. 4060*/ 4061struct sqlite3_module { 4062 int iVersion; 4063 int (*xCreate)(sqlite3*, void *pAux, 4064 int argc, const char *const*argv, 4065 sqlite3_vtab **ppVTab, char**); 4066 int (*xConnect)(sqlite3*, void *pAux, 4067 int argc, const char *const*argv, 4068 sqlite3_vtab **ppVTab, char**); 4069 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4070 int (*xDisconnect)(sqlite3_vtab *pVTab); 4071 int (*xDestroy)(sqlite3_vtab *pVTab); 4072 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4073 int (*xClose)(sqlite3_vtab_cursor*); 4074 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4075 int argc, sqlite3_value **argv); 4076 int (*xNext)(sqlite3_vtab_cursor*); 4077 int (*xEof)(sqlite3_vtab_cursor*); 4078 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4079 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4080 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4081 int (*xBegin)(sqlite3_vtab *pVTab); 4082 int (*xSync)(sqlite3_vtab *pVTab); 4083 int (*xCommit)(sqlite3_vtab *pVTab); 4084 int (*xRollback)(sqlite3_vtab *pVTab); 4085 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4086 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4087 void **ppArg); 4088 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4089}; 4090 4091/* 4092** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> 4093** KEYWORDS: sqlite3_index_info 4094** EXPERIMENTAL 4095** 4096** The sqlite3_index_info structure and its substructures is used to 4097** pass information into and receive the reply from the xBestIndex 4098** method of an sqlite3_module. The fields under **Inputs** are the 4099** inputs to xBestIndex and are read-only. xBestIndex inserts its 4100** results into the **Outputs** fields. 4101** 4102** The aConstraint[] array records WHERE clause constraints of the form: 4103** 4104** <pre>column OP expr</pre> 4105** 4106** where OP is =, <, <=, >, or >=. The particular operator is 4107** stored in aConstraint[].op. The index of the column is stored in 4108** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 4109** expr on the right-hand side can be evaluated (and thus the constraint 4110** is usable) and false if it cannot. 4111** 4112** The optimizer automatically inverts terms of the form "expr OP column" 4113** and makes other simplifications to the WHERE clause in an attempt to 4114** get as many WHERE clause terms into the form shown above as possible. 4115** The aConstraint[] array only reports WHERE clause terms in the correct 4116** form that refer to the particular virtual table being queried. 4117** 4118** Information about the ORDER BY clause is stored in aOrderBy[]. 4119** Each term of aOrderBy records a column of the ORDER BY clause. 4120** 4121** The xBestIndex method must fill aConstraintUsage[] with information 4122** about what parameters to pass to xFilter. If argvIndex>0 then 4123** the right-hand side of the corresponding aConstraint[] is evaluated 4124** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 4125** is true, then the constraint is assumed to be fully handled by the 4126** virtual table and is not checked again by SQLite. 4127** 4128** The idxNum and idxPtr values are recorded and passed into xFilter. 4129** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. 4130** 4131** The orderByConsumed means that output from xFilter will occur in 4132** the correct order to satisfy the ORDER BY clause so that no separate 4133** sorting step is required. 4134** 4135** The estimatedCost value is an estimate of the cost of doing the 4136** particular lookup. A full scan of a table with N entries should have 4137** a cost of N. A binary search of a table of N entries should have a 4138** cost of approximately log(N). 4139** 4140** This interface is experimental and is subject to change or 4141** removal in future releases of SQLite. 4142*/ 4143struct sqlite3_index_info { 4144 /* Inputs */ 4145 int nConstraint; /* Number of entries in aConstraint */ 4146 struct sqlite3_index_constraint { 4147 int iColumn; /* Column on left-hand side of constraint */ 4148 unsigned char op; /* Constraint operator */ 4149 unsigned char usable; /* True if this constraint is usable */ 4150 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4151 } *aConstraint; /* Table of WHERE clause constraints */ 4152 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4153 struct sqlite3_index_orderby { 4154 int iColumn; /* Column number */ 4155 unsigned char desc; /* True for DESC. False for ASC. */ 4156 } *aOrderBy; /* The ORDER BY clause */ 4157 /* Outputs */ 4158 struct sqlite3_index_constraint_usage { 4159 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4160 unsigned char omit; /* Do not code a test for this constraint */ 4161 } *aConstraintUsage; 4162 int idxNum; /* Number used to identify the index */ 4163 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4164 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4165 int orderByConsumed; /* True if output is already ordered */ 4166 double estimatedCost; /* Estimated cost of using this index */ 4167}; 4168#define SQLITE_INDEX_CONSTRAINT_EQ 2 4169#define SQLITE_INDEX_CONSTRAINT_GT 4 4170#define SQLITE_INDEX_CONSTRAINT_LE 8 4171#define SQLITE_INDEX_CONSTRAINT_LT 16 4172#define SQLITE_INDEX_CONSTRAINT_GE 32 4173#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4174 4175/* 4176** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> 4177** EXPERIMENTAL 4178** 4179** This routine is used to register a new module name with a 4180** [database connection]. Module names must be registered before 4181** creating new virtual tables on the module, or before using 4182** preexisting virtual tables of the module. 4183** 4184** This interface is experimental and is subject to change or 4185** removal in future releases of SQLite. 4186*/ 4187SQLITE_EXPERIMENTAL int sqlite3_create_module( 4188 sqlite3 *db, /* SQLite connection to register module with */ 4189 const char *zName, /* Name of the module */ 4190 const sqlite3_module *, /* Methods for the module */ 4191 void * /* Client data for xCreate/xConnect */ 4192); 4193 4194/* 4195** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> 4196** EXPERIMENTAL 4197** 4198** This routine is identical to the [sqlite3_create_module()] method above, 4199** except that it allows a destructor function to be specified. It is 4200** even more experimental than the rest of the virtual tables API. 4201*/ 4202SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( 4203 sqlite3 *db, /* SQLite connection to register module with */ 4204 const char *zName, /* Name of the module */ 4205 const sqlite3_module *, /* Methods for the module */ 4206 void *, /* Client data for xCreate/xConnect */ 4207 void(*xDestroy)(void*) /* Module destructor function */ 4208); 4209 4210/* 4211** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> 4212** KEYWORDS: sqlite3_vtab 4213** EXPERIMENTAL 4214** 4215** Every module implementation uses a subclass of the following structure 4216** to describe a particular instance of the module. Each subclass will 4217** be tailored to the specific needs of the module implementation. 4218** The purpose of this superclass is to define certain fields that are 4219** common to all module implementations. 4220** 4221** Virtual tables methods can set an error message by assigning a 4222** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 4223** take care that any prior string is freed by a call to [sqlite3_free()] 4224** prior to assigning a new string to zErrMsg. After the error message 4225** is delivered up to the client application, the string will be automatically 4226** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note 4227** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field 4228** since virtual tables are commonly implemented in loadable extensions which 4229** do not have access to sqlite3MPrintf() or sqlite3Free(). 