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 1.304 2008/04/10 17:14:07 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** Make sure these symbols where not defined by some previous header 56** file. 57*/ 58#ifdef SQLITE_VERSION 59# undef SQLITE_VERSION 60#endif 61#ifdef SQLITE_VERSION_NUMBER 62# undef SQLITE_VERSION_NUMBER 63#endif 64 65/* 66** CAPI3REF: Compile-Time Library Version Numbers {F10010} 67** 68** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in 69** the sqlite3.h file specify the version of SQLite with which 70** that header file is associated. 71** 72** The "version" of SQLite is a string of the form "X.Y.Z". 73** The phrase "alpha" or "beta" might be appended after the Z. 74** The X value is major version number always 3 in SQLite3. 75** The X value only changes when backwards compatibility is 76** broken and we intend to never break 77** backwards compatibility. The Y value is the minor version 78** number and only changes when 79** there are major feature enhancements that are forwards compatible 80** but not backwards compatible. The Z value is release number 81** and is incremented with 82** each release but resets back to 0 when Y is incremented. 83** 84** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. 85** 86** INVARIANTS: 87** 88** {F10011} The SQLITE_VERSION #define in the sqlite3.h header file 89** evaluates to a string literal that is the SQLite version 90** with which the header file is associated. 91** 92** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer 93** with the value (X*1000000 + Y*1000 + Z) where X, Y, and 94** Z are the major version, minor version, and release number. 95*/ 96#define SQLITE_VERSION "--VERS--" 97#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 98 99/* 100** CAPI3REF: Run-Time Library Version Numbers {F10020} 101** KEYWORDS: sqlite3_version 102** 103** These features provide the same information as the [SQLITE_VERSION] 104** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated 105** with the library instead of the header file. Cautious programmers might 106** include a check in their application to verify that 107** sqlite3_libversion_number() always returns the value 108** [SQLITE_VERSION_NUMBER]. 109** 110** The sqlite3_libversion() function returns the same information as is 111** in the sqlite3_version[] string constant. The function is provided 112** for use in DLLs since DLL users usually do not have direct access to string 113** constants within the DLL. 114** 115** INVARIANTS: 116** 117** {F10021} The [sqlite3_libversion_number()] interface returns an integer 118** equal to [SQLITE_VERSION_NUMBER]. 119** 120** {F10022} The [sqlite3_version] string constant contains the text of the 121** [SQLITE_VERSION] string. 122** 123** {F10023} The [sqlite3_libversion()] function returns 124** a pointer to the [sqlite3_version] string constant. 125*/ 126SQLITE_EXTERN const char sqlite3_version[]; 127const char *sqlite3_libversion(void); 128int sqlite3_libversion_number(void); 129 130/* 131** CAPI3REF: Test To See If The Library Is Threadsafe {F10100} 132** 133** SQLite can be compiled with or without mutexes. When 134** the SQLITE_THREADSAFE C preprocessor macro is true, mutexes 135** are enabled and SQLite is threadsafe. When that macro is false, 136** the mutexes are omitted. Without the mutexes, it is not safe 137** to use SQLite from more than one thread. 138** 139** There is a measurable performance penalty for enabling mutexes. 140** So if speed is of utmost importance, it makes sense to disable 141** the mutexes. But for maximum safety, mutexes should be enabled. 142** The default behavior is for mutexes to be enabled. 143** 144** This interface can be used by a program to make sure that the 145** version of SQLite that it is linking against was compiled with 146** the desired setting of the SQLITE_THREADSAFE macro. 147** 148** INVARIANTS: 149** 150** {F10101} The [sqlite3_threadsafe()] function returns nonzero if 151** SQLite was compiled with its mutexes enabled or zero 152** if SQLite was compiled with mutexes disabled. 153*/ 154int sqlite3_threadsafe(void); 155 156/* 157** CAPI3REF: Database Connection Handle {F12000} 158** KEYWORDS: {database connection} 159** 160** Each open SQLite database is represented by pointer to an instance of the 161** opaque structure named "sqlite3". It is useful to think of an sqlite3 162** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 163** [sqlite3_open_v2()] interfaces are its constructors 164** and [sqlite3_close()] is its destructor. There are many other interfaces 165** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and 166** [sqlite3_busy_timeout()] to name but three) that are methods on this 167** object. 168*/ 169typedef struct sqlite3 sqlite3; 170 171 172/* 173** CAPI3REF: 64-Bit Integer Types {F10200} 174** KEYWORDS: sqlite_int64 sqlite_uint64 175** 176** Because there is no cross-platform way to specify 64-bit integer types 177** SQLite includes typedefs for 64-bit signed and unsigned integers. 178** 179** The sqlite3_int64 and sqlite3_uint64 are the preferred type 180** definitions. The sqlite_int64 and sqlite_uint64 types are 181** supported for backwards compatibility only. 182** 183** INVARIANTS: 184** 185** {F10201} The [sqlite_int64] and [sqlite3_int64] types specify a 186** 64-bit signed integer. 187** 188** {F10202} The [sqlite_uint64] and [sqlite3_uint64] types specify 189** a 64-bit unsigned integer. 190*/ 191#ifdef SQLITE_INT64_TYPE 192 typedef SQLITE_INT64_TYPE sqlite_int64; 193 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 194#elif defined(_MSC_VER) || defined(__BORLANDC__) 195 typedef __int64 sqlite_int64; 196 typedef unsigned __int64 sqlite_uint64; 197#else 198 typedef long long int sqlite_int64; 199 typedef unsigned long long int sqlite_uint64; 200#endif 201typedef sqlite_int64 sqlite3_int64; 202typedef sqlite_uint64 sqlite3_uint64; 203 204/* 205** If compiling for a processor that lacks floating point support, 206** substitute integer for floating-point 207*/ 208#ifdef SQLITE_OMIT_FLOATING_POINT 209# define double sqlite3_int64 210#endif 211 212/* 213** CAPI3REF: Closing A Database Connection {F12010} 214** 215** This routine is the destructor for the [sqlite3] object. 216** 217** Applications should [sqlite3_finalize | finalize] all 218** [prepared statements] and 219** [sqlite3_blob_close | close] all [sqlite3_blob | BLOBs] 220** associated with the [sqlite3] object prior 221** to attempting to close the [sqlite3] object. 222** 223** <todo>What happens to pending transactions? Are they 224** rolled back, or abandoned?</todo> 225** 226** INVARIANTS: 227** 228** {F12011} The [sqlite3_close()] interface destroys an [sqlite3] object 229** allocated by a prior call to [sqlite3_open()], 230** [sqlite3_open16()], or [sqlite3_open_v2()]. 231** 232** {F12012} The [sqlite3_close()] function releases all memory used by the 233** connection and closes all open files. 234** 235** {F12013} If the database connection contains 236** [prepared statements] that have not been 237** finalized by [sqlite3_finalize()], then [sqlite3_close()] 238** returns [SQLITE_BUSY] and leaves the connection open. 239** 240** {F12014} Giving sqlite3_close() a NULL pointer is a harmless no-op. 241** 242** LIMITATIONS: 243** 244** {U12015} The parameter to [sqlite3_close()] must be an [sqlite3] object 245** pointer previously obtained from [sqlite3_open()] or the 246** equivalent, or NULL. 247** 248** {U12016} The parameter to [sqlite3_close()] must not have been previously 249** closed. 250*/ 251int sqlite3_close(sqlite3 *); 252 253/* 254** The type for a callback function. 255** This is legacy and deprecated. It is included for historical 256** compatibility and is not documented. 257*/ 258typedef int (*sqlite3_callback)(void*,int,char**, char**); 259 260/* 261** CAPI3REF: One-Step Query Execution Interface {F12100} 262** 263** The sqlite3_exec() interface is a convenient way of running 264** one or more SQL statements without a lot of C code. The 265** SQL statements are passed in as the second parameter to 266** sqlite3_exec(). The statements are evaluated one by one 267** until either an error or an interrupt is encountered or 268** until they are all done. The 3rd parameter is an optional 269** callback that is invoked once for each row of any query results 270** produced by the SQL statements. The 5th parameter tells where 271** to write any error messages. 272** 273** The sqlite3_exec() interface is implemented in terms of 274** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 275** The sqlite3_exec() routine does nothing that cannot be done 276** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 277** The sqlite3_exec() is just a convenient wrapper. 278** 279** INVARIANTS: 280** 281** {F12101} The [sqlite3_exec()] interface evaluates zero or more UTF-8 282** encoded, semicolon-separated, SQL statements in the 283** zero-terminated string of its 2nd parameter within the 284** context of the [sqlite3] object given in the 1st parameter. 285** 286** {F12104} The return value of [sqlite3_exec()] is SQLITE_OK if all 287** SQL statements run successfully. 288** 289** {F12105} The return value of [sqlite3_exec()] is an appropriate 290** non-zero error code if any SQL statement fails. 291** 292** {F12107} If one or more of the SQL statements handed to [sqlite3_exec()] 293** return results and the 3rd parameter is not NULL, then 294** the callback function specified by the 3rd parameter is 295** invoked once for each row of result. 296** 297** {F12110} If the callback returns a non-zero value then [sqlite3_exec()] 298** will aborted the SQL statement it is currently evaluating, 299** skip all subsequent SQL statements, and return [SQLITE_ABORT]. 300** <todo>What happens to *errmsg here? Does the result code for 301** sqlite3_errcode() get set?</todo> 302** 303** {F12113} The [sqlite3_exec()] routine will pass its 4th parameter through 304** as the 1st parameter of the callback. 305** 306** {F12116} The [sqlite3_exec()] routine sets the 2nd parameter of its 307** callback to be the number of columns in the current row of 308** result. 309** 310** {F12119} The [sqlite3_exec()] routine sets the 3rd parameter of its 311** callback to be an array of pointers to strings holding the 312** values for each column in the current result set row as 313** obtained from [sqlite3_column_text()]. 314** 315** {F12122} The [sqlite3_exec()] routine sets the 4th parameter of its 316** callback to be an array of pointers to strings holding the 317** names of result columns as obtained from [sqlite3_column_name()]. 318** 319** {F12125} If the 3rd parameter to [sqlite3_exec()] is NULL then 320** [sqlite3_exec()] never invokes a callback. All query 321** results are silently discarded. 322** 323** {F12128} If an error occurs while parsing or evaluating any of the SQL 324** statements handed to [sqlite3_exec()] then [sqlite3_exec()] will 325** return an [error code] other than [SQLITE_OK]. 326** 327** {F12131} If an error occurs while parsing or evaluating any of the SQL 328** handed to [sqlite3_exec()] and if the 5th parameter (errmsg) 329** to [sqlite3_exec()] is not NULL, then an error message is 330** allocated using the equivalent of [sqlite3_mprintf()] and 331** *errmsg is made to point to that message. 332** 333** {F12134} The [sqlite3_exec()] routine does not change the value of 334** *errmsg if errmsg is NULL or if there are no errors. 335** 336** {F12137} The [sqlite3_exec()] function sets the error code and message 337** accessible via [sqlite3_errcode()], [sqlite3_errmsg()], and 338** [sqlite3_errmsg16()]. 339** 340** LIMITATIONS: 341** 342** {U12141} The first parameter to [sqlite3_exec()] must be an valid and open 343** [database connection]. 344** 345** {U12142} The database connection must not be closed while 346** [sqlite3_exec()] is running. 347** 348** {U12143} The calling function is should use [sqlite3_free()] to free 349** the memory that *errmsg is left pointing at once the error 350** message is no longer needed. 351** 352** {U12145} The SQL statement text in the 2nd parameter to [sqlite3_exec()] 353** must remain unchanged while [sqlite3_exec()] is running. 354*/ 355int sqlite3_exec( 356 sqlite3*, /* An open database */ 357 const char *sql, /* SQL to be evaluted */ 358 int (*callback)(void*,int,char**,char**), /* Callback function */ 359 void *, /* 1st argument to callback */ 360 char **errmsg /* Error msg written here */ 361); 362 363/* 364** CAPI3REF: Result Codes {F10210} 365** KEYWORDS: SQLITE_OK {error code} {error codes} 366** 367** Many SQLite functions return an integer result code from the set shown 368** here in order to indicates success or failure. 369** 370** See also: [SQLITE_IOERR_READ | extended result codes] 371*/ 372#define SQLITE_OK 0 /* Successful result */ 373/* beginning-of-error-codes */ 374#define SQLITE_ERROR 1 /* SQL error or missing database */ 375#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 376#define SQLITE_PERM 3 /* Access permission denied */ 377#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 378#define SQLITE_BUSY 5 /* The database file is locked */ 379#define SQLITE_LOCKED 6 /* A table in the database is locked */ 380#define SQLITE_NOMEM 7 /* A malloc() failed */ 381#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 382#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 383#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 384#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 385#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 386#define SQLITE_FULL 13 /* Insertion failed because database is full */ 387#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 388#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 389#define SQLITE_EMPTY 16 /* Database is empty */ 390#define SQLITE_SCHEMA 17 /* The database schema changed */ 391#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 392#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 393#define SQLITE_MISMATCH 20 /* Data type mismatch */ 394#define SQLITE_MISUSE 21 /* Library used incorrectly */ 395#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 396#define SQLITE_AUTH 23 /* Authorization denied */ 397#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 398#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 399#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 400#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 401#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 402/* end-of-error-codes */ 403 404/* 405** CAPI3REF: Extended Result Codes {F10220} 406** KEYWORDS: {extended error code} {extended error codes} 407** KEYWORDS: {extended result codes} 408** 409** In its default configuration, SQLite API routines return one of 26 integer 410** [SQLITE_OK | result codes]. However, experience has shown that 411** many of these result codes are too course-grained. They do not provide as 412** much information about problems as programmers might like. In an effort to 413** address this, newer versions of SQLite (version 3.3.8 and later) include 414** support for additional result codes that provide more detailed information 415** about errors. The extended result codes are enabled or disabled 416** for each database connection using the [sqlite3_extended_result_codes()] 417** API. 418** 419** Some of the available extended result codes are listed here. 420** One may expect the number of extended result codes will be expand 421** over time. Software that uses extended result codes should expect 422** to see new result codes in future releases of SQLite. 423** 424** The SQLITE_OK result code will never be extended. It will always 425** be exactly zero. 426** 427** INVARIANTS: 428** 429** {F10223} The symbolic name for an extended result code always contains 430** a related primary result code as a prefix. 431** 432** {F10224} Primary result code names contain a single "_" character. 433** 434** {F10225} Extended result code names contain two or more "_" characters. 435** 436** {F10226} The numeric value of an extended result code contains the 437** numeric value of its corresponding primary result code in 438** its least significant 8 bits. 439*/ 440#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 441#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 442#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 443#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 444#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 445#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 446#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 447#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 448#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 449#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 450#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 451#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 452 453/* 454** CAPI3REF: Flags For File Open Operations {F10230} 455** 456** These bit values are intended for use in the 457** 3rd parameter to the [sqlite3_open_v2()] interface and 458** in the 4th parameter to the xOpen method of the 459** [sqlite3_vfs] object. 460*/ 461#define SQLITE_OPEN_READONLY 0x00000001 462#define SQLITE_OPEN_READWRITE 0x00000002 463#define SQLITE_OPEN_CREATE 0x00000004 464#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 465#define SQLITE_OPEN_EXCLUSIVE 0x00000010 466#define SQLITE_OPEN_MAIN_DB 0x00000100 467#define SQLITE_OPEN_TEMP_DB 0x00000200 468#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 469#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 470#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 471#define SQLITE_OPEN_SUBJOURNAL 0x00002000 472#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 473 474/* 475** CAPI3REF: Device Characteristics {F10240} 476** 477** The xDeviceCapabilities method of the [sqlite3_io_methods] 478** object returns an integer which is a vector of the these 479** bit values expressing I/O characteristics of the mass storage 480** device that holds the file that the [sqlite3_io_methods] 481** refers to. 482** 483** The SQLITE_IOCAP_ATOMIC property means that all writes of 484** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 485** mean that writes of blocks that are nnn bytes in size and 486** are aligned to an address which is an integer multiple of 487** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 488** that when data is appended to a file, the data is appended 489** first then the size of the file is extended, never the other 490** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 491** information is written to disk in the same order as calls 492** to xWrite(). 493*/ 494#define SQLITE_IOCAP_ATOMIC 0x00000001 495#define SQLITE_IOCAP_ATOMIC512 0x00000002 496#define SQLITE_IOCAP_ATOMIC1K 0x00000004 497#define SQLITE_IOCAP_ATOMIC2K 0x00000008 498#define SQLITE_IOCAP_ATOMIC4K 0x00000010 499#define SQLITE_IOCAP_ATOMIC8K 0x00000020 500#define SQLITE_IOCAP_ATOMIC16K 0x00000040 501#define SQLITE_IOCAP_ATOMIC32K 0x00000080 502#define SQLITE_IOCAP_ATOMIC64K 0x00000100 503#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 504#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 505 506/* 507** CAPI3REF: File Locking Levels {F10250} 508** 509** SQLite uses one of these integer values as the second 510** argument to calls it makes to the xLock() and xUnlock() methods 511** of an [sqlite3_io_methods] object. 512*/ 513#define SQLITE_LOCK_NONE 0 514#define SQLITE_LOCK_SHARED 1 515#define SQLITE_LOCK_RESERVED 2 516#define SQLITE_LOCK_PENDING 3 517#define SQLITE_LOCK_EXCLUSIVE 4 518 519/* 520** CAPI3REF: Synchronization Type Flags {F10260} 521** 522** When SQLite invokes the xSync() method of an 523** [sqlite3_io_methods] object it uses a combination of 524** these integer values as the second argument. 525** 526** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 527** sync operation only needs to flush data to mass storage. Inode 528** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 529** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 530** to use Mac OS-X style fullsync instead of fsync(). 531*/ 532#define SQLITE_SYNC_NORMAL 0x00002 533#define SQLITE_SYNC_FULL 0x00003 534#define SQLITE_SYNC_DATAONLY 0x00010 535 536 537/* 538** CAPI3REF: OS Interface Open File Handle {F11110} 539** 540** An [sqlite3_file] object represents an open file in the OS 541** interface layer. Individual OS interface implementations will 542** want to subclass this object by appending additional fields 543** for their own use. The pMethods entry is a pointer to an 544** [sqlite3_io_methods] object that defines methods for performing 545** I/O operations on the open file. 546*/ 547typedef struct sqlite3_file sqlite3_file; 548struct sqlite3_file { 549 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 550}; 551 552/* 553** CAPI3REF: OS Interface File Virtual Methods Object {F11120} 554** 555** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to 556** an instance of this object. This object defines the 557** methods used to perform various operations against the open file. 558** 559** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 560** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 561* The second choice is an 562** OS-X style fullsync. The SQLITE_SYNC_DATA flag may be ORed in to 563** indicate that only the data of the file and not its inode needs to be 564** synced. 565** 566** The integer values to xLock() and xUnlock() are one of 567** <ul> 568** <li> [SQLITE_LOCK_NONE], 569** <li> [SQLITE_LOCK_SHARED], 570** <li> [SQLITE_LOCK_RESERVED], 571** <li> [SQLITE_LOCK_PENDING], or 572** <li> [SQLITE_LOCK_EXCLUSIVE]. 573** </ul> 574** xLock() increases the lock. xUnlock() decreases the lock. 575** The xCheckReservedLock() method looks 576** to see if any database connection, either in this 577** process or in some other process, is holding an RESERVED, 578** PENDING, or EXCLUSIVE lock on the file. It returns true 579** if such a lock exists and false if not. 580** 581** The xFileControl() method is a generic interface that allows custom 582** VFS implementations to directly control an open file using the 583** [sqlite3_file_control()] interface. The second "op" argument 584** is an integer opcode. The third 585** argument is a generic pointer which is intended to be a pointer 586** to a structure that may contain arguments or space in which to 587** write return values. Potential uses for xFileControl() might be 588** functions to enable blocking locks with timeouts, to change the 589** locking strategy (for example to use dot-file locks), to inquire 590** about the status of a lock, or to break stale locks. The SQLite 591** core reserves opcodes less than 100 for its own use. 592** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 593** Applications that define a custom xFileControl method should use opcodes 594** greater than 100 to avoid conflicts. 595** 596** The xSectorSize() method returns the sector size of the 597** device that underlies the file. The sector size is the 598** minimum write that can be performed without disturbing 599** other bytes in the file. The xDeviceCharacteristics() 600** method returns a bit vector describing behaviors of the 601** underlying device: 602** 603** <ul> 604** <li> [SQLITE_IOCAP_ATOMIC] 605** <li> [SQLITE_IOCAP_ATOMIC512] 606** <li> [SQLITE_IOCAP_ATOMIC1K] 607** <li> [SQLITE_IOCAP_ATOMIC2K] 608** <li> [SQLITE_IOCAP_ATOMIC4K] 609** <li> [SQLITE_IOCAP_ATOMIC8K] 610** <li> [SQLITE_IOCAP_ATOMIC16K] 611** <li> [SQLITE_IOCAP_ATOMIC32K] 612** <li> [SQLITE_IOCAP_ATOMIC64K] 613** <li> [SQLITE_IOCAP_SAFE_APPEND] 614** <li> [SQLITE_IOCAP_SEQUENTIAL] 615** </ul> 616** 617** The SQLITE_IOCAP_ATOMIC property means that all writes of 618** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 619** mean that writes of blocks that are nnn bytes in size and 620** are aligned to an address which is an integer multiple of 621** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 622** that when data is appended to a file, the data is appended 623** first then the size of the file is extended, never the other 624** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 625** information is written to disk in the same order as calls 626** to xWrite(). 627*/ 628typedef struct sqlite3_io_methods sqlite3_io_methods; 629struct sqlite3_io_methods { 630 int iVersion; 631 int (*xClose)(sqlite3_file*); 632 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 633 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 634 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 635 int (*xSync)(sqlite3_file*, int flags); 636 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 637 int (*xLock)(sqlite3_file*, int); 638 int (*xUnlock)(sqlite3_file*, int); 639 int (*xCheckReservedLock)(sqlite3_file*); 640 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 641 int (*xSectorSize)(sqlite3_file*); 642 int (*xDeviceCharacteristics)(sqlite3_file*); 643 /* Additional methods may be added in future releases */ 644}; 645 646/* 647** CAPI3REF: Standard File Control Opcodes {F11310} 648** 649** These integer constants are opcodes for the xFileControl method 650** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()] 651** interface. 652** 653** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 654** opcode causes the xFileControl method to write the current state of 655** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 656** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 657** into an integer that the pArg argument points to. This capability 658** is used during testing and only needs to be supported when SQLITE_TEST 659** is defined. 660*/ 661#define SQLITE_FCNTL_LOCKSTATE 1 662 663/* 664** CAPI3REF: Mutex Handle {F17110} 665** 666** The mutex module within SQLite defines [sqlite3_mutex] to be an 667** abstract type for a mutex object. The SQLite core never looks 668** at the internal representation of an [sqlite3_mutex]. It only 669** deals with pointers to the [sqlite3_mutex] object. 670** 671** Mutexes are created using [sqlite3_mutex_alloc()]. 672*/ 673typedef struct sqlite3_mutex sqlite3_mutex; 674 675/* 676** CAPI3REF: OS Interface Object {F11140} 677** 678** An instance of this object defines the interface between the 679** SQLite core and the underlying operating system. The "vfs" 680** in the name of the object stands for "virtual file system". 681** 682** The iVersion field is initially 1 but may be larger for future 683** versions of SQLite. Additional fields may be appended to this 684** object when the iVersion value is increased. 685** 686** The szOsFile field is the size of the subclassed [sqlite3_file] 687** structure used by this VFS. mxPathname is the maximum length of 688** a pathname in this VFS. 689** 690** Registered sqlite3_vfs objects are kept on a linked list formed by 691** the pNext pointer. The [sqlite3_vfs_register()] 692** and [sqlite3_vfs_unregister()] interfaces manage this list 693** in a thread-safe way. The [sqlite3_vfs_find()] interface 694** searches the list. 695** 696** The pNext field is the only field in the sqlite3_vfs 697** structure that SQLite will ever modify. SQLite will only access 698** or modify this field while holding a particular static mutex. 699** The application should never modify anything within the sqlite3_vfs 700** object once the object has been registered. 701** 702** The zName field holds the name of the VFS module. The name must 703** be unique across all VFS modules. 704** 705** {F11141} SQLite will guarantee that the zFilename string passed to 706** xOpen() is a full pathname as generated by xFullPathname() and 707** that the string will be valid and unchanged until xClose() is 708** called. {END} So the [sqlite3_file] can store a pointer to the 709** filename if it needs to remember the filename for some reason. 710** 711** {F11142} The flags argument to xOpen() includes all bits set in 712** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 713** or [sqlite3_open16()] is used, then flags includes at least 714** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END} 715** If xOpen() opens a file read-only then it sets *pOutFlags to 716** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be 717** set. 718** 719** {F11143} SQLite will also add one of the following flags to the xOpen() 720** call, depending on the object being opened: 721** 722** <ul> 723** <li> [SQLITE_OPEN_MAIN_DB] 724** <li> [SQLITE_OPEN_MAIN_JOURNAL] 725** <li> [SQLITE_OPEN_TEMP_DB] 726** <li> [SQLITE_OPEN_TEMP_JOURNAL] 727** <li> [SQLITE_OPEN_TRANSIENT_DB] 728** <li> [SQLITE_OPEN_SUBJOURNAL] 729** <li> [SQLITE_OPEN_MASTER_JOURNAL] 730** </ul> {END} 731** 732** The file I/O implementation can use the object type flags to 733** changes the way it deals with files. For example, an application 734** that does not care about crash recovery or rollback might make 735** the open of a journal file a no-op. Writes to this journal would 736** also be no-ops, and any attempt to read the journal would return 737** SQLITE_IOERR. Or the implementation might recognize that a database 738** file will be doing page-aligned sector reads and writes in a random 739** order and set up its I/O subsystem accordingly. 740** 741** SQLite might also add one of the following flags to the xOpen 742** method: 743** 744** <ul> 745** <li> [SQLITE_OPEN_DELETEONCLOSE] 746** <li> [SQLITE_OPEN_EXCLUSIVE] 747** </ul> 748** 749** {F11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 750** deleted when it is closed. {F11146} The [SQLITE_OPEN_DELETEONCLOSE] 751** will be set for TEMP databases, journals and for subjournals. 752** {F11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 753** for exclusive access. This flag is set for all files except 754** for the main database file. {END} 755** 756** {F11148} At least szOsFile bytes of memory are allocated by SQLite 757** to hold the [sqlite3_file] structure passed as the third 758** argument to xOpen. {END} The xOpen method does not have to 759** allocate the structure; it should just fill it in. 760** 761** {F11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 762** to test for the existance of a file, 763** or [SQLITE_ACCESS_READWRITE] to test to see 764** if a file is readable and writable, or [SQLITE_ACCESS_READ] 765** to test to see if a file is at least readable. {END} The file can be a 766** directory. 767** 768** {F11150} SQLite will always allocate at least mxPathname+1 bytes for 769** the output buffers for xGetTempname and xFullPathname. {F11151} The exact 770** size of the output buffer is also passed as a parameter to both 771** methods. {END} If the output buffer is not large enough, SQLITE_CANTOPEN 772** should be returned. As this is handled as a fatal error by SQLite, 773** vfs implementations should endeavor to prevent this by setting 774** mxPathname to a sufficiently large value. 775** 776** The xRandomness(), xSleep(), and xCurrentTime() interfaces 777** are not strictly a part of the filesystem, but they are 778** included in the VFS structure for completeness. 