includes/db/DatabaseSqlite.php

   1 <?php
   2 /**
   3  * This is the SQLite database abstraction layer.
   4  * See maintenance/sqlite/README for development notes and other specific information
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Database
  23  */
  24
  25 /**
  26  * @ingroup Database
  27  */
  28 class DatabaseSqlite extends DatabaseBase {
  29         /** @var bool Whether full text is enabled */
  30         private static $fulltextEnabled = null;
  31
  32         /** @var string File name for SQLite database file */
  33         public $mDatabaseFile;
  34
  35         /** @var int The number of rows affected as an integer */
  36         protected $mAffectedRows;
  37
  38         /** @var resource */
  39         protected $mLastResult;
  40
  41         /**
  42          * @var string
  43          * @todo Seems to serve no purpose. Remove?
  44          */
  45         private $mName;
  46
  47         /** @var PDO */
  48         protected $mConn;
  49
  50         function __construct( $p = null ) {
  51                 global $wgSharedDB;
  52
  53                 if ( !is_array( $p ) ) { // legacy calling pattern
  54                         wfDeprecated( __METHOD__ . " method called without parameter array.", "1.22" );
  55                         $args = func_get_args();
  56                         $p = array(
  57                                 'host' => isset( $args[0] ) ? $args[0] : false,
  58                                 'user' => isset( $args[1] ) ? $args[1] : false,
  59                                 'password' => isset( $args[2] ) ? $args[2] : false,
  60                                 'dbname' => isset( $args[3] ) ? $args[3] : false,
  61                                 'flags' => isset( $args[4] ) ? $args[4] : 0,
  62                                 'tablePrefix' => isset( $args[5] ) ? $args[5] : 'get from global',
  63                                 'foreign' => isset( $args[6] ) ? $args[6] : false
  64                         );
  65                 }
  66                 $this->mName = $p['dbname'];
  67                 parent::__construct( $p );
  68                 // parent doesn't open when $user is false, but we can work with $dbName
  69                 if ( $p['dbname'] && !$this->isOpen() ) {
  70                         if ( $this->open( $p['host'], $p['user'], $p['password'], $p['dbname'] ) ) {
  71                                 if ( $wgSharedDB ) {
  72                                         $this->attachDatabase( $wgSharedDB );
  73                                 }
  74                         }
  75                 }
  76         }
  77
  78         /**
  79          * @return string
  80          */
  81         function getType() {
  82                 return 'sqlite';
  83         }
  84
  85         /**
  86          * @todo Check if it should be true like parent class
  87          *
  88          * @return bool
  89          */
  90         function implicitGroupby() {
  91                 return false;
  92         }
  93
  94         /** Open an SQLite database and return a resource handle to it
  95          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  96          *
  97          * @param string $server
  98          * @param string $user
  99          * @param string $pass
 100          * @param string $dbName
 101          *
 102          * @throws DBConnectionError
 103          * @return PDO
 104          */
 105         function open( $server, $user, $pass, $dbName ) {
 106                 global $wgSQLiteDataDir;
 107
 108                 $this->close();
 109                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
 110                 if ( !is_readable( $fileName ) ) {
 111                         $this->mConn = false;
 112                         throw new DBConnectionError( $this, "SQLite database not accessible" );
 113                 }
 114                 $this->openFile( $fileName );
 115
 116                 return $this->mConn;
 117         }
 118
 119         /**
 120          * Opens a database file
 121          *
 122          * @param string $fileName
 123          * @throws DBConnectionError
 124          * @return PDO|bool SQL connection or false if failed
 125          */
 126         function openFile( $fileName ) {
 127                 $err = false;
 128
 129                 $this->mDatabaseFile = $fileName;
 130                 try {
 131                         if ( $this->mFlags & DBO_PERSISTENT ) {
 132                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
 133                                         array( PDO::ATTR_PERSISTENT => true ) );
 134                         } else {
 135                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
 136                         }
 137                 } catch ( PDOException $e ) {
 138                         $err = $e->getMessage();
 139                 }
 140
 141                 if ( !$this->mConn ) {
 142                         wfDebug( "DB connection error: $err\n" );
 143                         throw new DBConnectionError( $this, $err );
 144                 }
 145
 146                 $this->mOpened = !!$this->mConn;
 147                 # set error codes only, don't raise exceptions
 148                 if ( $this->mOpened ) {
 149                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
 150                         # Enforce LIKE to be case sensitive, just like MySQL
 151                         $this->query( 'PRAGMA case_sensitive_like = 1' );
 152
 153                         return $this->mConn;
 154                 }
 155
 156                 return false;
 157         }
 158
 159         /**
 160          * Does not actually close the connection, just destroys the reference for GC to do its work
 161          * @return bool
 162          */
 163         protected function closeConnection() {
 164                 $this->mConn = null;
 165
 166                 return true;
 167         }
 168
 169         /**
 170          * Generates a database file name. Explicitly public for installer.