4230** 4231** This interface is experimental and is subject to change or 4232** removal in future releases of SQLite. 4233*/ 4234struct sqlite3_vtab { 4235 const sqlite3_module *pModule; /* The module for this virtual table */ 4236 int nRef; /* Used internally */ 4237 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 4238 /* Virtual table implementations will typically add additional fields */ 4239}; 4240 4241/* 4242** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> 4243** KEYWORDS: sqlite3_vtab_cursor 4244** EXPERIMENTAL 4245** 4246** Every module implementation uses a subclass of the following structure 4247** to describe cursors that point into the virtual table and are used 4248** to loop through the virtual table. Cursors are created using the 4249** xOpen method of the module. Each module implementation will define 4250** the content of a cursor structure to suit its own needs. 4251** 4252** This superclass exists in order to define fields of the cursor that 4253** are common to all implementations. 4254** 4255** This interface is experimental and is subject to change or 4256** removal in future releases of SQLite. 4257*/ 4258struct sqlite3_vtab_cursor { 4259 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 4260 /* Virtual table implementations will typically add additional fields */ 4261}; 4262 4263/* 4264** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> 4265** EXPERIMENTAL 4266** 4267** The xCreate and xConnect methods of a module use the following API 4268** to declare the format (the names and datatypes of the columns) of 4269** the virtual tables they implement. 4270** 4271** This interface is experimental and is subject to change or 4272** removal in future releases of SQLite. 4273*/ 4274SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); 4275 4276/* 4277** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> 4278** EXPERIMENTAL 4279** 4280** Virtual tables can provide alternative implementations of functions 4281** using the xFindFunction method. But global versions of those functions 4282** must exist in order to be overloaded. 4283** 4284** This API makes sure a global version of a function with a particular 4285** name and number of parameters exists. If no such function exists 4286** before this API is called, a new function is created. The implementation 4287** of the new function always causes an exception to be thrown. So 4288** the new function is not good for anything by itself. Its only 4289** purpose is to be a placeholder function that can be overloaded 4290** by virtual tables. 4291** 4292** This API should be considered part of the virtual table interface, 4293** which is experimental and subject to change. 4294*/ 4295SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 4296 4297/* 4298** The interface to the virtual-table mechanism defined above (back up 4299** to a comment remarkably similar to this one) is currently considered 4300** to be experimental. The interface might change in incompatible ways. 4301** If this is a problem for you, do not use the interface at this time. 4302** 4303** When the virtual-table mechanism stabilizes, we will declare the 4304** interface fixed, support it indefinitely, and remove this comment. 4305** 4306****** EXPERIMENTAL - subject to change without notice ************** 4307*/ 4308 4309/* 4310** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> 4311** KEYWORDS: {BLOB handle} {BLOB handles} 4312** 4313** An instance of this object represents an open BLOB on which 4314** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 4315** Objects of this type are created by [sqlite3_blob_open()] 4316** and destroyed by [sqlite3_blob_close()]. 4317** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 4318** can be used to read or write small subsections of the BLOB. 4319** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 4320*/ 4321typedef struct sqlite3_blob sqlite3_blob; 4322 4323/* 4324** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> 4325** 4326** This interfaces opens a [BLOB handle | handle] to the BLOB located 4327** in row iRow, column zColumn, table zTable in database zDb; 4328** in other words, the same BLOB that would be selected by: 4329** 4330** <pre> 4331** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 4332** </pre> {END} 4333** 4334** If the flags parameter is non-zero, the the BLOB is opened for read 4335** and write access. If it is zero, the BLOB is opened for read access. 4336** 4337** Note that the database name is not the filename that contains 4338** the database but rather the symbolic name of the database that 4339** is assigned when the database is connected using [ATTACH]. 4340** For the main database file, the database name is "main". 4341** For TEMP tables, the database name is "temp". 4342** 4343** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 4344** to *ppBlob. Otherwise an [error code] is returned and any value written 4345** to *ppBlob should not be used by the caller. 4346** This function sets the [database connection] error code and message 4347** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 4348** 4349** If the row that a BLOB handle points to is modified by an 4350** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 4351** then the BLOB handle is marked as "expired". 4352** This is true if any column of the row is changed, even a column 4353** other than the one the BLOB handle is open on. 4354** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 4355** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. 4356** Changes written into a BLOB prior to the BLOB expiring are not 4357** rollback by the expiration of the BLOB. Such changes will eventually 4358** commit if the transaction continues to completion. 4359** 4360** Requirements: 4361** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] 4362*/ 4363int sqlite3_blob_open( 4364 sqlite3*, 4365 const char *zDb, 4366 const char *zTable, 4367 const char *zColumn, 4368 sqlite3_int64 iRow, 4369 int flags, 4370 sqlite3_blob **ppBlob 4371); 4372 4373/* 4374** CAPI3REF: Close A BLOB Handle {H17830} <S30230> 4375** 4376** Closes an open [BLOB handle]. 4377** 4378** Closing a BLOB shall cause the current transaction to commit 4379** if there are no other BLOBs, no pending prepared statements, and the 4380** database connection is in [autocommit mode]. 4381** If any writes were made to the BLOB, they might be held in cache 4382** until the close operation if they will fit. {END} 4383** 4384** Closing the BLOB often forces the changes 4385** out to disk and so if any I/O errors occur, they will likely occur 4386** at the time when the BLOB is closed. {H17833} Any errors that occur during 4387** closing are reported as a non-zero return value. 4388** 4389** The BLOB is closed unconditionally. Even if this routine returns 4390** an error code, the BLOB is still closed. 4391** 4392** Requirements: 4393** [H17833] [H17836] [H17839] 4394*/ 4395int sqlite3_blob_close(sqlite3_blob *); 4396 4397/* 4398** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> 4399** 4400** Returns the size in bytes of the BLOB accessible via the open 4401** []BLOB handle] in its only argument. 4402** 4403** Requirements: 4404** [H17843] 4405*/ 4406int sqlite3_blob_bytes(sqlite3_blob *); 4407 4408/* 4409** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> 4410** 4411** This function is used to read data from an open [BLOB handle] into a 4412** caller-supplied buffer. N bytes of data are copied into buffer Z 4413** from the open BLOB, starting at offset iOffset. 4414** 4415** If offset iOffset is less than N bytes from the end of the BLOB, 4416** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 4417** less than zero, [SQLITE_ERROR] is returned and no data is read. 4418** 4419** An attempt to read from an expired [BLOB handle] fails with an 4420** error code of [SQLITE_ABORT]. 