includes/Database.php

   1 <?php
   2 /**
   3  * This file deals with MySQL interface functions
   4  * and query specifics/optimisations
   5  * @package MediaWiki
   6  */
   7
   8 /** Number of times to re-try an operation in case of deadlock */
   9 define( 'DEADLOCK_TRIES', 4 );
  10 /** Minimum time to wait before retry, in microseconds */
  11 define( 'DEADLOCK_DELAY_MIN', 500000 );
  12 /** Maximum time to wait before retry */
  13 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  14
  15 /******************************************************************************
  16  * Utility classes
  17  *****************************************************************************/
  18
  19 class DBObject {
  20         public $mData;
  21
  22         function DBObject($data) {
  23                 $this->mData = $data;
  24         }
  25
  26         function isLOB() {
  27                 return false;
  28         }
  29
  30         function data() {
  31                 return $this->mData;
  32         }
  33 };
  34
  35 /******************************************************************************
  36  * Error classes
  37  *****************************************************************************/
  38
  39 /**
  40  * Database error base class
  41  */
  42 class DBError extends MWException {
  43         public $db;
  44
  45         /**
  46          * Construct a database error
  47          * @param Database $db The database object which threw the error
  48          * @param string $error A simple error message to be used for debugging
  49          */
  50         function __construct( Database &$db, $error ) {
  51                 $this->db =& $db;
  52                 parent::__construct( $error );
  53         }
  54 }
  55
  56 class DBConnectionError extends DBError {
  57         public $error;
  58
  59         function __construct( Database &$db, $error = 'unknown error' ) {
  60                 $msg = 'DB connection error';
  61                 if ( trim( $error ) != '' ) {
  62                         $msg .= ": $error";
  63                 }
  64                 $this->error = $error;
  65                 parent::__construct( $db, $msg );
  66         }
  67
  68         function useOutputPage() {
  69                 // Not likely to work
  70                 return false;
  71         }
  72
  73         function useMessageCache() {
  74                 // Not likely to work
  75                 return false;
  76         }
  77
  78         function getText() {
  79                 return $this->getMessage() . "\n";
  80         }
  81
  82         function getLogMessage() {
  83                 # Don't send to the exception log
  84                 return false;
  85         }
  86
  87         function getPageTitle() {
  88                 global $wgSitename;
  89                 return "$wgSitename has a problem";
  90         }
  91
  92         function getHTML() {
  93                 global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding;
  94                 global $wgSitename, $wgServer, $wgMessageCache;
  95
  96                 # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
  97                 # Hard coding strings instead.
  98
  99                 $noconnect = "<p><strong>Sorry! This site is experiencing technical difficulties.</strong></p><p>Try waiting a few minutes and reloading.</p><p><small>(Can't contact the database server: $1)</small></p>";
 100                 $mainpage = 'Main Page';
 101                 $searchdisabled = <<<EOT
 102 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
 103 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
 104 EOT;
 105
 106                 $googlesearch = "
 107 <!-- SiteSearch Google -->
 108 <FORM method=GET action=\"http://www.google.com/search\">
 109 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
 110 <A HREF=\"http://www.google.com/\">
 111 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
 112 border=\"0\" ALT=\"Google\"></A>
 113 </td>
 114 <td>
 115 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
 116 <INPUT type=submit name=btnG VALUE=\"Google Search\">
 117 <font size=-1>
 118 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
 119 <input type='hidden' name='ie' value='$2'>
 120 <input type='hidden' name='oe' value='$2'>
 121 </font>
 122 </td></tr></TABLE>
 123 </FORM>
 124 <!-- SiteSearch Google -->";
 125                 $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
 126
 127                 # No database access
 128                 if ( is_object( $wgMessageCache ) ) {
 129                         $wgMessageCache->disable();
 130                 }
 131
 132                 if ( trim( $this->error ) == '' ) {
 133                         $this->error = $this->db->getProperty('mServer');
 134                 }
 135
 136                 $text = str_replace( '$1', $this->error, $noconnect );
 137                 $text .= wfGetSiteNotice();
 138
 139                 if($wgUseFileCache) {
 140                         if($wgTitle) {
 141                                 $t =& $wgTitle;
 142                         } else {
 143                                 if($title) {
 144                                         $t = Title::newFromURL( $title );
 145                                 } elseif (@/**/$_REQUEST['search']) {
 146                                         $search = $_REQUEST['search'];
 147                                         return $searchdisabled .
 148                                           str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
 149                                           $wgInputEncoding ), $googlesearch );
 150                                 } else {
 151                                         $t = Title::newFromText( $mainpage );
 152                                 }
 153                         }
 154
 155                         $cache = new HTMLFileCache( $t );
 156                         if( $cache->isFileCached() ) {
 157                                 $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
 158                                         $cachederror . "</b></p>\n";
 159
 160                                 $tag = '<div id="article">';
 161                                 $text = str_replace(
 162                                         $tag,
 163                                         $tag . $msg,
 164                                         $cache->fetchPageText() );
 165                         }
 166                 }
 167
 168                 return $text;
 169         }
 170 }
 171
 172 class DBQueryError extends DBError {
 173         public $error, $errno, $sql, $fname;
 174
 175         function __construct( Database &$db, $error, $errno, $sql, $fname ) {
 176                 $message = "A database error has occurred\n" .
 177                   "Query: $sql\n" .
 178                   "Function: $fname\n" .
 179                   "Error: $errno $error\n";
 180
 181                 parent::__construct( $db, $message );
 182                 $this->error = $error;
 183                 $this->errno = $errno;
 184                 $this->sql = $sql;
 185                 $this->fname = $fname;
 186         }
 187
 188         function getText() {
 189                 if ( $this->useMessageCache() ) {
 190                         return wfMsg( 'dberrortextcl', htmlspecialchars( $this->getSQL() ),
 191                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) ) . "\n";
 192                 } else {
 193                         return $this->getMessage();
 194                 }
 195         }
 196
 197         function getSQL() {
 198                 global $wgShowSQLErrors;
 199                 if( !$wgShowSQLErrors ) {
 200                         return $this->msg( 'sqlhidden', 'SQL hidden' );
 201                 } else {
 202                         return $this->sql;
 203                 }
 204         }
 205
 206         function getLogMessage() {
 207                 # Don't send to the exception log
 208                 return false;
 209         }
 210
 211         function getPageTitle() {
 212                 return $this->msg( 'databaseerror', 'Database error' );
 213         }
 214
 215         function getHTML() {
 216                 if ( $this->useMessageCache() ) {
 217                         return wfMsgNoDB( 'dberrortext', htmlspecialchars( $this->getSQL() ),
 218                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) );
 219                 } else {
 220                         return nl2br( htmlspecialchars( $this->getMessage() ) );
 221                 }
 222         }
 223 }
 224
 225 class DBUnexpectedError extends DBError {}
 226
 227 /******************************************************************************/
 228
 229 /**
 230  * Database abstraction object
 231  * @package MediaWiki
 232  */
 233 class Database {
 234
 235 #------------------------------------------------------------------------------
 236 # Variables
 237 #------------------------------------------------------------------------------
 238
 239         protected $mLastQuery = '';
 240
 241         protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
 242         protected $mOut, $mOpened = false;
 243
 244         protected $mFailFunction;
 245         protected $mTablePrefix;
 246         protected $mFlags;
 247         protected $mTrxLevel = 0;
 248         protected $mErrorCount = 0;
 249         protected $mLBInfo = array();
 250         protected $mCascadingDeletes = false;
 251         protected $mCleanupTriggers = false;
 252         protected $mStrictIPs = false;
 253         protected $mRealTimestamps = false;
 254
 255 #------------------------------------------------------------------------------
 256 # Accessors
 257 #------------------------------------------------------------------------------
 258         # These optionally set a variable and return the previous state
 259
 260         /**
 261          * Fail function, takes a Database as a parameter
 262          * Set to false for default, 1 for ignore errors
 263          */
 264         function failFunction( $function = NULL ) {
 265                 return wfSetVar( $this->mFailFunction, $function );
 266         }
 267
 268         /**
 269          * Output page, used for reporting errors
 270          * FALSE means discard output
 271          */
 272         function setOutputPage( $out ) {
 273                 $this->mOut = $out;
 274         }
 275
 276         /**
 277          * Boolean, controls output of large amounts of debug information
 278          */
 279         function debug( $debug = NULL ) {
 280                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
 281         }
 282
 283         /**
 284          * Turns buffering of SQL result sets on (true) or off (false).