 171          * @param string $dir Directory where database resides
 172          * @param string $dbName Database name
 173          * @return string
 174          */
 175         public static function generateFileName( $dir, $dbName ) {
 176                 return "$dir/$dbName.sqlite";
 177         }
 178
 179         /**
 180          * Check if the searchindext table is FTS enabled.
 181          * @return bool False if not enabled.
 182          */
 183         function checkForEnabledSearch() {
 184                 if ( self::$fulltextEnabled === null ) {
 185                         self::$fulltextEnabled = false;
 186                         $table = $this->tableName( 'searchindex' );
 187                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = '$table'", __METHOD__ );
 188                         if ( $res ) {
 189                                 $row = $res->fetchRow();
 190                                 self::$fulltextEnabled = stristr( $row['sql'], 'fts' ) !== false;
 191                         }
 192                 }
 193
 194                 return self::$fulltextEnabled;
 195         }
 196
 197         /**
 198          * Returns version of currently supported SQLite fulltext search module or false if none present.
 199          * @return string
 200          */
 201         static function getFulltextSearchModule() {
 202                 static $cachedResult = null;
 203                 if ( $cachedResult !== null ) {
 204                         return $cachedResult;
 205                 }
 206                 $cachedResult = false;
 207                 $table = 'dummy_search_test';
 208
 209                 $db = new DatabaseSqliteStandalone( ':memory:' );
 210
 211                 if ( $db->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 212                         $cachedResult = 'FTS3';
 213                 }
 214                 $db->close();
 215
 216                 return $cachedResult;
 217         }
 218
 219         /**
 220          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 221          * for details.
 222          *
 223          * @param string $name Database name to be used in queries like
 224          *   SELECT foo FROM dbname.table
 225          * @param bool|string $file Database file name. If omitted, will be generated
 226          *   using $name and $wgSQLiteDataDir
 227          * @param string $fname Calling function name
 228          * @return ResultWrapper
 229          */
 230         function attachDatabase( $name, $file = false, $fname = __METHOD__ ) {
 231                 global $wgSQLiteDataDir;
 232                 if ( !$file ) {
 233                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 234                 }
 235                 $file = $this->addQuotes( $file );
 236
 237                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 238         }
 239
 240         /**
 241          * @see DatabaseBase::isWriteQuery()
 242          *
 243          * @param $sql string
 244          * @return bool
 245          */
 246         function isWriteQuery( $sql ) {
 247                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 248         }
 249
 250         /**
 251          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 252          *
 253          * @param string $sql
 254          * @return bool|ResultWrapper
 255          */
 256         protected function doQuery( $sql ) {
 257                 $res = $this->mConn->query( $sql );
 258                 if ( $res === false ) {
 259                         return false;
 260                 } else {
 261                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 262                         $this->mAffectedRows = $r->rowCount();
 263                         $res = new ResultWrapper( $this, $r->fetchAll() );
 264                 }
 265
 266                 return $res;
 267         }
 268
 269         /**
 270          * @param ResultWrapper|mixed $res
 271          */
 272         function freeResult( $res ) {
 273                 if ( $res instanceof ResultWrapper ) {
 274                         $res->result = null;
 275                 } else {
 276                         $res = null;
 277                 }
 278         }
 279
 280         /**
 281          * @param ResultWrapper|array $res
 282          * @return stdClass|bool
 283          */
 284         function fetchObject( $res ) {
 285                 if ( $res instanceof ResultWrapper ) {
 286                         $r =& $res->result;
 287                 } else {
 288                         $r =& $res;
 289                 }
 290
 291                 $cur = current( $r );
 292                 if ( is_array( $cur ) ) {
 293                         next( $r );
 294                         $obj = new stdClass;
 295                         foreach ( $cur as $k => $v ) {
 296                                 if ( !is_numeric( $k ) ) {
 297                                         $obj->$k = $v;
 298                                 }
 299                         }
 300
 301                         return $obj;
 302                 }
 303
 304                 return false;
 305         }
 306
 307         /**
 308          * @param ResultWrapper|mixed $res
 309          * @return array|bool
 310          */
 311         function fetchRow( $res ) {
 312                 if ( $res instanceof ResultWrapper ) {