779** The xRandomness() function attempts to return nBytes bytes 780** of good-quality randomness into zOut. The return value is 781** the actual number of bytes of randomness obtained. The 782** xSleep() method causes the calling thread to sleep for at 783** least the number of microseconds given. The xCurrentTime() 784** method returns a Julian Day Number for the current date and 785** time. 786*/ 787typedef struct sqlite3_vfs sqlite3_vfs; 788struct sqlite3_vfs { 789 int iVersion; /* Structure version number */ 790 int szOsFile; /* Size of subclassed sqlite3_file */ 791 int mxPathname; /* Maximum file pathname length */ 792 sqlite3_vfs *pNext; /* Next registered VFS */ 793 const char *zName; /* Name of this virtual file system */ 794 void *pAppData; /* Pointer to application-specific data */ 795 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 796 int flags, int *pOutFlags); 797 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 798 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags); 799 int (*xGetTempname)(sqlite3_vfs*, int nOut, char *zOut); 800 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 801 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 802 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 803 void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol); 804 void (*xDlClose)(sqlite3_vfs*, void*); 805 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 806 int (*xSleep)(sqlite3_vfs*, int microseconds); 807 int (*xCurrentTime)(sqlite3_vfs*, double*); 808 /* New fields may be appended in figure versions. The iVersion 809 ** value will increment whenever this happens. */ 810}; 811 812/* 813** CAPI3REF: Flags for the xAccess VFS method {F11190} 814** 815** {F11191} These integer constants can be used as the third parameter to 816** the xAccess method of an [sqlite3_vfs] object. {END} They determine 817** what kind of permissions the xAccess method is 818** looking for. {F11192} With SQLITE_ACCESS_EXISTS, the xAccess method 819** simply checks to see if the file exists. {F11193} With 820** SQLITE_ACCESS_READWRITE, the xAccess method checks to see 821** if the file is both readable and writable. {F11194} With 822** SQLITE_ACCESS_READ the xAccess method 823** checks to see if the file is readable. 824*/ 825#define SQLITE_ACCESS_EXISTS 0 826#define SQLITE_ACCESS_READWRITE 1 827#define SQLITE_ACCESS_READ 2 828 829/* 830** CAPI3REF: Enable Or Disable Extended Result Codes {F12200} 831** 832** The sqlite3_extended_result_codes() routine enables or disables the 833** [SQLITE_IOERR_READ | extended result codes] feature of SQLite. 834** The extended result codes are disabled by default for historical 835** compatibility. 836** 837** INVARIANTS: 838** 839** {F12201} Each new [database connection] has the 840** [extended result codes] feature 841** disabled by default. 842** 843** {F12202} The [sqlite3_extended_result_codes(D,F)] interface will enable 844** [extended result codes] for the 845** [database connection] D if the F parameter 846** is true, or disable them if F is false. 847*/ 848int sqlite3_extended_result_codes(sqlite3*, int onoff); 849 850/* 851** CAPI3REF: Last Insert Rowid {F12220} 852** 853** Each entry in an SQLite table has a unique 64-bit signed 854** integer key called the "rowid". The rowid is always available 855** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 856** names are not also used by explicitly declared columns. If 857** the table has a column of type INTEGER PRIMARY KEY then that column 858** is another alias for the rowid. 859** 860** This routine returns the rowid of the most recent 861** successful INSERT into the database from the database connection 862** shown in the first argument. If no successful inserts 863** have ever occurred on this database connection, zero is returned. 864** 865** If an INSERT occurs within a trigger, then the rowid of the 866** inserted row is returned by this routine as long as the trigger 867** is running. But once the trigger terminates, the value returned 868** by this routine reverts to the last value inserted before the 869** trigger fired. 870** 871** An INSERT that fails due to a constraint violation is not a 872** successful insert and does not change the value returned by this 873** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 874** and INSERT OR ABORT make no changes to the return value of this 875** routine when their insertion fails. When INSERT OR REPLACE 876** encounters a constraint violation, it does not fail. The 877** INSERT continues to completion after deleting rows that caused 878** the constraint problem so INSERT OR REPLACE will always change 879** the return value of this interface. 880** 881** For the purposes of this routine, an insert is considered to 882** be successful even if it is subsequently rolled back. 883** 884** INVARIANTS: 885** 886** {F12221} The [sqlite3_last_insert_rowid()] function returns the 887** rowid of the most recent successful insert done 888** on the same database connection and within the same 889** trigger context, or zero if there have 890** been no qualifying inserts on that connection. 891** 892** {F12223} The [sqlite3_last_insert_rowid()] function returns 893** same value when called from the same trigger context 894** immediately before and after a ROLLBACK. 895** 896** LIMITATIONS: 897** 898** {U12232} If a separate thread does a new insert on the same 899** database connection while the [sqlite3_last_insert_rowid()] 900** function is running and thus changes the last insert rowid, 901** then the value returned by [sqlite3_last_insert_rowid()] is 902** unpredictable and might not equal either the old or the new 903** last insert rowid. 904*/ 905sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 906 907/* 908** CAPI3REF: Count The Number Of Rows Modified {F12240} 909** 910** This function returns the number of database rows that were changed 911** or inserted or deleted by the most recently completed SQL statement 912** on the connection specified by the first parameter. Only 913** changes that are directly specified by the INSERT, UPDATE, or 914** DELETE statement are counted. Auxiliary changes caused by 915** triggers are not counted. Use the [sqlite3_total_changes()] function 916** to find the total number of changes including changes caused by triggers. 917** 918** A "row change" is a change to a single row of a single table 919** caused by an INSERT, DELETE, or UPDATE statement. Rows that 920** are changed as side effects of REPLACE constraint resolution, 921** rollback, ABORT processing, DROP TABLE, or by any other 922** mechanisms do not count as direct row changes. 923** 924** A "trigger context" is a scope of execution that begins and 925** ends with the script of a trigger. Most SQL statements are 926** evaluated outside of any trigger. This is the "top level" 927** trigger context. If a trigger fires from the top level, a 928** new trigger context is entered for the duration of that one 929** trigger. Subtriggers create subcontexts for their duration. 930** 931** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 932** not create a new trigger context. 933** 934** This function returns the number of direct row changes in the 935** most recent INSERT, UPDATE, or DELETE statement within the same 936** trigger context. 937** 938** So when called from the top level, this function returns the 939** number of changes in the most recent INSERT, UPDATE, or DELETE 940** that also occurred at the top level. 941** Within the body of a trigger, the sqlite3_changes() interface 942** can be called to find the number of 943** changes in the most recently completed INSERT, UPDATE, or DELETE 944** statement within the body of the same trigger. 945** However, the number returned does not include in changes 946** caused by subtriggers since they have their own context. 947** 948** SQLite implements the command "DELETE FROM table" without 949** a WHERE clause by dropping and recreating the table. (This is much 950** faster than going through and deleting individual elements from the 951** table.) Because of this optimization, the deletions in 952** "DELETE FROM table" are not row changes and will not be counted 953** by the sqlite3_changes() or [sqlite3_total_changes()] functions. 954** To get an accurate count of the number of rows deleted, use 955** "DELETE FROM table WHERE 1" instead. 956** 957** INVARIANTS: 958** 959** {F12241} The [sqlite3_changes()] function returns the number of 960** row changes caused by the most recent INSERT, UPDATE, 961** or DELETE statement on the same database connection and 962** within the same trigger context, or zero if there have 963** not been any qualifying row changes. 964** 965** LIMITATIONS: 966** 967** {U12252} If a separate thread makes changes on the same database connection 968** while [sqlite3_changes()] is running then the value returned 969** is unpredictable and unmeaningful. 970*/ 971int sqlite3_changes(sqlite3*); 972 973/* 974** CAPI3REF: Total Number Of Rows Modified {F12260} 975*** 976** This function returns the number of row changes caused 977** by INSERT, UPDATE or DELETE statements since the database handle 978** was opened. The count includes all changes from all trigger 979** contexts. But the count does not include changes used to 980** implement REPLACE constraints, do rollbacks or ABORT processing, 981** or DROP table processing. 982** The changes 983** are counted as soon as the statement that makes them is completed 984** (when the statement handle is passed to [sqlite3_reset()] or 985** [sqlite3_finalize()]). 986** 987** SQLite implements the command "DELETE FROM table" without 988** a WHERE clause by dropping and recreating the table. (This is much 989** faster than going 990** through and deleting individual elements from the table.) Because of 991** this optimization, the change count for "DELETE FROM table" will be 992** zero regardless of the number of elements that were originally in the 993** table. To get an accurate count of the number of rows deleted, use 994** "DELETE FROM table WHERE 1" instead. 995** 996** See also the [sqlite3_changes()] interface. 997** 998** INVARIANTS: 999** 1000** {F12261} The [sqlite3_total_changes()] returns the total number 1001** of row changes caused by INSERT, UPDATE, and/or DELETE 1002** statements on the same [database connection], in any 1003** trigger context, since the database connection was 1004** created. 1005** 1006** LIMITATIONS: 1007** 1008** {U12264} If a separate thread makes changes on the same database connection 1009** while [sqlite3_total_changes()] is running then the value 1010** returned is unpredictable and unmeaningful. 1011*/ 1012int sqlite3_total_changes(sqlite3*); 1013 1014/* 1015** CAPI3REF: Interrupt A Long-Running Query {F12270} 1016** 1017** This function causes any pending database operation to abort and 1018** return at its earliest opportunity. This routine is typically 1019** called in response to a user action such as pressing "Cancel" 1020** or Ctrl-C where the user wants a long query operation to halt 1021** immediately. 1022** 1023** It is safe to call this routine from a thread different from the 1024** thread that is currently running the database operation. But it 1025** is not safe to call this routine with a database connection that 1026** is closed or might close before sqlite3_interrupt() returns. 1027** 1028** If an SQL is very nearly finished at the time when sqlite3_interrupt() 1029** is called, then it might not have an opportunity to be interrupted. 1030** It might continue to completion. 1031** An SQL operation that is interrupted will return 1032** [SQLITE_INTERRUPT]. If the interrupted SQL operation is an 1033** INSERT, UPDATE, or DELETE that is inside an explicit transaction, 1034** then the entire transaction will be rolled back automatically. 1035** A call to sqlite3_interrupt() has no effect on SQL statements 1036** that are started after sqlite3_interrupt() returns. 1037** 1038** INVARIANTS: 1039** 1040** {F12271} The [sqlite3_interrupt()] interface will force all running 1041** SQL statements associated with the same database connection 1042** to halt after processing at most one additional row of 1043** data. 1044** 1045** {F12272} Any SQL statement that is interrupted by [sqlite3_interrupt()] 1046** will return [SQLITE_INTERRUPT]. 1047** 1048** LIMITATIONS: 1049** 1050** {U12279} If the database connection closes while [sqlite3_interrupt()] 1051** is running then bad things will likely happen. 1052*/ 1053void sqlite3_interrupt(sqlite3*); 1054 1055/* 1056** CAPI3REF: Determine If An SQL Statement Is Complete {F10510} 1057** 1058** These routines are useful for command-line input to determine if the 1059** currently entered text seems to form complete a SQL statement or 1060** if additional input is needed before sending the text into 1061** SQLite for parsing. These routines return true if the input string 1062** appears to be a complete SQL statement. A statement is judged to be 1063** complete if it ends with a semicolon token and is not a fragment of a 1064** CREATE TRIGGER statement. Semicolons that are embedded within 1065** string literals or quoted identifier names or comments are not 1066** independent tokens (they are part of the token in which they are 1067** embedded) and thus do not count as a statement terminator. 1068** 1069** These routines do not parse the SQL and 1070** so will not detect syntactically incorrect SQL. 1071** 1072** INVARIANTS: 1073** 1074** {F10511} The sqlite3_complete() and sqlite3_complete16() functions 1075** return true (non-zero) if and only if the last 1076** non-whitespace token in their input is a semicolon that 1077** is not in between the BEGIN and END of a CREATE TRIGGER 1078** statement. 1079** 1080** LIMITATIONS: 1081** 1082** {U10512} The input to sqlite3_complete() must be a zero-terminated 1083** UTF-8 string. 1084** 1085** {U10513} The input to sqlite3_complete16() must be a zero-terminated 1086** UTF-16 string in native byte order. 1087*/ 1088int sqlite3_complete(const char *sql); 1089int sqlite3_complete16(const void *sql); 1090 1091/* 1092** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310} 1093** 1094** This routine identifies a callback function that might be 1095** invoked whenever an attempt is made to open a database table 1096** that another thread or process has locked. 1097** If the busy callback is NULL, then [SQLITE_BUSY] 1098** or [SQLITE_IOERR_BLOCKED] 1099** is returned immediately upon encountering the lock. 1100** If the busy callback is not NULL, then the 1101** callback will be invoked with two arguments. The 1102** first argument to the handler is a copy of the void* pointer which 1103** is the third argument to this routine. The second argument to 1104** the handler is the number of times that the busy handler has 1105** been invoked for this locking event. If the 1106** busy callback returns 0, then no additional attempts are made to 1107** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1108** If the callback returns non-zero, then another attempt 1109** is made to open the database for reading and the cycle repeats. 1110** 1111** The presence of a busy handler does not guarantee that 1112** it will be invoked when there is lock contention. 1113** If SQLite determines that invoking the busy handler could result in 1114** a deadlock, it will go ahead and return [SQLITE_BUSY] or 1115** [SQLITE_IOERR_BLOCKED] instead of invoking the 1116** busy handler. 1117** Consider a scenario where one process is holding a read lock that 1118** it is trying to promote to a reserved lock and 1119** a second process is holding a reserved lock that it is trying 1120** to promote to an exclusive lock. The first process cannot proceed 1121** because it is blocked by the second and the second process cannot 1122** proceed because it is blocked by the first. If both processes 1123** invoke the busy handlers, neither will make any progress. Therefore, 1124** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1125** will induce the first process to release its read lock and allow 1126** the second process to proceed. 1127** 1128** The default busy callback is NULL. 1129** 1130** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1131** when SQLite is in the middle of a large transaction where all the 1132** changes will not fit into the in-memory cache. SQLite will 1133** already hold a RESERVED lock on the database file, but it needs 1134** to promote this lock to EXCLUSIVE so that it can spill cache 1135** pages into the database file without harm to concurrent 1136** readers. If it is unable to promote the lock, then the in-memory 1137** cache will be left in an inconsistent state and so the error 1138** code is promoted from the relatively benign [SQLITE_BUSY] to 1139** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1140** forces an automatic rollback of the changes. See the 1141** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1142** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1143** this is important. 1144** 1145** There can only be a single busy handler defined for each database 1146** connection. Setting a new busy handler clears any previous one. 1147** Note that calling [sqlite3_busy_timeout()] will also set or clear 1148** the busy handler. 1149** 1150** INVARIANTS: 1151** 1152** {F12311} The [sqlite3_busy_handler()] function replaces the busy handler 1153** callback in the database connection identified by the 1st 1154** parameter with a new busy handler identified by the 2nd and 3rd 1155** parameters. 1156** 1157** {F12312} The default busy handler for new database connections is NULL. 1158** 1159** {F12314} When two or more database connection share a common cache, 1160** the busy handler for the database connection currently using 1161** the cache is invoked when the cache encounters a lock. 1162** 1163** {F12316} If a busy handler callback returns zero, then the SQLite 1164** interface that provoked the locking event will return 1165** [SQLITE_BUSY]. 1166** 1167** {F12318} SQLite will invokes the busy handler with two argument which 1168** are a copy of the pointer supplied by the 3rd parameter to 1169** [sqlite3_busy_handler()] and a count of the number of prior 1170** invocations of the busy handler for the same locking event. 1171** 1172** LIMITATIONS: 1173** 1174** {U12319} A busy handler should not call close the database connection 1175** or prepared statement that invoked the busy handler. 1176*/ 1177int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1178 1179/* 1180** CAPI3REF: Set A Busy Timeout {F12340} 1181** 1182** This routine sets a [sqlite3_busy_handler | busy handler] 1183** that sleeps for a while when a 1184** table is locked. The handler will sleep multiple times until 1185** at least "ms" milliseconds of sleeping have been done. {F12343} After 1186** "ms" milliseconds of sleeping, the handler returns 0 which 1187** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1188** 1189** Calling this routine with an argument less than or equal to zero 1190** turns off all busy handlers. 1191** 1192** There can only be a single busy handler for a particular database 1193** connection. If another busy handler was defined 1194** (using [sqlite3_busy_handler()]) prior to calling 1195** this routine, that other busy handler is cleared. 1196** 1197** INVARIANTS: 1198** 1199** {F12341} The [sqlite3_busy_timeout()] function overrides any prior 1200** [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting 1201** on the same database connection. 1202** 1203** {F12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than 1204** or equal to zero, then the busy handler is cleared so that 1205** all subsequent locking events immediately return [SQLITE_BUSY]. 1206** 1207** {F12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive 1208** number N, then a busy handler is set that repeatedly calls 1209** the xSleep() method in the VFS interface until either the 1210** lock clears or until the cumulative sleep time reported back 1211** by xSleep() exceeds N milliseconds. 1212*/ 1213int sqlite3_busy_timeout(sqlite3*, int ms); 1214 1215/* 1216** CAPI3REF: Convenience Routines For Running Queries {F12370} 1217** 1218** Definition: A <b>result table</b> is memory data structure created by the 1219** [sqlite3_get_table()] interface. A result table records the 1220** complete query results from one or more queries. 1221** 1222** The table conceptually has a number of rows and columns. But 1223** these numbers are not part of the result table itself. These 1224** numbers are obtained separately. Let N be the number of rows 1225** and M be the number of columns. 1226** 1227** A result table is an array of pointers to zero-terminated 1228** UTF-8 strings. There are (N+1)*M elements in the array. 1229** The first M pointers point to zero-terminated strings that 1230** contain the names of the columns. 1231** The remaining entries all point to query results. NULL 1232** values are give a NULL pointer. All other values are in 1233** their UTF-8 zero-terminated string representation as returned by 1234** [sqlite3_column_text()]. 1235** 1236** A result table might consists of one or more memory allocations. 1237** It is not safe to pass a result table directly to [sqlite3_free()]. 1238** A result table should be deallocated using [sqlite3_free_table()]. 1239** 1240** As an example of the result table format, suppose a query result 1241** is as follows: 1242** 1243** <blockquote><pre> 1244** Name | Age 1245** ----------------------- 1246** Alice | 43 1247** Bob | 28 1248** Cindy | 21 1249** </pre></blockquote> 1250** 1251** There are two column (M==2) and three rows (N==3). Thus the 1252** result table has 8 entries. Suppose the result table is stored 1253** in an array names azResult. Then azResult holds this content: 1254** 1255** <blockquote><pre> 1256** azResult[0] = "Name"; 1257** azResult[1] = "Age"; 1258** azResult[2] = "Alice"; 1259** azResult[3] = "43"; 1260** azResult[4] = "Bob"; 1261** azResult[5] = "28"; 1262** azResult[6] = "Cindy"; 1263** azResult[7] = "21"; 1264** </pre></blockquote> 1265** 1266** The sqlite3_get_table() function evaluates one or more 1267** semicolon-separated SQL statements in the zero-terminated UTF-8 1268** string of its 2nd parameter. It returns a result table to the 1269** pointer given in its 3rd parameter. 1270** 1271** After the calling function has finished using the result, it should 1272** pass the pointer to the result table to sqlite3_free_table() in order to 1273** release the memory that was malloc-ed. Because of the way the 1274** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1275** function must not try to call [sqlite3_free()] directly. Only 1276** [sqlite3_free_table()] is able to release the memory properly and safely. 1277** 1278** The sqlite3_get_table() interface is implemented as a wrapper around 1279** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1280** to any internal data structures of SQLite. It uses only the public 1281** interface defined here. As a consequence, errors that occur in the 1282** wrapper layer outside of the internal [sqlite3_exec()] call are not 1283** reflected in subsequent calls to [sqlite3_errcode()] or 1284** [sqlite3_errmsg()]. 1285** 1286** INVARIANTS: 1287** 1288** {F12371} If a [sqlite3_get_table()] fails a memory allocation, then 1289** it frees the result table under construction, aborts the 1290** query in process, skips any subsequent queries, sets the 1291** *resultp output pointer to NULL and returns [SQLITE_NOMEM]. 1292** 1293** {F12373} If the ncolumn parameter to [sqlite3_get_table()] is not NULL 1294** then [sqlite3_get_table()] write the number of columns in the 1295** result set of the query into *ncolumn if the query is 1296** successful (if the function returns SQLITE_OK). 1297** 1298** {F12374} If the nrow parameter to [sqlite3_get_table()] is not NULL 1299** then [sqlite3_get_table()] write the number of rows in the 1300** result set of the query into *nrow if the query is 1301** successful (if the function returns SQLITE_OK). 1302** 1303** {F12376} The [sqlite3_get_table()] function sets its *ncolumn value 1304** to the number of columns in the result set of the query in the 1305** sql parameter, or to zero if the query in sql has an empty 1306** result set. 1307*/ 1308int sqlite3_get_table( 1309 sqlite3*, /* An open database */ 1310 const char *sql, /* SQL to be evaluated */ 1311 char ***pResult, /* Results of the query */ 1312 int *nrow, /* Number of result rows written here */ 1313 int *ncolumn, /* Number of result columns written here */ 1314 char **errmsg /* Error msg written here */ 1315); 1316void sqlite3_free_table(char **result); 1317 1318/* 1319** CAPI3REF: Formatted String Printing Functions {F17400} 1320** 1321** These routines are workalikes of the "printf()" family of functions 1322** from the standard C library. 1323** 1324** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1325** results into memory obtained from [sqlite3_malloc()]. 1326** The strings returned by these two routines should be 1327** released by [sqlite3_free()]. Both routines return a 1328** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1329** memory to hold the resulting string. 1330** 1331** In sqlite3_snprintf() routine is similar to "snprintf()" from 1332** the standard C library. The result is written into the 1333** buffer supplied as the second parameter whose size is given by 1334** the first parameter. Note that the order of the 1335** first two parameters is reversed from snprintf(). This is an 1336** historical accident that cannot be fixed without breaking 1337** backwards compatibility. Note also that sqlite3_snprintf() 1338** returns a pointer to its buffer instead of the number of 1339** characters actually written into the buffer. We admit that 1340** the number of characters written would be a more useful return 1341** value but we cannot change the implementation of sqlite3_snprintf() 1342** now without breaking compatibility. 1343** 1344** As long as the buffer size is greater than zero, sqlite3_snprintf() 1345** guarantees that the buffer is always zero-terminated. The first 1346** parameter "n" is the total size of the buffer, including space for 1347** the zero terminator. So the longest string that can be completely 1348** written will be n-1 characters. 1349** 1350** These routines all implement some additional formatting 1351** options that are useful for constructing SQL statements. 1352** All of the usual printf formatting options apply. In addition, there 1353** is are "%q", "%Q", and "%z" options. 1354** 1355** The %q option works like %s in that it substitutes a null-terminated 1356** string from the argument list. But %q also doubles every '\'' character. 1357** %q is designed for use inside a string literal. By doubling each '\'' 1358** character it escapes that character and allows it to be inserted into 1359** the string. 1360** 1361** For example, so some string variable contains text as follows: 1362** 1363** <blockquote><pre> 1364** char *zText = "It's a happy day!"; 1365** </pre></blockquote> 1366** 1367** One can use this text in an SQL statement as follows: 1368** 1369** <blockquote><pre> 1370** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1371** sqlite3_exec(db, zSQL, 0, 0, 0); 1372** sqlite3_free(zSQL); 1373** </pre></blockquote> 1374** 1375** Because the %q format string is used, the '\'' character in zText 1376** is escaped and the SQL generated is as follows: 1377** 1378** <blockquote><pre> 1379** INSERT INTO table1 VALUES('It''s a happy day!') 1380** </pre></blockquote> 1381** 1382** This is correct. Had we used %s instead of %q, the generated SQL 1383** would have looked like this: 1384** 1385** <blockquote><pre> 1386** INSERT INTO table1 VALUES('It's a happy day!'); 1387** </pre></blockquote> 1388** 1389** This second example is an SQL syntax error. As a general rule you 1390** should always use %q instead of %s when inserting text into a string 1391** literal. 1392** 1393** The %Q option works like %q except it also adds single quotes around 1394** the outside of the total string. Or if the parameter in the argument 1395** list is a NULL pointer, %Q substitutes the text "NULL" (without single 1396** quotes) in place of the %Q option. {END} So, for example, one could say: 1397** 1398** <blockquote><pre> 1399** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1400** sqlite3_exec(db, zSQL, 0, 0, 0); 1401** sqlite3_free(zSQL); 1402** </pre></blockquote> 1403** 1404** The code above will render a correct SQL statement in the zSQL 1405** variable even if the zText variable is a NULL pointer. 1406** 1407** The "%z" formatting option works exactly like "%s" with the 1408** addition that after the string has been read and copied into 1409** the result, [sqlite3_free()] is called on the input string. {END} 1410** 1411** INVARIANTS: 1412** 1413** {F17403} The [sqlite3_mprintf()] and [sqlite3_vmprintf()] interfaces 1414** return either pointers to zero-terminated UTF-8 strings held in 1415** memory obtained from [sqlite3_malloc()] or NULL pointers if 1416** a call to [sqlite3_malloc()] fails. 1417** 1418** {F17406} The [sqlite3_snprintf()] interface writes a zero-terminated 1419** UTF-8 string into the buffer pointed to by the second parameter 1420** provided that the first parameter is greater than zero. 1421** 1422** {F17407} The [sqlite3_snprintf()] interface does not writes slots of 1423** its output buffer (the second parameter) outside the range 1424** of 0 through N-1 (where N is the first parameter) 1425** regardless of the length of the string 1426** requested by the format specification. 1427** 1428*/ 1429char *sqlite3_mprintf(const char*,...); 1430char *sqlite3_vmprintf(const char*, va_list); 1431char *sqlite3_snprintf(int,char*,const char*, ...); 1432 1433/* 1434** CAPI3REF: Memory Allocation Subsystem {F17300} 1435** 1436** The SQLite core uses these three routines for all of its own 1437** internal memory allocation needs. "Core" in the previous sentence 1438** does not include operating-system specific VFS implementation. The 1439** windows VFS uses native malloc and free for some operations. 1440** 1441** The sqlite3_malloc() routine returns a pointer to a block 1442** of memory at least N bytes in length, where N is the parameter. 1443** If sqlite3_malloc() is unable to obtain sufficient free 1444** memory, it returns a NULL pointer. If the parameter N to 1445** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1446** a NULL pointer. 1447** 1448** Calling sqlite3_free() with a pointer previously returned 1449** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1450** that it might be reused. The sqlite3_free() routine is 1451** a no-op if is called with a NULL pointer. Passing a NULL pointer 1452** to sqlite3_free() is harmless. After being freed, memory 1453** should neither be read nor written. Even reading previously freed 1454** memory might result in a segmentation fault or other severe error. 1455** Memory corruption, a segmentation fault, or other severe error 1456** might result if sqlite3_free() is called with a non-NULL pointer that 1457** was not obtained from sqlite3_malloc() or sqlite3_free(). 1458** 1459** The sqlite3_realloc() interface attempts to resize a 1460** prior memory allocation to be at least N bytes, where N is the 1461** second parameter. The memory allocation to be resized is the first 1462** parameter. If the first parameter to sqlite3_realloc() 1463** is a NULL pointer then its behavior is identical to calling 1464** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1465** If the second parameter to sqlite3_realloc() is zero or 1466** negative then the behavior is exactly the same as calling 1467** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1468** Sqlite3_realloc() returns a pointer to a memory allocation 1469** of at least N bytes in size or NULL if sufficient memory is unavailable. 1470** If M is the size of the prior allocation, then min(N,M) bytes 1471** of the prior allocation are copied into the beginning of buffer returned 1472** by sqlite3_realloc() and the prior allocation is freed. 1473** If sqlite3_realloc() returns NULL, then the prior allocation 1474** is not freed. 