 285          * Default is "on" and it should not be changed without good reasons.
 286          */
 287         function bufferResults( $buffer = NULL ) {
 288                 if ( is_null( $buffer ) ) {
 289                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
 290                 } else {
 291                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
 292                 }
 293         }
 294
 295         /**
 296          * Turns on (false) or off (true) the automatic generation and sending
 297          * of a "we're sorry, but there has been a database error" page on
 298          * database errors. Default is on (false). When turned off, the
 299          * code should use lastErrno() and lastError() to handle the
 300          * situation as appropriate.
 301          */
 302         function ignoreErrors( $ignoreErrors = NULL ) {
 303                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
 304         }
 305
 306         /**
 307          * The current depth of nested transactions
 308          * @param $level Integer: , default NULL.
 309          */
 310         function trxLevel( $level = NULL ) {
 311                 return wfSetVar( $this->mTrxLevel, $level );
 312         }
 313
 314         /**
 315          * Number of errors logged, only useful when errors are ignored
 316          */
 317         function errorCount( $count = NULL ) {
 318                 return wfSetVar( $this->mErrorCount, $count );
 319         }
 320
 321         /**
 322          * Properties passed down from the server info array of the load balancer
 323          */
 324         function getLBInfo( $name = NULL ) {
 325                 if ( is_null( $name ) ) {
 326                         return $this->mLBInfo;
 327                 } else {
 328                         if ( array_key_exists( $name, $this->mLBInfo ) ) {
 329                                 return $this->mLBInfo[$name];
 330                         } else {
 331                                 return NULL;
 332                         }
 333                 }
 334         }
 335
 336         function setLBInfo( $name, $value = NULL ) {
 337                 if ( is_null( $value ) ) {
 338                         $this->mLBInfo = $name;
 339                 } else {
 340                         $this->mLBInfo[$name] = $value;
 341                 }
 342         }
 343
 344         /**
 345          * Returns true if this database supports (and uses) cascading deletes
 346          */
 347         function cascadingDeletes() {
 348                 return $this->mCascadingDeletes;
 349         }
 350
 351         /**
 352          * Returns true if this database supports (and uses) triggers (e.g. on the page table)
 353          */
 354         function cleanupTriggers() {
 355                 return $this->mCleanupTriggers;
 356         }
 357
 358         /**
 359          * Returns true if this database is strict about what can be put into an IP field.
 360          * Specifically, it uses a NULL value instead of an empty string.
 361          */
 362         function strictIPs() {
 363                 return $this->mStrictIPs;
 364         }
 365
 366         /**
 367          * Returns true if this database uses timestamps rather than integers
 368         */
 369         function realTimestamps() {
 370                 return $this->mRealTimestamps;
 371         }
 372
 373         /**#@+
 374          * Get function
 375          */
 376         function lastQuery() { return $this->mLastQuery; }
 377         function isOpen() { return $this->mOpened; }
 378         /**#@-*/
 379
 380         function setFlag( $flag ) {
 381                 $this->mFlags |= $flag;
 382         }
 383
 384         function clearFlag( $flag ) {
 385                 $this->mFlags &= ~$flag;
 386         }
 387
 388         function getFlag( $flag ) {
 389                 return !!($this->mFlags & $flag);
 390         }
 391
 392         /**
 393          * General read-only accessor
 394          */
 395         function getProperty( $name ) {
 396                 return $this->$name;
 397         }
 398
 399 #------------------------------------------------------------------------------
 400 # Other functions
 401 #------------------------------------------------------------------------------
 402
 403         /**@{{
 404          * @param string $server database server host
 405          * @param string $user database user name
 406          * @param string $password database user password
 407          * @param string $dbname database name
 408          */
 409
 410         /**
 411          * @param failFunction
 412          * @param $flags
 413          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 414          */
 415         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 416                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 417
 418                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 419                 # Can't get a reference if it hasn't been set yet
 420                 if ( !isset( $wgOut ) ) {
 421                         $wgOut = NULL;
 422                 }
 423                 $this->mOut =& $wgOut;
 424
 425                 $this->mFailFunction = $failFunction;
 426                 $this->mFlags = $flags;
 427
 428                 if ( $this->mFlags & DBO_DEFAULT ) {
 429                         if ( $wgCommandLineMode ) {
 430                                 $this->mFlags &= ~DBO_TRX;
 431                         } else {
 432                                 $this->mFlags |= DBO_TRX;
 433                         }
 434                 }
 435
 436                 /*
 437                 // Faster read-only access
 438                 if ( wfReadOnly() ) {
 439                         $this->mFlags |= DBO_PERSISTENT;
 440                         $this->mFlags &= ~DBO_TRX;
 441                 }*/
 442
 443                 /** Get the default table prefix*/
 444                 if ( $tablePrefix == 'get from global' ) {
 445                         $this->mTablePrefix = $wgDBprefix;
 446                 } else {
 447                         $this->mTablePrefix = $tablePrefix;
 448                 }
 449
 450                 if ( $server ) {
 451                         $this->open( $server, $user, $password, $dbName );
 452                 }
 453         }
 454
 455         /**
 456          * @static
 457          * @param failFunction
 458          * @param $flags
 459          */
 460         static function newFromParams( $server, $user, $password, $dbName,
 461                 $failFunction = false, $flags = 0 )
 462         {
 463                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 464         }
 465
 466         /**
 467          * Usually aborts on failure
 468          * If the failFunction is set to a non-zero integer, returns success
 469          */
 470         function open( $server, $user, $password, $dbName ) {
 471                 global $wguname;
 472                 wfProfileIn( __METHOD__ );
 473
 474                 # Test for missing mysql.so
 475                 # First try to load it
 476                 if (!@extension_loaded('mysql')) {
 477                         @dl('mysql.so');
 478                 }
 479
 480                 # Fail now
 481                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 482                 if ( !function_exists( 'mysql_connect' ) ) {
 483                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 484                 }
 485
 486                 $this->close();
 487                 $this->mServer = $server;
 488                 $this->mUser = $user;
 489                 $this->mPassword = $password;
 490                 $this->mDBname = $dbName;
 491
 492                 $success = false;
 493
 494                 wfProfileIn("dbconnect-$server");
 495
 496                 # LIVE PATCH by Tim, ask Domas for why: retry loop
 497                 $this->mConn = false;
 498                 $max = 3;
 499                 for ( $i = 0; $i < $max && !$this->mConn; $i++ ) {
 500                         if ( $i > 1 ) {
 501                                 usleep( 1000 );
 502                         }
 503                         if ( $this->mFlags & DBO_PERSISTENT ) {
 504                                 @/**/$this->mConn = mysql_pconnect( $server, $user, $password );
 505                         } else {
 506                                 # Create a new connection...