 313                         $r =& $res->result;
 314                 } else {
 315                         $r =& $res;
 316                 }
 317                 $cur = current( $r );
 318                 if ( is_array( $cur ) ) {
 319                         next( $r );
 320
 321                         return $cur;
 322                 }
 323
 324                 return false;
 325         }
 326
 327         /**
 328          * The PDO::Statement class implements the array interface so count() will work
 329          *
 330          * @param ResultWrapper|array $res
 331          * @return int
 332          */
 333         function numRows( $res ) {
 334                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 335
 336                 return count( $r );
 337         }
 338
 339         /**
 340          * @param ResultWrapper $res
 341          * @return int
 342          */
 343         function numFields( $res ) {
 344                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 345
 346                 return is_array( $r ) ? count( $r[0] ) : 0;
 347         }
 348
 349         /**
 350          * @param ResultWrapper $res
 351          * @param $n
 352          * @return bool
 353          */
 354         function fieldName( $res, $n ) {
 355                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 356                 if ( is_array( $r ) ) {
 357                         $keys = array_keys( $r[0] );
 358
 359                         return $keys[$n];
 360                 }
 361
 362                 return false;
 363         }
 364
 365         /**
 366          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 367          *
 368          * @param string $name
 369          * @param string $format
 370          * @return string
 371          */
 372         function tableName( $name, $format = 'quoted' ) {
 373                 // table names starting with sqlite_ are reserved
 374                 if ( strpos( $name, 'sqlite_' ) === 0 ) {
 375                         return $name;
 376                 }
 377
 378                 return str_replace( '"', '', parent::tableName( $name, $format ) );
 379         }
 380
 381         /**
 382          * Index names have DB scope
 383          *
 384          * @param string $index
 385          * @return string
 386          */
 387         function indexName( $index ) {
 388                 return $index;
 389         }
 390
 391         /**
 392          * This must be called after nextSequenceVal
 393          *
 394          * @return int
 395          */
 396         function insertId() {
 397                 // PDO::lastInsertId yields a string :(
 398                 return intval( $this->mConn->lastInsertId() );
 399         }
 400
 401         /**
 402          * @param ResultWrapper|array $res
 403          * @param int $row
 404          */
 405         function dataSeek( $res, $row ) {
 406                 if ( $res instanceof ResultWrapper ) {
 407                         $r =& $res->result;
 408                 } else {
 409                         $r =& $res;
 410                 }
 411                 reset( $r );
 412                 if ( $row > 0 ) {
 413                         for ( $i = 0; $i < $row; $i++ ) {
 414                                 next( $r );
 415                         }
 416                 }
 417         }
 418
 419         /**
 420          * @return string
 421          */
 422         function lastError() {
 423                 if ( !is_object( $this->mConn ) ) {
 424                         return "Cannot return last error, no db connection";
 425                 }
 426                 $e = $this->mConn->errorInfo();
 427
 428                 return isset( $e[2] ) ? $e[2] : '';
 429         }
 430
 431         /**
 432          * @return string
 433          */
 434         function lastErrno() {
 435                 if ( !is_object( $this->mConn ) ) {
 436                         return "Cannot return last error, no db connection";
 437                 } else {
 438                         $info = $this->mConn->errorInfo();
 439
 440                         return $info[1];
 441                 }
 442         }
 443
 444         /**
 445          * @return int
 446          */
 447         function affectedRows() {
 448                 return $this->mAffectedRows;
 449         }
 450
 451         /**
 452          * Returns information about an index
 453          * Returns false if the index does not exist
 454          * - if errors are explicitly ignored, returns NULL on failure
 455          *
 456          * @param string $table
 457          * @param string $index
 458          * @param string $fname
 459          * @return array
 460          */
 461         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 462                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 463                 $res = $this->query( $sql, $fname );
 464                 if ( !$res ) {
 465                         return null;
 466                 }
 467                 if ( $res->numRows() == 0 ) {
 468                         return false;
 469                 }
 470                 $info = array();
 471                 foreach ( $res as $row ) {
 472                         $info[] = $row->name;
 473                 }
 474
 475                 return $info;
 476         }
 477
 478         /**
 479          * @param string $table
