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