 507                                 @/**/$this->mConn = mysql_connect( $server, $user, $password, true );
 508                         }
 509                         if ($this->mConn === false) {
 510                                 $iplus = $i + 1;
 511                                 wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 512                         }
 513                 }
 514
 515                 wfProfileOut("dbconnect-$server");
 516
 517                 if ( $dbName != '' ) {
 518                         if ( $this->mConn !== false ) {
 519                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 520                                 if ( !$success ) {
 521                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 522                                                 "from client host {$wguname['nodename']}\n";
 523                                         wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 524                                         wfDebug( $error );
 525                                 }
 526                         } else {
 527                                 wfDebug( "DB connection error\n" );
 528                                 wfDebug( "Server: $server, User: $user, Password: " .
 529                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 530                                 $success = false;
 531                         }
 532                 } else {
 533                         # Delay USE query
 534                         $success = (bool)$this->mConn;
 535                 }
 536
 537                 if ( $success ) {
 538                         global $wgDBmysql5;
 539                         if( $wgDBmysql5 ) {
 540                                 // Tell the server we're communicating with it in UTF-8.
 541                                 // This may engage various charset conversions.
 542                                 $this->query( 'SET NAMES utf8' );
 543                         }
 544                 } else {
 545                         $this->reportConnectionError();
 546                 }
 547
 548                 $this->mOpened = $success;
 549                 wfProfileOut( __METHOD__ );
 550                 return $success;
 551         }
 552         /**@}}*/
 553
 554         /**
 555          * Closes a database connection.
 556          * if it is open : commits any open transactions
 557          *
 558          * @return bool operation success. true if already closed.
 559          */
 560         function close()
 561         {
 562                 $this->mOpened = false;
 563                 if ( $this->mConn ) {
 564                         if ( $this->trxLevel() ) {
 565                                 $this->immediateCommit();
 566                         }
 567                         return mysql_close( $this->mConn );
 568                 } else {
 569                         return true;
 570                 }
 571         }
 572
 573         /**
 574          * @param string $error fallback error message, used if none is given by MySQL
 575          */
 576         function reportConnectionError( $error = 'Unknown error' ) {
 577                 $myError = $this->lastError();
 578                 if ( $myError ) {
 579                         $error = $myError;
 580                 }
 581
 582                 if ( $this->mFailFunction ) {
 583                         # Legacy error handling method
 584                         if ( !is_int( $this->mFailFunction ) ) {
 585                                 $ff = $this->mFailFunction;
 586                                 $ff( $this, $error );
 587                         }
 588                 } else {
 589                         # New method
 590                         wfLogDBError( "Connection error: $error\n" );
 591                         throw new DBConnectionError( $this, $error );
 592                 }
 593         }
 594
 595         /**
 596          * Usually aborts on failure
 597          * If errors are explicitly ignored, returns success
 598          */
 599         function query( $sql, $fname = '', $tempIgnore = false ) {
 600                 global $wgProfiling;
 601
 602                 if ( $wgProfiling ) {
 603                         # generalizeSQL will probably cut down the query to reasonable
 604                         # logging size most of the time. The substr is really just a sanity check.
 605
 606                         # Who's been wasting my precious column space? -- TS
 607                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 608
 609                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 610                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 611                                 $totalProf = 'Database::query';
 612                         } else {
 613                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 614                                 $totalProf = 'Database::query-master';
 615                         }
 616                         wfProfileIn( $totalProf );
 617                         wfProfileIn( $queryProf );
 618                 }
 619
 620                 $this->mLastQuery = $sql;
 621
 622                 # Add a comment for easy SHOW PROCESSLIST interpretation
 623                 if ( $fname ) {
 624                         $commentedSql = preg_replace('/\s/', " /* $fname */ ", $sql, 1);
 625                 } else {
 626                         $commentedSql = $sql;
 627                 }
 628
 629                 # If DBO_TRX is set, start a transaction
 630                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 631                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 632                 ) {
 633                         $this->begin();
 634                 }
 635
 636                 if ( $this->debug() ) {
 637                         $sqlx = substr( $commentedSql, 0, 500 );
 638                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 639                         wfDebug( "SQL: $sqlx\n" );
 640                 }
 641
 642                 # Do the query and handle errors
 643                 $ret = $this->doQuery( $commentedSql );
 644
 645                 # Try reconnecting if the connection was lost
 646                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 647                         # Transaction is gone, like it or not
 648                         $this->mTrxLevel = 0;
 649                         wfDebug( "Connection lost, reconnecting...\n" );
 650                         if ( $this->ping() ) {
 651                                 wfDebug( "Reconnected\n" );
 652                                 $ret = $this->doQuery( $commentedSql );
 653                         } else {
 654                                 wfDebug( "Failed\n" );
 655                         }
 656                 }
 657
 658                 if ( false === $ret ) {
 659                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 660                 }
 661
 662                 if ( $wgProfiling ) {
 663                         wfProfileOut( $queryProf );
 664                         wfProfileOut( $totalProf );
 665                 }
 666                 return $ret;
 667         }
 668
 669         /**
 670          * The DBMS-dependent part of query()
 671          * @param string $sql SQL query.
 672          */
 673         function doQuery( $sql ) {
 674                 if( $this->bufferResults() ) {
 675                         $ret = mysql_query( $sql, $this->mConn );
 676                 } else {
 677                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 678                 }
 679                 return $ret;
 680         }
 681
 682         /**
 683          * @param $error
 684          * @param $errno
 685          * @param $sql
 686          * @param string $fname
 687          * @param bool $tempIgnore
 688          */
 689         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 690                 global $wgCommandLineMode;
 691                 # Ignore errors during error handling to avoid infinite recursion
 692                 $ignore = $this->ignoreErrors( true );
 693                 ++$this->mErrorCount;
 694
 695                 if( $ignore || $tempIgnore ) {
 696                         wfDebug("SQL ERROR (ignored): $error\n");
 697                         $this->ignoreErrors( $ignore );
 698                 } else {
 699                         $sql1line = str_replace( "\n", "\\n", $sql );
 700                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 701                         wfDebug("SQL ERROR: " . $error . "\n");
 702                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 703                 }
 704         }
 705
 706
 707         /**
 708          * Intended to be compatible with the PEAR::DB wrapper functions.
 709          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 710          *
 711          * ? = scalar value, quoted as necessary
 712          * ! = raw SQL bit (a function for instance)
 713          * & = filename; reads the file and inserts as a blob
 714          *     (we don't use this though...)
 715          */
 716         function prepare( $sql, $func = 'Database::prepare' ) {
 717                 /* MySQL doesn't support prepared statements (yet), so just
 718                    pack up the query for reference. We'll manually replace
 719                    the bits later. */
 720                 return array( 'query' => $sql, 'func' => $func );
 721         }
 722
 723         function freePrepared( $prepared ) {
 724                 /* No-op for MySQL */
 725         }
 726
 727         /**
 728          * Execute a prepared query with the various arguments
 729          * @param string $prepared the prepared sql
 730          * @param mixed $args Either an array here, or put scalars as varargs
 731          */
 732         function execute( $prepared, $args = null ) {
 733                 if( !is_array( $args ) ) {
 734                         # Pull the var args
 735                         $args = func_get_args();
 736                         array_shift( $args );
 737                 }
 738                 $sql = $this->fillPrepared( $prepared['query'], $args );
 739                 return $this->query( $sql, $prepared['func'] );
 740         }
 741
 742         /**
 743          * Prepare & execute an SQL statement, quoting and inserting arguments
 744          * in the appropriate places.
 745          * @param string $query
 746          * @param string $args ...
 747          */
 748         function safeQuery( $query, $args = null ) {
 749                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 750                 if( !is_array( $args ) ) {
 751                         # Pull the var args
 752                         $args = func_get_args();
 753                         array_shift( $args );
 754                 }
 755                 $retval = $this->execute( $prepared, $args );
 756                 $this->freePrepared( $prepared );
 757                 return $retval;
 758         }
 759
 760         /**
 761          * For faking prepared SQL statements on DBs that don't support
 762          * it directly.