 480          * @param string $index
 481          * @param string $fname
 482          * @return bool|null
 483          */
 484         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 485                 $row = $this->selectRow( 'sqlite_master', '*',
 486                         array(
 487                                 'type' => 'index',
 488                                 'name' => $this->indexName( $index ),
 489                         ), $fname );
 490                 if ( !$row || !isset( $row->sql ) ) {
 491                         return null;
 492                 }
 493
 494                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 495                 $indexPos = strpos( $row->sql, 'INDEX' );
 496                 if ( $indexPos === false ) {
 497                         return null;
 498                 }
 499                 $firstPart = substr( $row->sql, 0, $indexPos );
 500                 $options = explode( ' ', $firstPart );
 501
 502                 return in_array( 'UNIQUE', $options );
 503         }
 504
 505         /**
 506          * Filter the options used in SELECT statements
 507          *
 508          * @param array $options
 509          * @return array
 510          */
 511         function makeSelectOptions( $options ) {
 512                 foreach ( $options as $k => $v ) {
 513                         if ( is_numeric( $k ) && ( $v == 'FOR UPDATE' || $v == 'LOCK IN SHARE MODE' ) ) {
 514                                 $options[$k] = '';
 515                         }
 516                 }
 517
 518                 return parent::makeSelectOptions( $options );
 519         }
 520
 521         /**
 522          * @param array $options
 523          * @return string
 524          */
 525         protected function makeUpdateOptions( $options ) {
 526                 $options = self::fixIgnore( $options );
 527
 528                 return parent::makeUpdateOptions( $options );
 529         }
 530
 531         /**
 532          * @param array $options
 533          * @return array
 534          */
 535         static function fixIgnore( $options ) {
 536                 # SQLite uses OR IGNORE not just IGNORE
 537                 foreach ( $options as $k => $v ) {
 538                         if ( $v == 'IGNORE' ) {
 539                                 $options[$k] = 'OR IGNORE';
 540                         }
 541                 }
 542
 543                 return $options;
 544         }
 545
 546         /**
 547          * @param array $options
 548          * @return string
 549          */
 550         function makeInsertOptions( $options ) {
 551                 $options = self::fixIgnore( $options );
 552
 553                 return parent::makeInsertOptions( $options );
 554         }
 555
 556         /**
 557          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 558          * @param string $table
 559          * @param array $a
 560          * @param string $fname
 561          * @param array $options
 562          * @return bool
 563          */
 564         function insert( $table, $a, $fname = __METHOD__, $options = array() ) {
 565                 if ( !count( $a ) ) {
 566                         return true;
 567                 }
 568
 569                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 570                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 571                         $ret = true;
 572                         foreach ( $a as $v ) {
 573                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 574                                         $ret = false;
 575                                 }
 576                         }
 577                 } else {
 578                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 579                 }
 580
 581                 return $ret;
 582         }
 583
 584         /**
 585          * @param string $table
 586          * @param array $uniqueIndexes Unused
 587          * @param string|array $rows
 588          * @param string $fname
 589          * @return bool|ResultWrapper
 590          */
 591         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 592                 if ( !count( $rows ) ) {
 593                         return true;
 594                 }
 595
 596                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 597                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 598                         $ret = true;
 599                         foreach ( $rows as $v ) {
 600                                 if ( !$this->nativeReplace( $table, $v, "$fname/multi-row" ) ) {
 601                                         $ret = false;
 602                                 }
 603                         }
 604                 } else {
 605                         $ret = $this->nativeReplace( $table, $rows, "$fname/single-row" );
 606                 }
 607
 608                 return $ret;
 609         }
 610
 611         /**
 612          * Returns the size of a text field, or -1 for "unlimited"
 613          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 614          *
 615          * @param string $table
 616          * @param string $field
 617          * @return int
 618          */
 619         function textFieldSize( $table, $field ) {
 620                 return -1;
 621         }
 622
 623         /**