1475** 1476** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1477** is always aligned to at least an 8 byte boundary. {END} 1478** 1479** The default implementation 1480** of the memory allocation subsystem uses the malloc(), realloc() 1481** and free() provided by the standard C library. {F17382} However, if 1482** SQLite is compiled with the following C preprocessor macro 1483** 1484** <blockquote> SQLITE_MEMORY_SIZE=<i>NNN</i> </blockquote> 1485** 1486** where <i>NNN</i> is an integer, then SQLite create a static 1487** array of at least <i>NNN</i> bytes in size and use that array 1488** for all of its dynamic memory allocation needs. {END} Additional 1489** memory allocator options may be added in future releases. 1490** 1491** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1492** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1493** implementation of these routines to be omitted. That capability 1494** is no longer provided. Only built-in memory allocators can be 1495** used. 1496** 1497** The windows OS interface layer calls 1498** the system malloc() and free() directly when converting 1499** filenames between the UTF-8 encoding used by SQLite 1500** and whatever filename encoding is used by the particular windows 1501** installation. Memory allocation errors are detected, but 1502** they are reported back as [SQLITE_CANTOPEN] or 1503** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1504** 1505** INVARIANTS: 1506** 1507** {F17303} The [sqlite3_malloc(N)] interface returns either a pointer to 1508** newly checked-out block of at least N bytes of memory 1509** that is 8-byte aligned, 1510** or it returns NULL if it is unable to fulfill the request. 1511** 1512** {F17304} The [sqlite3_malloc(N)] interface returns a NULL pointer if 1513** N is less than or equal to zero. 1514** 1515** {F17305} The [sqlite3_free(P)] interface releases memory previously 1516** returned from [sqlite3_malloc()] or [sqlite3_realloc()], 1517** making it available for reuse. 1518** 1519** {F17306} A call to [sqlite3_free(NULL)] is a harmless no-op. 1520** 1521** {F17310} A call to [sqlite3_realloc(0,N)] is equivalent to a call 1522** to [sqlite3_malloc(N)]. 1523** 1524** {F17312} A call to [sqlite3_realloc(P,0)] is equivalent to a call 1525** to [sqlite3_free(P)]. 1526** 1527** {F17315} The SQLite core uses [sqlite3_malloc()], [sqlite3_realloc()], 1528** and [sqlite3_free()] for all of its memory allocation and 1529** deallocation needs. 1530** 1531** {F17318} The [sqlite3_realloc(P,N)] interface returns either a pointer 1532** to a block of checked-out memory of at least N bytes in size 1533** that is 8-byte aligned, or a NULL pointer. 1534** 1535** {F17321} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first 1536** copies the first K bytes of content from P into the newly allocated 1537** where K is the lessor of N and the size of the buffer P. 1538** 1539** {F17322} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first 1540** releases the buffer P. 1541** 1542** {F17323} When [sqlite3_realloc(P,N)] returns NULL, the buffer P is 1543** not modified or released. 1544** 1545** LIMITATIONS: 1546** 1547** {U17350} The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1548** must be either NULL or else a pointer obtained from a prior 1549** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that has 1550** not been released. 1551** 1552** {U17351} The application must not read or write any part of 1553** a block of memory after it has been released using 1554** [sqlite3_free()] or [sqlite3_realloc()]. 1555** 1556*/ 1557void *sqlite3_malloc(int); 1558void *sqlite3_realloc(void*, int); 1559void sqlite3_free(void*); 1560 1561/* 1562** CAPI3REF: Memory Allocator Statistics {F17370} 1563** 1564** SQLite provides these two interfaces for reporting on the status 1565** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1566** the memory allocation subsystem included within the SQLite. 1567** 1568** INVARIANTS: 1569** 1570** {F17371} The [sqlite3_memory_used()] routine returns the 1571** number of bytes of memory currently outstanding 1572** (malloced but not freed). 1573** 1574** {F17373} The [sqlite3_memory_highwater()] routine returns the maximum 1575** value of [sqlite3_memory_used()] 1576** since the highwater mark was last reset. 1577** 1578** {F17374} The values returned by [sqlite3_memory_used()] and 1579** [sqlite3_memory_highwater()] include any overhead 1580** added by SQLite in its implementation of [sqlite3_malloc()], 1581** but not overhead added by the any underlying system library 1582** routines that [sqlite3_malloc()] may call. 1583** 1584** {F17375} The memory highwater mark is reset to the current value of 1585** [sqlite3_memory_used()] if and only if the parameter to 1586** [sqlite3_memory_highwater()] is true. The value returned 1587** by [sqlite3_memory_highwater(1)] is the highwater mark 1588** prior to the reset. 1589*/ 1590sqlite3_int64 sqlite3_memory_used(void); 1591sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1592 1593/* 1594** CAPI3REF: Pseudo-Random Number Generator {F17390} 1595** 1596** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1597** select random ROWIDs when inserting new records into a table that 1598** already uses the largest possible ROWID. The PRNG is also used for 1599** the build-in random() and randomblob() SQL functions. This interface allows 1600** appliations to access the same PRNG for other purposes. 1601** 1602** A call to this routine stores N bytes of randomness into buffer P. 1603** 1604** The first time this routine is invoked (either internally or by 1605** the application) the PRNG is seeded using randomness obtained 1606** from the xRandomness method of the default [sqlite3_vfs] object. 1607** On all subsequent invocations, the pseudo-randomness is generated 1608** internally and without recourse to the [sqlite3_vfs] xRandomness 1609** method. 1610** 1611** INVARIANTS: 1612** 1613** {F17392} The [sqlite3_randomness(N,P)] interface writes N bytes of 1614** high-quality pseudo-randomness into buffer P. 1615*/ 1616void sqlite3_randomness(int N, void *P); 1617 1618/* 1619** CAPI3REF: Compile-Time Authorization Callbacks {F12500} 1620** 1621** This routine registers a authorizer callback with a particular 1622** [database connection], supplied in the first argument. 1623** The authorizer callback is invoked as SQL statements are being compiled 1624** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1625** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1626** points during the compilation process, as logic is being created 1627** to perform various actions, the authorizer callback is invoked to 1628** see if those actions are allowed. The authorizer callback should 1629** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1630** specific action but allow the SQL statement to continue to be 1631** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1632** rejected with an error. If the authorizer callback returns 1633** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1634** then [sqlite3_prepare_v2()] or equivalent call that triggered 1635** the authorizer will fail with an error message. 1636** 1637** When the callback returns [SQLITE_OK], that means the operation 1638** requested is ok. When the callback returns [SQLITE_DENY], the 1639** [sqlite3_prepare_v2()] or equivalent call that triggered the 1640** authorizer will fail with an error message explaining that 1641** access is denied. If the authorizer code is [SQLITE_READ] 1642** and the callback returns [SQLITE_IGNORE] then the 1643** [prepared statement] statement is constructed to substitute 1644** a NULL value in place of the table column that would have 1645** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1646** return can be used to deny an untrusted user access to individual 1647** columns of a table. 1648** 1649** The first parameter to the authorizer callback is a copy of 1650** the third parameter to the sqlite3_set_authorizer() interface. 1651** The second parameter to the callback is an integer 1652** [SQLITE_COPY | action code] that specifies the particular action 1653** to be authorized. The third through sixth 1654** parameters to the callback are zero-terminated strings that contain 1655** additional details about the action to be authorized. 1656** 1657** An authorizer is used when [sqlite3_prepare | preparing] 1658** SQL statements from an untrusted 1659** source, to ensure that the SQL statements do not try to access data 1660** that they are not allowed to see, or that they do not try to 1661** execute malicious statements that damage the database. For 1662** example, an application may allow a user to enter arbitrary 1663** SQL queries for evaluation by a database. But the application does 1664** not want the user to be able to make arbitrary changes to the 1665** database. An authorizer could then be put in place while the 1666** user-entered SQL is being [sqlite3_prepare | prepared] that 1667** disallows everything except [SELECT] statements. 1668** 1669** Applications that need to process SQL from untrusted sources 1670** might also consider lowering resource limits using [sqlite3_limit()] 1671** and limiting database size using the [max_page_count] [PRAGMA] 1672** in addition to using an authorizer. 1673** 1674** Only a single authorizer can be in place on a database connection 1675** at a time. Each call to sqlite3_set_authorizer overrides the 1676** previous call. Disable the authorizer by installing a NULL callback. 1677** The authorizer is disabled by default. 1678** 1679** Note that the authorizer callback is invoked only during 1680** [sqlite3_prepare()] or its variants. Authorization is not 1681** performed during statement evaluation in [sqlite3_step()]. 1682** 1683** INVARIANTS: 1684** 1685** {F12501} The [sqlite3_set_authorizer(D,...)] interface registers a 1686** authorizer callback with database connection D. 1687** 1688** {F12502} The authorizer callback is invoked as SQL statements are 1689** being compiled 1690** 1691** {F12503} If the authorizer callback returns any value other than 1692** [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] then 1693** the [sqlite3_prepare_v2()] or equivalent call that caused 1694** the authorizer callback to run shall fail with an 1695** [SQLITE_ERROR] error code and an appropriate error message. 1696** 1697** {F12504} When the authorizer callback returns [SQLITE_OK], the operation 1698** described is coded normally. 1699** 1700** {F12505} When the authorizer callback returns [SQLITE_DENY], the 1701** [sqlite3_prepare_v2()] or equivalent call that caused the 1702** authorizer callback to run shall fail 1703** with an [SQLITE_ERROR] error code and an error message 1704** explaining that access is denied. 1705** 1706** {F12506} If the authorizer code (the 2nd parameter to the authorizer 1707** callback) is [SQLITE_READ] and the authorizer callback returns 1708** [SQLITE_IGNORE] then the prepared statement is constructed to 1709** insert a NULL value in place of the table column that would have 1710** been read if [SQLITE_OK] had been returned. 1711** 1712** {F12507} If the authorizer code (the 2nd parameter to the authorizer 1713** callback) is anything other than [SQLITE_READ], then 1714** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 1715** 1716** {F12510} The first parameter to the authorizer callback is a copy of 1717** the third parameter to the [sqlite3_set_authorizer()] interface. 1718** 1719** {F12511} The second parameter to the callback is an integer 1720** [SQLITE_COPY | action code] that specifies the particular action 1721** to be authorized. 1722** 1723** {F12512} The third through sixth parameters to the callback are 1724** zero-terminated strings that contain 1725** additional details about the action to be authorized. 1726** 1727** {F12520} Each call to [sqlite3_set_authorizer()] overrides the 1728** any previously installed authorizer. 1729** 1730** {F12521} A NULL authorizer means that no authorization 1731** callback is invoked. 1732** 1733** {F12522} The default authorizer is NULL. 1734*/ 1735int sqlite3_set_authorizer( 1736 sqlite3*, 1737 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1738 void *pUserData 1739); 1740 1741/* 1742** CAPI3REF: Authorizer Return Codes {F12590} 1743** 1744** The [sqlite3_set_authorizer | authorizer callback function] must 1745** return either [SQLITE_OK] or one of these two constants in order 1746** to signal SQLite whether or not the action is permitted. See the 1747** [sqlite3_set_authorizer | authorizer documentation] for additional 1748** information. 1749*/ 1750#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1751#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1752 1753/* 1754** CAPI3REF: Authorizer Action Codes {F12550} 1755** 1756** The [sqlite3_set_authorizer()] interface registers a callback function 1757** that is invoked to authorizer certain SQL statement actions. The 1758** second parameter to the callback is an integer code that specifies 1759** what action is being authorized. These are the integer action codes that 1760** the authorizer callback may be passed. 1761** 1762** These action code values signify what kind of operation is to be 1763** authorized. The 3rd and 4th parameters to the authorization 1764** callback function will be parameters or NULL depending on which of these 1765** codes is used as the second parameter. The 5th parameter to the 1766** authorizer callback is the name of the database ("main", "temp", 1767** etc.) if applicable. The 6th parameter to the authorizer callback 1768** is the name of the inner-most trigger or view that is responsible for 1769** the access attempt or NULL if this access attempt is directly from 1770** top-level SQL code. 1771** 1772** INVARIANTS: 1773** 1774** {F12551} The second parameter to an 1775** [sqlite3_set_authorizer | authorizer callback is always an integer 1776** [SQLITE_COPY | authorizer code] that specifies what action 1777** is being authorized. 1778** 1779** {F12552} The 3rd and 4th parameters to the 1780** [sqlite3_set_authorizer | authorization callback function] 1781** will be parameters or NULL depending on which 1782** [SQLITE_COPY | authorizer code] is used as the second parameter. 1783** 1784** {F12553} The 5th parameter to the 1785** [sqlite3_set_authorizer | authorizer callback] is the name 1786** of the database (example: "main", "temp", etc.) if applicable. 1787** 1788** {F12554} The 6th parameter to the 1789** [sqlite3_set_authorizer | authorizer callback] is the name 1790** of the inner-most trigger or view that is responsible for 1791** the access attempt or NULL if this access attempt is directly from 1792** top-level SQL code. 1793*/ 1794/******************************************* 3rd ************ 4th ***********/ 1795#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1796#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1797#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1798#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1799#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1800#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1801#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1802#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1803#define SQLITE_DELETE 9 /* Table Name NULL */ 1804#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1805#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1806#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1807#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1808#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1809#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1810#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1811#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1812#define SQLITE_INSERT 18 /* Table Name NULL */ 1813#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 1814#define SQLITE_READ 20 /* Table Name Column Name */ 1815#define SQLITE_SELECT 21 /* NULL NULL */ 1816#define SQLITE_TRANSACTION 22 /* NULL NULL */ 1817#define SQLITE_UPDATE 23 /* Table Name Column Name */ 1818#define SQLITE_ATTACH 24 /* Filename NULL */ 1819#define SQLITE_DETACH 25 /* Database Name NULL */ 1820#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 1821#define SQLITE_REINDEX 27 /* Index Name NULL */ 1822#define SQLITE_ANALYZE 28 /* Table Name NULL */ 1823#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 1824#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 1825#define SQLITE_FUNCTION 31 /* Function Name NULL */ 1826#define SQLITE_COPY 0 /* No longer used */ 1827 1828/* 1829** CAPI3REF: Tracing And Profiling Functions {F12280} 1830** 1831** These routines register callback functions that can be used for 1832** tracing and profiling the execution of SQL statements. 1833** 1834** The callback function registered by sqlite3_trace() is invoked at 1835** various times when an SQL statement is being run by [sqlite3_step()]. 1836** The callback returns a UTF-8 rendering of the SQL statement text 1837** as the statement first begins executing. Additional callbacks occur 1838** as each triggersubprogram is entered. The callbacks for triggers 1839** contain a UTF-8 SQL comment that identifies the trigger. 1840** 1841** The callback function registered by sqlite3_profile() is invoked 1842** as each SQL statement finishes. The profile callback contains 1843** the original statement text and an estimate of wall-clock time 1844** of how long that statement took to run. 1845** 1846** The sqlite3_profile() API is currently considered experimental and 1847** is subject to change or removal in a future release. 1848** 1849** The trigger reporting feature of the trace callback is considered 1850** experimental and is subject to change or removal in future releases. 1851** Future versions of SQLite might also add new trace callback 1852** invocations. 1853** 1854** INVARIANTS: 1855** 1856** {F12281} The callback function registered by [sqlite3_trace()] is 1857** whenever an SQL statement first begins to execute and 1858** whenever a trigger subprogram first begins to run. 1859** 1860** {F12282} Each call to [sqlite3_trace()] overrides the previously 1861** registered trace callback. 1862** 1863** {F12283} A NULL trace callback disables tracing. 1864** 1865** {F12284} The first argument to the trace callback is a copy of 1866** the pointer which was the 3rd argument to [sqlite3_trace()]. 1867** 1868** {F12285} The second argument to the trace callback is a 1869** zero-terminated UTF8 string containing the original text 1870** of the SQL statement as it was passed into [sqlite3_prepare_v2()] 1871** or the equivalent, or an SQL comment indicating the beginning 1872** of a trigger subprogram. 1873** 1874** {F12287} The callback function registered by [sqlite3_profile()] is invoked 1875** as each SQL statement finishes. 1876** 1877** {F12288} The first parameter to the profile callback is a copy of 1878** the 3rd parameter to [sqlite3_profile()]. 1879** 1880** {F12289} The second parameter to the profile callback is a 1881** zero-terminated UTF-8 string that contains the complete text of 1882** the SQL statement as it was processed by [sqlite3_prepare_v2()] 1883** or the equivalent. 1884** 1885** {F12290} The third parameter to the profile callback is an estimate 1886** of the number of nanoseconds of wall-clock time required to 1887** run the SQL statement from start to finish. 1888*/ 1889void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 1890void *sqlite3_profile(sqlite3*, 1891 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 1892 1893/* 1894** CAPI3REF: Query Progress Callbacks {F12910} 1895** 1896** This routine configures a callback function - the 1897** progress callback - that is invoked periodically during long 1898** running calls to [sqlite3_exec()], [sqlite3_step()] and 1899** [sqlite3_get_table()]. An example use for this 1900** interface is to keep a GUI updated during a large query. 1901** 1902** If the progress callback returns non-zero, the opertion is 1903** interrupted. This feature can be used to implement a 1904** "Cancel" button on a GUI dialog box. 1905** 1906** INVARIANTS: 1907** 1908** {F12911} The callback function registered by [sqlite3_progress_handler()] 1909** is invoked periodically during long running calls to 1910** [sqlite3_step()]. 1911** 1912** {F12912} The progress callback is invoked once for every N virtual 1913** machine opcodes, where N is the second argument to 1914** the [sqlite3_progress_handler()] call that registered 1915** the callback. <todo>What if N is less than 1?</todo> 1916** 1917** {F12913} The progress callback itself is identified by the third 1918** argument to [sqlite3_progress_handler()]. 1919** 1920** {F12914} The fourth argument [sqlite3_progress_handler()] is a 1921*** void pointer passed to the progress callback 1922** function each time it is invoked. 1923** 1924** {F12915} If a call to [sqlite3_step()] results in fewer than 1925** N opcodes being executed, 1926** then the progress callback is never invoked. {END} 1927** 1928** {F12916} Every call to [sqlite3_progress_handler()] 1929** overwrites any previously registere progress handler. 1930** 1931** {F12917} If the progress handler callback is NULL then no progress 1932** handler is invoked. 1933** 1934** {F12918} If the progress callback returns a result other than 0, then 1935** the behavior is a if [sqlite3_interrupt()] had been called. 1936*/ 1937void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 1938 1939/* 1940** CAPI3REF: Opening A New Database Connection {F12700} 1941** 1942** These routines open an SQLite database file whose name 1943** is given by the filename argument. 1944** The filename argument is interpreted as UTF-8 1945** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16 1946** in the native byte order for [sqlite3_open16()]. 1947** An [sqlite3*] handle is usually returned in *ppDb, even 1948** if an error occurs. The only exception is if SQLite is unable 1949** to allocate memory to hold the [sqlite3] object, a NULL will 1950** be written into *ppDb instead of a pointer to the [sqlite3] object. 1951** If the database is opened (and/or created) 1952** successfully, then [SQLITE_OK] is returned. Otherwise an 1953** error code is returned. The 1954** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 1955** an English language description of the error. 1956** 1957** The default encoding for the database will be UTF-8 if 1958** [sqlite3_open()] or [sqlite3_open_v2()] is called and 1959** UTF-16 in the native byte order if [sqlite3_open16()] is used. 1960** 1961** Whether or not an error occurs when it is opened, resources 1962** associated with the [sqlite3*] handle should be released by passing it 1963** to [sqlite3_close()] when it is no longer required. 1964** 1965** The [sqlite3_open_v2()] interface works like [sqlite3_open()] 1966** except that it acccepts two additional parameters for additional control 1967** over the new database connection. The flags parameter can be 1968** one of: 1969** 1970** <ol> 1971** <li> [SQLITE_OPEN_READONLY] 1972** <li> [SQLITE_OPEN_READWRITE] 1973** <li> [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE] 1974** </ol> 1975** 1976** The first value opens the database read-only. 1977** If the database does not previously exist, an error is returned. 1978** The second option opens 1979** the database for reading and writing if possible, or reading only if 1980** if the file is write protected. In either case the database 1981** must already exist or an error is returned. The third option 1982** opens the database for reading and writing and creates it if it does 1983** not already exist. 1984** The third options is behavior that is always used for [sqlite3_open()] 1985** and [sqlite3_open16()]. 1986** 1987** If the 4th parameter to [sqlite3_open_v2()] is not one of the 1988** combinations shown above then the behavior is undefined. 1989** 1990** If the filename is ":memory:", then an private 1991** in-memory database is created for the connection. This in-memory 1992** database will vanish when the database connection is closed. Future 1993** version of SQLite might make use of additional special filenames 1994** that begin with the ":" character. It is recommended that 1995** when a database filename really does begin with 1996** ":" that you prefix the filename with a pathname like "./" to 1997** avoid ambiguity. 1998** 1999** If the filename is an empty string, then a private temporary 2000** on-disk database will be created. This private database will be 2001** automatically deleted as soon as the database connection is closed. 2002** 2003** The fourth parameter to sqlite3_open_v2() is the name of the 2004** [sqlite3_vfs] object that defines the operating system 2005** interface that the new database connection should use. If the 2006** fourth parameter is a NULL pointer then the default [sqlite3_vfs] 2007** object is used. 2008** 2009** <b>Note to windows users:</b> The encoding used for the filename argument 2010** of [sqlite3_open()] and [sqlite3_open_v2()] must be UTF-8, not whatever 2011** codepage is currently defined. Filenames containing international 2012** characters must be converted to UTF-8 prior to passing them into 2013** [sqlite3_open()] or [sqlite3_open_v2()]. 2014** 2015** INVARIANTS: 2016** 2017** {F12701} The [sqlite3_open()], [sqlite3_open16()], and 2018** [sqlite3_open_v2()] interfaces create a new 2019** [database connection] associated with 2020** the database file given in their first parameter. 2021** 2022** {F12702} The filename argument is interpreted as UTF-8 2023** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16 2024** in the native byte order for [sqlite3_open16()]. 2025** 2026** {F12703} A successful invocation of [sqlite3_open()], [sqlite3_open16()], 2027** or [sqlite3_open_v2()] writes a pointer to a new 2028** [database connection] into *ppDb. 2029** 2030** {F12704} The [sqlite3_open()], [sqlite3_open16()], and 2031** [sqlite3_open_v2()] interfaces return [SQLITE_OK] upon success, 2032** or an appropriate [error code] on failure. 2033** 2034** {F12706} The default text encoding for a new database created using 2035** [sqlite3_open()] or [sqlite3_open_v2()] will be UTF-8. 2036** 2037** {F12707} The default text encoding for a new database created using 2038** [sqlite3_open16()] will be UTF-16. 2039** 2040** {F12709} The [sqlite3_open(F,D)] interface is equivalent to 2041** [sqlite3_open_v2(F,D,G,0)] where the G parameter is 2042** [SQLITE_OPEN_READWRITE]|[SQLITE_OPEN_CREATE]. 2043** 2044** {F12711} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the 2045** bit value [SQLITE_OPEN_READONLY] then the database is opened 2046** for reading only. 2047** 2048** {F12712} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the 2049** bit value [SQLITE_OPEN_READWRITE] then the database is opened 2050** reading and writing if possible, or for reading only if the 2051** file is write protected by the operating system. 2052** 2053** {F12713} If the G parameter to [sqlite3_open(v2(F,D,G,V)] omits the 2054** bit value [SQLITE_OPEN_CREATE] and the database does not 2055** previously exist, an error is returned. 2056** 2057** {F12714} If the G parameter to [sqlite3_open(v2(F,D,G,V)] contains the 2058** bit value [SQLITE_OPEN_CREATE] and the database does not 2059** previously exist, then an attempt is made to create and 2060** initialize the database. 2061** 2062** {F12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()], 2063** or [sqlite3_open_v2()] is ":memory:", then an private, 2064** ephemeral, in-memory database is created for the connection. 2065** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required 2066** in sqlite3_open_v2()?</todo> 2067** 2068** {F12719} If the filename is NULL or an empty string, then a private, 2069** ephermeral on-disk database will be created. 2070** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required 2071** in sqlite3_open_v2()?</todo> 2072** 2073** {F12721} The [database connection] created by 2074** [sqlite3_open_v2(F,D,G,V)] will use the 2075** [sqlite3_vfs] object identified by the V parameter, or 2076** the default [sqlite3_vfs] object is V is a NULL pointer. 2077*/ 2078int sqlite3_open( 2079 const char *filename, /* Database filename (UTF-8) */ 2080 sqlite3 **ppDb /* OUT: SQLite db handle */ 2081); 2082int sqlite3_open16( 2083 const void *filename, /* Database filename (UTF-16) */ 2084 sqlite3 **ppDb /* OUT: SQLite db handle */ 2085); 2086int sqlite3_open_v2( 2087 const char *filename, /* Database filename (UTF-8) */ 2088 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2089 int flags, /* Flags */ 2090 const char *zVfs /* Name of VFS module to use */ 2091); 2092 2093/* 2094** CAPI3REF: Error Codes And Messages {F12800} 2095** 2096** The sqlite3_errcode() interface returns the numeric 2097** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code] 2098** for the most recent failed sqlite3_* API call associated 2099** with [sqlite3] handle 'db'. If a prior API call failed but the 2100** most recent API call succeeded, the return value from sqlite3_errcode() 2101** is undefined. 2102** 2103** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2104** text that describes the error, as either UTF8 or UTF16 respectively. 2105** Memory to hold the error message string is managed internally. 2106** The application does not need to worry with freeing the result. 2107** However, the error string might be overwritten or deallocated by 2108** subsequent calls to other SQLite interface functions. 2109** 2110** INVARIANTS: 2111** 2112** {F12801} The [sqlite3_errcode(D)] interface returns the numeric 2113** [SQLITE_OK | result code] or 2114** [SQLITE_IOERR_READ | extended result code] 2115** for the most recently failed interface call associated 2116** with [database connection] D. 2117** 2118** {F12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)] 2119** interfaces return English-language text that describes 2120** the error in the mostly recently failed interface call, 2121** encoded as either UTF8 or UTF16 respectively. 2122** 2123** {F12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()] 2124** are valid until the next SQLite interface call. 2125** 2126** {F12808} Calls to API routines that do not return an error code 2127** (example: [sqlite3_data_count()]) do not 2128** change the error code or message returned by 2129** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()]. 2130** 2131** {F12809} Interfaces that are not associated with a specific 2132** [database connection] (examples: 2133** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()] 2134** do not change the values returned by 2135** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()]. 2136*/ 2137int sqlite3_errcode(sqlite3 *db); 2138const char *sqlite3_errmsg(sqlite3*); 2139const void *sqlite3_errmsg16(sqlite3*); 2140 2141/* 2142** CAPI3REF: SQL Statement Object {F13000} 2143** KEYWORDS: {prepared statement} {prepared statements} 2144** 2145** An instance of this object represent single SQL statements. This 2146** object is variously known as a "prepared statement" or a 2147** "compiled SQL statement" or simply as a "statement". 2148** 2149** The life of a statement object goes something like this: 2150** 2151** <ol> 2152** <li> Create the object using [sqlite3_prepare_v2()] or a related 2153** function. 2154** <li> Bind values to host parameters using 2155** [sqlite3_bind_blob | sqlite3_bind_* interfaces]. 2156** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2157** <li> Reset the statement using [sqlite3_reset()] then go back 2158** to step 2. Do this zero or more times. 2159** <li> Destroy the object using [sqlite3_finalize()]. 2160** </ol> 2161** 2162** Refer to documentation on individual methods above for additional 2163** information. 