 763          * @param string $preparedSql - a 'preparable' SQL statement
 764          * @param array $args - array of arguments to fill it with
 765          * @return string executable SQL
 766          */
 767         function fillPrepared( $preparedQuery, $args ) {
 768                 reset( $args );
 769                 $this->preparedArgs =& $args;
 770                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 771                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 772         }
 773
 774         /**
 775          * preg_callback func for fillPrepared()
 776          * The arguments should be in $this->preparedArgs and must not be touched
 777          * while we're doing this.
 778          *
 779          * @param array $matches
 780          * @return string
 781          * @private
 782          */
 783         function fillPreparedArg( $matches ) {
 784                 switch( $matches[1] ) {
 785                         case '\\?': return '?';
 786                         case '\\!': return '!';
 787                         case '\\&': return '&';
 788                 }
 789                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 790                 switch( $matches[1] ) {
 791                         case '?': return $this->addQuotes( $arg );
 792                         case '!': return $arg;
 793                         case '&':
 794                                 # return $this->addQuotes( file_get_contents( $arg ) );
 795                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 796                         default:
 797                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 798                 }
 799         }
 800
 801         /**#@+
 802          * @param mixed $res A SQL result
 803          */
 804         /**
 805          * Free a result object
 806          */
 807         function freeResult( $res ) {
 808                 if ( !@/**/mysql_free_result( $res ) ) {
 809                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 810                 }
 811         }
 812
 813         /**
 814          * Fetch the next row from the given result object, in object form
 815          */
 816         function fetchObject( $res ) {
 817                 @/**/$row = mysql_fetch_object( $res );
 818                 if( $this->lastErrno() ) {
 819                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 820                 }
 821                 return $row;
 822         }
 823
 824         /**
 825          * Fetch the next row from the given result object
 826          * Returns an array
 827          */
 828         function fetchRow( $res ) {
 829                 @/**/$row = mysql_fetch_array( $res );
 830                 if ( $this->lastErrno() ) {
 831                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 832                 }
 833                 return $row;
 834         }
 835
 836         /**
 837          * Get the number of rows in a result object
 838          */
 839         function numRows( $res ) {
 840                 @/**/$n = mysql_num_rows( $res );
 841                 if( $this->lastErrno() ) {
 842                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 843                 }
 844                 return $n;
 845         }
 846
 847         /**
 848          * Get the number of fields in a result object
 849          * See documentation for mysql_num_fields()
 850          */
 851         function numFields( $res ) { return mysql_num_fields( $res ); }
 852
 853         /**
 854          * Get a field name in a result object
 855          * See documentation for mysql_field_name():
 856          * http://www.php.net/mysql_field_name
 857          */
 858         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 859
 860         /**
 861          * Get the inserted value of an auto-increment row
 862          *
 863          * The value inserted should be fetched from nextSequenceValue()
 864          *
 865          * Example:
 866          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 867          * $dbw->insert('page',array('page_id' => $id));
 868          * $id = $dbw->insertId();
 869          */
 870         function insertId() { return mysql_insert_id( $this->mConn ); }
 871
 872         /**
 873          * Change the position of the cursor in a result object
 874          * See mysql_data_seek()
 875          */
 876         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 877
 878         /**
 879          * Get the last error number
 880          * See mysql_errno()
 881          */
 882         function lastErrno() {
 883                 if ( $this->mConn ) {
 884                         return mysql_errno( $this->mConn );
 885                 } else {
 886                         return mysql_errno();
 887                 }
 888         }
 889
 890         /**
 891          * Get a description of the last error
 892          * See mysql_error() for more details
 893          */
 894         function lastError() {
 895                 if ( $this->mConn ) {
 896                         # Even if it's non-zero, it can still be invalid
 897                         wfSuppressWarnings();
 898                         $error = mysql_error( $this->mConn );
 899                         if ( !$error ) {
 900                                 $error = mysql_error();
 901                         }
 902                         wfRestoreWarnings();
 903                 } else {
 904                         $error = mysql_error();
 905                 }
 906                 if( $error ) {
 907                         $error .= ' (' . $this->mServer . ')';
 908                 }
 909                 return $error;
 910         }
 911         /**
 912          * Get the number of rows affected by the last write query
 913          * See mysql_affected_rows() for more details
 914          */
 915         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 916         /**#@-*/ // end of template : @param $result
 917
 918         /**
 919          * Simple UPDATE wrapper
 920          * Usually aborts on failure
 921          * If errors are explicitly ignored, returns success
 922          *
 923          * This function exists for historical reasons, Database::update() has a more standard
 924          * calling convention and feature set
 925          */
 926         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 927         {
 928                 $table = $this->tableName( $table );
 929                 $sql = "UPDATE $table SET $var = '" .
 930                   $this->strencode( $value ) . "' WHERE ($cond)";
 931                 return (bool)$this->query( $sql, $fname );
 932         }
 933
 934         /**
 935          * Simple SELECT wrapper, returns a single field, input must be encoded
 936          * Usually aborts on failure
 937          * If errors are explicitly ignored, returns FALSE on failure
 938          */
 939         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 940                 if ( !is_array( $options ) ) {
 941                         $options = array( $options );
 942                 }
 943                 $options['LIMIT'] = 1;
 944
 945                 $res = $this->select( $table, $var, $cond, $fname, $options );
 946                 if ( $res === false || !$this->numRows( $res ) ) {
 947                         return false;
 948                 }
 949                 $row = $this->fetchRow( $res );
 950                 if ( $row !== false ) {
 951                         $this->freeResult( $res );
 952                         return $row[0];
 953                 } else {
 954                         return false;
 955                 }
 956         }
 957
 958         /**
 959          * Returns an optional USE INDEX clause to go after the table, and a
 960          * string to go at the end of the query
 961          *
 962          * @private
 963          *
 964          * @param array $options an associative array of options to be turned into
 965          *              an SQL query, valid keys are listed in the function.
 966          * @return array
 967          */
 968         function makeSelectOptions( $options ) {
 969                 $tailOpts = '';
 970                 $startOpts = '';
 971
 972                 $noKeyOptions = array();
 973                 foreach ( $options as $key => $option ) {
 974                         if ( is_numeric( $key ) ) {
 975                                 $noKeyOptions[$option] = true;
 976                         }
 977                 }
 978
 979                 if ( isset( $options['GROUP BY'] ) ) $tailOpts .= " GROUP BY {$options['GROUP BY']}";
 980                 if ( isset( $options['ORDER BY'] ) ) $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 981
 982                 if (isset($options['LIMIT'])) {
 983                         $tailOpts .= $this->limitResult('', $options['LIMIT'],
 984                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
 985                 }
 986
 987                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $tailOpts .= ' FOR UPDATE';
 988                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $tailOpts .= ' LOCK IN SHARE MODE';
 989                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
 990
 991                 # Various MySQL extensions
 992                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
 993                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
 994                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
 995                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
 996                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
 997                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
 998                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
 999                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
1000
1001                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1002                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1003                 } else {
1004                         $useIndex = '';
1005                 }
1006
1007                 return array( $startOpts, $useIndex, $tailOpts );
1008         }
1009
1010         /**
1011          * SELECT wrapper
1012          */
1013         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1014         {
1015                 if( is_array( $vars ) ) {
1016                         $vars = implode( ',', $vars );
1017                 }
1018                 if( !is_array( $options ) ) {
1019                         $options = array( $options );
1020                 }
1021                 if( is_array( $table ) ) {
1022                         if ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1023                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1024                         else
1025                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1026                 } elseif ($table!='') {
1027                         $from = ' FROM ' . $this->tableName( $table );
1028                 } else {
1029                         $from = '';
1030                 }
1031
1032                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );
1033
1034                 if( !empty( $conds ) ) {
1035                         if ( is_array( $conds ) ) {
1036                                 $conds = $this->makeList( $conds, LIST_AND );
1037                         }
1038                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $tailOpts";
1039                 } else {
1040                         $sql = "SELECT $startOpts $vars $from $useIndex $tailOpts";
1041                 }
1042
1043                 return $this->query( $sql, $fname );
1044         }
1045
1046         /**
1047          * Single row SELECT wrapper
1048          * Aborts or returns FALSE on error
1049          *
1050          * $vars: the selected variables
1051          * $conds: a condition map, terms are ANDed together.
