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  * @file
   7  * @ingroup Database
   8  */
   9
  10 /**
  11  * @ingroup Database
  12  */
  13 class DatabaseSqlite extends DatabaseBase {
  14
  15         private static $fulltextEnabled = null;
  16
  17         var $mAffectedRows;
  18         var $mLastResult;
  19         var $mDatabaseFile;
  20         var $mName;
  21
  22         /**
  23          * Constructor.
  24          * Parameters $server, $user and $password are not used.
  25          */
  26         function __construct( $server = false, $user = false, $password = false, $dbName = false, $failFunction = false, $flags = 0 ) {
  27                 global $wgSharedDB;
  28                 $this->mFailFunction = $failFunction;
  29                 $this->mFlags = $flags;
  30                 $this->mName = $dbName;
  31
  32                 if ( $this->open( $server, $user, $password, $dbName ) && $wgSharedDB ) {
  33                         $this->attachDatabase( $wgSharedDB );
  34                 }
  35         }
  36
  37         function getType() {
  38                 return 'sqlite';
  39         }
  40
  41         /**
  42          * @todo: check if it should be true like parent class
  43          */
  44         function implicitGroupby()   { return false; }
  45
  46         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 ) {
  47                 return new DatabaseSqlite( $server, $user, $password, $dbName, $failFunction, $flags );
  48         }
  49
  50         /** Open an SQLite database and return a resource handle to it
  51          *  NOTE: only $dbName is used, the other parameters are irrelevant for SQLite databases
  52          */
  53         function open( $server, $user, $pass, $dbName ) {
  54                 global $wgSQLiteDataDir;
  55
  56                 $fileName = self::generateFileName( $wgSQLiteDataDir, $dbName );
  57                 if ( !is_readable( $fileName ) ) {
  58                         $this->mConn = false;
  59                         throw new DBConnectionError( $this, "SQLite database not accessible" );
  60                 }
  61                 $this->openFile( $fileName );
  62                 return $this->mConn;
  63         }
  64
  65         /**
  66          * Opens a database file
  67          * @return SQL connection or false if failed
  68          */
  69         function openFile( $fileName ) {
  70                 $this->mDatabaseFile = $fileName;
  71                 try {
  72                         if ( $this->mFlags & DBO_PERSISTENT ) {
  73                                 $this->mConn = new PDO( "sqlite:$fileName", '', '',
  74                                         array( PDO::ATTR_PERSISTENT => true ) );
  75                         } else {
  76                                 $this->mConn = new PDO( "sqlite:$fileName", '', '' );
  77                         }
  78                 } catch ( PDOException $e ) {
  79                         $err = $e->getMessage();
  80                 }
  81                 if ( !$this->mConn ) {
  82                         wfDebug( "DB connection error: $err\n" );
  83                         if ( !$this->mFailFunction ) {
  84                                 throw new DBConnectionError( $this, $err );
  85                         } else {
  86                                 return false;
  87                         }
  88
  89                 }
  90                 $this->mOpened = !!$this->mConn;
  91                 # set error codes only, don't raise exceptions
  92                 if ( $this->mOpened ) {
  93                         $this->mConn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT );
  94                         return true;
  95                 }
  96         }
  97
  98         /**
  99          * Close an SQLite database
 100          */
 101         function close() {
 102                 $this->mOpened = false;
 103                 if ( is_object( $this->mConn ) ) {
 104                         if ( $this->trxLevel() ) $this->commit();
 105                         $this->mConn = null;
 106                 }
 107                 return true;
 108         }
 109
 110         /**
 111          * Generates a database file name. Explicitly public for installer.
 112          * @param $dir String: Directory where database resides
 113          * @param $dbName String: Database name
 114          * @return String
 115          */
 116         public static function generateFileName( $dir, $dbName ) {
 117                 return "$dir/$dbName.sqlite";
 118         }
 119
 120         /**
 121          * Check if the searchindext table is FTS enabled.
 122          * @returns false if not enabled.
 123          */
 124         function checkForEnabledSearch() {
 125                 if ( self::$fulltextEnabled === null ) {
 126                         self::$fulltextEnabled = false;
 127                         $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name = 'searchindex'", __METHOD__ );
 128                         if ( $res ) {
 129                                 $row = $res->fetchRow();
 130                                 self::$fulltextEnabled = stristr($row['sql'], 'fts' ) !== false;
 131                         }
 132                 }
 133                 return self::$fulltextEnabled;
 134         }
 135
 136         /**
 137          * Returns version of currently supported SQLite fulltext search module or false if none present.