2164*/ 2165typedef struct sqlite3_stmt sqlite3_stmt; 2166 2167/* 2168** CAPI3REF: Run-time Limits {F12760} 2169** 2170** This interface allows the size of various constructs to be limited 2171** on a connection by connection basis. The first parameter is the 2172** [database connection] whose limit is to be set or queried. The 2173** second parameter is one of the [limit categories] that define a 2174** class of constructs to be size limited. The third parameter is the 2175** new limit for that construct. The function returns the old limit. 2176** 2177** If the new limit is a negative number, the limit is unchanged. 2178** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper 2179** bound set by a compile-time C-preprocess macro named SQLITE_MAX_XYZ. 2180** (The "_LIMIT_" in the name is changed to "_MAX_".) 2181** Attempts to increase a limit above its hard upper bound are 2182** silently truncated to the hard upper limit. 2183** 2184** Run time limits are intended for use in applications that manage 2185** both their own internal database and also databases that are controlled 2186** by untrusted external sources. An example application might be a 2187** webbrowser that has its own databases for storing history and 2188** separate databases controlled by javascript applications downloaded 2189** off the internet. The internal databases can be given the 2190** large, default limits. Databases managed by external sources can 2191** be given much smaller limits designed to prevent a denial of service 2192** attach. Developers might also want to use the [sqlite3_set_authorizer()] 2193** interface to further control untrusted SQL. The size of the database 2194** created by an untrusted script can be contained using the 2195** [max_page_count] [PRAGMA]. 2196** 2197** This interface is currently considered experimental and is subject 2198** to change or removal without prior notice. 2199** 2200** INVARIANTS: 2201** 2202** {F12762} A successful call to [sqlite3_limit(D,C,V)] where V is 2203** positive changes the 2204** limit on the size of construct C in [database connection] D 2205** to the lessor of V and the hard upper bound on the size 2206** of C that is set at compile-time. 2207** 2208** {F12764} A successful call to [sqlite3_limit(D,C,V)] where V is zero 2209** changes the limit on the size of construct C in 2210** [database connection] D to be the hard upper bound on the size 2211** of C that is set at compile-time. 2212** 2213** {F12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative 2214** leaves the state of [database connection] D unchanged. 2215** 2216** {F12769} A successful call to [sqlite3_limit(D,C,V)] returns the 2217** value of the limit on the size of construct C in 2218** in [database connection] D as it was prior to the call. 2219*/ 2220int sqlite3_limit(sqlite3*, int id, int newVal); 2221 2222/* 2223** CAPI3REF: Run-Time Limit Categories {F12790} 2224** KEYWORDS: {limit category} {limit categories} 2225** 2226** These constants define various aspects of a [database connection] 2227** that can be limited in size by calls to [sqlite3_limit()]. 2228** The meanings of the various limits are as follows: 2229** 2230** <dl> 2231** <dt>SQLITE_LIMIT_LENGTH</dt> 2232** <dd>The maximum size of any 2233** string or blob or table row.<dd> 2234** 2235** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2236** <dd>The maximum length of an SQL statement.</dd> 2237** 2238** <dt>SQLITE_LIMIT_COLUMN</dt> 2239** <dd>The maximum number of columns in a table definition or in the 2240** result set of a SELECT or the maximum number of columns in an index 2241** or in an ORDER BY or GROUP BY clause.</dd> 2242** 2243** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2244** <dd>The maximum depth of the parse tree on any expression.</dd> 2245** 2246** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2247** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2248** 2249** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2250** <dd>The maximum number of instructions in a virtual machine program 2251** used to implement an SQL statement.</dd> 2252** 2253** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2254** <dd>The maximum number of arguments on a function.</dd> 2255** 2256** <dt>SQLITE_LIMIT_ATTACHED</dt> 2257** <dd>The maximum number of attached databases.</dd> 2258** 2259** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2260** <dd>The maximum length of the pattern argument to the LIKE or 2261** GLOB operators.</dd> 2262** 2263** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2264** <dd>The maximum number of variables in an SQL statement that can 2265** be bound.</dd> 2266** </dl> 2267*/ 2268#define SQLITE_LIMIT_LENGTH 0 2269#define SQLITE_LIMIT_SQL_LENGTH 1 2270#define SQLITE_LIMIT_COLUMN 2 2271#define SQLITE_LIMIT_EXPR_DEPTH 3 2272#define SQLITE_LIMIT_COMPOUND_SELECT 4 2273#define SQLITE_LIMIT_VDBE_OP 5 2274#define SQLITE_LIMIT_FUNCTION_ARG 6 2275#define SQLITE_LIMIT_ATTACHED 7 2276#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2277#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2278 2279/* 2280** CAPI3REF: Compiling An SQL Statement {F13010} 2281** 2282** To execute an SQL query, it must first be compiled into a byte-code 2283** program using one of these routines. 2284** 2285** The first argument "db" is an [database connection] 2286** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()] 2287** or [sqlite3_open16()]. 2288** The second argument "zSql" is the statement to be compiled, encoded 2289** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2290** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2() 2291** use UTF-16. {END} 2292** 2293** If the nByte argument is less 2294** than zero, then zSql is read up to the first zero terminator. 2295** If nByte is non-negative, then it is the maximum number of 2296** bytes read from zSql. When nByte is non-negative, the 2297** zSql string ends at either the first '\000' or '\u0000' character or 2298** until the nByte-th byte, whichever comes first. If the caller knows 2299** that the supplied string is nul-terminated, then there is a small 2300** performance advantage to be had by passing an nByte parameter that 2301** is equal to the number of bytes in the input string <i>including</i> 2302** the nul-terminator bytes.{END} 2303** 2304** *pzTail is made to point to the first byte past the end of the 2305** first SQL statement in zSql. These routines only compiles the first 2306** statement in zSql, so *pzTail is left pointing to what remains 2307** uncompiled. 2308** 2309** *ppStmt is left pointing to a compiled [prepared statement] that can be 2310** executed using [sqlite3_step()]. Or if there is an error, *ppStmt is 2311** set to NULL. If the input text contains no SQL (if the input 2312** is and empty string or a comment) then *ppStmt is set to NULL. 2313** {U13018} The calling procedure is responsible for deleting the 2314** compiled SQL statement 2315** using [sqlite3_finalize()] after it has finished with it. 2316** 2317** On success, [SQLITE_OK] is returned. Otherwise an 2318** [error code] is returned. 2319** 2320** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2321** recommended for all new programs. The two older interfaces are retained 2322** for backwards compatibility, but their use is discouraged. 2323** In the "v2" interfaces, the prepared statement 2324** that is returned (the [sqlite3_stmt] object) contains a copy of the 2325** original SQL text. {END} This causes the [sqlite3_step()] interface to 2326** behave a differently in two ways: 2327** 2328** <ol> 2329** <li> 2330** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2331** always used to do, [sqlite3_step()] will automatically recompile the SQL 2332** statement and try to run it again. If the schema has changed in 2333** a way that makes the statement no longer valid, [sqlite3_step()] will still 2334** return [SQLITE_SCHEMA]. But unlike the legacy behavior, 2335** [SQLITE_SCHEMA] is now a fatal error. Calling 2336** [sqlite3_prepare_v2()] again will not make the 2337** error go away. Note: use [sqlite3_errmsg()] to find the text 2338** of the parsing error that results in an [SQLITE_SCHEMA] return. {END} 2339** </li> 2340** 2341** <li> 2342** When an error occurs, 2343** [sqlite3_step()] will return one of the detailed 2344** [error codes] or [extended error codes]. 2345** The legacy behavior was that [sqlite3_step()] would only return a generic 2346** [SQLITE_ERROR] result code and you would have to make a second call to 2347** [sqlite3_reset()] in order to find the underlying cause of the problem. 2348** With the "v2" prepare interfaces, the underlying reason for the error is 2349** returned immediately. 2350** </li> 2351** </ol> 2352** 2353** INVARIANTS: 2354** 2355** {F13011} The [sqlite3_prepare(db,zSql,...)] and 2356** [sqlite3_prepare_v2(db,zSql,...)] interfaces interpret the 2357** text in their zSql parameter as UTF-8. 2358** 2359** {F13012} The [sqlite3_prepare16(db,zSql,...)] and 2360** [sqlite3_prepare16_v2(db,zSql,...)] interfaces interpret the 2361** text in their zSql parameter as UTF-16 in the native byte order. 2362** 2363** {F13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)] 2364** and its variants is less than zero, then SQL text is 2365** read from zSql is read up to the first zero terminator. 2366** 2367** {F13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)] 2368** and its variants is non-negative, then nBytes bytes 2369** SQL text is read from zSql. 2370** 2371** {F13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants 2372** if the zSql input text contains more than one SQL statement 2373** and pzTail is not NULL, then *pzTail is made to point to the 2374** first byte past the end of the first SQL statement in zSql. 2375** <todo>What does *pzTail point to if there is one statement?</todo> 2376** 2377** {F13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)] 2378** or one of its variants writes into *ppStmt a pointer to a new 2379** [prepared statement] or a pointer to NULL 2380** if zSql contains nothing other than whitespace or comments. 2381** 2382** {F13019} The [sqlite3_prepare_v2()] interface and its variants return 2383** [SQLITE_OK] or an appropriate [error code] upon failure. 2384** 2385** {F13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its 2386** variants returns an error (any value other than [SQLITE_OK]) 2387** it first sets *ppStmt to NULL. 2388*/ 2389int sqlite3_prepare( 2390 sqlite3 *db, /* Database handle */ 2391 const char *zSql, /* SQL statement, UTF-8 encoded */ 2392 int nByte, /* Maximum length of zSql in bytes. */ 2393 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2394 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2395); 2396int sqlite3_prepare_v2( 2397 sqlite3 *db, /* Database handle */ 2398 const char *zSql, /* SQL statement, UTF-8 encoded */ 2399 int nByte, /* Maximum length of zSql in bytes. */ 2400 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2401 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2402); 2403int sqlite3_prepare16( 2404 sqlite3 *db, /* Database handle */ 2405 const void *zSql, /* SQL statement, UTF-16 encoded */ 2406 int nByte, /* Maximum length of zSql in bytes. */ 2407 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2408 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2409); 2410int sqlite3_prepare16_v2( 2411 sqlite3 *db, /* Database handle */ 2412 const void *zSql, /* SQL statement, UTF-16 encoded */ 2413 int nByte, /* Maximum length of zSql in bytes. */ 2414 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2415 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2416); 2417 2418/* 2419** CAPIREF: Retrieving Statement SQL {F13100} 2420** 2421** This intereface can be used to retrieve a saved copy of the original 2422** SQL text used to create a [prepared statement]. 2423** 2424** INVARIANTS: 2425** 2426** {F13101} If the [prepared statement] passed as 2427** the an argument to [sqlite3_sql()] was compiled 2428** compiled using either [sqlite3_prepare_v2()] or 2429** [sqlite3_prepare16_v2()], 2430** then [sqlite3_sql()] function returns a pointer to a 2431** zero-terminated string containing a UTF-8 rendering 2432** of the original SQL statement. 2433** 2434** {F13102} If the [prepared statement] passed as 2435** the an argument to [sqlite3_sql()] was compiled 2436** compiled using either [sqlite3_prepare()] or 2437** [sqlite3_prepare16()], 2438** then [sqlite3_sql()] function returns a NULL pointer. 2439** 2440** {F13103} The string returned by [sqlite3_sql(S)] is valid until the 2441** [prepared statement] S is deleted using [sqlite3_finalize(S)]. 2442*/ 2443const char *sqlite3_sql(sqlite3_stmt *pStmt); 2444 2445/* 2446** CAPI3REF: Dynamically Typed Value Object {F15000} 2447** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2448** 2449** SQLite uses the sqlite3_value object to represent all values 2450** that can be stored in a database table. 2451** SQLite uses dynamic typing for the values it stores. 2452** Values stored in sqlite3_value objects can be 2453** be integers, floating point values, strings, BLOBs, or NULL. 2454** 2455** An sqlite3_value object may be either "protected" or "unprotected". 2456** Some interfaces require a protected sqlite3_value. Other interfaces 2457** will accept either a protected or an unprotected sqlite3_value. 2458** Every interface that accepts sqlite3_value arguments specifies 2459** whether or not it requires a protected sqlite3_value. 2460** 2461** The terms "protected" and "unprotected" refer to whether or not 2462** a mutex is held. A internal mutex is held for a protected 2463** sqlite3_value object but no mutex is held for an unprotected 2464** sqlite3_value object. If SQLite is compiled to be single-threaded 2465** (with SQLITE_THREADSAFE=0 and with [sqlite3_threadsafe()] returning 0) 2466** then there is no distinction between 2467** protected and unprotected sqlite3_value objects and they can be 2468** used interchangable. However, for maximum code portability it 2469** is recommended that applications make the distinction between 2470** between protected and unprotected sqlite3_value objects even if 2471** they are single threaded. 2472** 2473** The sqlite3_value objects that are passed as parameters into the 2474** implementation of application-defined SQL functions are protected. 2475** The sqlite3_value object returned by 2476** [sqlite3_column_value()] is unprotected. 2477** Unprotected sqlite3_value objects may only be used with 2478** [sqlite3_result_value()] and [sqlite3_bind_value()]. All other 2479** interfaces that use sqlite3_value require protected sqlite3_value objects. 2480*/ 2481typedef struct Mem sqlite3_value; 2482 2483/* 2484** CAPI3REF: SQL Function Context Object {F16001} 2485** 2486** The context in which an SQL function executes is stored in an 2487** sqlite3_context object. A pointer to an sqlite3_context 2488** object is always first parameter to application-defined SQL functions. 2489*/ 2490typedef struct sqlite3_context sqlite3_context; 2491 2492/* 2493** CAPI3REF: Binding Values To Prepared Statements {F13500} 2494** 2495** In the SQL strings input to [sqlite3_prepare_v2()] and its 2496** variants, literals may be replace by a parameter in one 2497** of these forms: 2498** 2499** <ul> 2500** <li> ? 2501** <li> ?NNN 2502** <li> :VVV 2503** <li> @VVV 2504** <li> $VVV 2505** </ul> 2506** 2507** In the parameter forms shown above NNN is an integer literal, 2508** VVV alpha-numeric parameter name. 2509** The values of these parameters (also called "host parameter names" 2510** or "SQL parameters") 2511** can be set using the sqlite3_bind_*() routines defined here. 2512** 2513** The first argument to the sqlite3_bind_*() routines always 2514** is a pointer to the [sqlite3_stmt] object returned from 2515** [sqlite3_prepare_v2()] or its variants. The second 2516** argument is the index of the parameter to be set. The 2517** first parameter has an index of 1. When the same named 2518** parameter is used more than once, second and subsequent 2519** occurrences have the same index as the first occurrence. 2520** The index for named parameters can be looked up using the 2521** [sqlite3_bind_parameter_name()] API if desired. The index 2522** for "?NNN" parameters is the value of NNN. 2523** The NNN value must be between 1 and the compile-time 2524** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999). 2525** 2526** The third argument is the value to bind to the parameter. 2527** 2528** In those 2529** routines that have a fourth argument, its value is the number of bytes 2530** in the parameter. To be clear: the value is the number of <u>bytes</u> 2531** in the value, not the number of characters. The number 2532** of bytes does not include the zero-terminator at the end of strings. 2533** If the fourth parameter is negative, the length of the string is 2534** number of bytes up to the first zero terminator. 2535** 2536** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2537** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2538** string after SQLite has finished with it. If the fifth argument is 2539** the special value [SQLITE_STATIC], then SQLite assumes that the 2540** information is in static, unmanaged space and does not need to be freed. 2541** If the fifth argument has the value [SQLITE_TRANSIENT], then 2542** SQLite makes its own private copy of the data immediately, before 2543** the sqlite3_bind_*() routine returns. 2544** 2545** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2546** is filled with zeros. A zeroblob uses a fixed amount of memory 2547** (just an integer to hold it size) while it is being processed. 2548** Zeroblobs are intended to serve as place-holders for BLOBs whose 2549** content is later written using 2550** [sqlite3_blob_open | increment BLOB I/O] routines. A negative 2551** value for the zeroblob results in a zero-length BLOB. 2552** 2553** The sqlite3_bind_*() routines must be called after 2554** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2555** before [sqlite3_step()]. 2556** Bindings are not cleared by the [sqlite3_reset()] routine. 2557** Unbound parameters are interpreted as NULL. 2558** 2559** These routines return [SQLITE_OK] on success or an error code if 2560** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2561** index is out of range. [SQLITE_NOMEM] is returned if malloc fails. 2562** [SQLITE_MISUSE] might be returned if these routines are called on a 2563** virtual machine that is the wrong state or which has already been finalized. 2564** Detection of misuse is unreliable. Applications should not depend 2565** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2566** a logic error in the application. Future versions of SQLite might 2567** panic rather than return SQLITE_MISUSE. 2568** 2569** See also: [sqlite3_bind_parameter_count()], 2570** [sqlite3_bind_parameter_name()], and 2571** [sqlite3_bind_parameter_index()]. 2572** 2573** INVARIANTS: 2574** 2575** {F13506} The [sqlite3_prepare | SQL statement compiler] recognizes 2576** tokens of the forms "?", "?NNN", "$VVV", ":VVV", and "@VVV" 2577** as SQL parameters, where NNN is any sequence of one or more 2578** digits and where VVV is any sequence of one or more 2579** alphanumeric characters or "::" optionally followed by 2580** a string containing no spaces and contained within parentheses. 2581** 2582** {F13509} The initial value of an SQL parameter is NULL. 2583** 2584** {F13512} The index of an "?" SQL parameter is one larger than the 2585** largest index of SQL parameter to the left, or 1 if 2586** the "?" is the leftmost SQL parameter. 2587** 2588** {F13515} The index of an "?NNN" SQL parameter is the integer NNN. 2589** 2590** {F13518} The index of an ":VVV", "$VVV", or "@VVV" SQL parameter is 2591** the same as the index of leftmost occurances of the same 2592** parameter, or one more than the largest index over all 2593** parameters to the left if this is the first occurrance 2594** of this parameter, or 1 if this is the leftmost parameter. 2595** 2596** {F13521} The [sqlite3_prepare | SQL statement compiler] fail with 2597** an [SQLITE_RANGE] error if the index of an SQL parameter 2598** is less than 1 or greater than SQLITE_MAX_VARIABLE_NUMBER. 2599** 2600** {F13524} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,V,...)] 2601** associate the value V with all SQL parameters having an 2602** index of N in the [prepared statement] S. 2603** 2604** {F13527} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,...)] 2605** override prior calls with the same values of S and N. 2606** 2607** {F13530} Bindings established by [sqlite3_bind_text | sqlite3_bind(S,...)] 2608** persist across calls to [sqlite3_reset(S)]. 2609** 2610** {F13533} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2611** [sqlite3_bind_text(S,N,V,L,D)], or 2612** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds the first L 2613** bytes of the blob or string pointed to by V, when L 2614** is non-negative. 2615** 2616** {F13536} In calls to [sqlite3_bind_text(S,N,V,L,D)] or 2617** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds characters 2618** from V through the first zero character when L is negative. 2619** 2620** {F13539} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2621** [sqlite3_bind_text(S,N,V,L,D)], or 2622** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special 2623** constant [SQLITE_STATIC], SQLite assumes that the value V 2624** is held in static unmanaged space that will not change 2625** during the lifetime of the binding. 2626** 2627** {F13542} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2628** [sqlite3_bind_text(S,N,V,L,D)], or 2629** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special 2630** constant [SQLITE_TRANSIENT], the routine makes a 2631** private copy of V value before it returns. 2632** 2633** {F13545} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2634** [sqlite3_bind_text(S,N,V,L,D)], or 2635** [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to 2636** a function, SQLite invokes that function to destroy the 2637** V value after it has finished using the V value. 2638** 2639** {F13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound 2640** is a blob of L bytes, or a zero-length blob if L is negative. 2641** 2642** {F13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may 2643** be either a [protected sqlite3_value] object or an 2644** [unprotected sqlite3_value] object. 2645*/ 2646int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2647int sqlite3_bind_double(sqlite3_stmt*, int, double); 2648int sqlite3_bind_int(sqlite3_stmt*, int, int); 2649int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2650int sqlite3_bind_null(sqlite3_stmt*, int); 2651int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2652int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2653int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2654int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2655 2656/* 2657** CAPI3REF: Number Of SQL Parameters {F13600} 2658** 2659** This routine can be used to find the number of SQL parameters 2660** in a prepared statement. SQL parameters are tokens of the 2661** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2662** place-holders for values that are [sqlite3_bind_blob | bound] 2663** to the parameters at a later time. 2664** 2665** This routine actually returns the index of the largest parameter. 2666** For all forms except ?NNN, this will correspond to the number of 2667** unique parameters. If parameters of the ?NNN are used, there may 2668** be gaps in the list. 2669** 2670** See also: [sqlite3_bind_blob|sqlite3_bind()], 2671** [sqlite3_bind_parameter_name()], and 2672** [sqlite3_bind_parameter_index()]. 2673** 2674** INVARIANTS: 2675** 2676** {F13601} The [sqlite3_bind_parameter_count(S)] interface returns 2677** the largest index of all SQL parameters in the 2678** [prepared statement] S, or 0 if S 2679** contains no SQL parameters. 2680*/ 2681int sqlite3_bind_parameter_count(sqlite3_stmt*); 2682 2683/* 2684** CAPI3REF: Name Of A Host Parameter {F13620} 2685** 2686** This routine returns a pointer to the name of the n-th 2687** SQL parameter in a [prepared statement]. 2688** SQL parameters of the form ":AAA" or "@AAA" or "$AAA" have a name 2689** which is the string ":AAA" or "@AAA" or "$VVV". 2690** In other words, the initial ":" or "$" or "@" 2691** is included as part of the name. 2692** Parameters of the form "?" or "?NNN" have no name. 2693** 2694** The first host parameter has an index of 1, not 0. 2695** 2696** If the value n is out of range or if the n-th parameter is 2697** nameless, then NULL is returned. The returned string is 2698** always in the UTF-8 encoding even if the named parameter was 2699** originally specified as UTF-16 in [sqlite3_prepare16()] or 2700** [sqlite3_prepare16_v2()]. 2701** 2702** See also: [sqlite3_bind_blob|sqlite3_bind()], 2703** [sqlite3_bind_parameter_count()], and 2704** [sqlite3_bind_parameter_index()]. 2705** 2706** INVARIANTS: 2707** 2708** {F13621} The [sqlite3_bind_parameter_name(S,N)] interface returns 2709** a UTF-8 rendering of the name of the SQL parameter in 2710** [prepared statement] S having index N, or 2711** NULL if there is no SQL parameter with index N or if the 2712** parameter with index N is an anonymous parameter "?" or 2713** a numbered parameter "?NNN". 2714*/ 2715const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2716 2717/* 2718** CAPI3REF: Index Of A Parameter With A Given Name {F13640} 2719** 2720** Return the index of an SQL parameter given its name. The 2721** index value returned is suitable for use as the second 2722** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 2723** is returned if no matching parameter is found. The parameter 2724** name must be given in UTF-8 even if the original statement 2725** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2726** 2727** See also: [sqlite3_bind_blob|sqlite3_bind()], 2728** [sqlite3_bind_parameter_count()], and 2729** [sqlite3_bind_parameter_index()]. 2730** 2731** INVARIANTS: 2732** 2733** {F13641} The [sqlite3_bind_parameter_index(S,N)] interface returns 2734** the index of SQL parameter in [prepared statement] 2735** S whose name matches the UTF-8 string N, or 0 if there is 2736** no match. 2737*/ 2738int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2739 2740/* 2741** CAPI3REF: Reset All Bindings On A Prepared Statement {F13660} 2742** 2743** Contrary to the intuition of many, [sqlite3_reset()] does not 2744** reset the [sqlite3_bind_blob | bindings] on a 2745** [prepared statement]. Use this routine to 2746** reset all host parameters to NULL. 2747** 2748** INVARIANTS: 2749** 2750** {F13661} The [sqlite3_clear_bindings(S)] interface resets all 2751** SQL parameter bindings in [prepared statement] S 2752** back to NULL. 2753*/ 2754int sqlite3_clear_bindings(sqlite3_stmt*); 2755 2756/* 2757** CAPI3REF: Number Of Columns In A Result Set {F13710} 2758** 2759** Return the number of columns in the result set returned by the 2760** [prepared statement]. This routine returns 0 2761** if pStmt is an SQL statement that does not return data (for 2762** example an UPDATE). 2763** 2764** INVARIANTS: 2765** 2766** {F13711} The [sqlite3_column_count(S)] interface returns the number of 2767** columns in the result set generated by the 2768** [prepared statement] S, or 0 if S does not generate 2769** a result set. 2770*/ 2771int sqlite3_column_count(sqlite3_stmt *pStmt); 2772 2773/* 2774** CAPI3REF: Column Names In A Result Set {F13720} 2775** 2776** These routines return the name assigned to a particular column 2777** in the result set of a SELECT statement. The sqlite3_column_name() 2778** interface returns a pointer to a zero-terminated UTF8 string 2779** and sqlite3_column_name16() returns a pointer to a zero-terminated 2780** UTF16 string. The first parameter is the 2781** [prepared statement] that implements the SELECT statement. 2782** The second parameter is the column number. The left-most column is 2783** number 0. 2784** 2785** The returned string pointer is valid until either the 2786** [prepared statement] is destroyed by [sqlite3_finalize()] 2787** or until the next call sqlite3_column_name() or sqlite3_column_name16() 2788** on the same column. 2789** 2790** If sqlite3_malloc() fails during the processing of either routine 2791** (for example during a conversion from UTF-8 to UTF-16) then a 2792** NULL pointer is returned. 2793** 2794** The name of a result column is the value of the "AS" clause for 2795** that column, if there is an AS clause. If there is no AS clause 2796** then the name of the column is unspecified and may change from 2797** one release of SQLite to the next. 2798** 2799** INVARIANTS: 2800** 2801** {F13721} A successful invocation of the [sqlite3_column_name(S,N)] 2802** interface returns the name 2803** of the Nth column (where 0 is the left-most column) for the 2804** result set of [prepared statement] S as a 2805** zero-terminated UTF-8 string. 2806** 2807** {F13723} A successful invocation of the [sqlite3_column_name16(S,N)] 2808** interface returns the name 2809** of the Nth column (where 0 is the left-most column) for the 2810** result set of [prepared statement] S as a 2811** zero-terminated UTF-16 string in the native byte order. 2812** 2813** {F13724} The [sqlite3_column_name()] and [sqlite3_column_name16()] 2814** interfaces return a NULL pointer if they are unable to 2815** allocate memory memory to hold there normal return strings. 2816** 2817** {F13725} If the N parameter to [sqlite3_column_name(S,N)] or 2818** [sqlite3_column_name16(S,N)] is out of range, then the 2819** interfaces returns a NULL pointer. 2820** 2821** {F13726} The strings returned by [sqlite3_column_name(S,N)] and 2822** [sqlite3_column_name16(S,N)] are valid until the next 2823** call to either routine with the same S and N parameters 2824** or until [sqlite3_finalize(S)] is called. 2825** 2826** {F13727} When a result column of a [SELECT] statement contains 2827** an AS clause, the name of that column is the indentifier 2828** to the right of the AS keyword. 2829*/ 2830const char *sqlite3_column_name(sqlite3_stmt*, int N); 2831const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2832 2833/* 2834** CAPI3REF: Source Of Data In A Query Result {F13740} 2835** 2836** These routines provide a means to determine what column of what 2837** table in which database a result of a SELECT statement comes from. 2838** The name of the database or table or column can be returned as 2839** either a UTF8 or UTF16 string. The _database_ routines return 2840** the database name, the _table_ routines return the table name, and 2841** the origin_ routines return the column name. 2842** The returned string is valid until 2843** the [prepared statement] is destroyed using 2844** [sqlite3_finalize()] or until the same information is requested 2845** again in a different encoding. 2846** 2847** The names returned are the original un-aliased names of the 2848** database, table, and column. 2849** 2850** The first argument to the following calls is a [prepared statement]. 2851** These functions return information about the Nth column returned by 2852** the statement, where N is the second function argument. 