1052          *   Items with numeric keys are taken to be literal conditions
1053          * Takes an array of selected variables, and a condition map, which is ANDed
1054          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1055          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1056          * $obj- >page_id is the ID of the Astronomy article
1057          *
1058          * @todo migrate documentation to phpdocumentor format
1059          */
1060         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1061                 $options['LIMIT'] = 1;
1062                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1063                 if ( $res === false )
1064                         return false;
1065                 if ( !$this->numRows($res) ) {
1066                         $this->freeResult($res);
1067                         return false;
1068                 }
1069                 $obj = $this->fetchObject( $res );
1070                 $this->freeResult( $res );
1071                 return $obj;
1072
1073         }
1074
1075         /**
1076          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1077          * It's only slightly flawed. Don't use for anything important.
1078          *
1079          * @param string $sql A SQL Query
1080          * @static
1081          */
1082         static function generalizeSQL( $sql ) {
1083                 # This does the same as the regexp below would do, but in such a way
1084                 # as to avoid crashing php on some large strings.
1085                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1086
1087                 $sql = str_replace ( "\\\\", '', $sql);
1088                 $sql = str_replace ( "\\'", '', $sql);
1089                 $sql = str_replace ( "\\\"", '', $sql);
1090                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1091                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1092
1093                 # All newlines, tabs, etc replaced by single space
1094                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1095
1096                 # All numbers => N
1097                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1098
1099                 return $sql;
1100         }
1101
1102         /**
1103          * Determines whether a field exists in a table
1104          * Usually aborts on failure
1105          * If errors are explicitly ignored, returns NULL on failure
1106          */
1107         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1108                 $table = $this->tableName( $table );
1109                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1110                 if ( !$res ) {
1111                         return NULL;
1112                 }
1113
1114                 $found = false;
1115
1116                 while ( $row = $this->fetchObject( $res ) ) {
1117                         if ( $row->Field == $field ) {
1118                                 $found = true;
1119                                 break;
1120                         }
1121                 }
1122                 return $found;
1123         }
1124
1125         /**
1126          * Determines whether an index exists
1127          * Usually aborts on failure
1128          * If errors are explicitly ignored, returns NULL on failure
1129          */
1130         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1131                 $info = $this->indexInfo( $table, $index, $fname );
1132                 if ( is_null( $info ) ) {
1133                         return NULL;
1134                 } else {
1135                         return $info !== false;
1136                 }
1137         }
1138
1139
1140         /**
1141          * Get information about an index into an object
1142          * Returns false if the index does not exist
1143          */
1144         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1145                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1146                 # SHOW INDEX should work for 3.x and up:
1147                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1148                 $table = $this->tableName( $table );
1149                 $sql = 'SHOW INDEX FROM '.$table;
1150                 $res = $this->query( $sql, $fname );
1151                 if ( !$res ) {
1152                         return NULL;
1153                 }
1154
1155                 $result = array();
1156                 while ( $row = $this->fetchObject( $res ) ) {
1157                         if ( $row->Key_name == $index ) {
1158                                 $result[] = $row;
1159                         }
1160                 }
1161                 $this->freeResult($res);
1162
1163                 return empty($result) ? false : $result;
1164         }
1165
1166         /**
1167          * Query whether a given table exists
1168          */
1169         function tableExists( $table ) {
1170                 $table = $this->tableName( $table );
1171                 $old = $this->ignoreErrors( true );
1172                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1173                 $this->ignoreErrors( $old );
1174                 if( $res ) {
1175                         $this->freeResult( $res );
1176                         return true;
1177                 } else {
1178                         return false;
1179                 }
1180         }
1181
1182         /**
1183          * mysql_fetch_field() wrapper
1184          * Returns false if the field doesn't exist
1185          *
1186          * @param $table
1187          * @param $field
1188          */
1189         function fieldInfo( $table, $field ) {
1190                 $table = $this->tableName( $table );
1191                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1192                 $n = mysql_num_fields( $res );
1193                 for( $i = 0; $i < $n; $i++ ) {
1194                         $meta = mysql_fetch_field( $res, $i );
1195                         if( $field == $meta->name ) {
1196                                 return $meta;
1197                         }
1198                 }
1199                 return false;
1200         }
1201
1202         /**
1203          * mysql_field_type() wrapper
1204          */
1205         function fieldType( $res, $index ) {
1206                 return mysql_field_type( $res, $index );
1207         }
1208
1209         /**
1210          * Determines if a given index is unique
1211          */
1212         function indexUnique( $table, $index ) {
1213                 $indexInfo = $this->indexInfo( $table, $index );
1214                 if ( !$indexInfo ) {
1215                         return NULL;
1216                 }
1217                 return !$indexInfo[0]->Non_unique;
1218         }
1219
1220         /**
1221          * INSERT wrapper, inserts an array into a table
1222          *
1223          * $a may be a single associative array, or an array of these with numeric keys, for
1224          * multi-row insert.
1225          *
1226          * Usually aborts on failure
1227          * If errors are explicitly ignored, returns success
1228          */
1229         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1230                 # No rows to insert, easy just return now
1231                 if ( !count( $a ) ) {
1232                         return true;
1233                 }
1234
1235                 $table = $this->tableName( $table );
1236                 if ( !is_array( $options ) ) {
1237                         $options = array( $options );
1238                 }
1239                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1240                         $multi = true;
1241                         $keys = array_keys( $a[0] );
1242                 } else {
1243                         $multi = false;
1244                         $keys = array_keys( $a );
1245                 }
1246
1247                 $sql = 'INSERT ' . implode( ' ', $options ) .