 138          * @return String
 139          */
 140         function getFulltextSearchModule() {
 141                 static $cachedResult = null;
 142                 if ( $cachedResult !== null ) {
 143                         return $cachedResult;
 144                 }
 145                 $cachedResult = false;
 146                 $table = 'dummy_search_test';
 147                 $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 148
 149                 if ( $this->query( "CREATE VIRTUAL TABLE $table USING FTS3(dummy_field)", __METHOD__, true ) ) {
 150                         $this->query( "DROP TABLE IF EXISTS $table", __METHOD__ );
 151                         $cachedResult = 'FTS3';
 152                 }
 153                 return $cachedResult;
 154         }
 155
 156         /**
 157          * Attaches external database to our connection, see http://sqlite.org/lang_attach.html
 158          * for details.
 159          * @param $name String: database name to be used in queries like SELECT foo FROM dbname.table
 160          * @param $file String: database file name. If omitted, will be generated using $name and $wgSQLiteDataDir
 161          * @param $fname String: calling function name
 162          */
 163         function attachDatabase( $name, $file = false, $fname = 'DatabaseSqlite::attachDatabase' ) {
 164                 global $wgSQLiteDataDir;
 165                 if ( !$file ) {
 166                         $file = self::generateFileName( $wgSQLiteDataDir, $name );
 167                 }
 168                 $file = $this->addQuotes( $file );
 169                 return $this->query( "ATTACH DATABASE $file AS $name", $fname );
 170         }
 171
 172         /**
 173          * @see DatabaseBase::isWriteQuery()
 174          */
 175         function isWriteQuery( $sql ) {
 176                 return parent::isWriteQuery( $sql ) && !preg_match( '/^ATTACH\b/i', $sql );
 177         }
 178
 179         /**
 180          * SQLite doesn't allow buffered results or data seeking etc, so we'll use fetchAll as the result
 181          */
 182         function doQuery( $sql ) {
 183                 $res = $this->mConn->query( $sql );
 184                 if ( $res === false ) {
 185                         return false;
 186                 } else {
 187                         $r = $res instanceof ResultWrapper ? $res->result : $res;
 188                         $this->mAffectedRows = $r->rowCount();
 189                         $res = new ResultWrapper( $this, $r->fetchAll() );
 190                 }
 191                 return $res;
 192         }
 193
 194         function freeResult( $res ) {
 195                 if ( $res instanceof ResultWrapper ) {
 196                         $res->result = null;
 197                 } else {
 198                         $res = null;
 199                 }
 200         }
 201
 202         function fetchObject( $res ) {
 203                 if ( $res instanceof ResultWrapper ) {
 204                         $r =& $res->result;
 205                 } else {
 206                         $r =& $res;
 207                 }
 208
 209                 $cur = current( $r );
 210                 if ( is_array( $cur ) ) {
 211                         next( $r );
 212                         $obj = new stdClass;
 213                         foreach ( $cur as $k => $v ) {
 214                                 if ( !is_numeric( $k ) ) {
 215                                         $obj->$k = $v;
 216                                 }
 217                         }
 218
 219                         return $obj;
 220                 }
 221                 return false;
 222         }
 223
 224         function fetchRow( $res ) {
 225                 if ( $res instanceof ResultWrapper ) {
 226                         $r =& $res->result;
 227                 } else {
 228                         $r =& $res;
 229                 }
 230                 $cur = current( $r );
 231                 if ( is_array( $cur ) ) {
 232                         next( $r );
 233                         return $cur;
 234                 }
 235                 return false;
 236         }
 237
 238         /**
 239          * The PDO::Statement class implements the array interface so count() will work
 240          */