 624          * @return bool
 625          */
 626         function unionSupportsOrderAndLimit() {
 627                 return false;
 628         }
 629
 630         /**
 631          * @param string $sqls
 632          * @param bool $all Whether to "UNION ALL" or not
 633          * @return string
 634          */
 635         function unionQueries( $sqls, $all ) {
 636                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 637
 638                 return implode( $glue, $sqls );
 639         }
 640
 641         /**
 642          * @return bool
 643          */
 644         function wasDeadlock() {
 645                 return $this->lastErrno() == 5; // SQLITE_BUSY
 646         }
 647
 648         /**
 649          * @return bool
 650          */
 651         function wasErrorReissuable() {
 652                 return $this->lastErrno() == 17; // SQLITE_SCHEMA;
 653         }
 654
 655         /**
 656          * @return bool
 657          */
 658         function wasReadOnlyError() {
 659                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 660         }
 661
 662         /**
 663          * @return string wikitext of a link to the server software's web site
 664          */
 665         public function getSoftwareLink() {
 666                 return "[{{int:version-db-sqlite-url}} SQLite]";
 667         }
 668
 669         /**
 670          * @return string Version information from the database
 671          */
 672         function getServerVersion() {
 673                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 674
 675                 return $ver;
 676         }
 677
 678         /**
 679          * @return string User-friendly database information
 680          */
 681         public function getServerInfo() {
 682                 return wfMessage( self::getFulltextSearchModule()
 683                         ? 'sqlite-has-fts'
 684                         : 'sqlite-no-fts', $this->getServerVersion() )->text();
 685         }
 686
 687         /**
 688          * Get information about a given field
 689          * Returns false if the field does not exist.
 690          *
 691          * @param string $table
 692          * @param string $field
 693          * @return SQLiteField|bool False on failure
 694          */
 695         function fieldInfo( $table, $field ) {
 696                 $tableName = $this->tableName( $table );
 697                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 698                 $res = $this->query( $sql, __METHOD__ );
 699                 foreach ( $res as $row ) {
 700                         if ( $row->name == $field ) {
 701                                 return new SQLiteField( $row, $tableName );
 702                         }
 703                 }
 704
 705                 return false;
 706         }
 707
 708         protected function doBegin( $fname = '' ) {
 709                 if ( $this->mTrxLevel == 1 ) {
 710                         $this->commit( __METHOD__ );
 711                 }
 712                 try {
 713                         $this->mConn->beginTransaction();
 714                 } catch ( PDOException $e ) {
 715                         throw new DBUnexpectedError( $this, 'Error in BEGIN query: ' . $e->getMessage() );
 716                 }
 717                 $this->mTrxLevel = 1;
 718         }
 719
 720         protected function doCommit( $fname = '' ) {
 721                 if ( $this->mTrxLevel == 0 ) {
 722                         return;
 723                 }
 724                 try {
 725                         $this->mConn->commit();
 726                 } catch ( PDOException $e ) {
 727                         throw new DBUnexpectedError( $this, 'Error in COMMIT query: ' . $e->getMessage() );
 728                 }
 729                 $this->mTrxLevel = 0;
 730         }
 731
 732         protected function doRollback( $fname = '' ) {
 733                 if ( $this->mTrxLevel == 0 ) {
 734                         return;
 735                 }
 736                 $this->mConn->rollBack();
 737                 $this->mTrxLevel = 0;
 738         }
 739
 740         /**
 741          * @param string $s
 742          * @return string
 743          */
 744         function strencode( $s ) {
 745                 return substr( $this->addQuotes( $s ), 1, -1 );
 746         }
 747
 748         /**
 749          * @param $b
 750          * @return Blob
 751          */
 752         function encodeBlob( $b ) {
 753                 return new Blob( $b );
 754         }
 755
 756         /**
 757          * @param $b Blob|string
 758          * @return string
 759          */
 760         function decodeBlob( $b ) {
 761                 if ( $b instanceof Blob ) {
 762                         $b = $b->fetch();
 763                 }
 764
 765                 return $b;
 766         }
 767
 768         /**
 769          * @param Blob|string $s
 770          * @return string
 771          */
 772         function addQuotes( $s ) {
 773                 if ( $s instanceof Blob ) {
 774                         return "x'" . bin2hex( $s->fetch() ) . "'";
 775                 } elseif ( is_bool( $s ) ) {
 776                         return (int)$s;
 777                 } elseif ( strpos( $s, "\0" ) !== false ) {
 778                         // SQLite doesn't support \0 in strings, so use the hex representation as a workaround.