1248                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1249
1250                 if ( $multi ) {
1251                         $first = true;
1252                         foreach ( $a as $row ) {
1253                                 if ( $first ) {
1254                                         $first = false;
1255                                 } else {
1256                                         $sql .= ',';
1257                                 }
1258                                 $sql .= '(' . $this->makeList( $row ) . ')';
1259                         }
1260                 } else {
1261                         $sql .= '(' . $this->makeList( $a ) . ')';
1262                 }
1263                 return (bool)$this->query( $sql, $fname );
1264         }
1265
1266         /**
1267          * Make UPDATE options for the Database::update function
1268          *
1269          * @private
1270          * @param array $options The options passed to Database::update
1271          * @return string
1272          */
1273         function makeUpdateOptions( $options ) {
1274                 if( !is_array( $options ) ) {
1275                         $options = array( $options );
1276                 }
1277                 $opts = array();
1278                 if ( in_array( 'LOW_PRIORITY', $options ) )
1279                         $opts[] = $this->lowPriorityOption();
1280                 if ( in_array( 'IGNORE', $options ) )
1281                         $opts[] = 'IGNORE';
1282                 return implode(' ', $opts);
1283         }
1284
1285         /**
1286          * UPDATE wrapper, takes a condition array and a SET array
1287          *
1288          * @param string $table  The table to UPDATE
1289          * @param array  $values An array of values to SET
1290          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1291          * @param string $fname  The Class::Function calling this function
1292          *                       (for the log)
1293          * @param array  $options An array of UPDATE options, can be one or
1294          *                        more of IGNORE, LOW_PRIORITY
1295          */
1296         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1297                 $table = $this->tableName( $table );
1298                 $opts = $this->makeUpdateOptions( $options );
1299                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1300                 if ( $conds != '*' ) {
1301                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1302                 }
1303                 $this->query( $sql, $fname );
1304         }
1305
1306         /**
1307          * Makes an encoded list of strings from an array
1308          * $mode:
1309          *        LIST_COMMA         - comma separated, no field names
1310          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1311          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1312          *        LIST_SET           - comma separated with field names, like a SET clause
1313          *        LIST_NAMES         - comma separated field names
1314          */
1315         function makeList( $a, $mode = LIST_COMMA ) {
1316                 if ( !is_array( $a ) ) {
1317                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1318                 }
1319
1320                 $first = true;
1321                 $list = '';
1322                 foreach ( $a as $field => $value ) {
1323                         if ( !$first ) {
1324                                 if ( $mode == LIST_AND ) {
1325                                         $list .= ' AND ';
1326                                 } elseif($mode == LIST_OR) {
1327                                         $list .= ' OR ';
1328                                 } else {
1329                                         $list .= ',';
1330                                 }
1331                         } else {
1332                                 $first = false;
1333                         }
1334                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1335                                 $list .= "($value)";
1336                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1337                                 $list .= $field." IN (".$this->makeList($value).") ";
1338                         } else {
1339                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1340                                         $list .= "$field = ";
1341                                 }
1342                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1343                         }
1344                 }
1345                 return $list;
1346         }
1347
1348         /**
1349          * Change the current database
1350          */
1351         function selectDB( $db ) {
1352                 $this->mDBname = $db;
1353                 return mysql_select_db( $db, $this->mConn );
1354         }
1355
1356         /**
1357          * Format a table name ready for use in constructing an SQL query
1358          *
1359          * This does two important things: it quotes table names which as necessary,
1360          * and it adds a table prefix if there is one.
1361          *
1362          * All functions of this object which require a table name call this function
1363          * themselves. Pass the canonical name to such functions. This is only needed
1364          * when calling query() directly.
1365          *
1366          * @param string $name database table name
1367          */
1368         function tableName( $name ) {
1369                 global $wgSharedDB;
1370                 # Skip quoted literals
1371                 if ( $name{0} != '`' ) {
1372                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1373                                 $name = "{$this->mTablePrefix}$name";
1374                         }
1375                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1376                                 $name = "`$wgSharedDB`.`$name`";
1377                         } else {
1378                                 # Standard quoting
1379                                 $name = "`$name`";
1380                         }
1381                 }
1382                 return $name;
1383         }
1384
1385         /**
1386          * Fetch a number of table names into an array
1387          * This is handy when you need to construct SQL for joins
1388          *
1389          * Example:
1390          * extract($dbr->tableNames('user','watchlist'));
1391          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1392          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1393          */
1394         public function tableNames() {
1395                 $inArray = func_get_args();
1396                 $retVal = array();
1397                 foreach ( $inArray as $name ) {
1398                         $retVal[$name] = $this->tableName( $name );
1399                 }
1400                 return $retVal;
1401         }
1402
1403         /**
1404          * @desc: Fetch a number of table names into an zero-indexed numerical array
1405          * This is handy when you need to construct SQL for joins
1406          *
1407          * Example:
1408          * list( $user, $watchlist ) = $dbr->tableNames('user','watchlist');
1409          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1410          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1411          */
1412         public function tableNamesN() {
1413                 $inArray = func_get_args();
1414                 $retVal = array();
1415                 foreach ( $inArray as $name ) {
1416                         $retVal[] = $this->tableName( $name );
1417                 }
1418                 return $retVal;
1419         }
1420
1421         /**
1422          * @private
1423          */
1424         function tableNamesWithUseIndex( $tables, $use_index ) {
1425                 $ret = array();
1426
1427                 foreach ( $tables as $table )
1428                         if ( @$use_index[$table] !== null )
1429                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1430                         else
1431                                 $ret[] = $this->tableName( $table );
1432
1433                 return implode( ',', $ret );
1434         }
1435
1436         /**
1437          * Wrapper for addslashes()
1438          * @param string $s String to be slashed.
1439          * @return string slashed string.
1440          */
1441         function strencode( $s ) {
1442                 return mysql_real_escape_string( $s, $this->mConn );
1443         }
1444
1445         /**
1446          * If it's a string, adds quotes and backslashes
1447          * Otherwise returns as-is
1448          */
1449         function addQuotes( $s ) {
1450                 if ( is_null( $s ) ) {
1451                         return 'NULL';
1452                 } else {
1453                         # This will also quote numeric values. This should be harmless,
1454                         # and protects against weird problems that occur when they really
1455                         # _are_ strings such as article titles and string->number->string
1456                         # conversion is not 1:1.
1457                         return "'" . $this->strencode( $s ) . "'";
1458                 }
1459         }
1460
1461         /**
1462          * Escape string for safe LIKE usage
1463          */
1464         function escapeLike( $s ) {
1465                 $s=$this->strencode( $s );
1466                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1467                 return $s;
1468         }
1469
1470         /**
1471          * Returns an appropriately quoted sequence value for inserting a new row.
1472          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1473          * subclass will return an integer, and save the value for insertId()
1474          */
1475         function nextSequenceValue( $seqName ) {
1476                 return NULL;
1477         }
1478
1479         /**
1480          * USE INDEX clause
1481          * PostgreSQL doesn't have them and returns ""
1482          */
1483         function useIndexClause( $index ) {
1484                 return "FORCE INDEX ($index)";
1485         }
1486
1487         /**
1488          * REPLACE query wrapper
1489          * PostgreSQL simulates this with a DELETE followed by INSERT
1490          * $row is the row to insert, an associative array
1491          * $uniqueIndexes is an array of indexes. Each element may be either a
1492          * field name or an array of field names
1493          *
1494          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1495          * However if you do this, you run the risk of encountering errors which wouldn't have
1496          * occurred in MySQL
1497          *
1498          * @todo migrate comment to phodocumentor format
1499          */
1500         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1501                 $table = $this->tableName( $table );
1502
1503                 # Single row case
1504                 if ( !is_array( reset( $rows ) ) ) {
1505                         $rows = array( $rows );
1506                 }
1507
1508                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1509                 $first = true;
1510                 foreach ( $rows as $row ) {
1511                         if ( $first ) {
1512                                 $first = false;
1513                         } else {
1514                                 $sql .= ',';
1515                         }
1516                         $sql .= '(' . $this->makeList( $row ) . ')';
1517                 }
1518                 return $this->query( $sql, $fname );
1519         }
1520
1521         /**
1522          * DELETE where the condition is a join
1523          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1524          *
1525          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1526          * join condition matches, set $conds='*'
1527          *
1528          * DO NOT put the join condition in $conds
1529          *
1530          * @param string $delTable The table to delete from.
1531          * @param string $joinTable The other table.
1532          * @param string $delVar The variable to join on, in the first table.
1533          * @param string $joinVar The variable to join on, in the second table.