 241         function numRows( $res ) {
 242                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 243                 return count( $r );
 244         }
 245
 246         function numFields( $res ) {
 247                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 248                 return is_array( $r ) ? count( $r[0] ) : 0;
 249         }
 250
 251         function fieldName( $res, $n ) {
 252                 $r = $res instanceof ResultWrapper ? $res->result : $res;
 253                 if ( is_array( $r ) ) {
 254                         $keys = array_keys( $r[0] );
 255                         return $keys[$n];
 256                 }
 257                 return  false;
 258         }
 259
 260         /**
 261          * Use MySQL's naming (accounts for prefix etc) but remove surrounding backticks
 262          */
 263         function tableName( $name ) {
 264                 // table names starting with sqlite_ are reserved
 265                 if ( strpos( $name, 'sqlite_' ) === 0 ) return $name;
 266                 return str_replace( '`', '', parent::tableName( $name ) );
 267         }
 268
 269         /**
 270          * Index names have DB scope
 271          */
 272         function indexName( $index ) {
 273                 return $index;
 274         }
 275
 276         /**
 277          * This must be called after nextSequenceVal
 278          */
 279         function insertId() {
 280                 return $this->mConn->lastInsertId();
 281         }
 282
 283         function dataSeek( $res, $row ) {
 284                 if ( $res instanceof ResultWrapper ) {
 285                         $r =& $res->result;
 286                 } else {
 287                         $r =& $res;
 288                 }
 289                 reset( $r );
 290                 if ( $row > 0 ) {
 291                         for ( $i = 0; $i < $row; $i++ ) {
 292                                 next( $r );
 293                         }
 294                 }
 295         }
 296
 297         function lastError() {
 298                 if ( !is_object( $this->mConn ) ) {
 299                         return "Cannot return last error, no db connection";
 300                 }
 301                 $e = $this->mConn->errorInfo();
 302                 return isset( $e[2] ) ? $e[2] : '';
 303         }
 304
 305         function lastErrno() {
 306                 if ( !is_object( $this->mConn ) ) {
 307                         return "Cannot return last error, no db connection";
 308                 } else {
 309                         $info = $this->mConn->errorInfo();
 310                         return $info[1];
 311                 }
 312         }
 313
 314         function affectedRows() {
 315                 return $this->mAffectedRows;
 316         }
 317
 318         /**
 319          * Returns information about an index
 320          * Returns false if the index does not exist
 321          * - if errors are explicitly ignored, returns NULL on failure
 322          */
 323         function indexInfo( $table, $index, $fname = 'DatabaseSqlite::indexExists' ) {
 324                 $sql = 'PRAGMA index_info(' . $this->addQuotes( $this->indexName( $index ) ) . ')';
 325                 $res = $this->query( $sql, $fname );
 326                 if ( !$res ) {
 327                         return null;
 328                 }
 329                 if ( $res->numRows() == 0 ) {
 330                         return false;
 331                 }
 332                 $info = array();
 333                 foreach ( $res as $row ) {
 334                         $info[] = $row->name;
 335                 }
 336                 return $info;
 337         }
 338
 339         function indexUnique( $table, $index, $fname = 'DatabaseSqlite::indexUnique' ) {
 340                 $row = $this->selectRow( 'sqlite_master', '*',
 341                         array(
 342                                 'type' => 'index',
 343                                 'name' => $this->indexName( $index ),
 344                         ), $fname );
 345                 if ( !$row || !isset( $row->sql ) ) {
 346                         return null;
 347                 }
 348
 349                 // $row->sql will be of the form CREATE [UNIQUE] INDEX ...