 779                         // This is a known limitation of SQLite's mprintf function which PDO should work around,
 780                         // but doesn't. I have reported this to php.net as bug #63419:
 781                         // https://bugs.php.net/bug.php?id=63419
 782                         // There was already a similar report for SQLite3::escapeString, bug #62361:
 783                         // https://bugs.php.net/bug.php?id=62361
 784                         return "x'" . bin2hex( $s ) . "'";
 785                 } else {
 786                         return $this->mConn->quote( $s );
 787                 }
 788         }
 789
 790         /**
 791          * @return string
 792          */
 793         function buildLike() {
 794                 $params = func_get_args();
 795                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 796                         $params = $params[0];
 797                 }
 798
 799                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 800         }
 801
 802         /**
 803          * @return string
 804          */
 805         public function getSearchEngine() {
 806                 return "SearchSqlite";
 807         }
 808
 809         /**
 810          * No-op version of deadlockLoop
 811          *
 812          * @return mixed
 813          */
 814         public function deadlockLoop( /*...*/ ) {
 815                 $args = func_get_args();
 816                 $function = array_shift( $args );
 817
 818                 return call_user_func_array( $function, $args );
 819         }
 820
 821         /**
 822          * @param string $s
 823          * @return string
 824          */
 825         protected function replaceVars( $s ) {
 826                 $s = parent::replaceVars( $s );
 827                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 828                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 829
 830                         // binary/varbinary column type -> blob
 831                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 832                         // no such thing as unsigned
 833                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 834                         // INT -> INTEGER
 835                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 836                         // floating point types -> REAL
 837                         $s = preg_replace(
 838                                 '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i',
 839                                 'REAL',
 840                                 $s
 841                         );
 842                         // varchar -> TEXT
 843                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 844                         // TEXT normalization
 845                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 846                         // BLOB normalization
 847                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 848                         // BOOL -> INTEGER
 849                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 850                         // DATETIME -> TEXT
 851                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 852                         // No ENUM type
 853                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 854                         // binary collation type -> nothing
 855                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 856                         // auto_increment -> autoincrement
 857                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 858                         // No explicit options
 859                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 860                         // AUTOINCREMENT should immedidately follow PRIMARY KEY
 861                         $s = preg_replace( '/primary key (.*?) autoincrement/i', 'PRIMARY KEY AUTOINCREMENT $1', $s );
 862                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 863                         // No truncated indexes
 864                         $s = preg_replace( '/\(\d+\)/', '', $s );
 865                         // No FULLTEXT
 866                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 867                 } elseif ( preg_match( '/^\s*DROP INDEX/i', $s ) ) {
 868                         // DROP INDEX is database-wide, not table-specific, so no ON <table> clause.