1534          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1535          */
1536         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1537                 if ( !$conds ) {
1538                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1539                 }
1540
1541                 $delTable = $this->tableName( $delTable );
1542                 $joinTable = $this->tableName( $joinTable );
1543                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1544                 if ( $conds != '*' ) {
1545                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1546                 }
1547
1548                 return $this->query( $sql, $fname );
1549         }
1550
1551         /**
1552          * Returns the size of a text field, or -1 for "unlimited"
1553          */
1554         function textFieldSize( $table, $field ) {
1555                 $table = $this->tableName( $table );
1556                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1557                 $res = $this->query( $sql, 'Database::textFieldSize' );
1558                 $row = $this->fetchObject( $res );
1559                 $this->freeResult( $res );
1560
1561                 $m = array();
1562                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1563                         $size = $m[1];
1564                 } else {
1565                         $size = -1;
1566                 }
1567                 return $size;
1568         }
1569
1570         /**
1571          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1572          */
1573         function lowPriorityOption() {
1574                 return 'LOW_PRIORITY';
1575         }
1576
1577         /**
1578          * DELETE query wrapper
1579          *
1580          * Use $conds == "*" to delete all rows
1581          */
1582         function delete( $table, $conds, $fname = 'Database::delete' ) {
1583                 if ( !$conds ) {
1584                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1585                 }
1586                 $table = $this->tableName( $table );
1587                 $sql = "DELETE FROM $table";
1588                 if ( $conds != '*' ) {
1589                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1590                 }
1591                 return $this->query( $sql, $fname );
1592         }
1593
1594         /**
1595          * INSERT SELECT wrapper
1596          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1597          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1598          * $conds may be "*" to copy the whole table
1599          * srcTable may be an array of tables.
1600          */
1601         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1602                 $insertOptions = array(), $selectOptions = array() )
1603         {
1604                 $destTable = $this->tableName( $destTable );
1605                 if ( is_array( $insertOptions ) ) {
1606                         $insertOptions = implode( ' ', $insertOptions );
1607                 }
1608                 if( !is_array( $selectOptions ) ) {
1609                         $selectOptions = array( $selectOptions );
1610                 }
1611                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1612                 if( is_array( $srcTable ) ) {
1613                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1614                 } else {
1615                         $srcTable = $this->tableName( $srcTable );
1616                 }
1617                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1618                         " SELECT $startOpts " . implode( ',', $varMap ) .
1619                         " FROM $srcTable $useIndex ";
1620                 if ( $conds != '*' ) {
1621                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1622                 }
1623                 $sql .= " $tailOpts";
1624                 return $this->query( $sql, $fname );
1625         }
1626
1627         /**
1628          * Construct a LIMIT query with optional offset
1629          * This is used for query pages
1630          * $sql string SQL query we will append the limit too
1631          * $limit integer the SQL limit
1632          * $offset integer the SQL offset (default false)
1633          */
1634         function limitResult($sql, $limit, $offset=false) {
1635                 if( !is_numeric($limit) ) {
1636                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1637                 }
1638                 return " $sql LIMIT "
1639                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1640                                 . "{$limit} ";
1641         }
1642         function limitResultForUpdate($sql, $num) {
1643                 return $this->limitResult($sql, $num, 0);
1644         }
1645
1646         /**
1647          * Returns an SQL expression for a simple conditional.
1648          * Uses IF on MySQL.
1649          *
1650          * @param string $cond SQL expression which will result in a boolean value
1651          * @param string $trueVal SQL expression to return if true
1652          * @param string $falseVal SQL expression to return if false
1653          * @return string SQL fragment
1654          */
1655         function conditional( $cond, $trueVal, $falseVal ) {
1656                 return " IF($cond, $trueVal, $falseVal) ";
1657         }
1658
1659         /**
1660          * Determines if the last failure was due to a deadlock
1661          */
1662         function wasDeadlock() {
1663                 return $this->lastErrno() == 1213;
1664         }
1665
1666         /**
1667          * Perform a deadlock-prone transaction.
1668          *
1669          * This function invokes a callback function to perform a set of write
1670          * queries. If a deadlock occurs during the processing, the transaction
1671          * will be rolled back and the callback function will be called again.
1672          *
1673          * Usage:
1674          *   $dbw->deadlockLoop( callback, ... );
1675          *
1676          * Extra arguments are passed through to the specified callback function.
1677          *
1678          * Returns whatever the callback function returned on its successful,
1679          * iteration, or false on error, for example if the retry limit was
1680          * reached.
1681          */
1682         function deadlockLoop() {
1683                 $myFname = 'Database::deadlockLoop';
1684
1685                 $this->begin();
1686                 $args = func_get_args();
1687                 $function = array_shift( $args );
1688                 $oldIgnore = $this->ignoreErrors( true );
1689                 $tries = DEADLOCK_TRIES;
1690                 if ( is_array( $function ) ) {
1691                         $fname = $function[0];
1692                 } else {
1693                         $fname = $function;
1694                 }
1695                 do {
1696                         $retVal = call_user_func_array( $function, $args );
1697                         $error = $this->lastError();
1698                         $errno = $this->lastErrno();
1699                         $sql = $this->lastQuery();
1700
1701                         if ( $errno ) {
1702                                 if ( $this->wasDeadlock() ) {
1703                                         # Retry
1704                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1705                                 } else {
1706                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1707                                 }
1708                         }
1709                 } while( $this->wasDeadlock() && --$tries > 0 );
1710                 $this->ignoreErrors( $oldIgnore );
1711                 if ( $tries <= 0 ) {
1712                         $this->query( 'ROLLBACK', $myFname );
1713                         $this->reportQueryError( $error, $errno, $sql, $fname );
1714                         return false;
1715                 } else {
1716                         $this->query( 'COMMIT', $myFname );
1717                         return $retVal;
1718                 }
1719         }
1720
1721         /**
1722          * Do a SELECT MASTER_POS_WAIT()
1723          *
1724          * @param string $file the binlog file
1725          * @param string $pos the binlog position
1726          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1727          */
1728         function masterPosWait( $file, $pos, $timeout ) {
1729                 $fname = 'Database::masterPosWait';
1730                 wfProfileIn( $fname );
1731
1732
1733                 # Commit any open transactions
1734                 $this->immediateCommit();
1735
1736                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1737                 $encFile = $this->strencode( $file );
1738                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1739                 $res = $this->doQuery( $sql );
1740                 if ( $res && $row = $this->fetchRow( $res ) ) {
1741                         $this->freeResult( $res );
1742                         wfProfileOut( $fname );
1743                         return $row[0];
1744                 } else {
1745                         wfProfileOut( $fname );
1746                         return false;
1747                 }
1748         }
1749
1750         /**
1751          * Get the position of the master from SHOW SLAVE STATUS
1752          */
1753         function getSlavePos() {
1754                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1755                 $row = $this->fetchObject( $res );
1756                 if ( $row ) {
1757                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1758                 } else {
1759                         return array( false, false );
1760                 }
1761         }
1762
1763         /**
1764          * Get the position of the master from SHOW MASTER STATUS
1765          */
1766         function getMasterPos() {
1767                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1768                 $row = $this->fetchObject( $res );
1769                 if ( $row ) {
1770                         return array( $row->File, $row->Position );
1771                 } else {
1772                         return array( false, false );
1773                 }
1774         }
1775
1776         /**
1777          * Begin a transaction, committing any previously open transaction
1778          */
1779         function begin( $fname = 'Database::begin' ) {
1780                 $this->query( 'BEGIN', $fname );
1781                 $this->mTrxLevel = 1;
1782         }
1783
1784         /**
1785          * End a transaction
1786          */
1787         function commit( $fname = 'Database::commit' ) {
1788                 $this->query( 'COMMIT', $fname );
1789                 $this->mTrxLevel = 0;
1790         }
1791
1792         /**
1793          * Rollback a transaction
1794          */
1795         function rollback( $fname = 'Database::rollback' ) {
1796                 $this->query( 'ROLLBACK', $fname );
1797                 $this->mTrxLevel = 0;
1798         }
1799
1800         /**
1801          * Begin a transaction, committing any previously open transaction
1802          * @deprecated use begin()
1803          */
1804         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1805                 $this->begin();
1806         }
1807
1808         /**
1809          * Commit transaction, if one is open
1810          * @deprecated use commit()
1811          */
1812         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1813                 $this->commit();
1814         }
1815
1816         /**
1817          * Return MW-style timestamp used for MySQL schema
1818          */
1819         function timestamp( $ts=0 ) {
1820                 return wfTimestamp(TS_MW,$ts);
1821         }
1822
1823         /**
1824          * Local database timestamp format or null
1825          */
1826         function timestampOrNull( $ts = null ) {
1827                 if( is_null( $ts ) ) {
1828                         return null;
1829                 } else {
1830                         return $this->timestamp( $ts );
1831                 }
1832         }
1833
1834         /**
1835          * @todo document
1836          */
1837         function resultObject( $result ) {
1838                 if( empty( $result ) ) {
1839                         return NULL;
1840                 } else {
1841                         return new ResultWrapper( $this, $result );
1842                 }
1843         }
1844
1845         /**
1846          * Return aggregated value alias
1847          */
1848         function aggregateValue ($valuedata,$valuename='value') {
1849                 return $valuename;
1850         }
1851
1852         /**
1853          * @return string wikitext of a link to the server software's web site
1854          */
1855         function getSoftwareLink() {
1856                 return "[http://www.mysql.com/ MySQL]";
1857         }
1858
1859         /**
1860          * @return string Version information from the database
1861          */
1862         function getServerVersion() {
1863                 return mysql_get_server_info( $this->mConn );
1864         }
1865
1866         /**
1867          * Ping the server and try to reconnect if it there is no connection
1868          */
1869         function ping() {
1870                 if( function_exists( 'mysql_ping' ) ) {
1871                         return mysql_ping( $this->mConn );
1872                 } else {
1873                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
1874                         return true;
1875                 }
1876         }
1877
1878         /**
1879          * Get slave lag.