 350                 $indexPos = strpos( $row->sql, 'INDEX' );
 351                 if ( $indexPos === false ) {
 352                         return null;
 353                 }
 354                 $firstPart = substr( $row->sql, 0, $indexPos );
 355                 $options = explode( ' ', $firstPart );
 356                 return in_array( 'UNIQUE', $options );
 357         }
 358
 359         /**
 360          * Filter the options used in SELECT statements
 361          */
 362         function makeSelectOptions( $options ) {
 363                 foreach ( $options as $k => $v ) {
 364                         if ( is_numeric( $k ) && $v == 'FOR UPDATE' ) {
 365                                 $options[$k] = '';
 366                         }
 367                 }
 368                 return parent::makeSelectOptions( $options );
 369         }
 370
 371         /**
 372          * Based on generic method (parent) with some prior SQLite-sepcific adjustments
 373          */
 374         function insert( $table, $a, $fname = 'DatabaseSqlite::insert', $options = array() ) {
 375                 if ( !count( $a ) ) {
 376                         return true;
 377                 }
 378                 if ( !is_array( $options ) ) {
 379                         $options = array( $options );
 380                 }
 381
 382                 # SQLite uses OR IGNORE not just IGNORE
 383                 foreach ( $options as $k => $v ) {
 384                         if ( $v == 'IGNORE' ) {
 385                                 $options[$k] = 'OR IGNORE';
 386                         }
 387                 }
 388
 389                 # SQLite can't handle multi-row inserts, so divide up into multiple single-row inserts
 390                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 391                         $ret = true;
 392                         foreach ( $a as $v ) {
 393                                 if ( !parent::insert( $table, $v, "$fname/multi-row", $options ) ) {
 394                                         $ret = false;
 395                                 }
 396                         }
 397                 } else {
 398                         $ret = parent::insert( $table, $a, "$fname/single-row", $options );
 399                 }
 400
 401                 return $ret;
 402         }
 403
 404         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseSqlite::replace' ) {
 405                 if ( !count( $rows ) ) return true;
 406
 407                 # SQLite can't handle multi-row replaces, so divide up into multiple single-row queries
 408                 if ( isset( $rows[0] ) && is_array( $rows[0] ) ) {
 409                         $ret = true;
 410                         foreach ( $rows as $v ) {
 411                                 if ( !parent::replace( $table, $uniqueIndexes, $v, "$fname/multi-row" ) ) {
 412                                         $ret = false;
 413                                 }
 414                         }
 415                 } else {
 416                         $ret = parent::replace( $table, $uniqueIndexes, $rows, "$fname/single-row" );
 417                 }
 418
 419                 return $ret;
 420         }
 421
 422         /**
 423          * Returns the size of a text field, or -1 for "unlimited"
 424          * In SQLite this is SQLITE_MAX_LENGTH, by default 1GB. No way to query it though.
 425          */
 426         function textFieldSize( $table, $field ) {
 427                 return - 1;
 428         }
 429
 430         function unionSupportsOrderAndLimit() {
 431                 return false;
 432         }
 433
 434         function unionQueries( $sqls, $all ) {
 435                 $glue = $all ? ' UNION ALL ' : ' UNION ';
 436                 return implode( $glue, $sqls );
 437         }
 438
 439         function wasDeadlock() {
 440                 return $this->lastErrno() == 5; // SQLITE_BUSY
 441         }
 442
 443         function wasErrorReissuable() {
 444                 return $this->lastErrno() ==  17; // SQLITE_SCHEMA;
 445         }
 446
 447         function wasReadOnlyError() {
 448                 return $this->lastErrno() == 8; // SQLITE_READONLY;
 449         }
 450
 451         /**
 452          * @return string wikitext of a link to the server software's web site
 453          */
 454         public static function getSoftwareLink() {
 455                 return "[http://sqlite.org/ SQLite]";
 456         }
 457
 458         /**
 459          * @return string Version information from the database
 460          */
 461         function getServerVersion() {
 462                 $ver = $this->mConn->getAttribute( PDO::ATTR_SERVER_VERSION );
 463                 return $ver;
 464         }
 465
 466         /**
 467          * @return string User-friendly database information
 468          */
 469         public function getServerInfo() {
 470                 return wfMsg( $this->getFulltextSearchModule() ? 'sqlite-has-fts' : 'sqlite-no-fts', $this->getServerVersion() );
 471         }
 472
 473         /**
 474          * Get information about a given field
 475          * Returns false if the field does not exist.