4421** 4422** On success, SQLITE_OK is returned. 4423** Otherwise, an [error code] or an [extended error code] is returned. 4424** 4425** Requirements: 4426** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] 4427*/ 4428int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 4429 4430/* 4431** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> 4432** 4433** This function is used to write data into an open [BLOB handle] from a 4434** caller-supplied buffer. N bytes of data are copied from the buffer Z 4435** into the open BLOB, starting at offset iOffset. 4436** 4437** If the [BLOB handle] passed as the first argument was not opened for 4438** writing (the flags parameter to [sqlite3_blob_open()] was zero), 4439** this function returns [SQLITE_READONLY]. 4440** 4441** This function may only modify the contents of the BLOB; it is 4442** not possible to increase the size of a BLOB using this API. 4443** If offset iOffset is less than N bytes from the end of the BLOB, 4444** [SQLITE_ERROR] is returned and no data is written. If N is 4445** less than zero [SQLITE_ERROR] is returned and no data is written. 4446** 4447** An attempt to write to an expired [BLOB handle] fails with an 4448** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred 4449** before the [BLOB handle] expired are not rolled back by the 4450** expiration of the handle, though of course those changes might 4451** have been overwritten by the statement that expired the BLOB handle 4452** or by other independent statements. 4453** 4454** On success, SQLITE_OK is returned. 4455** Otherwise, an [error code] or an [extended error code] is returned. 4456** 4457** Requirements: 4458** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] 4459** [H17888] 4460*/ 4461int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 4462 4463/* 4464** CAPI3REF: Virtual File System Objects {H11200} <S20100> 4465** 4466** A virtual filesystem (VFS) is an [sqlite3_vfs] object 4467** that SQLite uses to interact 4468** with the underlying operating system. Most SQLite builds come with a 4469** single default VFS that is appropriate for the host computer. 4470** New VFSes can be registered and existing VFSes can be unregistered. 4471** The following interfaces are provided. 4472** 4473** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 4474** Names are case sensitive. 4475** Names are zero-terminated UTF-8 strings. 4476** If there is no match, a NULL pointer is returned. 4477** If zVfsName is NULL then the default VFS is returned. 4478** 4479** New VFSes are registered with sqlite3_vfs_register(). 4480** Each new VFS becomes the default VFS if the makeDflt flag is set. 4481** The same VFS can be registered multiple times without injury. 4482** To make an existing VFS into the default VFS, register it again 4483** with the makeDflt flag set. If two different VFSes with the 4484** same name are registered, the behavior is undefined. If a 4485** VFS is registered with a name that is NULL or an empty string, 4486** then the behavior is undefined. 4487** 4488** Unregister a VFS with the sqlite3_vfs_unregister() interface. 4489** If the default VFS is unregistered, another VFS is chosen as 4490** the default. The choice for the new VFS is arbitrary. 4491** 4492** Requirements: 4493** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] 4494*/ 4495sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 4496int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 4497int sqlite3_vfs_unregister(sqlite3_vfs*); 4498 4499/* 4500** CAPI3REF: Mutexes {H17000} <S20000> 4501** 4502** The SQLite core uses these routines for thread 4503** synchronization. Though they are intended for internal 4504** use by SQLite, code that links against SQLite is 4505** permitted to use any of these routines. 4506** 4507** The SQLite source code contains multiple implementations 4508** of these mutex routines. An appropriate implementation 4509** is selected automatically at compile-time. The following 4510** implementations are available in the SQLite core: 4511** 4512** <ul> 4513** <li> SQLITE_MUTEX_OS2 4514** <li> SQLITE_MUTEX_PTHREAD 4515** <li> SQLITE_MUTEX_W32 4516** <li> SQLITE_MUTEX_NOOP 4517** </ul> 4518** 4519** The SQLITE_MUTEX_NOOP implementation is a set of routines 4520** that does no real locking and is appropriate for use in 4521** a single-threaded application. The SQLITE_MUTEX_OS2, 4522** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 4523** are appropriate for use on OS/2, Unix, and Windows. 4524** 4525** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 4526** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 4527** implementation is included with the library. In this case the 4528** application must supply a custom mutex implementation using the 4529** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 4530** before calling sqlite3_initialize() or any other public sqlite3_ 4531** function that calls sqlite3_initialize(). 4532** 4533** {H17011} The sqlite3_mutex_alloc() routine allocates a new 4534** mutex and returns a pointer to it. {H17012} If it returns NULL 4535** that means that a mutex could not be allocated. {H17013} SQLite 4536** will unwind its stack and return an error. {H17014} The argument 4537** to sqlite3_mutex_alloc() is one of these integer constants: 4538** 4539** <ul> 4540** <li> SQLITE_MUTEX_FAST 4541** <li> SQLITE_MUTEX_RECURSIVE 4542** <li> SQLITE_MUTEX_STATIC_MASTER 4543** <li> SQLITE_MUTEX_STATIC_MEM 4544** <li> SQLITE_MUTEX_STATIC_MEM2 4545** <li> SQLITE_MUTEX_STATIC_PRNG 4546** <li> SQLITE_MUTEX_STATIC_LRU 4547** <li> SQLITE_MUTEX_STATIC_LRU2 4548** </ul> 4549** 4550** {H17015} The first two constants cause sqlite3_mutex_alloc() to create 4551** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 4552** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 4553** The mutex implementation does not need to make a distinction 4554** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 4555** not want to. {H17016} But SQLite will only request a recursive mutex in 4556** cases where it really needs one. {END} If a faster non-recursive mutex 4557** implementation is available on the host platform, the mutex subsystem 4558** might return such a mutex in response to SQLITE_MUTEX_FAST. 4559** 4560** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return 4561** a pointer to a static preexisting mutex. {END} Four static mutexes are 4562** used by the current version of SQLite. Future versions of SQLite 4563** may add additional static mutexes. Static mutexes are for internal 4564** use by SQLite only. Applications that use SQLite mutexes should 4565** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 4566** SQLITE_MUTEX_RECURSIVE. 4567** 4568** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 4569** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 4570** returns a different mutex on every call. {H17034} But for the static 4571** mutex types, the same mutex is returned on every call that has 4572** the same type number. 4573** 4574** {H17019} The sqlite3_mutex_free() routine deallocates a previously 4575** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every 4576** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in 4577** use when they are deallocated. {A17022} Attempting to deallocate a static 4578** mutex results in undefined behavior. {H17023} SQLite never deallocates 4579** a static mutex. {END} 4580** 4581** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 4582** to enter a mutex. {H17024} If another thread is already within the mutex, 4583** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 4584** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] 4585** upon successful entry. {H17026} Mutexes created using 4586** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 4587** {H17027} In such cases the, 4588** mutex must be exited an equal number of times before another thread 4589** can enter. {A17028} If the same thread tries to enter any other 4590** kind of mutex more than once, the behavior is undefined. 