2853** 2854** If the Nth column returned by the statement is an expression 2855** or subquery and is not a column value, then all of these functions 2856** return NULL. These routine might also return NULL if a memory 2857** allocation error occurs. Otherwise, they return the 2858** name of the attached database, table and column that query result 2859** column was extracted from. 2860** 2861** As with all other SQLite APIs, those postfixed with "16" return 2862** UTF-16 encoded strings, the other functions return UTF-8. {END} 2863** 2864** These APIs are only available if the library was compiled with the 2865** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined. 2866** 2867** {U13751} 2868** If two or more threads call one or more of these routines against the same 2869** prepared statement and column at the same time then the results are 2870** undefined. 2871** 2872** INVARIANTS: 2873** 2874** {F13741} The [sqlite3_column_database_name(S,N)] interface returns either 2875** the UTF-8 zero-terminated name of the database from which the 2876** Nth result column of [prepared statement] S 2877** is extracted, or NULL if the the Nth column of S is a 2878** general expression or if unable to allocate memory 2879** to store the name. 2880** 2881** {F13742} The [sqlite3_column_database_name16(S,N)] interface returns either 2882** the UTF-16 native byte order 2883** zero-terminated name of the database from which the 2884** Nth result column of [prepared statement] S 2885** is extracted, or NULL if the the Nth column of S is a 2886** general expression or if unable to allocate memory 2887** to store the name. 2888** 2889** {F13743} The [sqlite3_column_table_name(S,N)] interface returns either 2890** the UTF-8 zero-terminated name of the table from which the 2891** Nth result column of [prepared statement] S 2892** is extracted, or NULL if the the Nth column of S is a 2893** general expression or if unable to allocate memory 2894** to store the name. 2895** 2896** {F13744} The [sqlite3_column_table_name16(S,N)] interface returns either 2897** the UTF-16 native byte order 2898** zero-terminated name of the table from which the 2899** Nth result column of [prepared statement] S 2900** is extracted, or NULL if the the Nth column of S is a 2901** general expression or if unable to allocate memory 2902** to store the name. 2903** 2904** {F13745} The [sqlite3_column_origin_name(S,N)] interface returns either 2905** the UTF-8 zero-terminated name of the table column from which the 2906** Nth result column of [prepared statement] S 2907** is extracted, or NULL if the the Nth column of S is a 2908** general expression or if unable to allocate memory 2909** to store the name. 2910** 2911** {F13746} The [sqlite3_column_origin_name16(S,N)] interface returns either 2912** the UTF-16 native byte order 2913** zero-terminated name of the table column from which the 2914** Nth result column of [prepared statement] S 2915** is extracted, or NULL if the the Nth column of S is a 2916** general expression or if unable to allocate memory 2917** to store the name. 2918** 2919** {F13748} The return values from 2920** [sqlite3_column_database_name|column metadata interfaces] 2921** are valid 2922** for the lifetime of the [prepared statement] 2923** or until the encoding is changed by another metadata 2924** interface call for the same prepared statement and column. 2925** 2926** LIMITATIONS: 2927** 2928** {U13751} If two or more threads call one or more 2929** [sqlite3_column_database_name|column metadata interfaces] 2930** the same [prepared statement] and result column 2931** at the same time then the results are undefined. 2932*/ 2933const char *sqlite3_column_database_name(sqlite3_stmt*,int); 2934const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 2935const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2936const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2937const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2938const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2939 2940/* 2941** CAPI3REF: Declared Datatype Of A Query Result {F13760} 2942** 2943** The first parameter is a [prepared statement]. 2944** If this statement is a SELECT statement and the Nth column of the 2945** returned result set of that SELECT is a table column (not an 2946** expression or subquery) then the declared type of the table 2947** column is returned. If the Nth column of the result set is an 2948** expression or subquery, then a NULL pointer is returned. 2949** The returned string is always UTF-8 encoded. {END} 2950** For example, in the database schema: 2951** 2952** CREATE TABLE t1(c1 VARIANT); 2953** 2954** And the following statement compiled: 2955** 2956** SELECT c1 + 1, c1 FROM t1; 2957** 2958** Then this routine would return the string "VARIANT" for the second 2959** result column (i==1), and a NULL pointer for the first result column 2960** (i==0). 2961** 2962** SQLite uses dynamic run-time typing. So just because a column 2963** is declared to contain a particular type does not mean that the 2964** data stored in that column is of the declared type. SQLite is 2965** strongly typed, but the typing is dynamic not static. Type 2966** is associated with individual values, not with the containers 2967** used to hold those values. 2968** 2969** INVARIANTS: 2970** 2971** {F13761} A successful call to [sqlite3_column_decltype(S,N)] 2972** returns a zero-terminated UTF-8 string containing the 2973** the declared datatype of the table column that appears 2974** as the Nth column (numbered from 0) of the result set to the 2975** [prepared statement] S. 2976** 2977** {F13762} A successful call to [sqlite3_column_decltype16(S,N)] 2978** returns a zero-terminated UTF-16 native byte order string 2979** containing the declared datatype of the table column that appears 2980** as the Nth column (numbered from 0) of the result set to the 2981** [prepared statement] S. 2982** 2983** {F13763} If N is less than 0 or N is greater than or equal to 2984** the number of columns in [prepared statement] S 2985** or if the Nth column of S is an expression or subquery rather 2986** than a table column or if a memory allocation failure 2987** occurs during encoding conversions, then 2988** calls to [sqlite3_column_decltype(S,N)] or 2989** [sqlite3_column_decltype16(S,N)] return NULL. 2990*/ 2991const char *sqlite3_column_decltype(sqlite3_stmt*,int); 2992const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2993 2994/* 2995** CAPI3REF: Evaluate An SQL Statement {F13200} 2996** 2997** After an [prepared statement] has been prepared with a call 2998** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of 2999** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], 3000** then this function must be called one or more times to evaluate the 3001** statement. 3002** 3003** The details of the behavior of this sqlite3_step() interface depend 3004** on whether the statement was prepared using the newer "v2" interface 3005** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3006** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3007** new "v2" interface is recommended for new applications but the legacy 3008** interface will continue to be supported. 3009** 3010** In the lagacy interface, the return value will be either [SQLITE_BUSY], 3011** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3012** With the "v2" interface, any of the other [SQLITE_OK | result code] 3013** or [SQLITE_IOERR_READ | extended result code] might be returned as 3014** well. 3015** 3016** [SQLITE_BUSY] means that the database engine was unable to acquire the 3017** database locks it needs to do its job. If the statement is a COMMIT 3018** or occurs outside of an explicit transaction, then you can retry the 3019** statement. If the statement is not a COMMIT and occurs within a 3020** explicit transaction then you should rollback the transaction before 3021** continuing. 3022** 3023** [SQLITE_DONE] means that the statement has finished executing 3024** successfully. sqlite3_step() should not be called again on this virtual 3025** machine without first calling [sqlite3_reset()] to reset the virtual 3026** machine back to its initial state. 3027** 3028** If the SQL statement being executed returns any data, then 3029** [SQLITE_ROW] is returned each time a new row of data is ready 3030** for processing by the caller. The values may be accessed using 3031** the [sqlite3_column_int | column access functions]. 3032** sqlite3_step() is called again to retrieve the next row of data. 3033** 3034** [SQLITE_ERROR] means that a run-time error (such as a constraint 3035** violation) has occurred. sqlite3_step() should not be called again on 3036** the VM. More information may be found by calling [sqlite3_errmsg()]. 3037** With the legacy interface, a more specific error code (example: 3038** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3039** can be obtained by calling [sqlite3_reset()] on the 3040** [prepared statement]. In the "v2" interface, 3041** the more specific error code is returned directly by sqlite3_step(). 3042** 3043** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3044** Perhaps it was called on a [prepared statement] that has 3045** already been [sqlite3_finalize | finalized] or on one that had 3046** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3047** be the case that the same database connection is being used by two or 3048** more threads at the same moment in time. 3049** 3050** <b>Goofy Interface Alert:</b> 3051** In the legacy interface, 3052** the sqlite3_step() API always returns a generic error code, 3053** [SQLITE_ERROR], following any error other than [SQLITE_BUSY] 3054** and [SQLITE_MISUSE]. You must call [sqlite3_reset()] or 3055** [sqlite3_finalize()] in order to find one of the specific 3056** [error codes] that better describes the error. 3057** We admit that this is a goofy design. The problem has been fixed 3058** with the "v2" interface. If you prepare all of your SQL statements 3059** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3060** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the 3061** more specific [error codes] are returned directly 3062** by sqlite3_step(). The use of the "v2" interface is recommended. 3063** 3064** INVARIANTS: 3065** 3066** {F13202} If [prepared statement] S is ready to be 3067** run, then [sqlite3_step(S)] advances that prepared statement 3068** until to completion or until it is ready to return another 3069** row of the result set or an interrupt or run-time error occurs. 3070** 3071** {F15304} When a call to [sqlite3_step(S)] causes the 3072** [prepared statement] S to run to completion, 3073** the function returns [SQLITE_DONE]. 3074** 3075** {F15306} When a call to [sqlite3_step(S)] stops because it is ready 3076** to return another row of the result set, it returns 3077** [SQLITE_ROW]. 3078** 3079** {F15308} If a call to [sqlite3_step(S)] encounters an 3080** [sqlite3_interrupt|interrupt] or a run-time error, 3081** it returns an appropraite error code that is not one of 3082** [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE]. 3083** 3084** {F15310} If an [sqlite3_interrupt|interrupt] or run-time error 3085** occurs during a call to [sqlite3_step(S)] 3086** for a [prepared statement] S created using 3087** legacy interfaces [sqlite3_prepare()] or 3088** [sqlite3_prepare16()] then the function returns either 3089** [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE]. 3090*/ 3091int sqlite3_step(sqlite3_stmt*); 3092 3093/* 3094** CAPI3REF: Number of columns in a result set {F13770} 3095** 3096** Return the number of values in the current row of the result set. 3097** 3098** INVARIANTS: 3099** 3100** {F13771} After a call to [sqlite3_step(S)] that returns 3101** [SQLITE_ROW], the [sqlite3_data_count(S)] routine 3102** will return the same value as the 3103** [sqlite3_column_count(S)] function. 3104** 3105** {F13772} After [sqlite3_step(S)] has returned any value other than 3106** [SQLITE_ROW] or before [sqlite3_step(S)] has been 3107** called on the [prepared statement] for 3108** the first time since it was [sqlite3_prepare|prepared] 3109** or [sqlite3_reset|reset], the [sqlite3_data_count(S)] 3110** routine returns zero. 3111*/ 3112int sqlite3_data_count(sqlite3_stmt *pStmt); 3113 3114/* 3115** CAPI3REF: Fundamental Datatypes {F10265} 3116** KEYWORDS: SQLITE_TEXT 3117** 3118** {F10266}Every value in SQLite has one of five fundamental datatypes: 3119** 3120** <ul> 3121** <li> 64-bit signed integer 3122** <li> 64-bit IEEE floating point number 3123** <li> string 3124** <li> BLOB 3125** <li> NULL 3126** </ul> {END} 3127** 3128** These constants are codes for each of those types. 3129** 3130** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3131** for a completely different meaning. Software that links against both 3132** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not 3133** SQLITE_TEXT. 3134*/ 3135#define SQLITE_INTEGER 1 3136#define SQLITE_FLOAT 2 3137#define SQLITE_BLOB 4 3138#define SQLITE_NULL 5 3139#ifdef SQLITE_TEXT 3140# undef SQLITE_TEXT 3141#else 3142# define SQLITE_TEXT 3 3143#endif 3144#define SQLITE3_TEXT 3 3145 3146/* 3147** CAPI3REF: Results Values From A Query {F13800} 3148** 3149** These routines form the "result set query" interface. 3150** 3151** These routines return information about 3152** a single column of the current result row of a query. In every 3153** case the first argument is a pointer to the 3154** [prepared statement] that is being 3155** evaluated (the [sqlite3_stmt*] that was returned from 3156** [sqlite3_prepare_v2()] or one of its variants) and 3157** the second argument is the index of the column for which information 3158** should be returned. The left-most column of the result set 3159** has an index of 0. 3160** 3161** If the SQL statement is not currently point to a valid row, or if the 3162** the column index is out of range, the result is undefined. 3163** These routines may only be called when the most recent call to 3164** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3165** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently. 3166** If any of these routines are called after [sqlite3_reset()] or 3167** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3168** something other than [SQLITE_ROW], the results are undefined. 3169** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3170** are called from a different thread while any of these routines 3171** are pending, then the results are undefined. 3172** 3173** The sqlite3_column_type() routine returns 3174** [SQLITE_INTEGER | datatype code] for the initial data type 3175** of the result column. The returned value is one of [SQLITE_INTEGER], 3176** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3177** returned by sqlite3_column_type() is only meaningful if no type 3178** conversions have occurred as described below. After a type conversion, 3179** the value returned by sqlite3_column_type() is undefined. Future 3180** versions of SQLite may change the behavior of sqlite3_column_type() 3181** following a type conversion. 3182** 3183** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3184** routine returns the number of bytes in that BLOB or string. 3185** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3186** the string to UTF-8 and then returns the number of bytes. 3187** If the result is a numeric value then sqlite3_column_bytes() uses 3188** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3189** the number of bytes in that string. 3190** The value returned does not include the zero terminator at the end 3191** of the string. For clarity: the value returned is the number of 3192** bytes in the string, not the number of characters. 3193** 3194** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3195** even empty strings, are always zero terminated. The return 3196** value from sqlite3_column_blob() for a zero-length blob is an arbitrary 3197** pointer, possibly even a NULL pointer. 3198** 3199** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 3200** but leaves the result in UTF-16 in native byte order instead of UTF-8. 3201** The zero terminator is not included in this count. 3202** 3203** The object returned by [sqlite3_column_value()] is an 3204** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3205** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3206** If the [unprotected sqlite3_value] object returned by 3207** [sqlite3_column_value()] is used in any other way, including calls 3208** to routines like 3209** [sqlite3_value_int()], [sqlite3_value_text()], or [sqlite3_value_bytes()], 3210** then the behavior is undefined. 3211** 3212** These routines attempt to convert the value where appropriate. For 3213** example, if the internal representation is FLOAT and a text result 3214** is requested, [sqlite3_snprintf()] is used internally to do the conversion 3215** automatically. The following table details the conversions that 3216** are applied: 3217** 3218** <blockquote> 3219** <table border="1"> 3220** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3221** 3222** <tr><td> NULL <td> INTEGER <td> Result is 0 3223** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3224** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3225** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3226** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3227** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3228** <tr><td> INTEGER <td> BLOB <td> Same as for INTEGER->TEXT 3229** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3230** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3231** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3232** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3233** <tr><td> TEXT <td> FLOAT <td> Use atof() 3234** <tr><td> TEXT <td> BLOB <td> No change 3235** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3236** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3237** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3238** </table> 3239** </blockquote> 3240** 3241** The table above makes reference to standard C library functions atoi() 3242** and atof(). SQLite does not really use these functions. It has its 3243** on equavalent internal routines. The atoi() and atof() names are 3244** used in the table for brevity and because they are familiar to most 3245** C programmers. 3246** 3247** Note that when type conversions occur, pointers returned by prior 3248** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3249** sqlite3_column_text16() may be invalidated. 3250** Type conversions and pointer invalidations might occur 3251** in the following cases: 3252** 3253** <ul> 3254** <li><p> The initial content is a BLOB and sqlite3_column_text() 3255** or sqlite3_column_text16() is called. A zero-terminator might 3256** need to be added to the string.</p></li> 3257** 3258** <li><p> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3259** sqlite3_column_text16() is called. The content must be converted 3260** to UTF-16.</p></li> 3261** 3262** <li><p> The initial content is UTF-16 text and sqlite3_column_bytes() or 3263** sqlite3_column_text() is called. The content must be converted 3264** to UTF-8.</p></li> 3265** </ul> 3266** 3267** Conversions between UTF-16be and UTF-16le are always done in place and do 3268** not invalidate a prior pointer, though of course the content of the buffer 3269** that the prior pointer points to will have been modified. Other kinds 3270** of conversion are done in place when it is possible, but sometime it is 3271** not possible and in those cases prior pointers are invalidated. 3272** 3273** The safest and easiest to remember policy is to invoke these routines 3274** in one of the following ways: 3275** 3276** <ul> 3277** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3278** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3279** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3280** </ul> 3281** 3282** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(), 3283** or sqlite3_column_text16() first to force the result into the desired 3284** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to 3285** find the size of the result. Do not mix call to sqlite3_column_text() or 3286** sqlite3_column_blob() with calls to sqlite3_column_bytes16(). And do not 3287** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes(). 3288** 3289** The pointers returned are valid until a type conversion occurs as 3290** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3291** [sqlite3_finalize()] is called. The memory space used to hold strings 3292** and blobs is freed automatically. Do <b>not</b> pass the pointers returned 3293** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3294** [sqlite3_free()]. 3295** 3296** If a memory allocation error occurs during the evaluation of any 3297** of these routines, a default value is returned. The default value 3298** is either the integer 0, the floating point number 0.0, or a NULL 3299** pointer. Subsequent calls to [sqlite3_errcode()] will return 3300** [SQLITE_NOMEM]. 3301** 3302** INVARIANTS: 3303** 3304** {F13803} The [sqlite3_column_blob(S,N)] interface converts the 3305** Nth column in the current row of the result set for 3306** [prepared statement] S into a blob and then returns a 3307** pointer to the converted value. 3308** 3309** {F13806} The [sqlite3_column_bytes(S,N)] interface returns the 3310** number of bytes in the blob or string (exclusive of the 3311** zero terminator on the string) that was returned by the 3312** most recent call to [sqlite3_column_blob(S,N)] or 3313** [sqlite3_column_text(S,N)]. 3314** 3315** {F13809} The [sqlite3_column_bytes16(S,N)] interface returns the 3316** number of bytes in the string (exclusive of the 3317** zero terminator on the string) that was returned by the 3318** most recent call to [sqlite3_column_text16(S,N)]. 3319** 3320** {F13812} The [sqlite3_column_double(S,N)] interface converts the 3321** Nth column in the current row of the result set for 3322** [prepared statement] S into a floating point value and 3323** returns a copy of that value. 3324** 3325** {F13815} The [sqlite3_column_int(S,N)] interface converts the 3326** Nth column in the current row of the result set for 3327** [prepared statement] S into a 64-bit signed integer and 3328** returns the lower 32 bits of that integer. 3329** 3330** {F13818} The [sqlite3_column_int64(S,N)] interface converts the 3331** Nth column in the current row of the result set for 3332** [prepared statement] S into a 64-bit signed integer and 3333** returns a copy of that integer. 3334** 3335** {F13821} The [sqlite3_column_text(S,N)] interface converts the 3336** Nth column in the current row of the result set for 3337** [prepared statement] S into a zero-terminated UTF-8 3338** string and returns a pointer to that string. 3339** 3340** {F13824} The [sqlite3_column_text16(S,N)] interface converts the 3341** Nth column in the current row of the result set for 3342** [prepared statement] S into a zero-terminated 2-byte 3343** aligned UTF-16 native byte order 3344** string and returns a pointer to that string. 3345** 3346** {F13827} The [sqlite3_column_type(S,N)] interface returns 3347** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT], 3348** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for 3349** the Nth column in the current row of the result set for 3350** [prepared statement] S. 3351** 3352** {F13830} The [sqlite3_column_value(S,N)] interface returns a 3353** pointer to an [unprotected sqlite3_value] object for the 3354** Nth column in the current row of the result set for 3355** [prepared statement] S. 3356*/ 3357const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3358int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3359int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3360double sqlite3_column_double(sqlite3_stmt*, int iCol); 3361int sqlite3_column_int(sqlite3_stmt*, int iCol); 3362sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3363const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3364const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3365int sqlite3_column_type(sqlite3_stmt*, int iCol); 3366sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3367 3368/* 3369** CAPI3REF: Destroy A Prepared Statement Object {F13300} 3370** 3371** The sqlite3_finalize() function is called to delete a 3372** [prepared statement]. If the statement was 3373** executed successfully, or not executed at all, then SQLITE_OK is returned. 3374** If execution of the statement failed then an 3375** [error code] or [extended error code] 3376** is returned. 3377** 3378** This routine can be called at any point during the execution of the 3379** [prepared statement]. If the virtual machine has not 3380** completed execution when this routine is called, that is like 3381** encountering an error or an interrupt. (See [sqlite3_interrupt()].) 3382** Incomplete updates may be rolled back and transactions cancelled, 3383** depending on the circumstances, and the 3384** [error code] returned will be [SQLITE_ABORT]. 3385** 3386** INVARIANTS: 3387** 3388** {F11302} The [sqlite3_finalize(S)] interface destroys the 3389** [prepared statement] S and releases all 3390** memory and file resources held by that object. 3391** 3392** {F11304} If the most recent call to [sqlite3_step(S)] for the 3393** [prepared statement] S returned an error, 3394** then [sqlite3_finalize(S)] returns that same error. 3395*/ 3396int sqlite3_finalize(sqlite3_stmt *pStmt); 3397 3398/* 3399** CAPI3REF: Reset A Prepared Statement Object {F13330} 3400** 3401** The sqlite3_reset() function is called to reset a 3402** [prepared statement] object. 3403** back to its initial state, ready to be re-executed. 3404** Any SQL statement variables that had values bound to them using 3405** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3406** Use [sqlite3_clear_bindings()] to reset the bindings. 3407** 3408** {F11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3409** back to the beginning of its program. 3410** 3411** {F11334} If the most recent call to [sqlite3_step(S)] for 3412** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3413** or if [sqlite3_step(S)] has never before been called on S, 3414** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3415** 3416** {F11336} If the most recent call to [sqlite3_step(S)] for 3417** [prepared statement] S indicated an error, then 3418** [sqlite3_reset(S)] returns an appropriate [error code]. 3419** 3420** {F11338} The [sqlite3_reset(S)] interface does not change the values 3421** of any [sqlite3_bind_blob|bindings] on [prepared statement] S. 3422*/ 3423int sqlite3_reset(sqlite3_stmt *pStmt); 3424 3425/* 3426** CAPI3REF: Create Or Redefine SQL Functions {F16100} 3427** KEYWORDS: {function creation routines} 3428** 3429** These two functions (collectively known as 3430** "function creation routines") are used to add SQL functions or aggregates 3431** or to redefine the behavior of existing SQL functions or aggregates. The 3432** difference only between the two is that the second parameter, the 3433** name of the (scalar) function or aggregate, is encoded in UTF-8 for 3434** sqlite3_create_function() and UTF-16 for sqlite3_create_function16(). 3435** 3436** The first parameter is the [database connection] to which the SQL 3437** function is to be added. If a single 3438** program uses more than one [database connection] internally, then SQL 3439** functions must be added individually to each [database connection]. 3440** 3441** The second parameter is the name of the SQL function to be created 3442** or redefined. 3443** The length of the name is limited to 255 bytes, exclusive of the 3444** zero-terminator. Note that the name length limit is in bytes, not 3445** characters. Any attempt to create a function with a longer name 3446** will result in an SQLITE_ERROR error. 3447** 3448** The third parameter is the number of arguments that the SQL function or 3449** aggregate takes. If this parameter is negative, then the SQL function or 3450** aggregate may take any number of arguments. 3451** 3452** The fourth parameter, eTextRep, specifies what 3453** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3454** its parameters. Any SQL function implementation should be able to work 3455** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3456** more efficient with one encoding than another. It is allowed to 3457** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3458** times with the same function but with different values of eTextRep. 3459** When multiple implementations of the same function are available, SQLite 3460** will pick the one that involves the least amount of data conversion. 3461** If there is only a single implementation which does not care what 3462** text encoding is used, then the fourth argument should be 3463** [SQLITE_ANY]. 3464** 3465** The fifth parameter is an arbitrary pointer. The implementation 3466** of the function can gain access to this pointer using 3467** [sqlite3_user_data()]. 3468** 3469** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3470** pointers to C-language functions that implement the SQL 3471** function or aggregate. A scalar SQL function requires an implementation of 3472** the xFunc callback only, NULL pointers should be passed as the xStep 3473** and xFinal parameters. An aggregate SQL function requires an implementation 3474** of xStep and xFinal and NULL should be passed for xFunc. To delete an 3475** existing SQL function or aggregate, pass NULL for all three function 3476** callback. 3477** 3478** It is permitted to register multiple implementations of the same 3479** functions with the same name but with either differing numbers of 3480** arguments or differing perferred text encodings. SQLite will use 3481** the implementation most closely matches the way in which the 3482** SQL function is used. 3483** 3484** INVARIANTS: 3485** 3486** {F16103} The [sqlite3_create_function16()] interface behaves exactly 3487** like [sqlite3_create_function()] in every way except that it 3488** interprets the zFunctionName argument as 3489** zero-terminated UTF-16 native byte order instead of as a 3490** zero-terminated UTF-8. 3491** 3492** {F16106} A successful invocation of 3493** the [sqlite3_create_function(D,X,N,E,...)] interface registers 3494** or replaces callback functions in [database connection] D 3495** used to implement the SQL function named X with N parameters 3496** and having a perferred text encoding of E. 3497** 3498** {F16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3499** replaces the P, F, S, and L values from any prior calls with 3500** the same D, X, N, and E values. 3501** 3502** {F16112} The [sqlite3_create_function(D,X,...)] interface fails with 3503** a return code of [SQLITE_ERROR] if the SQL function name X is 3504** longer than 255 bytes exclusive of the zero terminator. 3505** 3506** {F16118} Either F must be NULL and S and L are non-NULL or else F 3507** is non-NULL and S and L are NULL, otherwise 3508** [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR]. 3509** 3510** {F16121} The [sqlite3_create_function(D,...)] interface fails with an 3511** error code of [SQLITE_BUSY] if there exist [prepared statements] 3512** associated with the [database connection] D. 3513** 3514** {F16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an 3515** error code of [SQLITE_ERROR] if parameter N (specifying the number 3516** of arguments to the SQL function being registered) is less 3517** than -1 or greater than 127. 3518** 3519** {F16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)] 3520** interface causes callbacks to be invoked for the SQL function 3521** named X when the number of arguments to the SQL function is 3522** exactly N. 3523** 3524** {F16130} When N is -1, the [sqlite3_create_function(D,X,N,...)] 3525** interface causes callbacks to be invoked for the SQL function 3526** named X with any number of arguments. 3527** 3528** {F16133} When calls to [sqlite3_create_function(D,X,N,...)] 