1880          * At the moment, this will only work if the DB user has the PROCESS privilege
1881          */
1882         function getLag() {
1883                 $res = $this->query( 'SHOW PROCESSLIST' );
1884                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
1885                 # dubious, but unfortunately there's no easy rigorous way
1886                 while ( $row = $this->fetchObject( $res ) ) {
1887                         /* This should work for most situations - when default db
1888                          * for thread is not specified, it had no events executed,
1889                          * and therefore it doesn't know yet how lagged it is.
1890                          *
1891                          * Relay log I/O thread does not select databases.
1892                          */
1893                         if ( $row->User == 'system user' &&
1894                                 $row->State != 'Waiting for master to send event' &&
1895                                 $row->State != 'Connecting to master' &&
1896                                 $row->State != 'Queueing master event to the relay log' &&
1897                                 $row->State != 'Waiting for master update' &&
1898                                 $row->State != 'Requesting binlog dump'
1899                                 ) {
1900                                 # This is it, return the time (except -ve)
1901                                 if ( $row->Time > 0x7fffffff ) {
1902                                         return false;
1903                                 } else {
1904                                         return $row->Time;
1905                                 }
1906                         }
1907                 }
1908                 return false;
1909         }
1910
1911         /**
1912          * Get status information from SHOW STATUS in an associative array
1913          */
1914         function getStatus($which="%") {
1915                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1916                 $status = array();
1917                 while ( $row = $this->fetchObject( $res ) ) {
1918                         $status[$row->Variable_name] = $row->Value;
1919                 }
1920                 return $status;
1921         }
1922
1923         /**
1924          * Return the maximum number of items allowed in a list, or 0 for unlimited.
1925          */
1926         function maxListLen() {
1927                 return 0;
1928         }
1929
1930         function encodeBlob($b) {
1931                 return $b;
1932         }
1933
1934         function decodeBlob($b) {
1935                 return $b;
1936         }
1937
1938         /**
1939          * Read and execute SQL commands from a file.
1940          * Returns true on success, error string on failure
1941          */
1942         function sourceFile( $filename ) {
1943                 $fp = fopen( $filename, 'r' );
1944                 if ( false === $fp ) {
1945                         return "Could not open \"{$filename}\".\n";
1946                 }
1947
1948                 $cmd = "";
1949                 $done = false;
1950                 $dollarquote = false;
1951
1952                 while ( ! feof( $fp ) ) {
1953                         $line = trim( fgets( $fp, 1024 ) );
1954                         $sl = strlen( $line ) - 1;
1955
1956                         if ( $sl < 0 ) { continue; }
1957                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
1958
1959                         ## Allow dollar quoting for function declarations
1960                         if (substr($line,0,4) == '$mw$') {
1961                                 if ($dollarquote) {
1962                                         $dollarquote = false;
1963                                         $done = true;
1964                                 }
1965                                 else {
1966                                         $dollarquote = true;
1967                                 }
1968                         }
1969                         else if (!$dollarquote) {
1970                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
1971                                         $done = true;
1972                                         $line = substr( $line, 0, $sl );
1973                                 }
1974                         }
1975
1976                         if ( '' != $cmd ) { $cmd .= ' '; }
1977                         $cmd .= "$line\n";
1978
1979                         if ( $done ) {
1980                                 $cmd = str_replace(';;', ";", $cmd);
1981                                 $cmd = $this->replaceVars( $cmd );
1982                                 $res = $this->query( $cmd, 'dbsource', true );
1983
1984                                 if ( false === $res ) {
1985                                         $err = $this->lastError();
1986                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
1987                                 }
1988
1989                                 $cmd = '';
1990                                 $done = false;
1991                         }
1992                 }
1993                 fclose( $fp );
1994                 return true;
1995         }
1996
1997         /**
1998          * Replace variables in sourced SQL
1999          */
2000         protected function replaceVars( $ins ) {
2001                 $varnames = array(
2002                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2003                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2004                         'wgDBadminuser', 'wgDBadminpassword',
2005                 );
2006
2007                 // Ordinary variables
2008                 foreach ( $varnames as $var ) {
2009                         if( isset( $GLOBALS[$var] ) ) {
2010                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2011                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2012                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2013                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2014                         }
2015                 }
2016
2017                 // Table prefixes
2018                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2019                         array( &$this, 'tableNameCallback' ), $ins );
2020                 return $ins;
2021         }
2022
2023         /**
2024          * Table name callback
2025          * @private
2026          */
2027         protected function tableNameCallback( $matches ) {
2028                 return $this->tableName( $matches[1] );
2029         }
2030
2031 }
2032
2033 /**
2034  * Database abstraction object for mySQL
2035  * Inherit all methods and properties of Database::Database()
2036  *
2037  * @package MediaWiki
2038  * @see Database
2039  */
2040 class DatabaseMysql extends Database {
2041         # Inherit all
2042 }
2043
2044
2045 /**
2046  * Result wrapper for grabbing data queried by someone else
2047  *
2048  * @package MediaWiki
2049  */
2050 class ResultWrapper {
2051         var $db, $result;
2052
2053         /**
2054          * @todo document
2055          */
2056         function ResultWrapper( &$database, $result ) {
2057                 $this->db =& $database;
2058                 $this->result =& $result;
2059         }
2060
2061         /**
2062          * @todo document
2063          */
2064         function numRows() {
2065                 return $this->db->numRows( $this->result );
2066         }
2067
2068         /**
2069          * @todo document
2070          */
2071         function fetchObject() {
2072                 return $this->db->fetchObject( $this->result );
2073         }
2074
2075         /**
2076          * @todo document
2077          */
2078         function fetchRow() {
2079                 return $this->db->fetchRow( $this->result );
2080         }
2081
2082         /**
2083          * @todo document
2084          */
2085         function free() {
2086                 $this->db->freeResult( $this->result );
2087                 unset( $this->result );
2088                 unset( $this->db );
2089         }
2090
2091         function seek( $row ) {
2092                 $this->db->dataSeek( $this->result, $row );
2093         }
2094
2095 }
2096
2097 ?>