4591** {H17029} SQLite will never exhibit 4592** such behavior in its own use of mutexes. 4593** 4594** Some systems (for example, Windows 95) do not support the operation 4595** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 4596** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses 4597** sqlite3_mutex_try() as an optimization so this is acceptable behavior. 4598** 4599** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was 4600** previously entered by the same thread. {A17032} The behavior 4601** is undefined if the mutex is not currently entered by the 4602** calling thread or is not currently allocated. {H17033} SQLite will 4603** never do either. {END} 4604** 4605** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 4606** sqlite3_mutex_leave() is a NULL pointer, then all three routines 4607** behave as no-ops. 4608** 4609** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 4610*/ 4611sqlite3_mutex *sqlite3_mutex_alloc(int); 4612void sqlite3_mutex_free(sqlite3_mutex*); 4613void sqlite3_mutex_enter(sqlite3_mutex*); 4614int sqlite3_mutex_try(sqlite3_mutex*); 4615void sqlite3_mutex_leave(sqlite3_mutex*); 4616 4617/* 4618** CAPI3REF: Mutex Methods Object {H17120} <S20130> 4619** EXPERIMENTAL 4620** 4621** An instance of this structure defines the low-level routines 4622** used to allocate and use mutexes. 4623** 4624** Usually, the default mutex implementations provided by SQLite are 4625** sufficient, however the user has the option of substituting a custom 4626** implementation for specialized deployments or systems for which SQLite 4627** does not provide a suitable implementation. In this case, the user 4628** creates and populates an instance of this structure to pass 4629** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 4630** Additionally, an instance of this structure can be used as an 4631** output variable when querying the system for the current mutex 4632** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 4633** 4634** The xMutexInit method defined by this structure is invoked as 4635** part of system initialization by the sqlite3_initialize() function. 4636** {H17001} The xMutexInit routine shall be called by SQLite once for each 4637** effective call to [sqlite3_initialize()]. 4638** 4639** The xMutexEnd method defined by this structure is invoked as 4640** part of system shutdown by the sqlite3_shutdown() function. The 4641** implementation of this method is expected to release all outstanding 4642** resources obtained by the mutex methods implementation, especially 4643** those obtained by the xMutexInit method. {H17003} The xMutexEnd() 4644** interface shall be invoked once for each call to [sqlite3_shutdown()]. 4645** 4646** The remaining seven methods defined by this structure (xMutexAlloc, 4647** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 4648** xMutexNotheld) implement the following interfaces (respectively): 4649** 4650** <ul> 4651** <li> [sqlite3_mutex_alloc()] </li> 4652** <li> [sqlite3_mutex_free()] </li> 4653** <li> [sqlite3_mutex_enter()] </li> 4654** <li> [sqlite3_mutex_try()] </li> 4655** <li> [sqlite3_mutex_leave()] </li> 4656** <li> [sqlite3_mutex_held()] </li> 4657** <li> [sqlite3_mutex_notheld()] </li> 4658** </ul> 4659** 4660** The only difference is that the public sqlite3_XXX functions enumerated 4661** above silently ignore any invocations that pass a NULL pointer instead 4662** of a valid mutex handle. The implementations of the methods defined 4663** by this structure are not required to handle this case, the results 4664** of passing a NULL pointer instead of a valid mutex handle are undefined 4665** (i.e. it is acceptable to provide an implementation that segfaults if 4666** it is passed a NULL pointer). 4667*/ 4668typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 4669struct sqlite3_mutex_methods { 4670 int (*xMutexInit)(void); 4671 int (*xMutexEnd)(void); 4672 sqlite3_mutex *(*xMutexAlloc)(int); 4673 void (*xMutexFree)(sqlite3_mutex *); 4674 void (*xMutexEnter)(sqlite3_mutex *); 4675 int (*xMutexTry)(sqlite3_mutex *); 4676 void (*xMutexLeave)(sqlite3_mutex *); 4677 int (*xMutexHeld)(sqlite3_mutex *); 4678 int (*xMutexNotheld)(sqlite3_mutex *); 4679}; 4680 4681/* 4682** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> 4683** 4684** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 4685** are intended for use inside assert() statements. {H17081} The SQLite core 4686** never uses these routines except inside an assert() and applications 4687** are advised to follow the lead of the core. {H17082} The core only 4688** provides implementations for these routines when it is compiled 4689** with the SQLITE_DEBUG flag. {A17087} External mutex implementations 4690** are only required to provide these routines if SQLITE_DEBUG is 4691** defined and if NDEBUG is not defined. 4692** 4693** {H17083} These routines should return true if the mutex in their argument 4694** is held or not held, respectively, by the calling thread. 4695** 4696** {X17084} The implementation is not required to provided versions of these 4697** routines that actually work. If the implementation does not provide working 4698** versions of these routines, it should at least provide stubs that always 4699** return true so that one does not get spurious assertion failures. 4700** 4701** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 4702** the routine should return 1. {END} This seems counter-intuitive since 4703** clearly the mutex cannot be held if it does not exist. But the 4704** the reason the mutex does not exist is because the build is not 4705** using mutexes. And we do not want the assert() containing the 4706** call to sqlite3_mutex_held() to fail, so a non-zero return is 4707** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() 4708** interface should also return 1 when given a NULL pointer. 4709*/ 4710int sqlite3_mutex_held(sqlite3_mutex*); 4711int sqlite3_mutex_notheld(sqlite3_mutex*); 4712 4713/* 4714** CAPI3REF: Mutex Types {H17001} <H17000> 4715** 4716** The [sqlite3_mutex_alloc()] interface takes a single argument 4717** which is one of these integer constants. 4718** 4719** The set of static mutexes may change from one SQLite release to the 4720** next. Applications that override the built-in mutex logic must be 4721** prepared to accommodate additional static mutexes. 4722*/ 4723#define SQLITE_MUTEX_FAST 0 4724#define SQLITE_MUTEX_RECURSIVE 1 4725#define SQLITE_MUTEX_STATIC_MASTER 2 4726#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 4727#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */ 4728#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 4729#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 4730#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 4731 4732/* 4733** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> 4734** 4735** This interface returns a pointer the [sqlite3_mutex] object that 4736** serializes access to the [database connection] given in the argument 4737** when the [threading mode] is Serialized. 4738** If the [threading mode] is Single-thread or Multi-thread then this 4739** routine returns a NULL pointer. 