3529** specify multiple implementations of the same function X 3530** and when one implementation has N>=0 and the other has N=(-1) 3531** the implementation with a non-zero N is preferred. 3532** 3533** {F16136} When calls to [sqlite3_create_function(D,X,N,E,...)] 3534** specify multiple implementations of the same function X with 3535** the same number of arguments N but with different 3536** encodings E, then the implementation where E matches the 3537** database encoding is preferred. 3538** 3539** {F16139} For an aggregate SQL function created using 3540** [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finializer 3541** function L will always be invoked exactly once if the 3542** step function S is called one or more times. 3543** 3544** {F16142} When SQLite invokes either the xFunc or xStep function of 3545** an application-defined SQL function or aggregate created 3546** by [sqlite3_create_function()] or [sqlite3_create_function16()], 3547** then the array of [sqlite3_value] objects passed as the 3548** third parameter are always [protected sqlite3_value] objects. 3549*/ 3550int sqlite3_create_function( 3551 sqlite3 *db, 3552 const char *zFunctionName, 3553 int nArg, 3554 int eTextRep, 3555 void *pApp, 3556 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3557 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3558 void (*xFinal)(sqlite3_context*) 3559); 3560int sqlite3_create_function16( 3561 sqlite3 *db, 3562 const void *zFunctionName, 3563 int nArg, 3564 int eTextRep, 3565 void *pApp, 3566 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3567 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3568 void (*xFinal)(sqlite3_context*) 3569); 3570 3571/* 3572** CAPI3REF: Text Encodings {F10267} 3573** 3574** These constant define integer codes that represent the various 3575** text encodings supported by SQLite. 3576*/ 3577#define SQLITE_UTF8 1 3578#define SQLITE_UTF16LE 2 3579#define SQLITE_UTF16BE 3 3580#define SQLITE_UTF16 4 /* Use native byte order */ 3581#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3582#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3583 3584/* 3585** CAPI3REF: Obsolete Functions 3586** 3587** These functions are all now obsolete. In order to maintain 3588** backwards compatibility with older code, we continue to support 3589** these functions. However, new development projects should avoid 3590** the use of these functions. To help encourage people to avoid 3591** using these functions, we are not going to tell you want they do. 3592*/ 3593int sqlite3_aggregate_count(sqlite3_context*); 3594int sqlite3_expired(sqlite3_stmt*); 3595int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3596int sqlite3_global_recover(void); 3597void sqlite3_thread_cleanup(void); 3598int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3599 3600/* 3601** CAPI3REF: Obtaining SQL Function Parameter Values {F15100} 3602** 3603** The C-language implementation of SQL functions and aggregates uses 3604** this set of interface routines to access the parameter values on 3605** the function or aggregate. 3606** 3607** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3608** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3609** define callbacks that implement the SQL functions and aggregates. 3610** The 4th parameter to these callbacks is an array of pointers to 3611** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3612** each parameter to the SQL function. These routines are used to 3613** extract values from the [sqlite3_value] objects. 3614** 3615** These routines work only with [protected sqlite3_value] objects. 3616** Any attempt to use these routines on an [unprotected sqlite3_value] 3617** object results in undefined behavior. 3618** 3619** These routines work just like the corresponding 3620** [sqlite3_column_blob | sqlite3_column_* routines] except that 3621** these routines take a single [protected sqlite3_value] object pointer 3622** instead of an [sqlite3_stmt*] pointer and an integer column number. 3623** 3624** The sqlite3_value_text16() interface extracts a UTF16 string 3625** in the native byte-order of the host machine. The 3626** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3627** extract UTF16 strings as big-endian and little-endian respectively. 3628** 3629** The sqlite3_value_numeric_type() interface attempts to apply 3630** numeric affinity to the value. This means that an attempt is 3631** made to convert the value to an integer or floating point. If 3632** such a conversion is possible without loss of information (in other 3633** words if the value is a string that looks like a number) 3634** then the conversion is done. Otherwise no conversion occurs. The 3635** [SQLITE_INTEGER | datatype] after conversion is returned. 3636** 3637** Please pay particular attention to the fact that the pointer that 3638** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or 3639** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3640** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3641** or [sqlite3_value_text16()]. 3642** 3643** These routines must be called from the same thread as 3644** the SQL function that supplied the [sqlite3_value*] parameters. 3645** 3646** 3647** INVARIANTS: 3648** 3649** {F15103} The [sqlite3_value_blob(V)] interface converts the 3650** [protected sqlite3_value] object V into a blob and then returns a 3651** pointer to the converted value. 3652** 3653** {F15106} The [sqlite3_value_bytes(V)] interface returns the 3654** number of bytes in the blob or string (exclusive of the 3655** zero terminator on the string) that was returned by the 3656** most recent call to [sqlite3_value_blob(V)] or 3657** [sqlite3_value_text(V)]. 3658** 3659** {F15109} The [sqlite3_value_bytes16(V)] interface returns the 3660** number of bytes in the string (exclusive of the 3661** zero terminator on the string) that was returned by the 3662** most recent call to [sqlite3_value_text16(V)], 3663** [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)]. 3664** 3665** {F15112} The [sqlite3_value_double(V)] interface converts the 3666** [protected sqlite3_value] object V into a floating point value and 3667** returns a copy of that value. 3668** 3669** {F15115} The [sqlite3_value_int(V)] interface converts the 3670** [protected sqlite3_value] object V into a 64-bit signed integer and 3671** returns the lower 32 bits of that integer. 3672** 3673** {F15118} The [sqlite3_value_int64(V)] interface converts the 3674** [protected sqlite3_value] object V into a 64-bit signed integer and 3675** returns a copy of that integer. 3676** 3677** {F15121} The [sqlite3_value_text(V)] interface converts the 3678** [protected sqlite3_value] object V into a zero-terminated UTF-8 3679** string and returns a pointer to that string. 3680** 3681** {F15124} The [sqlite3_value_text16(V)] interface converts the 3682** [protected sqlite3_value] object V into a zero-terminated 2-byte 3683** aligned UTF-16 native byte order 3684** string and returns a pointer to that string. 3685** 3686** {F15127} The [sqlite3_value_text16be(V)] interface converts the 3687** [protected sqlite3_value] object V into a zero-terminated 2-byte 3688** aligned UTF-16 big-endian 3689** string and returns a pointer to that string. 3690** 3691** {F15130} The [sqlite3_value_text16le(V)] interface converts the 3692** [protected sqlite3_value] object V into a zero-terminated 2-byte 3693** aligned UTF-16 little-endian 3694** string and returns a pointer to that string. 3695** 3696** {F15133} The [sqlite3_value_type(V)] interface returns 3697** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT], 3698** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for 3699** the [sqlite3_value] object V. 3700** 3701** {F15136} The [sqlite3_value_numeric_type(V)] interface converts 3702** the [protected sqlite3_value] object V into either an integer or 3703** a floating point value if it can do so without loss of 3704** information, and returns one of [SQLITE_NULL], 3705** [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or 3706** [SQLITE_BLOB] as appropriate for 3707** the [protected sqlite3_value] object V after the conversion attempt. 3708*/ 3709const void *sqlite3_value_blob(sqlite3_value*); 3710int sqlite3_value_bytes(sqlite3_value*); 3711int sqlite3_value_bytes16(sqlite3_value*); 3712double sqlite3_value_double(sqlite3_value*); 3713int sqlite3_value_int(sqlite3_value*); 3714sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3715const unsigned char *sqlite3_value_text(sqlite3_value*); 3716const void *sqlite3_value_text16(sqlite3_value*); 3717const void *sqlite3_value_text16le(sqlite3_value*); 3718const void *sqlite3_value_text16be(sqlite3_value*); 3719int sqlite3_value_type(sqlite3_value*); 3720int sqlite3_value_numeric_type(sqlite3_value*); 3721 3722/* 3723** CAPI3REF: Obtain Aggregate Function Context {F16210} 3724** 3725** The implementation of aggregate SQL functions use this routine to allocate 3726** a structure for storing their state. 3727** The first time the sqlite3_aggregate_context() routine is 3728** is called for a particular aggregate, SQLite allocates nBytes of memory 3729** zeros that memory, and returns a pointer to it. 3730** On second and subsequent calls to sqlite3_aggregate_context() 3731** for the same aggregate function index, the same buffer is returned. 3732** The implementation 3733** of the aggregate can use the returned buffer to accumulate data. 3734** 3735** SQLite automatically frees the allocated buffer when the aggregate 3736** query concludes. 3737** 3738** The first parameter should be a copy of the 3739** [sqlite3_context | SQL function context] that is the first 3740** parameter to the callback routine that implements the aggregate 3741** function. 3742** 3743** This routine must be called from the same thread in which 3744** the aggregate SQL function is running. 3745** 3746** INVARIANTS: 3747** 3748** {F16211} The first invocation of [sqlite3_aggregate_context(C,N)] for 3749** a particular instance of an aggregate function (for a particular 3750** context C) causes SQLite to allocation N bytes of memory, 3751** zero that memory, and return a pointer to the allocationed 3752** memory. 3753** 3754** {F16213} If a memory allocation error occurs during 3755** [sqlite3_aggregate_context(C,N)] then the function returns 0. 3756** 3757** {F16215} Second and subsequent invocations of 3758** [sqlite3_aggregate_context(C,N)] for the same context pointer C 3759** ignore the N parameter and return a pointer to the same 3760** block of memory returned by the first invocation. 3761** 3762** {F16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is 3763** automatically freed on the next call to [sqlite3_reset()] 3764** or [sqlite3_finalize()] for the [prepared statement] containing 3765** the aggregate function associated with context C. 3766*/ 3767void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3768 3769/* 3770** CAPI3REF: User Data For Functions {F16240} 3771** 3772** The sqlite3_user_data() interface returns a copy of 3773** the pointer that was the pUserData parameter (the 5th parameter) 3774** of the the [sqlite3_create_function()] 3775** and [sqlite3_create_function16()] routines that originally 3776** registered the application defined function. {END} 3777** 3778** This routine must be called from the same thread in which 3779** the application-defined function is running. 3780** 3781** INVARIANTS: 3782** 3783** {F16243} The [sqlite3_user_data(C)] interface returns a copy of the 3784** P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3785** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that 3786** registered the SQL function associated with 3787** [sqlite3_context] C. 3788*/ 3789void *sqlite3_user_data(sqlite3_context*); 3790 3791/* 3792** CAPI3REF: Database Connection For Functions {F16250} 3793** 3794** The sqlite3_context_db_handle() interface returns a copy of 3795** the pointer to the [database connection] (the 1st parameter) 3796** of the the [sqlite3_create_function()] 3797** and [sqlite3_create_function16()] routines that originally 3798** registered the application defined function. 3799** 3800** INVARIANTS: 3801** 3802** {F16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the 3803** D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3804** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that 3805** registered the SQL function associated with 3806** [sqlite3_context] C. 3807*/ 3808sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3809 3810/* 3811** CAPI3REF: Function Auxiliary Data {F16270} 3812** 3813** The following two functions may be used by scalar SQL functions to 3814** associate meta-data with argument values. If the same value is passed to 3815** multiple invocations of the same SQL function during query execution, under 3816** some circumstances the associated meta-data may be preserved. This may 3817** be used, for example, to add a regular-expression matching scalar 3818** function. The compiled version of the regular expression is stored as 3819** meta-data associated with the SQL value passed as the regular expression 3820** pattern. The compiled regular expression can be reused on multiple 3821** invocations of the same function so that the original pattern string 3822** does not need to be recompiled on each invocation. 3823** 3824** The sqlite3_get_auxdata() interface returns a pointer to the meta-data 3825** associated by the sqlite3_set_auxdata() function with the Nth argument 3826** value to the application-defined function. 3827** If no meta-data has been ever been set for the Nth 3828** argument of the function, or if the cooresponding function parameter 3829** has changed since the meta-data was set, then sqlite3_get_auxdata() 3830** returns a NULL pointer. 3831** 3832** The sqlite3_set_auxdata() interface saves the meta-data 3833** pointed to by its 3rd parameter as the meta-data for the N-th 3834** argument of the application-defined function. Subsequent 3835** calls to sqlite3_get_auxdata() might return this data, if it has 3836** not been destroyed. 3837** If it is not NULL, SQLite will invoke the destructor 3838** function given by the 4th parameter to sqlite3_set_auxdata() on 3839** the meta-data when the corresponding function parameter changes 3840** or when the SQL statement completes, whichever comes first. 3841** 3842** SQLite is free to call the destructor and drop meta-data on 3843** any parameter of any function at any time. The only guarantee 3844** is that the destructor will be called before the metadata is 3845** dropped. 3846** 3847** In practice, meta-data is preserved between function calls for 3848** expressions that are constant at compile time. This includes literal 3849** values and SQL variables. 3850** 3851** These routines must be called from the same thread in which 3852** the SQL function is running. 3853** 3854** INVARIANTS: 3855** 3856** {F16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer 3857** to metadata associated with the Nth parameter of the SQL function 3858** whose context is C, or NULL if there is no metadata associated 3859** with that parameter. 3860** 3861** {F16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata 3862** pointer P to the Nth parameter of the SQL function with context 3863** C. 3864** 3865** {F16276} SQLite will invoke the destructor D with a single argument 3866** which is the metadata pointer P following a call to 3867** [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold 3868** the metadata. 3869** 3870** {F16277} SQLite ceases to hold metadata for an SQL function parameter 3871** when the value of that parameter changes. 3872** 3873** {F16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor 3874** is called for any prior metadata associated with the same function 3875** context C and parameter N. 3876** 3877** {F16279} SQLite will call destructors for any metadata it is holding 3878** in a particular [prepared statement] S when either 3879** [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called. 3880*/ 3881void *sqlite3_get_auxdata(sqlite3_context*, int N); 3882void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3883 3884 3885/* 3886** CAPI3REF: Constants Defining Special Destructor Behavior {F10280} 3887** 3888** These are special value for the destructor that is passed in as the 3889** final argument to routines like [sqlite3_result_blob()]. If the destructor 3890** argument is SQLITE_STATIC, it means that the content pointer is constant 3891** and will never change. It does not need to be destroyed. The 3892** SQLITE_TRANSIENT value means that the content will likely change in 3893** the near future and that SQLite should make its own private copy of 3894** the content before returning. 3895** 3896** The typedef is necessary to work around problems in certain 3897** C++ compilers. See ticket #2191. 3898*/ 3899typedef void (*sqlite3_destructor_type)(void*); 3900#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3901#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3902 3903/* 3904** CAPI3REF: Setting The Result Of An SQL Function {F16400} 3905** 3906** These routines are used by the xFunc or xFinal callbacks that 3907** implement SQL functions and aggregates. See 3908** [sqlite3_create_function()] and [sqlite3_create_function16()] 3909** for additional information. 3910** 3911** These functions work very much like the 3912** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used 3913** to bind values to host parameters in prepared statements. 3914** Refer to the 3915** [sqlite3_bind_blob | sqlite3_bind_* documentation] for 3916** additional information. 3917** 3918** The sqlite3_result_blob() interface sets the result from 3919** an application defined function to be the BLOB whose content is pointed 3920** to by the second parameter and which is N bytes long where N is the 3921** third parameter. 3922** The sqlite3_result_zeroblob() inerfaces set the result of 3923** the application defined function to be a BLOB containing all zero 3924** bytes and N bytes in size, where N is the value of the 2nd parameter. 3925** 3926** The sqlite3_result_double() interface sets the result from 3927** an application defined function to be a floating point value specified 3928** by its 2nd argument. 3929** 3930** The sqlite3_result_error() and sqlite3_result_error16() functions 3931** cause the implemented SQL function to throw an exception. 3932** SQLite uses the string pointed to by the 3933** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3934** as the text of an error message. SQLite interprets the error 3935** message string from sqlite3_result_error() as UTF8. SQLite 3936** interprets the string from sqlite3_result_error16() as UTF16 in native 3937** byte order. If the third parameter to sqlite3_result_error() 3938** or sqlite3_result_error16() is negative then SQLite takes as the error 3939** message all text up through the first zero character. 3940** If the third parameter to sqlite3_result_error() or 3941** sqlite3_result_error16() is non-negative then SQLite takes that many 3942** bytes (not characters) from the 2nd parameter as the error message. 3943** The sqlite3_result_error() and sqlite3_result_error16() 3944** routines make a copy private copy of the error message text before 3945** they return. Hence, the calling function can deallocate or 3946** modify the text after they return without harm. 3947** The sqlite3_result_error_code() function changes the error code 3948** returned by SQLite as a result of an error in a function. By default, 3949** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 3950** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3951** 3952** The sqlite3_result_toobig() interface causes SQLite 3953** to throw an error indicating that a string or BLOB is to long 3954** to represent. The sqlite3_result_nomem() interface 3955** causes SQLite to throw an exception indicating that the a 3956** memory allocation failed. 3957** 3958** The sqlite3_result_int() interface sets the return value 3959** of the application-defined function to be the 32-bit signed integer 3960** value given in the 2nd argument. 3961** The sqlite3_result_int64() interface sets the return value 3962** of the application-defined function to be the 64-bit signed integer 3963** value given in the 2nd argument. 3964** 3965** The sqlite3_result_null() interface sets the return value 3966** of the application-defined function to be NULL. 3967** 3968** The sqlite3_result_text(), sqlite3_result_text16(), 3969** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3970** set the return value of the application-defined function to be 3971** a text string which is represented as UTF-8, UTF-16 native byte order, 3972** UTF-16 little endian, or UTF-16 big endian, respectively. 3973** SQLite takes the text result from the application from 3974** the 2nd parameter of the sqlite3_result_text* interfaces. 3975** If the 3rd parameter to the sqlite3_result_text* interfaces 3976** is negative, then SQLite takes result text from the 2nd parameter 3977** through the first zero character. 3978** If the 3rd parameter to the sqlite3_result_text* interfaces 3979** is non-negative, then as many bytes (not characters) of the text 3980** pointed to by the 2nd parameter are taken as the application-defined 3981** function result. 3982** If the 4th parameter to the sqlite3_result_text* interfaces 3983** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3984** function as the destructor on the text or blob result when it has 3985** finished using that result. 3986** If the 4th parameter to the sqlite3_result_text* interfaces 3987** or sqlite3_result_blob is the special constant SQLITE_STATIC, then 3988** SQLite assumes that the text or blob result is constant space and 3989** does not copy the space or call a destructor when it has 3990** finished using that result. 3991** If the 4th parameter to the sqlite3_result_text* interfaces 3992** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3993** then SQLite makes a copy of the result into space obtained from 3994** from [sqlite3_malloc()] before it returns. 3995** 3996** The sqlite3_result_value() interface sets the result of 3997** the application-defined function to be a copy the 3998** [unprotected sqlite3_value] object specified by the 2nd parameter. The 3999** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4000** so that [sqlite3_value] specified in the parameter may change or 4001** be deallocated after sqlite3_result_value() returns without harm. 4002** A [protected sqlite3_value] object may always be used where an 4003** [unprotected sqlite3_value] object is required, so either 4004** kind of [sqlite3_value] object can be used with this interface. 4005** 4006** If these routines are called from within the different thread 4007** than the one containing the application-defined function that recieved 4008** the [sqlite3_context] pointer, the results are undefined. 4009** 4010** INVARIANTS: 4011** 4012** {F16403} The default return value from any SQL function is NULL. 4013** 4014** {F16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the 4015** return value of function C to be a blob that is N bytes 4016** in length and with content pointed to by V. 4017** 4018** {F16409} The [sqlite3_result_double(C,V)] interface changes the 4019** return value of function C to be the floating point value V. 4020** 4021** {F16412} The [sqlite3_result_error(C,V,N)] interface changes the return 4022** value of function C to be an exception with error code 4023** [SQLITE_ERROR] and a UTF8 error message copied from V up to the 4024** first zero byte or until N bytes are read if N is positive. 4025** 4026** {F16415} The [sqlite3_result_error16(C,V,N)] interface changes the return 4027** value of function C to be an exception with error code 4028** [SQLITE_ERROR] and a UTF16 native byte order error message 4029** copied from V up to the first zero terminator or until N bytes 4030** are read if N is positive. 4031** 4032** {F16418} The [sqlite3_result_error_toobig(C)] interface changes the return 4033** value of the function C to be an exception with error code 4034** [SQLITE_TOOBIG] and an appropriate error message. 4035** 4036** {F16421} The [sqlite3_result_error_nomem(C)] interface changes the return 4037** value of the function C to be an exception with error code 4038** [SQLITE_NOMEM] and an appropriate error message. 4039** 4040** {F16424} The [sqlite3_result_error_code(C,E)] interface changes the return 4041** value of the function C to be an exception with error code E. 4042** The error message text is unchanged. 4043** 4044** {F16427} The [sqlite3_result_int(C,V)] interface changes the 4045** return value of function C to be the 32-bit integer value V. 4046** 4047** {F16430} The [sqlite3_result_int64(C,V)] interface changes the 4048** return value of function C to be the 64-bit integer value V. 4049** 4050** {F16433} The [sqlite3_result_null(C)] interface changes the 4051** return value of function C to be NULL. 4052** 4053** {F16436} The [sqlite3_result_text(C,V,N,D)] interface changes the 4054** return value of function C to be the UTF8 string 4055** V up through the first zero or until N bytes are read if N 4056** is positive. 4057** 4058** {F16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the 4059** return value of function C to be the UTF16 native byte order 4060** string V up through the first zero or until N bytes are read if N 4061** is positive. 4062** 4063** {F16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the 4064** return value of function C to be the UTF16 big-endian 4065** string V up through the first zero or until N bytes are read if N 4066** is positive. 4067** 4068** {F16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the 4069** return value of function C to be the UTF16 little-endian 4070** string V up through the first zero or until N bytes are read if N 4071** is positive. 4072** 4073** {F16448} The [sqlite3_result_value(C,V)] interface changes the 4074** return value of function C to be [unprotected sqlite3_value] 4075** object V. 4076** 4077** {F16451} The [sqlite3_result_zeroblob(C,N)] interface changes the 4078** return value of function C to be an N-byte blob of all zeros. 4079** 4080** {F16454} The [sqlite3_result_error()] and [sqlite3_result_error16()] 4081** interfaces make a copy of their error message strings before 4082** returning. 4083** 4084** {F16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4085** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4086** [sqlite3_result_text16be(C,V,N,D)], or 4087** [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC] 4088** then no destructor is ever called on the pointer V and SQLite 4089** assumes that V is immutable. 4090** 4091** {F16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4092** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4093** [sqlite3_result_text16be(C,V,N,D)], or 4094** [sqlite3_result_text16le(C,V,N,D)] is the constant 4095** [SQLITE_TRANSIENT] then the interfaces makes a copy of the 4096** content of V and retains the copy. 4097** 4098** {F16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4099** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4100** [sqlite3_result_text16be(C,V,N,D)], or 4101** [sqlite3_result_text16le(C,V,N,D)] is some value other than 4102** the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then 4103** SQLite will invoke the destructor D with V as its only argument 4104** when it has finished with the V value. 4105*/ 4106void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4107void sqlite3_result_double(sqlite3_context*, double); 4108void sqlite3_result_error(sqlite3_context*, const char*, int); 4109void sqlite3_result_error16(sqlite3_context*, const void*, int); 4110void sqlite3_result_error_toobig(sqlite3_context*); 4111void sqlite3_result_error_nomem(sqlite3_context*); 4112void sqlite3_result_error_code(sqlite3_context*, int); 4113void sqlite3_result_int(sqlite3_context*, int); 4114void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4115void sqlite3_result_null(sqlite3_context*); 4116void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4117void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4118void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4119void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4120void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4121void sqlite3_result_zeroblob(sqlite3_context*, int n); 4122 4123/* 4124** CAPI3REF: Define New Collating Sequences {F16600} 4125** 4126** These functions are used to add new collation sequences to the 4127** [sqlite3*] handle specified as the first argument. 4128** 4129** The name of the new collation sequence is specified as a UTF-8 string 4130** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4131** and a UTF-16 string for sqlite3_create_collation16(). In all cases 4132** the name is passed as the second function argument. 4133** 4134** The third argument may be one of the constants [SQLITE_UTF8], 4135** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 4136** routine expects to be passed pointers to strings encoded using UTF-8, 4137** UTF-16 little-endian or UTF-16 big-endian respectively. The 4138** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 4139** the routine expects pointers to 16-bit word aligned strings 4140** of UTF16 in the native byte order of the host computer. 4141** 4142** A pointer to the user supplied routine must be passed as the fifth 4143** argument. If it is NULL, this is the same as deleting the collation 4144** sequence (so that SQLite cannot call it anymore). 4145** Each time the application 4146** supplied function is invoked, it is passed a copy of the void* passed as 4147** the fourth argument to sqlite3_create_collation() or 4148** sqlite3_create_collation16() as its first parameter. 4149** 4150** The remaining arguments to the application-supplied routine are two strings, 4151** each represented by a (length, data) pair and encoded in the encoding 4152** that was passed as the third argument when the collation sequence was 4153** registered. {END} The application defined collation routine should 4154** return negative, zero or positive if 4155** the first string is less than, equal to, or greater than the second 4156** string. i.e. (STRING1 - STRING2). 4157** 4158** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4159** excapt that it takes an extra argument which is a destructor for 4160** the collation. The destructor is called when the collation is 4161** destroyed and is passed a copy of the fourth parameter void* pointer 4162** of the sqlite3_create_collation_v2(). 4163** Collations are destroyed when 4164** they are overridden by later calls to the collation creation functions 4165** or when the [sqlite3*] database handle is closed using [sqlite3_close()]. 4166** 4167** INVARIANTS: 4168** 4169** {F16603} A successful call to the 4170** [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface 4171** registers function F as the comparison function used to 4172** implement collation X on [database connection] B for 4173** databases having encoding E. 4174** 4175** {F16604} SQLite understands the X parameter to 4176** [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated 4177** UTF-8 string in which case is ignored for ASCII characters and 4178** is significant for non-ASCII characters. 4179** 4180** {F16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4181** with the same values for B, X, and E, override prior values 4182** of P, F, and D. 4183** 4184** {F16609} The destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4185** is not NULL then it is called with argument P when the 4186** collating function is dropped by SQLite. 