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