4740*/ 4741sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 4742 4743/* 4744** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> 4745** 4746** {H11301} The [sqlite3_file_control()] interface makes a direct call to the 4747** xFileControl method for the [sqlite3_io_methods] object associated 4748** with a particular database identified by the second argument. {H11302} The 4749** name of the database is the name assigned to the database by the 4750** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 4751** database. {H11303} To control the main database file, use the name "main" 4752** or a NULL pointer. {H11304} The third and fourth parameters to this routine 4753** are passed directly through to the second and third parameters of 4754** the xFileControl method. {H11305} The return value of the xFileControl 4755** method becomes the return value of this routine. 4756** 4757** {H11306} If the second parameter (zDbName) does not match the name of any 4758** open database file, then SQLITE_ERROR is returned. {H11307} This error 4759** code is not remembered and will not be recalled by [sqlite3_errcode()] 4760** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might 4761** also return SQLITE_ERROR. {A11309} There is no way to distinguish between 4762** an incorrect zDbName and an SQLITE_ERROR return from the underlying 4763** xFileControl method. {END} 4764** 4765** See also: [SQLITE_FCNTL_LOCKSTATE] 4766*/ 4767int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 4768 4769/* 4770** CAPI3REF: Testing Interface {H11400} <S30800> 4771** 4772** The sqlite3_test_control() interface is used to read out internal 4773** state of SQLite and to inject faults into SQLite for testing 4774** purposes. The first parameter is an operation code that determines 4775** the number, meaning, and operation of all subsequent parameters. 4776** 4777** This interface is not for use by applications. It exists solely 4778** for verifying the correct operation of the SQLite library. Depending 4779** on how the SQLite library is compiled, this interface might not exist. 4780** 4781** The details of the operation codes, their meanings, the parameters 4782** they take, and what they do are all subject to change without notice. 4783** Unlike most of the SQLite API, this function is not guaranteed to 4784** operate consistently from one release to the next. 4785*/ 4786int sqlite3_test_control(int op, ...); 4787 4788/* 4789** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> 4790** 4791** These constants are the valid operation code parameters used 4792** as the first argument to [sqlite3_test_control()]. 4793** 4794** These parameters and their meanings are subject to change 4795** without notice. These values are for testing purposes only. 4796** Applications should not use any of these parameters or the 4797** [sqlite3_test_control()] interface. 4798*/ 4799#define SQLITE_TESTCTRL_PRNG_SAVE 5 4800#define SQLITE_TESTCTRL_PRNG_RESTORE 6 4801#define SQLITE_TESTCTRL_PRNG_RESET 7 4802#define SQLITE_TESTCTRL_BITVEC_TEST 8 4803#define SQLITE_TESTCTRL_FAULT_INSTALL 9 4804#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 4805#define SQLITE_TESTCTRL_PENDING_BYTE 11 4806 4807/* 4808** CAPI3REF: SQLite Runtime Status {H17200} <S60200> 4809** EXPERIMENTAL 4810** 4811** This interface is used to retrieve runtime status information 4812** about the preformance of SQLite, and optionally to reset various 4813** highwater marks. The first argument is an integer code for 4814** the specific parameter to measure. Recognized integer codes 4815** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. 4816** The current value of the parameter is returned into *pCurrent. 4817** The highest recorded value is returned in *pHighwater. If the 4818** resetFlag is true, then the highest record value is reset after 4819** *pHighwater is written. Some parameters do not record the highest 4820** value. For those parameters 4821** nothing is written into *pHighwater and the resetFlag is ignored. 4822** Other parameters record only the highwater mark and not the current 4823** value. For these latter parameters nothing is written into *pCurrent. 4824** 4825** This routine returns SQLITE_OK on success and a non-zero 4826** [error code] on failure. 4827** 4828** This routine is threadsafe but is not atomic. This routine can 4829** called while other threads are running the same or different SQLite 4830** interfaces. However the values returned in *pCurrent and 4831** *pHighwater reflect the status of SQLite at different points in time 4832** and it is possible that another thread might change the parameter 4833** in between the times when *pCurrent and *pHighwater are written. 4834** 4835** See also: [sqlite3_db_status()] 4836*/ 4837SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 4838 4839 4840/* 4841** CAPI3REF: Status Parameters {H17250} <H17200> 4842** EXPERIMENTAL 4843** 4844** These integer constants designate various run-time status parameters 4845** that can be returned by [sqlite3_status()]. 4846** 4847** <dl> 4848** <dt>SQLITE_STATUS_MEMORY_USED</dt> 4849** <dd>This parameter is the current amount of memory checked out 4850** using [sqlite3_malloc()], either directly or indirectly. The 4851** figure includes calls made to [sqlite3_malloc()] by the application 4852** and internal memory usage by the SQLite library. Scratch memory 4853** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 4854** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 4855** this parameter. The amount returned is the sum of the allocation 4856** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> 4857** 4858** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> 4859** <dd>This parameter records the largest memory allocation request 4860** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 4861** internal equivalents). Only the value returned in the 4862** *pHighwater parameter to [sqlite3_status()] is of interest. 4863** The value written into the *pCurrent parameter is undefined.</dd> 4864** 4865** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> 4866** <dd>This parameter returns the number of pages used out of the 4867** [pagecache memory allocator] that was configured using 4868** [SQLITE_CONFIG_PAGECACHE]. The 4869** value returned is in pages, not in bytes.</dd> 4870** 4871** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 4872** <dd>This parameter returns the number of bytes of page cache 4873** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] 4874** buffer and where forced to overflow to [sqlite3_malloc()]. The 4875** returned value includes allocations that overflowed because they 4876** where too large (they were larger than the "sz" parameter to 4877** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 4878** no space was left in the page cache.</dd> 4879** 4880** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 4881** <dd>This parameter records the largest memory allocation request 4882** handed to [pagecache memory allocator]. Only the value returned in the 4883** *pHighwater parameter to [sqlite3_status()] is of interest. 4884** The value written into the *pCurrent parameter is undefined.</dd> 4885** 4886** <dt>SQLITE_STATUS_SCRATCH_USED</dt> 4887** <dd>This parameter returns the number of allocations used out of the 4888** [scratch memory allocator] configured using 4889** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 4890** in bytes. Since a single thread may only have one scratch allocation 4891** outstanding at time, this parameter also reports the number of threads 4892** using scratch memory at the same time.</dd> 4893** 4894** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 4895** <dd>This parameter returns the number of bytes of scratch memory 4896** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] 4897** buffer and where forced to overflow to [sqlite3_malloc()]. The values 4898** returned include overflows because the requested allocation was too 4899** larger (that is, because the requested allocation was larger than the 4900** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 4901** slots were available. 