4187** 4188** {F16612} A collating function is dropped when it is overloaded. 4189** 4190** {F16615} A collating function is dropped when the database connection 4191** is closed using [sqlite3_close()]. 4192** 4193** {F16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4194** is passed through as the first parameter to the comparison 4195** function F for all subsequent invocations of F. 4196** 4197** {F16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly 4198** the same as a call to [sqlite3_create_collation_v2()] with 4199** the same parameters and a NULL destructor. 4200** 4201** {F16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)], 4202** SQLite uses the comparison function F for all text comparison 4203** operations on [database connection] B on text values that 4204** use the collating sequence name X. 4205** 4206** {F16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same 4207** as [sqlite3_create_collation(B,X,E,P,F)] except that the 4208** collation name X is understood as UTF-16 in native byte order 4209** instead of UTF-8. 4210** 4211** {F16630} When multiple comparison functions are available for the same 4212** collating sequence, SQLite chooses the one whose text encoding 4213** requires the least amount of conversion from the default 4214** text encoding of the database. 4215*/ 4216int sqlite3_create_collation( 4217 sqlite3*, 4218 const char *zName, 4219 int eTextRep, 4220 void*, 4221 int(*xCompare)(void*,int,const void*,int,const void*) 4222); 4223int sqlite3_create_collation_v2( 4224 sqlite3*, 4225 const char *zName, 4226 int eTextRep, 4227 void*, 4228 int(*xCompare)(void*,int,const void*,int,const void*), 4229 void(*xDestroy)(void*) 4230); 4231int sqlite3_create_collation16( 4232 sqlite3*, 4233 const char *zName, 4234 int eTextRep, 4235 void*, 4236 int(*xCompare)(void*,int,const void*,int,const void*) 4237); 4238 4239/* 4240** CAPI3REF: Collation Needed Callbacks {F16700} 4241** 4242** To avoid having to register all collation sequences before a database 4243** can be used, a single callback function may be registered with the 4244** database handle to be called whenever an undefined collation sequence is 4245** required. 4246** 4247** If the function is registered using the sqlite3_collation_needed() API, 4248** then it is passed the names of undefined collation sequences as strings 4249** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used, the names 4250** are passed as UTF-16 in machine native byte order. A call to either 4251** function replaces any existing callback. 4252** 4253** When the callback is invoked, the first argument passed is a copy 4254** of the second argument to sqlite3_collation_needed() or 4255** sqlite3_collation_needed16(). The second argument is the database 4256** handle. The third argument is one of [SQLITE_UTF8], 4257** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most 4258** desirable form of the collation sequence function required. 4259** The fourth parameter is the name of the 4260** required collation sequence. 4261** 4262** The callback function should register the desired collation using 4263** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4264** [sqlite3_create_collation_v2()]. 4265** 4266** INVARIANTS: 4267** 4268** {F16702} A successful call to [sqlite3_collation_needed(D,P,F)] 4269** or [sqlite3_collation_needed16(D,P,F)] causes 4270** the [database connection] D to invoke callback F with first 4271** parameter P whenever it needs a comparison function for a 4272** collating sequence that it does not know about. 4273** 4274** {F16704} Each successful call to [sqlite3_collation_needed()] or 4275** [sqlite3_collation_needed16()] overrides the callback registered 4276** on the same [database connection] by prior calls to either 4277** interface. 4278** 4279** {F16706} The name of the requested collating function passed in the 4280** 4th parameter to the callback is in UTF-8 if the callback 4281** was registered using [sqlite3_collation_needed()] and 4282** is in UTF-16 native byte order if the callback was 4283** registered using [sqlite3_collation_needed16()]. 4284** 4285** 4286*/ 4287int sqlite3_collation_needed( 4288 sqlite3*, 4289 void*, 4290 void(*)(void*,sqlite3*,int eTextRep,const char*) 4291); 4292int sqlite3_collation_needed16( 4293 sqlite3*, 4294 void*, 4295 void(*)(void*,sqlite3*,int eTextRep,const void*) 4296); 4297 4298/* 4299** Specify the key for an encrypted database. This routine should be 4300** called right after sqlite3_open(). 4301** 4302** The code to implement this API is not available in the public release 4303** of SQLite. 4304*/ 4305int sqlite3_key( 4306 sqlite3 *db, /* Database to be rekeyed */ 4307 const void *pKey, int nKey /* The key */ 4308); 4309 4310/* 4311** Change the key on an open database. If the current database is not 4312** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4313** database is decrypted. 4314** 4315** The code to implement this API is not available in the public release 4316** of SQLite. 4317*/ 4318int sqlite3_rekey( 4319 sqlite3 *db, /* Database to be rekeyed */ 4320 const void *pKey, int nKey /* The new key */ 4321); 4322 4323/* 4324** CAPI3REF: Suspend Execution For A Short Time {F10530} 4325** 4326** The sqlite3_sleep() function 4327** causes the current thread to suspend execution 4328** for at least a number of milliseconds specified in its parameter. 4329** 4330** If the operating system does not support sleep requests with 4331** millisecond time resolution, then the time will be rounded up to 4332** the nearest second. The number of milliseconds of sleep actually 4333** requested from the operating system is returned. 4334** 4335** SQLite implements this interface by calling the xSleep() 4336** method of the default [sqlite3_vfs] object. 4337** 4338** INVARIANTS: 4339** 4340** {F10533} The [sqlite3_sleep(M)] interface invokes the xSleep 4341** method of the default [sqlite3_vfs|VFS] in order to 4342** suspend execution of the current thread for at least 4343** M milliseconds. 4344** 4345** {F10536} The [sqlite3_sleep(M)] interface returns the number of 4346** milliseconds of sleep actually requested of the operating 4347** system, which might be larger than the parameter M. 4348*/ 4349int sqlite3_sleep(int); 4350 4351/* 4352** CAPI3REF: Name Of The Folder Holding Temporary Files {F10310} 4353** 4354** If this global variable is made to point to a string which is 4355** the name of a folder (a.ka. directory), then all temporary files 4356** created by SQLite will be placed in that directory. If this variable 4357** is NULL pointer, then SQLite does a search for an appropriate temporary 4358** file directory. 4359** 4360** It is not safe to modify this variable once a database connection 4361** has been opened. It is intended that this variable be set once 4362** as part of process initialization and before any SQLite interface 4363** routines have been call and remain unchanged thereafter. 4364*/ 4365SQLITE_EXTERN char *sqlite3_temp_directory; 4366 4367/* 4368** CAPI3REF: Test To See If The Database Is In Auto-Commit Mode {F12930} 4369** 4370** The sqlite3_get_autocommit() interfaces returns non-zero or 4371** zero if the given database connection is or is not in autocommit mode, 4372** respectively. Autocommit mode is on 4373** by default. Autocommit mode is disabled by a [BEGIN] statement. 4374** Autocommit mode is reenabled by a [COMMIT] or [ROLLBACK]. 4375** 4376** If certain kinds of errors occur on a statement within a multi-statement 4377** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR], 4378** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4379** transaction might be rolled back automatically. The only way to 4380** find out if SQLite automatically rolled back the transaction after 4381** an error is to use this function. 4382** 4383** INVARIANTS: 4384** 4385** {F12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or 4386** zero if the [database connection] D is or is not in autocommit 4387** mode, respectively. 4388** 4389** {F12932} Autocommit mode is on by default. 4390** 4391** {F12933} Autocommit mode is disabled by a successful [BEGIN] statement. 4392** 4393** {F12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK] 4394** statement. 4395** 4396** 4397** LIMITATIONS: 4398*** 4399** {U12936} If another thread changes the autocommit status of the database 4400** connection while this routine is running, then the return value 4401** is undefined. 4402*/ 4403int sqlite3_get_autocommit(sqlite3*); 4404 4405/* 4406** CAPI3REF: Find The Database Handle Of A Prepared Statement {F13120} 4407** 4408** The sqlite3_db_handle interface 4409** returns the [sqlite3*] database handle to which a 4410** [prepared statement] belongs. 4411** The database handle returned by sqlite3_db_handle 4412** is the same database handle that was 4413** the first argument to the [sqlite3_prepare_v2()] or its variants 4414** that was used to create the statement in the first place. 4415** 4416** INVARIANTS: 4417** 4418** {F13123} The [sqlite3_db_handle(S)] interface returns a pointer 4419** to the [database connection] associated with 4420** [prepared statement] S. 4421*/ 4422sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4423 4424 4425/* 4426** CAPI3REF: Commit And Rollback Notification Callbacks {F12950} 4427** 4428** The sqlite3_commit_hook() interface registers a callback 4429** function to be invoked whenever a transaction is committed. 4430** Any callback set by a previous call to sqlite3_commit_hook() 4431** for the same database connection is overridden. 4432** The sqlite3_rollback_hook() interface registers a callback 4433** function to be invoked whenever a transaction is committed. 4434** Any callback set by a previous call to sqlite3_commit_hook() 4435** for the same database connection is overridden. 4436** The pArg argument is passed through 4437** to the callback. If the callback on a commit hook function 4438** returns non-zero, then the commit is converted into a rollback. 4439** 4440** If another function was previously registered, its 4441** pArg value is returned. Otherwise NULL is returned. 4442** 4443** Registering a NULL function disables the callback. 4444** 4445** For the purposes of this API, a transaction is said to have been 4446** rolled back if an explicit "ROLLBACK" statement is executed, or 4447** an error or constraint causes an implicit rollback to occur. 4448** The rollback callback is not invoked if a transaction is 4449** automatically rolled back because the database connection is closed. 4450** The rollback callback is not invoked if a transaction is 4451** rolled back because a commit callback returned non-zero. 4452** <todo> Check on this </todo> 4453** 4454** These are experimental interfaces and are subject to change. 4455** 4456** INVARIANTS: 4457** 4458** {F12951} The [sqlite3_commit_hook(D,F,P)] interface registers the 4459** callback function F to be invoked with argument P whenever 4460** a transaction commits on [database connection] D. 4461** 4462** {F12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P 4463** argument from the previous call with the same 4464** [database connection ] D , or NULL on the first call 4465** for a particular [database connection] D. 4466** 4467** {F12953} Each call to [sqlite3_commit_hook()] overwrites the callback 4468** registered by prior calls. 4469** 4470** {F12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL 4471** then the commit hook callback is cancelled and no callback 4472** is invoked when a transaction commits. 4473** 4474** {F12955} If the commit callback returns non-zero then the commit is 4475** converted into a rollback. 4476** 4477** {F12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the 4478** callback function F to be invoked with argument P whenever 4479** a transaction rolls back on [database connection] D. 4480** 4481** {F12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P 4482** argument from the previous call with the same 4483** [database connection ] D , or NULL on the first call 4484** for a particular [database connection] D. 4485** 4486** {F12963} Each call to [sqlite3_rollback_hook()] overwrites the callback 4487** registered by prior calls. 4488** 4489** {F12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL 4490** then the rollback hook callback is cancelled and no callback 4491** is invoked when a transaction rolls back. 4492*/ 4493void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4494void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4495 4496/* 4497** CAPI3REF: Data Change Notification Callbacks {F12970} 4498** 4499** The sqlite3_update_hook() interface 4500** registers a callback function with the database connection identified by the 4501** first argument to be invoked whenever a row is updated, inserted or deleted. 4502** Any callback set by a previous call to this function for the same 4503** database connection is overridden. 4504** 4505** The second argument is a pointer to the function to invoke when a 4506** row is updated, inserted or deleted. 4507** The first argument to the callback is 4508** a copy of the third argument to sqlite3_update_hook(). 4509** The second callback 4510** argument is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 4511** depending on the operation that caused the callback to be invoked. 4512** The third and 4513** fourth arguments to the callback contain pointers to the database and 4514** table name containing the affected row. 4515** The final callback parameter is 4516** the rowid of the row. 4517** In the case of an update, this is the rowid after 4518** the update takes place. 4519** 4520** The update hook is not invoked when internal system tables are 4521** modified (i.e. sqlite_master and sqlite_sequence). 4522** 4523** If another function was previously registered, its pArg value 4524** is returned. Otherwise NULL is returned. 4525** 4526** INVARIANTS: 4527** 4528** {F12971} The [sqlite3_update_hook(D,F,P)] interface causes callback 4529** function F to be invoked with first parameter P whenever 4530** a table row is modified, inserted, or deleted on 4531** [database connection] D. 4532** 4533** {F12973} The [sqlite3_update_hook(D,F,P)] interface returns the value 4534** of P for the previous call on the same [database connection] D, 4535** or NULL for the first call. 4536** 4537** {F12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)] 4538** is NULL then the no update callbacks are made. 4539** 4540** {F12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls 4541** to the same interface on the same [database connection] D. 4542** 4543** {F12979} The update hook callback is not invoked when internal system 4544** tables such as sqlite_master and sqlite_sequence are modified. 4545** 4546** {F12981} The second parameter to the update callback 4547** is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 4548** depending on the operation that caused the callback to be invoked. 4549** 4550** {F12983} The third and fourth arguments to the callback contain pointers 4551** to zero-terminated UTF-8 strings which are the names of the 4552** database and table that is being updated. 4553 4554** {F12985} The final callback parameter is the rowid of the row after 4555** the change occurs. 4556*/ 4557void *sqlite3_update_hook( 4558 sqlite3*, 4559 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4560 void* 4561); 4562 4563/* 4564** CAPI3REF: Enable Or Disable Shared Pager Cache {F10330} 4565** 4566** This routine enables or disables the sharing of the database cache 4567** and schema data structures between connections to the same database. 4568** Sharing is enabled if the argument is true and disabled if the argument 4569** is false. 4570** 4571** Cache sharing is enabled and disabled 4572** for an entire process. {END} This is a change as of SQLite version 3.5.0. 4573** In prior versions of SQLite, sharing was 4574** enabled or disabled for each thread separately. 4575** 4576** The cache sharing mode set by this interface effects all subsequent 4577** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4578** Existing database connections continue use the sharing mode 4579** that was in effect at the time they were opened. 4580** 4581** Virtual tables cannot be used with a shared cache. When shared 4582** cache is enabled, the [sqlite3_create_module()] API used to register 4583** virtual tables will always return an error. 4584** 4585** This routine returns [SQLITE_OK] if shared cache was 4586** enabled or disabled successfully. An [error code] 4587** is returned otherwise. 4588** 4589** Shared cache is disabled by default. But this might change in 4590** future releases of SQLite. Applications that care about shared 4591** cache setting should set it explicitly. 4592** 4593** INVARIANTS: 4594** 4595** {F10331} A successful invocation of [sqlite3_enable_shared_cache(B)] 4596** will enable or disable shared cache mode for any subsequently 4597** created [database connection] in the same process. 4598** 4599** {F10336} When shared cache is enabled, the [sqlite3_create_module()] 4600** interface will always return an error. 4601** 4602** {F10337} The [sqlite3_enable_shared_cache(B)] interface returns 4603** [SQLITE_OK] if shared cache was enabled or disabled successfully. 4604** 4605** {F10339} Shared cache is disabled by default. 4606*/ 4607int sqlite3_enable_shared_cache(int); 4608 4609/* 4610** CAPI3REF: Attempt To Free Heap Memory {F17340} 4611** 4612** The sqlite3_release_memory() interface attempts to 4613** free N bytes of heap memory by deallocating non-essential memory 4614** allocations held by the database labrary. {END} Memory used 4615** to cache database pages to improve performance is an example of 4616** non-essential memory. Sqlite3_release_memory() returns 4617** the number of bytes actually freed, which might be more or less 4618** than the amount requested. 4619** 4620** INVARIANTS: 4621** 4622** {F17341} The [sqlite3_release_memory(N)] interface attempts to 4623** free N bytes of heap memory by deallocating non-essential 4624** memory allocations held by the database labrary. 4625** 4626** {F16342} The [sqlite3_release_memory(N)] returns the number 4627** of bytes actually freed, which might be more or less 4628** than the amount requested. 4629*/ 4630int sqlite3_release_memory(int); 4631 4632/* 4633** CAPI3REF: Impose A Limit On Heap Size {F17350} 4634** 4635** The sqlite3_soft_heap_limit() interface 4636** places a "soft" limit on the amount of heap memory that may be allocated 4637** by SQLite. If an internal allocation is requested 4638** that would exceed the soft heap limit, [sqlite3_release_memory()] is 4639** invoked one or more times to free up some space before the allocation 4640** is made. 4641** 4642** The limit is called "soft", because if 4643** [sqlite3_release_memory()] cannot 4644** free sufficient memory to prevent the limit from being exceeded, 4645** the memory is allocated anyway and the current operation proceeds. 4646** 4647** A negative or zero value for N means that there is no soft heap limit and 4648** [sqlite3_release_memory()] will only be called when memory is exhausted. 4649** The default value for the soft heap limit is zero. 4650** 4651** SQLite makes a best effort to honor the soft heap limit. 4652** But if the soft heap limit cannot honored, execution will 4653** continue without error or notification. This is why the limit is 4654** called a "soft" limit. It is advisory only. 4655** 4656** Prior to SQLite version 3.5.0, this routine only constrained the memory 4657** allocated by a single thread - the same thread in which this routine 4658** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 4659** applied to all threads. The value specified for the soft heap limit 4660** is an upper bound on the total memory allocation for all threads. In 4661** version 3.5.0 there is no mechanism for limiting the heap usage for 4662** individual threads. 4663** 4664** INVARIANTS: 4665** 4666** {F16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit 4667** of N bytes on the amount of heap memory that may be allocated 4668** using [sqlite3_malloc()] or [sqlite3_realloc()] at any point 4669** in time. 4670** 4671** {F16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would 4672** cause the total amount of allocated memory to exceed the 4673** soft heap limit, then [sqlite3_release_memory()] is invoked 4674** in an attempt to reduce the memory usage prior to proceeding 4675** with the memory allocation attempt. 4676** 4677** {F16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger 4678** attempts to reduce memory usage through the soft heap limit 4679** mechanism continue even if the attempt to reduce memory 4680** usage is unsuccessful. 4681** 4682** {F16354} A negative or zero value for N in a call to 4683** [sqlite3_soft_heap_limit(N)] means that there is no soft 4684** heap limit and [sqlite3_release_memory()] will only be 4685** called when memory is completely exhausted. 4686** 4687** {F16355} The default value for the soft heap limit is zero. 4688** 4689** {F16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the 4690** values set by all prior calls. 4691*/ 4692void sqlite3_soft_heap_limit(int); 4693 4694/* 4695** CAPI3REF: Extract Metadata About A Column Of A Table {F12850} 4696** 4697** This routine 4698** returns meta-data about a specific column of a specific database 4699** table accessible using the connection handle passed as the first function 4700** argument. 4701** 4702** The column is identified by the second, third and fourth parameters to 4703** this function. The second parameter is either the name of the database 4704** (i.e. "main", "temp" or an attached database) containing the specified 4705** table or NULL. If it is NULL, then all attached databases are searched 4706** for the table using the same algorithm as the database engine uses to 4707** resolve unqualified table references. 4708** 4709** The third and fourth parameters to this function are the table and column 4710** name of the desired column, respectively. Neither of these parameters 4711** may be NULL. 4712** 4713** Meta information is returned by writing to the memory locations passed as 4714** the 5th and subsequent parameters to this function. Any of these 4715** arguments may be NULL, in which case the corresponding element of meta 4716** information is ommitted. 4717** 4718** <pre> 4719** Parameter Output Type Description 4720** ----------------------------------- 4721** 4722** 5th const char* Data type 4723** 6th const char* Name of the default collation sequence 4724** 7th int True if the column has a NOT NULL constraint 4725** 8th int True if the column is part of the PRIMARY KEY 4726** 9th int True if the column is AUTOINCREMENT 4727** </pre> 4728** 4729** 4730** The memory pointed to by the character pointers returned for the 4731** declaration type and collation sequence is valid only until the next 4732** call to any sqlite API function. 4733** 4734** If the specified table is actually a view, then an error is returned. 4735** 4736** If the specified column is "rowid", "oid" or "_rowid_" and an 4737** INTEGER PRIMARY KEY column has been explicitly declared, then the output 4738** parameters are set for the explicitly declared column. If there is no 4739** explicitly declared IPK column, then the output parameters are set as 4740** follows: 4741** 4742** <pre> 4743** data type: "INTEGER" 4744** collation sequence: "BINARY" 4745** not null: 0 4746** primary key: 1 4747** auto increment: 0 4748** </pre> 4749** 4750** This function may load one or more schemas from database files. If an 4751** error occurs during this process, or if the requested table or column 4752** cannot be found, an SQLITE error code is returned and an error message 4753** left in the database handle (to be retrieved using sqlite3_errmsg()). 4754** 4755** This API is only available if the library was compiled with the 4756** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined. 4757*/ 4758int sqlite3_table_column_metadata( 4759 sqlite3 *db, /* Connection handle */ 4760 const char *zDbName, /* Database name or NULL */ 4761 const char *zTableName, /* Table name */ 4762 const char *zColumnName, /* Column name */ 4763 char const **pzDataType, /* OUTPUT: Declared data type */ 4764 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4765 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4766 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4767 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4768); 4769 4770/* 4771** CAPI3REF: Load An Extension {F12600} 4772** 4773** {F12601} The sqlite3_load_extension() interface 4774** attempts to load an SQLite extension library contained in the file 4775** zFile. {F12602} The entry point is zProc. {F12603} zProc may be 0 4776** in which case the name of the entry point defaults 4777** to "sqlite3_extension_init". 4778** 4779** {F12604} The sqlite3_load_extension() interface shall 4780** return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4781** 4782** {F12605} 4783** If an error occurs and pzErrMsg is not 0, then the 4784** sqlite3_load_extension() interface shall attempt to fill *pzErrMsg with 4785** error message text stored in memory obtained from [sqlite3_malloc()]. 4786** {END} The calling function should free this memory 4787** by calling [sqlite3_free()]. 4788** 4789** {F12606} 4790** Extension loading must be enabled using [sqlite3_enable_load_extension()] 4791** prior to calling this API or an error will be returned. 4792*/ 4793int sqlite3_load_extension( 4794 sqlite3 *db, /* Load the extension into this database connection */ 4795 const char *zFile, /* Name of the shared library containing extension */ 4796 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4797 char **pzErrMsg /* Put error message here if not 0 */ 4798); 4799 4800/* 4801** CAPI3REF: Enable Or Disable Extension Loading {F12620} 4802** 4803** So as not to open security holes in older applications that are 4804** unprepared to deal with extension loading, and as a means of disabling 4805** extension loading while evaluating user-entered SQL, the following 4806** API is provided to turn the [sqlite3_load_extension()] mechanism on and 4807** off. {F12622} It is off by default. {END} See ticket #1863. 4808** 4809** {F12621} Call the sqlite3_enable_load_extension() routine 4810** with onoff==1 to turn extension loading on 4811** and call it with onoff==0 to turn it back off again. {END} 4812*/ 4813int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4814 4815/* 4816** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640} 4817** 4818** {F12641} This function 4819** registers an extension entry point that is automatically invoked 4820** whenever a new database connection is opened using 4821** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()]. {END} 4822** 4823** This API can be invoked at program startup in order to register 4824** one or more statically linked extensions that will be available 4825** to all new database connections. 4826** 4827** {F12642} Duplicate extensions are detected so calling this routine multiple 4828** times with the same extension is harmless. 4829** 4830** {F12643} This routine stores a pointer to the extension in an array 4831** that is obtained from sqlite_malloc(). {END} If you run a memory leak 4832** checker on your program and it reports a leak because of this 4833** array, then invoke [sqlite3_reset_auto_extension()] prior 4834** to shutdown to free the memory. 4835** 4836** {F12644} Automatic extensions apply across all threads. {END} 4837** 4838** This interface is experimental and is subject to change or 4839** removal in future releases of SQLite. 4840*/ 4841int sqlite3_auto_extension(void *xEntryPoint); 4842 4843 4844/* 4845** CAPI3REF: Reset Automatic Extension Loading {F12660} 4846** 4847** {F12661} This function disables all previously registered 4848** automatic extensions. {END} This 4849** routine undoes the effect of all prior [sqlite3_auto_extension()] 4850** calls. 4851** 4852** {F12662} This call disabled automatic extensions in all threads. {END} 4853** 4854** This interface is experimental and is subject to change or 4855** removal in future releases of SQLite. 4856*/ 4857void sqlite3_reset_auto_extension(void); 4858 4859 4860/* 4861****** EXPERIMENTAL - subject to change without notice ************** 4862** 4863** The interface to the virtual-table mechanism is currently considered 4864** to be experimental. The interface might change in incompatible ways. 4865** If this is a problem for you, do not use the interface at this time. 4866** 4867** When the virtual-table mechanism stablizes, we will declare the 4868** interface fixed, support it indefinitely, and remove this comment. 4869*/ 4870 4871/* 4872** Structures used by the virtual table interface 4873*/ 4874typedef struct sqlite3_vtab sqlite3_vtab; 4875typedef struct sqlite3_index_info sqlite3_index_info; 4876typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4877typedef struct sqlite3_module sqlite3_module; 4878 4879/* 4880** CAPI3REF: Virtual Table Object {F18000} 4881** KEYWORDS: sqlite3_module 4882** 4883** A module is a class of virtual tables. Each module is defined 4884** by an instance of the following structure. This structure consists 4885** mostly of methods for the module. 4886*/ 4887struct sqlite3_module { 4888 int iVersion; 4889 int (*xCreate)(sqlite3*, void *pAux, 4890 int argc, const char *const*argv, 4891 sqlite3_vtab **ppVTab, char**); 4892 int (*xConnect)(sqlite3*, void *pAux, 4893 int argc, const char *const*argv, 4894 sqlite3_vtab **ppVTab, char**); 4895 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4896 int (*xDisconnect)(sqlite3_vtab *pVTab); 4897 int (*xDestroy)(sqlite3_vtab *pVTab); 4898 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4899 int (*xClose)(sqlite3_vtab_cursor*); 4900 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4901 int argc, sqlite3_value **argv); 4902 int (*xNext)(sqlite3_vtab_cursor*); 4903 int (*xEof)(sqlite3_vtab_cursor*); 4904 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4905 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4906 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4907 int (*xBegin)(sqlite3_vtab *pVTab); 4908 int (*xSync)(sqlite3_vtab *pVTab); 4909 int (*xCommit)(sqlite3_vtab *pVTab); 4910 int (*xRollback)(sqlite3_vtab *pVTab); 4911 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4912 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4913 void **ppArg); 4914 4915 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4916}; 4917 4918/* 4919** CAPI3REF: Virtual Table Indexing Information {F18100} 4920** KEYWORDS: sqlite3_index_info 4921** 4922** The sqlite3_index_info structure and its substructures is used to 4923** pass information into and receive the reply from the xBestIndex 4924** method of an sqlite3_module. The fields under **Inputs** are the 4925** inputs to xBestIndex and are read-only. xBestIndex inserts its 4926** results into the **Outputs** fields. 4927** 4928** The aConstraint[] array records WHERE clause constraints of the 4929** form: 4930** 4931** column OP expr 4932** 4933** Where OP is =, <, <=, >, or >=. 4934** The particular operator is stored 4935** in aConstraint[].op. The index of the column is stored in 4936** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 4937** expr on the right-hand side can be evaluated (and thus the constraint 4938** is usable) and false if it cannot. 4939** 4940** The optimizer automatically inverts terms of the form "expr OP column" 4941** and makes other simplifications to the WHERE clause in an attempt to 4942** get as many WHERE clause terms into the form shown above as possible. 