 476          */
 477         function fieldInfo( $table, $field ) {
 478                 $tableName = $this->tableName( $table );
 479                 $sql = 'PRAGMA table_info(' . $this->addQuotes( $tableName ) . ')';
 480                 $res = $this->query( $sql, __METHOD__ );
 481                 foreach ( $res as $row ) {
 482                         if ( $row->name == $field ) {
 483                                 return new SQLiteField( $row, $tableName );
 484                         }
 485                 }
 486                 return false;
 487         }
 488
 489         function begin( $fname = '' ) {
 490                 if ( $this->mTrxLevel == 1 ) $this->commit();
 491                 $this->mConn->beginTransaction();
 492                 $this->mTrxLevel = 1;
 493         }
 494
 495         function commit( $fname = '' ) {
 496                 if ( $this->mTrxLevel == 0 ) return;
 497                 $this->mConn->commit();
 498                 $this->mTrxLevel = 0;
 499         }
 500
 501         function rollback( $fname = '' ) {
 502                 if ( $this->mTrxLevel == 0 ) return;
 503                 $this->mConn->rollBack();
 504                 $this->mTrxLevel = 0;
 505         }
 506
 507         function limitResultForUpdate( $sql, $num ) {
 508                 return $this->limitResult( $sql, $num );
 509         }
 510
 511         function strencode( $s ) {
 512                 return substr( $this->addQuotes( $s ), 1, - 1 );
 513         }
 514
 515         function encodeBlob( $b ) {
 516                 return new Blob( $b );
 517         }
 518
 519         function decodeBlob( $b ) {
 520                 if ( $b instanceof Blob ) {
 521                         $b = $b->fetch();
 522                 }
 523                 return $b;
 524         }
 525
 526         function addQuotes( $s ) {
 527                 if ( $s instanceof Blob ) {
 528                         return "x'" . bin2hex( $s->fetch() ) . "'";
 529                 } else {
 530                         return $this->mConn->quote( $s );
 531                 }
 532         }
 533
 534         function quote_ident( $s ) {
 535                 return $s;
 536         }
 537
 538         function buildLike() {
 539                 $params = func_get_args();
 540                 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
 541                         $params = $params[0];
 542                 }
 543                 return parent::buildLike( $params ) . "ESCAPE '\' ";
 544         }
 545
 546         /**
 547          * Called by the installer script
 548          * - this is the same way PostgreSQL works, MySQL reads in tables.sql and interwiki.sql using DatabaseBase::sourceFile()
 549          */
 550         public function setup_database() {
 551                 global $IP;
 552
 553                 # Process common MySQL/SQLite table definitions
 554                 $err = $this->sourceFile( "$IP/maintenance/tables.sql" );
 555                 if ( $err !== true ) {
 556                         echo " <b>FAILED</b></li>";
 557                         dieout( htmlspecialchars( $err ) );
 558                 }
 559                 echo " done.</li>";
 560
 561                 # Use DatabasePostgres's code to populate interwiki from MySQL template
 562                 $f = fopen( "$IP/maintenance/interwiki.sql", 'r' );
 563                 if ( !$f ) {
 564                         dieout( "Could not find the interwiki.sql file." );
 565                 }
 566
 567                 $sql = "INSERT INTO interwiki(iw_prefix,iw_url,iw_local,iw_api,iw_wikiid) VALUES ";
 568                 while ( !feof( $f ) ) {
 569                         $line = fgets( $f, 1024 );
 570                         $matches = array();
 571                         if ( !preg_match( '/^\s*(\(.+?),(\d)\)/', $line, $matches ) ) continue;
 572                         $this->query( "$sql $matches[1],$matches[2],'','')" );
 573                 }
 574         }
 575
 576         public function getSearchEngine() {
 577                 return "SearchSqlite";
 578         }
 579
 580         /**
 581          * No-op version of deadlockLoop
 582          */
 583         public function deadlockLoop( /*...*/ ) {
 584                 $args = func_get_args();
 585                 $function = array_shift( $args );
 586                 return call_user_func_array( $function, $args );
 587         }
 588
 589         protected function replaceVars( $s ) {
 590                 $s = parent::replaceVars( $s );
 591                 if ( preg_match( '/^\s*(CREATE|ALTER) TABLE/i', $s ) ) {
 592                         // CREATE TABLE hacks to allow schema file sharing with MySQL
 593
 594                         // binary/varbinary column type -> blob
 595                         $s = preg_replace( '/\b(var)?binary(\(\d+\))/i', 'BLOB', $s );
 596                         // no such thing as unsigned