4902** </dd> 4903** 4904** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 4905** <dd>This parameter records the largest memory allocation request 4906** handed to [scratch memory allocator]. Only the value returned in the 4907** *pHighwater parameter to [sqlite3_status()] is of interest. 4908** The value written into the *pCurrent parameter is undefined.</dd> 4909** 4910** <dt>SQLITE_STATUS_PARSER_STACK</dt> 4911** <dd>This parameter records the deepest parser stack. It is only 4912** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> 4913** </dl> 4914** 4915** New status parameters may be added from time to time. 4916*/ 4917#define SQLITE_STATUS_MEMORY_USED 0 4918#define SQLITE_STATUS_PAGECACHE_USED 1 4919#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 4920#define SQLITE_STATUS_SCRATCH_USED 3 4921#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 4922#define SQLITE_STATUS_MALLOC_SIZE 5 4923#define SQLITE_STATUS_PARSER_STACK 6 4924#define SQLITE_STATUS_PAGECACHE_SIZE 7 4925#define SQLITE_STATUS_SCRATCH_SIZE 8 4926 4927/* 4928** CAPI3REF: Database Connection Status {H17500} <S60200> 4929** EXPERIMENTAL 4930** 4931** This interface is used to retrieve runtime status information 4932** about a single [database connection]. The first argument is the 4933** database connection object to be interrogated. The second argument 4934** is the parameter to interrogate. Currently, the only allowed value 4935** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. 4936** Additional options will likely appear in future releases of SQLite. 4937** 4938** The current value of the requested parameter is written into *pCur 4939** and the highest instantaneous value is written into *pHiwtr. If 4940** the resetFlg is true, then the highest instantaneous value is 4941** reset back down to the current value. 4942** 4943** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 4944*/ 4945SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 4946 4947/* 4948** CAPI3REF: Status Parameters for database connections {H17520} <H17500> 4949** EXPERIMENTAL 4950** 4951** Status verbs for [sqlite3_db_status()]. 4952** 4953** <dl> 4954** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 4955** <dd>This parameter returns the number of lookaside memory slots currently 4956** checked out.</dd> 4957** </dl> 4958*/ 4959#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 4960 4961 4962/* 4963** CAPI3REF: Prepared Statement Status {H17550} <S60200> 4964** EXPERIMENTAL 4965** 4966** Each prepared statement maintains various 4967** [SQLITE_STMTSTATUS_SORT | counters] that measure the number 4968** of times it has performed specific operations. These counters can 4969** be used to monitor the performance characteristics of the prepared 4970** statements. For example, if the number of table steps greatly exceeds 4971** the number of table searches or result rows, that would tend to indicate 4972** that the prepared statement is using a full table scan rather than 4973** an index. 4974** 4975** This interface is used to retrieve and reset counter values from 4976** a [prepared statement]. The first argument is the prepared statement 4977** object to be interrogated. The second argument 4978** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] 4979** to be interrogated. 4980** The current value of the requested counter is returned. 4981** If the resetFlg is true, then the counter is reset to zero after this 4982** interface call returns. 4983** 4984** See also: [sqlite3_status()] and [sqlite3_db_status()]. 4985*/ 4986SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 4987 4988/* 4989** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> 4990** EXPERIMENTAL 4991** 4992** These preprocessor macros define integer codes that name counter 4993** values associated with the [sqlite3_stmt_status()] interface. 4994** The meanings of the various counters are as follows: 4995** 4996** <dl> 4997** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 4998** <dd>This is the number of times that SQLite has stepped forward in 4999** a table as part of a full table scan. Large numbers for this counter 5000** may indicate opportunities for performance improvement through 5001** careful use of indices.</dd> 5002** 5003** <dt>SQLITE_STMTSTATUS_SORT</dt> 5004** <dd>This is the number of sort operations that have occurred. 5005** A non-zero value in this counter may indicate an opportunity to 5006** improvement performance through careful use of indices.</dd> 5007** 5008** </dl> 5009*/ 5010#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 5011#define SQLITE_STMTSTATUS_SORT 2 5012 5013/* 5014** CAPI3REF: Custom Page Cache Object 5015** EXPERIMENTAL 5016** 5017** The sqlite3_pcache type is opaque. It is implemented by 5018** the pluggable module. The SQLite core has no knowledge of 5019** its size or internal structure and never deals with the 5020** sqlite3_pcache object except by holding and passing pointers 5021** to the object. 5022** 5023** See [sqlite3_pcache_methods] for additional information. 5024*/ 5025typedef struct sqlite3_pcache sqlite3_pcache; 5026 5027/* 5028** CAPI3REF: Application Defined Page Cache. 5029** EXPERIMENTAL 5030** 5031** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can 5032** register an alternative page cache implementation by passing in an 5033** instance of the sqlite3_pcache_methods structure. The majority of the 5034** heap memory used by sqlite is used by the page cache to cache data read 5035** from, or ready to be written to, the database file. By implementing a 5036** custom page cache using this API, an application can control more 5037** precisely the amount of memory consumed by sqlite, the way in which 5038** said memory is allocated and released, and the policies used to 5039** determine exactly which parts of a database file are cached and for 5040** how long. 5041** 5042** The contents of the structure are copied to an internal buffer by sqlite 5043** within the call to [sqlite3_config]. 5044** 5045** The xInit() method is called once for each call to [sqlite3_initialize()] 5046** (usually only once during the lifetime of the process). It is passed 5047** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set 5048** up global structures and mutexes required by the custom page cache 5049** implementation. The xShutdown() method is called from within 5050** [sqlite3_shutdown()], if the application invokes this API. It can be used 5051** to clean up any outstanding resources before process shutdown, if required. 5052** 5053** The xCreate() method is used to construct a new cache instance. The 5054** first parameter, szPage, is the size in bytes of the pages that must 5055** be allocated by the cache. szPage will not be a power of two. The 5056** second argument, bPurgeable, is true if the cache being created will 5057** be used to cache database pages read from a file stored on disk, or 5058** false if it is used for an in-memory database. The cache implementation 5059** does not have to do anything special based on the value of bPurgeable, 5060** it is purely advisory. 5061** 5062** The xCachesize() method may be called at any time by SQLite to set the 5063** suggested maximum cache-size (number of pages stored by) the cache 5064** instance passed as the first argument. This is the value configured using 5065** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, 5066** the implementation is not required to do anything special with this 5067** value, it is advisory only. 5068** 5069** The xPagecount() method should return the number of pages currently 5070** stored in the cache supplied as an argument. 