4943** The aConstraint[] array only reports WHERE clause terms in the correct 4944** form that refer to the particular virtual table being queried. 4945** 4946** Information about the ORDER BY clause is stored in aOrderBy[]. 4947** Each term of aOrderBy records a column of the ORDER BY clause. 4948** 4949** The xBestIndex method must fill aConstraintUsage[] with information 4950** about what parameters to pass to xFilter. If argvIndex>0 then 4951** the right-hand side of the corresponding aConstraint[] is evaluated 4952** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 4953** is true, then the constraint is assumed to be fully handled by the 4954** virtual table and is not checked again by SQLite. 4955** 4956** The idxNum and idxPtr values are recorded and passed into xFilter. 4957** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. 4958** 4959** The orderByConsumed means that output from xFilter will occur in 4960** the correct order to satisfy the ORDER BY clause so that no separate 4961** sorting step is required. 4962** 4963** The estimatedCost value is an estimate of the cost of doing the 4964** particular lookup. A full scan of a table with N entries should have 4965** a cost of N. A binary search of a table of N entries should have a 4966** cost of approximately log(N). 4967*/ 4968struct sqlite3_index_info { 4969 /* Inputs */ 4970 int nConstraint; /* Number of entries in aConstraint */ 4971 struct sqlite3_index_constraint { 4972 int iColumn; /* Column on left-hand side of constraint */ 4973 unsigned char op; /* Constraint operator */ 4974 unsigned char usable; /* True if this constraint is usable */ 4975 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4976 } *aConstraint; /* Table of WHERE clause constraints */ 4977 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4978 struct sqlite3_index_orderby { 4979 int iColumn; /* Column number */ 4980 unsigned char desc; /* True for DESC. False for ASC. */ 4981 } *aOrderBy; /* The ORDER BY clause */ 4982 4983 /* Outputs */ 4984 struct sqlite3_index_constraint_usage { 4985 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4986 unsigned char omit; /* Do not code a test for this constraint */ 4987 } *aConstraintUsage; 4988 int idxNum; /* Number used to identify the index */ 4989 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4990 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4991 int orderByConsumed; /* True if output is already ordered */ 4992 double estimatedCost; /* Estimated cost of using this index */ 4993}; 4994#define SQLITE_INDEX_CONSTRAINT_EQ 2 4995#define SQLITE_INDEX_CONSTRAINT_GT 4 4996#define SQLITE_INDEX_CONSTRAINT_LE 8 4997#define SQLITE_INDEX_CONSTRAINT_LT 16 4998#define SQLITE_INDEX_CONSTRAINT_GE 32 4999#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5000 5001/* 5002** CAPI3REF: Register A Virtual Table Implementation {F18200} 5003** 5004** This routine is used to register a new module name with an SQLite 5005** connection. Module names must be registered before creating new 5006** virtual tables on the module, or before using preexisting virtual 5007** tables of the module. 5008*/ 5009int sqlite3_create_module( 5010 sqlite3 *db, /* SQLite connection to register module with */ 5011 const char *zName, /* Name of the module */ 5012 const sqlite3_module *, /* Methods for the module */ 5013 void * /* Client data for xCreate/xConnect */ 5014); 5015 5016/* 5017** CAPI3REF: Register A Virtual Table Implementation {F18210} 5018** 5019** This routine is identical to the sqlite3_create_module() method above, 5020** except that it allows a destructor function to be specified. It is 5021** even more experimental than the rest of the virtual tables API. 5022*/ 5023int sqlite3_create_module_v2( 5024 sqlite3 *db, /* SQLite connection to register module with */ 5025 const char *zName, /* Name of the module */ 5026 const sqlite3_module *, /* Methods for the module */ 5027 void *, /* Client data for xCreate/xConnect */ 5028 void(*xDestroy)(void*) /* Module destructor function */ 5029); 5030 5031/* 5032** CAPI3REF: Virtual Table Instance Object {F18010} 5033** KEYWORDS: sqlite3_vtab 5034** 5035** Every module implementation uses a subclass of the following structure 5036** to describe a particular instance of the module. Each subclass will 5037** be tailored to the specific needs of the module implementation. The 5038** purpose of this superclass is to define certain fields that are common 5039** to all module implementations. 5040** 5041** Virtual tables methods can set an error message by assigning a 5042** string obtained from sqlite3_mprintf() to zErrMsg. The method should 5043** take care that any prior string is freed by a call to sqlite3_free() 5044** prior to assigning a new string to zErrMsg. After the error message 5045** is delivered up to the client application, the string will be automatically 5046** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note 5047** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field 5048** since virtual tables are commonly implemented in loadable extensions which 5049** do not have access to sqlite3MPrintf() or sqlite3Free(). 5050*/ 5051struct sqlite3_vtab { 5052 const sqlite3_module *pModule; /* The module for this virtual table */ 5053 int nRef; /* Used internally */ 5054 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5055 /* Virtual table implementations will typically add additional fields */ 5056}; 5057 5058/* 5059** CAPI3REF: Virtual Table Cursor Object {F18020} 5060** KEYWORDS: sqlite3_vtab_cursor 5061** 5062** Every module implementation uses a subclass of the following structure 5063** to describe cursors that point into the virtual table and are used 5064** to loop through the virtual table. Cursors are created using the 5065** xOpen method of the module. Each module implementation will define 5066** the content of a cursor structure to suit its own needs. 5067** 5068** This superclass exists in order to define fields of the cursor that 5069** are common to all implementations. 5070*/ 5071struct sqlite3_vtab_cursor { 5072 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5073 /* Virtual table implementations will typically add additional fields */ 5074}; 5075 5076/* 5077** CAPI3REF: Declare The Schema Of A Virtual Table {F18280} 5078** 5079** The xCreate and xConnect methods of a module use the following API 5080** to declare the format (the names and datatypes of the columns) of 5081** the virtual tables they implement. 5082*/ 5083int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); 5084 5085/* 5086** CAPI3REF: Overload A Function For A Virtual Table {F18300} 5087** 5088** Virtual tables can provide alternative implementations of functions 5089** using the xFindFunction method. But global versions of those functions 5090** must exist in order to be overloaded. 5091** 5092** This API makes sure a global version of a function with a particular 5093** name and number of parameters exists. If no such function exists 5094** before this API is called, a new function is created. The implementation 5095** of the new function always causes an exception to be thrown. So 5096** the new function is not good for anything by itself. Its only 5097** purpose is to be a place-holder function that can be overloaded 5098** by virtual tables. 5099** 5100** This API should be considered part of the virtual table interface, 5101** which is experimental and subject to change. 5102*/ 5103int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5104 5105/* 5106** The interface to the virtual-table mechanism defined above (back up 5107** to a comment remarkably similar to this one) is currently considered 5108** to be experimental. The interface might change in incompatible ways. 5109** If this is a problem for you, do not use the interface at this time. 5110** 5111** When the virtual-table mechanism stabilizes, we will declare the 5112** interface fixed, support it indefinitely, and remove this comment. 5113** 5114****** EXPERIMENTAL - subject to change without notice ************** 5115*/ 5116 5117/* 5118** CAPI3REF: A Handle To An Open BLOB {F17800} 5119** 5120** An instance of this object represents an open BLOB on which 5121** incremental I/O can be preformed. 5122** Objects of this type are created by 5123** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()]. 5124** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5125** can be used to read or write small subsections of the blob. 5126** The [sqlite3_blob_bytes()] interface returns the size of the 5127** blob in bytes. 5128*/ 5129typedef struct sqlite3_blob sqlite3_blob; 5130 5131/* 5132** CAPI3REF: Open A BLOB For Incremental I/O {F17810} 5133** 5134** This interfaces opens a handle to the blob located 5135** in row iRow, column zColumn, table zTable in database zDb; 5136** in other words, the same blob that would be selected by: 5137** 5138** <pre> 5139** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow; 5140** </pre> {END} 5141** 5142** If the flags parameter is non-zero, the blob is opened for 5143** read and write access. If it is zero, the blob is opened for read 5144** access. 5145** 5146** Note that the database name is not the filename that contains 5147** the database but rather the symbolic name of the database that 5148** is assigned when the database is connected using [ATTACH]. 5149** For the main database file, the database name is "main". For 5150** TEMP tables, the database name is "temp". 5151** 5152** On success, [SQLITE_OK] is returned and the new 5153** [sqlite3_blob | blob handle] is written to *ppBlob. 5154** Otherwise an error code is returned and 5155** any value written to *ppBlob should not be used by the caller. 5156** This function sets the database-handle error code and message 5157** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 5158** 5159** INVARIANTS: 5160** 5161** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)] 5162** interface opens an [sqlite3_blob] object P on the blob 5163** in column C of table T in database B on [database connection] D. 5164** 5165** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] starts 5166** a new transaction on [database connection] D if that connection 5167** is not already in a transaction. 5168** 5169** {F17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface opens the blob 5170** for read and write access if and only if the F parameter 5171** is non-zero. 5172** 5173** {F17819} The [sqlite3_blob_open()] interface returns [SQLITE_OK] on 5174** success and an appropriate [error code] on failure. 5175** 5176** {F17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)] 5177** then subsequent calls to [sqlite3_errcode(D)], 5178** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return 5179** information approprate for that error. 5180*/ 5181int sqlite3_blob_open( 5182 sqlite3*, 5183 const char *zDb, 5184 const char *zTable, 5185 const char *zColumn, 5186 sqlite3_int64 iRow, 5187 int flags, 5188 sqlite3_blob **ppBlob 5189); 5190 5191/* 5192** CAPI3REF: Close A BLOB Handle {F17830} 5193** 5194** Close an open [sqlite3_blob | blob handle]. 5195** 5196** Closing a BLOB shall cause the current transaction to commit 5197** if there are no other BLOBs, no pending prepared statements, and the 5198** database connection is in autocommit mode. 5199** If any writes were made to the BLOB, they might be held in cache 5200** until the close operation if they will fit. {END} 5201** Closing the BLOB often forces the changes 5202** out to disk and so if any I/O errors occur, they will likely occur 5203** at the time when the BLOB is closed. {F17833} Any errors that occur during 5204** closing are reported as a non-zero return value. 5205** 5206** The BLOB is closed unconditionally. Even if this routine returns 5207** an error code, the BLOB is still closed. 5208** 5209** INVARIANTS: 5210** 5211** {F17833} The [sqlite3_blob_close(P)] interface closes an 5212** [sqlite3_blob] object P previously opened using 5213** [sqlite3_blob_open()]. 5214** 5215** {F17836} Closing an [sqlite3_blob] object using 5216** [sqlite3_blob_close()] shall cause the current transaction to 5217** commit if there are no other open [sqlite3_blob] objects 5218** or [prepared statements] on the same [database connection] and 5219** the [database connection] is in 5220** [sqlite3_get_autocommit | autocommit mode]. 5221** 5222** {F17839} The [sqlite3_blob_close(P)] interfaces closes the 5223** [sqlite3_blob] object P unconditionally, even if 5224** [sqlite3_blob_close(P)] returns something other than [SQLITE_OK]. 5225** 5226*/ 5227int sqlite3_blob_close(sqlite3_blob *); 5228 5229/* 5230** CAPI3REF: Return The Size Of An Open BLOB {F17840} 5231** 5232** Return the size in bytes of the blob accessible via the open 5233** [sqlite3_blob] object in its only argument. 5234** 5235** INVARIANTS: 5236** 5237** {F17843} The [sqlite3_blob_bytes(P)] interface returns the size 5238** in bytes of the BLOB that the [sqlite3_blob] object P 5239** refers to. 5240*/ 5241int sqlite3_blob_bytes(sqlite3_blob *); 5242 5243/* 5244** CAPI3REF: Read Data From A BLOB Incrementally {F17850} 5245** 5246** This function is used to read data from an open 5247** [sqlite3_blob | blob-handle] into a caller supplied buffer. 5248** N bytes of data are copied into buffer 5249** Z from the open blob, starting at offset iOffset. 5250** 5251** If offset iOffset is less than N bytes from the end of the blob, 5252** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 5253** less than zero [SQLITE_ERROR] is returned and no data is read. 5254** 5255** On success, SQLITE_OK is returned. Otherwise, an 5256** [error code] or an [extended error code] is returned. 5257** 5258** INVARIANTS: 5259** 5260** {F17853} The [sqlite3_blob_read(P,Z,N,X)] interface reads N bytes 5261** beginning at offset X from 5262** the blob that [sqlite3_blob] object P refers to 5263** and writes those N bytes into buffer Z. 5264** 5265** {F17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the blob 5266** is less than N+X bytes, then the function returns [SQLITE_ERROR] 5267** and nothing is read from the blob. 5268** 5269** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero 5270** then the function returns [SQLITE_ERROR] 5271** and nothing is read from the blob. 5272** 5273** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface returns [SQLITE_OK] 5274** if N bytes where successfully read into buffer Z. 5275** 5276** {F17865} If the requested read could not be completed, 5277** the [sqlite3_blob_read(P,Z,N,X)] interface returns an 5278** appropriate [error code] or [extended error code]. 5279** 5280** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(D,...)] 5281** then subsequent calls to [sqlite3_errcode(D)], 5282** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return 5283** information approprate for that error. 5284*/ 5285int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5286 5287/* 5288** CAPI3REF: Write Data Into A BLOB Incrementally {F17870} 5289** 5290** This function is used to write data into an open 5291** [sqlite3_blob | blob-handle] from a user supplied buffer. 5292** n bytes of data are copied from the buffer 5293** pointed to by z into the open blob, starting at offset iOffset. 5294** 5295** If the [sqlite3_blob | blob-handle] passed as the first argument 5296** was not opened for writing (the flags parameter to [sqlite3_blob_open()] 5297*** was zero), this function returns [SQLITE_READONLY]. 5298** 5299** This function may only modify the contents of the blob; it is 5300** not possible to increase the size of a blob using this API. 5301** If offset iOffset is less than n bytes from the end of the blob, 5302** [SQLITE_ERROR] is returned and no data is written. If n is 5303** less than zero [SQLITE_ERROR] is returned and no data is written. 5304** 5305** On success, SQLITE_OK is returned. Otherwise, an 5306** [error code] or an [extended error code] is returned. 5307** 5308** INVARIANTS: 5309** 5310** {F17873} The [sqlite3_blob_write(P,Z,N,X)] interface writes N bytes 5311** from buffer Z into 5312** the blob that [sqlite3_blob] object P refers to 5313** beginning at an offset of X into the blob. 5314** 5315** {F17875} The [sqlite3_blob_write(P,Z,N,X)] interface returns 5316** [SQLITE_READONLY] if the [sqlite3_blob] object P was 5317** [sqlite3_blob_open | opened] for reading only. 5318** 5319** {F17876} In [sqlite3_blob_write(P,Z,N,X)] if the size of the blob 5320** is less than N+X bytes, then the function returns [SQLITE_ERROR] 5321** and nothing is written into the blob. 5322** 5323** {F17879} In [sqlite3_blob_write(P,Z,N,X)] if X or N is less than zero 5324** then the function returns [SQLITE_ERROR] 5325** and nothing is written into the blob. 5326** 5327** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface returns [SQLITE_OK] 5328** if N bytes where successfully written into blob. 5329** 5330** {F17885} If the requested write could not be completed, 5331** the [sqlite3_blob_write(P,Z,N,X)] interface returns an 5332** appropriate [error code] or [extended error code]. 5333** 5334** {F17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)] 5335** then subsequent calls to [sqlite3_errcode(D)], 5336** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return 5337** information approprate for that error. 5338*/ 5339int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5340 5341/* 5342** CAPI3REF: Virtual File System Objects {F11200} 5343** 5344** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5345** that SQLite uses to interact 5346** with the underlying operating system. Most SQLite builds come with a 5347** single default VFS that is appropriate for the host computer. 5348** New VFSes can be registered and existing VFSes can be unregistered. 5349** The following interfaces are provided. 5350** 5351** The sqlite3_vfs_find() interface returns a pointer to 5352** a VFS given its name. Names are case sensitive. 5353** Names are zero-terminated UTF-8 strings. 5354** If there is no match, a NULL 5355** pointer is returned. If zVfsName is NULL then the default 5356** VFS is returned. 5357** 5358** New VFSes are registered with sqlite3_vfs_register(). 5359** Each new VFS becomes the default VFS if the makeDflt flag is set. 5360** The same VFS can be registered multiple times without injury. 5361** To make an existing VFS into the default VFS, register it again 5362** with the makeDflt flag set. If two different VFSes with the 5363** same name are registered, the behavior is undefined. If a 5364** VFS is registered with a name that is NULL or an empty string, 5365** then the behavior is undefined. 5366** 5367** Unregister a VFS with the sqlite3_vfs_unregister() interface. 5368** If the default VFS is unregistered, another VFS is chosen as 5369** the default. The choice for the new VFS is arbitrary. 5370** 5371** INVARIANTS: 5372** 5373** {F11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the 5374** registered [sqlite3_vfs] object whose name exactly matches 5375** the zero-terminated UTF-8 string N, or it returns NULL if 5376** there is no match. 5377** 5378** {F11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then 5379** the function returns a pointer to the default [sqlite3_vfs] 5380** object if there is one, or NULL if there is no default 5381** [sqlite3_vfs] object. 5382** 5383** {F11209} The [sqlite3_vfs_register(P,F)] interface registers the 5384** well-formed [sqlite3_vfs] object P using the name given 5385** by the zName field of the object. 5386** 5387** {F11212} Using the [sqlite3_vfs_register(P,F)] interface to register 5388** the same [sqlite3_vfs] object multiple times is a harmless no-op. 5389** 5390** {F11215} The [sqlite3_vfs_register(P,F)] interface makes the 5391** the [sqlite3_vfs] object P the default [sqlite3_vfs] object 5392** if F is non-zero. 5393** 5394** {F11218} The [sqlite3_vfs_unregister(P)] interface unregisters the 5395** [sqlite3_vfs] object P so that it is no longer returned by 5396** subsequent calls to [sqlite3_vfs_find()]. 5397*/ 5398sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5399int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5400int sqlite3_vfs_unregister(sqlite3_vfs*); 5401 5402/* 5403** CAPI3REF: Mutexes {F17000} 5404** 5405** The SQLite core uses these routines for thread 5406** synchronization. Though they are intended for internal 5407** use by SQLite, code that links against SQLite is 5408** permitted to use any of these routines. 5409** 5410** The SQLite source code contains multiple implementations 5411** of these mutex routines. An appropriate implementation 5412** is selected automatically at compile-time. The following 5413** implementations are available in the SQLite core: 5414** 5415** <ul> 5416** <li> SQLITE_MUTEX_OS2 5417** <li> SQLITE_MUTEX_PTHREAD 5418** <li> SQLITE_MUTEX_W32 5419** <li> SQLITE_MUTEX_NOOP 5420** </ul> 5421** 5422** The SQLITE_MUTEX_NOOP implementation is a set of routines 5423** that does no real locking and is appropriate for use in 5424** a single-threaded application. The SQLITE_MUTEX_OS2, 5425** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 5426** are appropriate for use on os/2, unix, and windows. 5427** 5428** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5429** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5430** implementation is included with the library. The 5431** mutex interface routines defined here become external 5432** references in the SQLite library for which implementations 5433** must be provided by the application. This facility allows an 5434** application that links against SQLite to provide its own mutex 5435** implementation without having to modify the SQLite core. 5436** 5437** {F17011} The sqlite3_mutex_alloc() routine allocates a new 5438** mutex and returns a pointer to it. {F17012} If it returns NULL 5439** that means that a mutex could not be allocated. {F17013} SQLite 5440** will unwind its stack and return an error. {F17014} The argument 5441** to sqlite3_mutex_alloc() is one of these integer constants: 5442** 5443** <ul> 5444** <li> SQLITE_MUTEX_FAST 5445** <li> SQLITE_MUTEX_RECURSIVE 5446** <li> SQLITE_MUTEX_STATIC_MASTER 5447** <li> SQLITE_MUTEX_STATIC_MEM 5448** <li> SQLITE_MUTEX_STATIC_MEM2 5449** <li> SQLITE_MUTEX_STATIC_PRNG 5450** <li> SQLITE_MUTEX_STATIC_LRU 5451** <li> SQLITE_MUTEX_STATIC_LRU2 5452** </ul> {END} 5453** 5454** {F17015} The first two constants cause sqlite3_mutex_alloc() to create 5455** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5456** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 5457** The mutex implementation does not need to make a distinction 5458** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5459** not want to. {F17016} But SQLite will only request a recursive mutex in 5460** cases where it really needs one. {END} If a faster non-recursive mutex 5461** implementation is available on the host platform, the mutex subsystem 5462** might return such a mutex in response to SQLITE_MUTEX_FAST. 5463** 5464** {F17017} The other allowed parameters to sqlite3_mutex_alloc() each return 5465** a pointer to a static preexisting mutex. {END} Four static mutexes are 5466** used by the current version of SQLite. Future versions of SQLite 5467** may add additional static mutexes. Static mutexes are for internal 5468** use by SQLite only. Applications that use SQLite mutexes should 5469** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5470** SQLITE_MUTEX_RECURSIVE. 5471** 5472** {F17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5473** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5474** returns a different mutex on every call. {F17034} But for the static 5475** mutex types, the same mutex is returned on every call that has 5476** the same type number. {END} 5477** 5478** {F17019} The sqlite3_mutex_free() routine deallocates a previously 5479** allocated dynamic mutex. {F17020} SQLite is careful to deallocate every 5480** dynamic mutex that it allocates. {U17021} The dynamic mutexes must not be in 5481** use when they are deallocated. {U17022} Attempting to deallocate a static 5482** mutex results in undefined behavior. {F17023} SQLite never deallocates 5483** a static mutex. {END} 5484** 5485** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5486** to enter a mutex. {F17024} If another thread is already within the mutex, 5487** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5488** SQLITE_BUSY. {F17025} The sqlite3_mutex_try() interface returns SQLITE_OK 5489** upon successful entry. {F17026} Mutexes created using 5490** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5491** {F17027} In such cases the, 5492** mutex must be exited an equal number of times before another thread 5493** can enter. {U17028} If the same thread tries to enter any other 5494** kind of mutex more than once, the behavior is undefined. 5495** {F17029} SQLite will never exhibit 5496** such behavior in its own use of mutexes. {END} 5497** 5498** Some systems (ex: windows95) do not the operation implemented by 5499** sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() will 5500** always return SQLITE_BUSY. {F17030} The SQLite core only ever uses 5501** sqlite3_mutex_try() as an optimization so this is acceptable behavior. {END} 5502** 5503** {F17031} The sqlite3_mutex_leave() routine exits a mutex that was 5504** previously entered by the same thread. {U17032} The behavior 5505** is undefined if the mutex is not currently entered by the 5506** calling thread or is not currently allocated. {F17033} SQLite will 5507** never do either. {END} 5508** 5509** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5510*/ 5511sqlite3_mutex *sqlite3_mutex_alloc(int); 5512void sqlite3_mutex_free(sqlite3_mutex*); 5513void sqlite3_mutex_enter(sqlite3_mutex*); 5514int sqlite3_mutex_try(sqlite3_mutex*); 5515void sqlite3_mutex_leave(sqlite3_mutex*); 5516 5517/* 5518** CAPI3REF: Mutex Verifcation Routines {F17080} 5519** 5520** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5521** are intended for use inside assert() statements. {F17081} The SQLite core 5522** never uses these routines except inside an assert() and applications 5523** are advised to follow the lead of the core. {F17082} The core only 5524** provides implementations for these routines when it is compiled 5525** with the SQLITE_DEBUG flag. {U17087} External mutex implementations 5526** are only required to provide these routines if SQLITE_DEBUG is 5527** defined and if NDEBUG is not defined. 5528** 5529** {F17083} These routines should return true if the mutex in their argument 5530** is held or not held, respectively, by the calling thread. {END} 5531** 5532** {X17084} The implementation is not required to provided versions of these 5533** routines that actually work. 5534** If the implementation does not provide working 5535** versions of these routines, it should at least provide stubs 5536** that always return true so that one does not get spurious 5537** assertion failures. {END} 5538** 5539** {F17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 5540** the routine should return 1. {END} This seems counter-intuitive since 5541** clearly the mutex cannot be held if it does not exist. But the 5542** the reason the mutex does not exist is because the build is not 5543** using mutexes. And we do not want the assert() containing the 5544** call to sqlite3_mutex_held() to fail, so a non-zero return is 5545** the appropriate thing to do. {F17086} The sqlite3_mutex_notheld() 5546** interface should also return 1 when given a NULL pointer. 5547*/ 5548int sqlite3_mutex_held(sqlite3_mutex*); 5549int sqlite3_mutex_notheld(sqlite3_mutex*); 5550 5551/* 5552** CAPI3REF: Mutex Types {F17001} 5553** 5554** {F17002} The [sqlite3_mutex_alloc()] interface takes a single argument 5555** which is one of these integer constants. {END} 5556*/ 5557#define SQLITE_MUTEX_FAST 0 5558#define SQLITE_MUTEX_RECURSIVE 1 5559#define SQLITE_MUTEX_STATIC_MASTER 2 5560#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5561#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */ 5562#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5563#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5564#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 5565 5566/* 5567** CAPI3REF: Low-Level Control Of Database Files {F11300} 5568** 5569** {F11301} The [sqlite3_file_control()] interface makes a direct call to the 5570** xFileControl method for the [sqlite3_io_methods] object associated 5571** with a particular database identified by the second argument. {F11302} The 5572** name of the database is the name assigned to the database by the 5573** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 5574** database. {F11303} To control the main database file, use the name "main" 5575** or a NULL pointer. {F11304} The third and fourth parameters to this routine 5576** are passed directly through to the second and third parameters of 5577** the xFileControl method. {F11305} The return value of the xFileControl 5578** method becomes the return value of this routine. 5579** 5580** {F11306} If the second parameter (zDbName) does not match the name of any 5581** open database file, then SQLITE_ERROR is returned. {F11307} This error 5582** code is not remembered and will not be recalled by [sqlite3_errcode()] 5583** or [sqlite3_errmsg()]. {U11308} The underlying xFileControl method might 5584** also return SQLITE_ERROR. {U11309} There is no way to distinguish between 5585** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5586** xFileControl method. {END} 5587** 5588** See also: [SQLITE_FCNTL_LOCKSTATE] 5589*/ 5590int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5591 5592/* 5593** CAPI3REF: Testing Interface {F11400} 5594** 5595** The sqlite3_test_control() interface is used to read out internal 5596** state of SQLite and to inject faults into SQLite for testing 5597** purposes. The first parameter a operation code that determines 5598** the number, meaning, and operation of all subsequent parameters. 5599** 5600** This interface is not for use by applications. It exists solely 5601** for verifying the correct operation of the SQLite library. Depending 5602** on how the SQLite library is compiled, this interface might not exist. 5603** 5604** The details of the operation codes, their meanings, the parameters 5605** they take, and what they do are all subject to change without notice. 5606** Unlike most of the SQLite API, this function is not guaranteed to 5607** operate consistently from one release to the next. 5608*/ 5609int sqlite3_test_control(int op, ...); 5610 5611/* 5612** CAPI3REF: Testing Interface Operation Codes {F11410} 5613** 5614** These constants are the valid operation code parameters used 5615** as the first argument to [sqlite3_test_control()]. 5616** 5617** These parameters and their meansing are subject to change 5618** without notice. These values are for testing purposes only. 5619** Applications should not use any of these parameters or the 5620** [sqlite3_test_control()] interface. 5621*/ 5622#define SQLITE_TESTCTRL_FAULT_CONFIG 1 5623#define SQLITE_TESTCTRL_FAULT_FAILURES 2 5624#define SQLITE_TESTCTRL_FAULT_BENIGN_FAILURES 3 5625#define SQLITE_TESTCTRL_FAULT_PENDING 4 5626#define SQLITE_TESTCTRL_PRNG_SAVE 5 5627#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5628#define SQLITE_TESTCTRL_PRNG_RESET 7 5629#define SQLITE_TESTCTRL_BITVEC_TEST 8 5630 5631 5632/* 5633** Undo the hack that converts floating point types to integer for 5634** builds on processors without floating point support. 5635*/ 5636#ifdef SQLITE_OMIT_FLOATING_POINT 5637# undef double 5638#endif 5639 5640#ifdef __cplusplus 5641} /* End of the 'extern "C"' block */ 5642#endif 5643#endif 5644