 597                         $s = preg_replace( '/\b(un)?signed\b/i', '', $s );
 598                         // INT -> INTEGER
 599                         $s = preg_replace( '/\b(tiny|small|medium|big|)int(\s*\(\s*\d+\s*\)|\b)/i', 'INTEGER', $s );
 600                         // floating point types -> REAL
 601                         $s = preg_replace( '/\b(float|double(\s+precision)?)(\s*\(\s*\d+\s*(,\s*\d+\s*)?\)|\b)/i', 'REAL', $s );
 602                         // varchar -> TEXT
 603                         $s = preg_replace( '/\b(var)?char\s*\(.*?\)/i', 'TEXT', $s );
 604                         // TEXT normalization
 605                         $s = preg_replace( '/\b(tiny|medium|long)text\b/i', 'TEXT', $s );
 606                         // BLOB normalization
 607                         $s = preg_replace( '/\b(tiny|small|medium|long|)blob\b/i', 'BLOB', $s );
 608                         // BOOL -> INTEGER
 609                         $s = preg_replace( '/\bbool(ean)?\b/i', 'INTEGER', $s );
 610                         // DATETIME -> TEXT
 611                         $s = preg_replace( '/\b(datetime|timestamp)\b/i', 'TEXT', $s );
 612                         // No ENUM type
 613                         $s = preg_replace( '/\benum\s*\([^)]*\)/i', 'TEXT', $s );
 614                         // binary collation type -> nothing
 615                         $s = preg_replace( '/\bbinary\b/i', '', $s );
 616                         // auto_increment -> autoincrement
 617                         $s = preg_replace( '/\bauto_increment\b/i', 'AUTOINCREMENT', $s );
 618                         // No explicit options
 619                         $s = preg_replace( '/\)[^);]*(;?)\s*$/', ')\1', $s );
 620                 } elseif ( preg_match( '/^\s*CREATE (\s*(?:UNIQUE|FULLTEXT)\s+)?INDEX/i', $s ) ) {
 621                         // No truncated indexes
 622                         $s = preg_replace( '/\(\d+\)/', '', $s );
 623                         // No FULLTEXT
 624                         $s = preg_replace( '/\bfulltext\b/i', '', $s );
 625                 }
 626                 return $s;
 627         }
 628
 629         /*
 630          * Build a concatenation list to feed into a SQL query
 631          */
 632         function buildConcat( $stringList ) {
 633                 return '(' . implode( ') || (', $stringList ) . ')';
 634         }
 635
 636         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseSqlite::duplicateTableStructure' ) {
 637                 $res = $this->query( "SELECT sql FROM sqlite_master WHERE tbl_name='$oldName' AND type='table'", $fname );
 638                 $obj = $this->fetchObject( $res );
 639                 if ( !$obj ) {
 640                         throw new MWException( "Couldn't retrieve structure for table $oldName" );
 641                 }
 642                 $sql = $obj->sql;
 643                 $sql = preg_replace( '/\b' . preg_quote( $oldName ) . '\b/', $newName, $sql, 1 );
 644                 return $this->query( $sql, $fname );
 645         }
 646
 647 } // end DatabaseSqlite class
 648
 649 /**
 650  * This class allows simple acccess to a SQLite database independently from main database settings
 651  * @ingroup Database
 652  */
 653 class DatabaseSqliteStandalone extends DatabaseSqlite {
 654         public function __construct( $fileName, $flags = 0 ) {
 655                 $this->mFlags = $flags;
 656                 $this->tablePrefix( null );
 657                 $this->openFile( $fileName );
 658         }
 659 }
 660
 661 /**
 662  * @ingroup Database
 663  */
 664 class SQLiteField {
 665         private $info, $tableName;
 666         function __construct( $info, $tableName ) {
 667                 $this->info = $info;
 668                 $this->tableName = $tableName;
 669         }
 670
 671         function name() {
 672                 return $this->info->name;
 673         }
 674
 675         function tableName() {
 676                 return $this->tableName;
 677         }
 678
 679         function defaultValue() {
 680                 if ( is_string( $this->info->dflt_value ) ) {
 681                         // Typically quoted
 682                         if ( preg_match( '/^\'(.*)\'$', $this->info->dflt_value ) ) {
 683                                 return str_replace( "''", "'", $this->info->dflt_value );
 684                         }
 685                 }
 686                 return $this->info->dflt_value;
 687         }
 688
 689         function maxLength() {
 690                 return -1;
 691         }
 692
 693         function nullable() {
 694                 // SQLite dynamic types are always nullable
 695                 return true;
 696         }
 697
 698         # isKey(),  isMultipleKey() not implemented, MySQL-specific concept.
 699         # Suggest removal from base class [TS]
 700
 701         function type() {
 702                 return $this->info->type;
 703         }
 704
 705 } // end SQLiteField