5071** 5072** The xFetch() method is used to fetch a page and return a pointer to it. 5073** A 'page', in this context, is a buffer of szPage bytes aligned at an 5074** 8-byte boundary. The page to be fetched is determined by the key. The 5075** mimimum key value is 1. After it has been retrieved using xFetch, the page 5076** is considered to be pinned. 5077** 5078** If the requested page is already in the page cache, then a pointer to 5079** the cached buffer should be returned with its contents intact. If the 5080** page is not already in the cache, then the expected behaviour of the 5081** cache is determined by the value of the createFlag parameter passed 5082** to xFetch, according to the following table: 5083** 5084** <table border=1 width=85% align=center> 5085** <tr><th>createFlag<th>Expected Behaviour 5086** <tr><td>0<td>NULL should be returned. No new cache entry is created. 5087** <tr><td>1<td>If createFlag is set to 1, this indicates that 5088** SQLite is holding pinned pages that can be unpinned 5089** by writing their contents to the database file (a 5090** relatively expensive operation). In this situation the 5091** cache implementation has two choices: it can return NULL, 5092** in which case SQLite will attempt to unpin one or more 5093** pages before re-requesting the same page, or it can 5094** allocate a new page and return a pointer to it. If a new 5095** page is allocated, then the first sizeof(void*) bytes of 5096** it (at least) must be zeroed before it is returned. 5097** <tr><td>2<td>If createFlag is set to 2, then SQLite is not holding any 5098** pinned pages associated with the specific cache passed 5099** as the first argument to xFetch() that can be unpinned. The 5100** cache implementation should attempt to allocate a new 5101** cache entry and return a pointer to it. Again, the first 5102** sizeof(void*) bytes of the page should be zeroed before 5103** it is returned. If the xFetch() method returns NULL when 5104** createFlag==2, SQLite assumes that a memory allocation 5105** failed and returns SQLITE_NOMEM to the user. 5106** </table> 5107** 5108** xUnpin() is called by SQLite with a pointer to a currently pinned page 5109** as its second argument. If the third parameter, discard, is non-zero, 5110** then the page should be evicted from the cache. In this case SQLite 5111** assumes that the next time the page is retrieved from the cache using 5112** the xFetch() method, it will be zeroed. If the discard parameter is 5113** zero, then the page is considered to be unpinned. The cache implementation 5114** may choose to reclaim (free or recycle) unpinned pages at any time. 5115** SQLite assumes that next time the page is retrieved from the cache 5116** it will either be zeroed, or contain the same data that it did when it 5117** was unpinned. 5118** 5119** The cache is not required to perform any reference counting. A single 5120** call to xUnpin() unpins the page regardless of the number of prior calls 5121** to xFetch(). 5122** 5123** The xRekey() method is used to change the key value associated with the 5124** page passed as the second argument from oldKey to newKey. If the cache 5125** previously contains an entry associated with newKey, it should be 5126** discarded. Any prior cache entry associated with newKey is guaranteed not 5127** to be pinned. 5128** 5129** When SQLite calls the xTruncate() method, the cache must discard all 5130** existing cache entries with page numbers (keys) greater than or equal 5131** to the value of the iLimit parameter passed to xTruncate(). If any 5132** of these pages are pinned, they are implicitly unpinned, meaning that 5133** they can be safely discarded. 5134** 5135** The xDestroy() method is used to delete a cache allocated by xCreate(). 5136** All resources associated with the specified cache should be freed. After 5137** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 5138** handle invalid, and will not use it with any other sqlite3_pcache_methods 5139** functions. 5140*/ 5141typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 5142struct sqlite3_pcache_methods { 5143 void *pArg; 5144 int (*xInit)(void*); 5145 void (*xShutdown)(void*); 5146 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 5147 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 5148 int (*xPagecount)(sqlite3_pcache*); 5149 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 5150 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 5151 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 5152 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 5153 void (*xDestroy)(sqlite3_pcache*); 5154}; 5155 5156/* 5157** CAPI3REF: Online Backup Object 5158** EXPERIMENTAL 5159** 5160** The sqlite3_backup object records state information about an ongoing 5161** online backup operation. The sqlite3_backup object is created by 5162** a call to [sqlite3_backup_init()] and is destroyed by a call to 5163** [sqlite3_backup_finish()]. 5164** 5165** See Also: [Using the SQLite Online Backup API] 5166*/ 5167typedef struct sqlite3_backup sqlite3_backup; 5168 5169/* 5170** CAPI3REF: Online Backup API. 5171** EXPERIMENTAL 5172** 5173** This API is used to overwrite the contents of one database with that 5174** of another. It is useful either for creating backups of databases or 5175** for copying in-memory databases to or from persistent files. 5176** 5177** See Also: [Using the SQLite Online Backup API] 5178** 5179** Exclusive access is required to the destination database for the 5180** duration of the operation. However the source database is only 5181** read-locked while it is actually being read, it is not locked 5182** continuously for the entire operation. Thus, the backup may be 5183** performed on a live database without preventing other users from 5184** writing to the database for an extended period of time. 5185** 5186** To perform a backup operation: 5187** <ol> 5188** <li><b>sqlite3_backup_init()</b> is called once to initialize the 5189** backup, 5190** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 5191** the data between the two databases, and finally 5192** <li><b>sqlite3_backup_finish()</b> is called to release all resources 5193** associated with the backup operation. 5194** </ol> 5195** There should be exactly one call to sqlite3_backup_finish() for each 5196** successful call to sqlite3_backup_init(). 5197** 5198** <b>sqlite3_backup_init()</b> 5199** 5200** The first two arguments passed to [sqlite3_backup_init()] are the database 5201** handle associated with the destination database and the database name 5202** used to attach the destination database to the handle. The database name 5203** is "main" for the main database, "temp" for the temporary database, or 5204** the name specified as part of the [ATTACH] statement if the destination is 5205** an attached database. The third and fourth arguments passed to 5206** sqlite3_backup_init() identify the [database connection] 5207** and database name used 5208** to access the source database. The values passed for the source and 5209** destination [database connection] parameters must not be the same. 5210** 5211** If an error occurs within sqlite3_backup_init(), then NULL is returned 5212** and an error code and error message written into the [database connection] 5213** passed as the first argument. They may be retrieved using the 5214** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. 5215** Otherwise, if successful, a pointer to an [sqlite3_backup] object is 5216** returned. This pointer may be used with the sqlite3_backup_step() and 5217** sqlite3_backup_finish() functions to perform the specified backup 5218** operation. 