 869                         $s = preg_replace( '/\sON\s+[^\s]*/i', '', $s );
 870                 }
 871
 872                 return $s;
 873         }
 874
 875         /**
 876          * Build a concatenation list to feed into a SQL query
 877          *
 878          * @param string[] $stringList
 879          * @return string
 880          */
 881         function buildConcat( $stringList ) {
 882                 return '(' . implode( ') || (', $stringList ) . ')';
 883         }
 884
 885         public function buildGroupConcatField(
 886                 $delim, $table, $field, $conds = '', $join_conds = array()
 887         ) {
 888                 $fld = "group_concat($field," . $this->addQuotes( $delim ) . ')';
 889
 890                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
 891         }
 892
 893         /**
 894          * @throws MWException
 895          * @param string $oldName
 896          * @param string $newName
 897          * @param bool $temporary
 898          * @param string $fname
 899          * @return bool|ResultWrapper
 900          */
 901         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 902                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name=" .
 903                         $this->addQuotes( $oldName ) . " AND type='table'", $fname );
 904                 $obj = $this->fetchObject( $res );
 905                 if ( !$obj ) {
 906                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 907                 }
 908                 $sql = $obj->sql;
 909                 $sql = preg_replace(
 910                         '/(?<=\W)"?' . preg_quote( trim( $this->addIdentifierQuotes( $oldName ), '"' ) ) . '"?(?=\W)/',
 911                         $this->addIdentifierQuotes( $newName ),
 912                         $sql,
 913                         1
 914                 );
 915                 if ( $temporary ) {
 916                         if ( preg_match( '/^\\s*CREATE\\s+VIRTUAL\\s+TABLE\b/i', $sql ) ) {
 917                                 wfDebug( "Table $oldName is virtual, can't create a temporary duplicate.\n" );
 918                         } else {
 919                                 $sql = str_replace( 'CREATE TABLE', 'CREATE TEMPORARY TABLE', $sql );
 920                         }
 921                 }
 922
 923                 return $this->query( $sql, $fname );
 924         }
 925
 926         /**
 927          * List all tables on the database
 928          *
 929          * @param string $prefix Only show tables with this prefix, e.g. mw_
 930          * @param string $fname Calling function name
 931          *
 932          * @return array
 933          */
 934         function listTables( $prefix = null, $fname = __METHOD__ ) {
 935                 $result = $this->select(
 936                         'sqlite_master',
 937                         'name',
 938                         "type='table'"
 939                 );
 940
 941                 $endArray = array();
 942
 943                 foreach ( $result as $table ) {
 944                         $vars = get_object_vars( $table );
 945                         $table = array_pop( $vars );
 946
 947                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 948                                 if ( strpos( $table, 'sqlite_' ) !== 0 ) {
 949                                         $endArray[] = $table;
 950                                 }
 951                         }
 952                 }
 953
 954                 return $endArray;
 955         }
 956 } // end DatabaseSqlite class
 957
 958 /**
 959  * This class allows simple acccess to a SQLite database independently from main database settings
 960  * @ingroup Database
 961  */
 962 class DatabaseSqliteStandalone extends DatabaseSqlite {
 963         public function __construct( $fileName, $flags = 0 ) {
 964                 $this->mFlags = $flags;
 965                 $this->tablePrefix( null );
 966                 $this->openFile( $fileName );
 967         }
 968 }
 969
 970 /**
 971  * @ingroup Database
 972  */
 973 class SQLiteField implements Field {
 974         private $info, $tableName;
 975
 976         function __construct( $info, $tableName ) {
 977                 $this->info = $info;
 978                 $this->tableName = $tableName;
 979         }
 980
 981         function name() {
 982                 return $this->info->name;
 983         }
 984
 985         function tableName() {
 986                 return $this->tableName;
 987         }
 988
 989         function defaultValue() {
 990                 if ( is_string( $this->info->dflt_value ) ) {
 991                         // Typically quoted
 992                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 993                                 return str_replace( "''", "'", $this->info->dflt_value );
 994                         }
 995                 }
 996
 997                 return $this->info->dflt_value;
 998         }
 999
1000         /**
1001          * @return bool
1002          */
1003         function isNullable() {
1004                 return !$this->info->notnull;
1005         }
1006
1007         function type() {
1008                 return $this->info->type;
1009         }
1010 } // end SQLiteField