5219** 5220** <b>sqlite3_backup_step()</b> 5221** 5222** Function [sqlite3_backup_step()] is used to copy up to nPage pages between 5223** the source and destination databases, where nPage is the value of the 5224** second parameter passed to sqlite3_backup_step(). If nPage is a negative 5225** value, all remaining source pages are copied. If the required pages are 5226** succesfully copied, but there are still more pages to copy before the 5227** backup is complete, it returns [SQLITE_OK]. If no error occured and there 5228** are no more pages to copy, then [SQLITE_DONE] is returned. If an error 5229** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and 5230** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 5231** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 5232** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 5233** 5234** As well as the case where the destination database file was opened for 5235** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if 5236** the destination is an in-memory database with a different page size 5237** from the source database. 5238** 5239** If sqlite3_backup_step() cannot obtain a required file-system lock, then 5240** the [sqlite3_busy_handler | busy-handler function] 5241** is invoked (if one is specified). If the 5242** busy-handler returns non-zero before the lock is available, then 5243** [SQLITE_BUSY] is returned to the caller. In this case the call to 5244** sqlite3_backup_step() can be retried later. If the source 5245** [database connection] 5246** is being used to write to the source database when sqlite3_backup_step() 5247** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this 5248** case the call to sqlite3_backup_step() can be retried later on. If 5249** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 5250** [SQLITE_READONLY] is returned, then 5251** there is no point in retrying the call to sqlite3_backup_step(). These 5252** errors are considered fatal. At this point the application must accept 5253** that the backup operation has failed and pass the backup operation handle 5254** to the sqlite3_backup_finish() to release associated resources. 5255** 5256** Following the first call to sqlite3_backup_step(), an exclusive lock is 5257** obtained on the destination file. It is not released until either 5258** sqlite3_backup_finish() is called or the backup operation is complete 5259** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time 5260** a call to sqlite3_backup_step() is made a [shared lock] is obtained on 5261** the source database file. This lock is released before the 5262** sqlite3_backup_step() call returns. Because the source database is not 5263** locked between calls to sqlite3_backup_step(), it may be modified mid-way 5264** through the backup procedure. If the source database is modified by an 5265** external process or via a database connection other than the one being 5266** used by the backup operation, then the backup will be transparently 5267** restarted by the next call to sqlite3_backup_step(). If the source 5268** database is modified by the using the same database connection as is used 5269** by the backup operation, then the backup database is transparently 5270** updated at the same time. 5271** 5272** <b>sqlite3_backup_finish()</b> 5273** 5274** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the 5275** application wishes to abandon the backup operation, the [sqlite3_backup] 5276** object should be passed to sqlite3_backup_finish(). This releases all 5277** resources associated with the backup operation. If sqlite3_backup_step() 5278** has not yet returned [SQLITE_DONE], then any active write-transaction on the 5279** destination database is rolled back. The [sqlite3_backup] object is invalid 5280** and may not be used following a call to sqlite3_backup_finish(). 5281** 5282** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error 5283** occurred, regardless or whether or not sqlite3_backup_step() was called 5284** a sufficient number of times to complete the backup operation. Or, if 5285** an out-of-memory condition or IO error occured during a call to 5286** sqlite3_backup_step() then [SQLITE_NOMEM] or an 5287** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code 5288** is returned. In this case the error code and an error message are 5289** written to the destination [database connection]. 5290** 5291** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is 5292** not a permanent error and does not affect the return value of 5293** sqlite3_backup_finish(). 5294** 5295** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> 5296** 5297** Each call to sqlite3_backup_step() sets two values stored internally 5298** by an [sqlite3_backup] object. The number of pages still to be backed 5299** up, which may be queried by sqlite3_backup_remaining(), and the total 5300** number of pages in the source database file, which may be queried by 5301** sqlite3_backup_pagecount(). 5302** 5303** The values returned by these functions are only updated by 5304** sqlite3_backup_step(). If the source database is modified during a backup 5305** operation, then the values are not updated to account for any extra 5306** pages that need to be updated or the size of the source database file 5307** changing. 5308** 5309** <b>Concurrent Usage of Database Handles</b> 5310** 5311** The source [database connection] may be used by the application for other 5312** purposes while a backup operation is underway or being initialized. 5313** If SQLite is compiled and configured to support threadsafe database 5314** connections, then the source database connection may be used concurrently 5315** from within other threads. 5316** 5317** However, the application must guarantee that the destination database 5318** connection handle is not passed to any other API (by any thread) after 5319** sqlite3_backup_init() is called and before the corresponding call to 5320** sqlite3_backup_finish(). Unfortunately SQLite does not currently check 5321** for this, if the application does use the destination [database connection] 5322** for some other purpose during a backup operation, things may appear to 5323** work correctly but in fact be subtly malfunctioning. Use of the 5324** destination database connection while a backup is in progress might 5325** also cause a mutex deadlock. 5326** 5327** Furthermore, if running in [shared cache mode], the application must 5328** guarantee that the shared cache used by the destination database 5329** is not accessed while the backup is running. In practice this means 5330** that the application must guarantee that the file-system file being 5331** backed up to is not accessed by any connection within the process, 5332** not just the specific connection that was passed to sqlite3_backup_init(). 5333** 5334** The [sqlite3_backup] object itself is partially threadsafe. Multiple 5335** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 5336** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 5337** APIs are not strictly speaking threadsafe. If they are invoked at the 5338** same time as another thread is invoking sqlite3_backup_step() it is 5339** possible that they return invalid values. 5340*/ 5341sqlite3_backup *sqlite3_backup_init( 5342 sqlite3 *pDest, /* Destination database handle */ 5343 const char *zDestName, /* Destination database name */ 5344 sqlite3 *pSource, /* Source database handle */ 5345 const char *zSourceName /* Source database name */ 5346); 5347int sqlite3_backup_step(sqlite3_backup *p, int nPage); 5348int sqlite3_backup_finish(sqlite3_backup *p); 5349int sqlite3_backup_remaining(sqlite3_backup *p); 5350int sqlite3_backup_pagecount(sqlite3_backup *p); 5351 5352/* 5353** Undo the hack that converts floating point types to integer for 5354** builds on processors without floating point support. 5355*/ 5356#ifdef SQLITE_OMIT_FLOATING_POINT 5357# undef double 5358#endif 5359 5360#ifdef __cplusplus 5361} /* End of the 'extern "C"' block */ 5362#endif 5363#endif 5364