includes/Database.php

   1 <?php
   2 # $Id$
   3 # This file deals with MySQL interface functions
   4 # and query specifics/optimisations
   5 #
   6 require_once( "CacheManager.php" );
   7
   8 define( "LIST_COMMA", 0 );
   9 define( "LIST_AND", 1 );
  10 define( "LIST_SET", 2 );
  11
  12 class Database {
  13
  14 #------------------------------------------------------------------------------
  15 # Variables
  16 #------------------------------------------------------------------------------
  17         /* private */ var $mLastQuery = "";
  18         /* private */ var $mBufferResults = true;
  19         /* private */ var $mIgnoreErrors = false;
  20
  21         /* private */ var $mServer, $mUser, $mPassword, $mConn, $mDBname;
  22         /* private */ var $mOut, $mDebug, $mOpened = false;
  23
  24         /* private */ var $mFailFunction;
  25
  26 #------------------------------------------------------------------------------
  27 # Accessors
  28 #------------------------------------------------------------------------------
  29         # Set functions
  30         # These set a variable and return the previous state
  31
  32         # Fail function, takes a Database as a parameter
  33         # Set to false for default, 1 for ignore errors
  34         function setFailFunction( $function ) { return wfSetVar( $this->mFailFunction, $function ); }
  35
  36         # Output page, used for reporting errors
  37         # FALSE means discard output
  38         function &setOutputPage( &$out ) { $this->mOut =& $out; }
  39
  40         # Boolean, controls output of large amounts of debug information
  41         function setDebug( $debug ) { return wfSetVar( $this->mDebug, $debug ); }
  42
  43         # Turns buffering of SQL result sets on (true) or off (false). Default is
  44         # "on" and it should not be changed without good reasons.
  45         function setBufferResults( $buffer ) { return wfSetVar( $this->mBufferResults, $buffer ); }
  46
  47         # Turns on (false) or off (true) the automatic generation and sending
  48         # of a "we're sorry, but there has been a database error" page on
  49         # database errors. Default is on (false). When turned off, the
  50         # code should use wfLastErrno() and wfLastError() to handle the
  51         # situation as appropriate.
  52         function setIgnoreErrors( $ignoreErrors ) { return wfSetVar( $this->mIgnoreErrors, $ignoreErrors ); }
  53
  54         # Get functions
  55
  56         function lastQuery() { return $this->mLastQuery; }
  57         function isOpen() { return $this->mOpened; }
  58
  59 #------------------------------------------------------------------------------
  60 # Other functions
  61 #------------------------------------------------------------------------------
  62
  63         function Database( $server = false, $user = false, $password = false, $dbName = false,
  64                 $failFunction = false, $debug = false, $bufferResults = true, $ignoreErrors = false )
  65         {
  66                 global $wgOut;
  67                 # Can't get a reference if it hasn't been set yet
  68                 if ( !isset( $wgOut ) ) {
  69                         $wgOut = NULL;
  70                 }
  71                 $this->mOut =& $wgOut;
  72
  73                 $this->mFailFunction = $failFunction;
  74                 $this->mIgnoreErrors = $ignoreErrors;
  75                 $this->mDebug = $debug;
  76                 $this->mBufferResults = $bufferResults;
  77                 if ( $server ) {
  78                         $this->open( $server, $user, $password, $dbName );
  79                 }
  80         }
  81
  82         /* static */ function newFromParams( $server, $user, $password, $dbName,
  83                 $failFunction = false, $debug = false, $bufferResults = true, $ignoreErrors = false )
  84         {
  85                 return new Database( $server, $user, $password, $dbName, $failFunction, $debug,
  86                   $bufferResults, $ignoreErrors );
  87         }
  88
  89         # Usually aborts on failure
  90         # If the failFunction is set to a non-zero integer, returns success
  91         function open( $server, $user, $password, $dbName )
  92         {
  93                 # Test for missing mysql.so
  94                 # Otherwise we get a suppressed fatal error, which is very hard to track down
  95                 if ( !function_exists( 'mysql_connect' ) ) {
  96                         die( "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  97                 }
  98
  99                 $this->close();
 100                 $this->mServer = $server;
 101                 $this->mUser = $user;
 102                 $this->mPassword = $password;
 103                 $this->mDBname = $dbName;
 104
 105                 $success = false;
 106
 107                 @$this->mConn = mysql_connect( $server, $user, $password );
 108                 if ( $dbName != "" ) {
 109                         if ( $this->mConn !== false ) {
 110                                 $success = @mysql_select_db( $dbName, $this->mConn );
 111                                 if ( !$success ) {
 112                                         wfDebug( "Error selecting database \"$dbName\": " . $this->lastError() . "\n" );
 113                                 }
 114                         } else {
 115                                 wfDebug( "DB connection error\n" );
 116                                 wfDebug( "Server: $server, User: $user, Password: " .
 117                                         substr( $password, 0, 3 ) . "...\n" );
 118                                 $success = false;
 119                         }
 120                 } else {
 121                         # Delay USE query
 122                         $success = !!$this->mConn;
 123                 }
 124
 125                 if ( !$success ) {
 126                         $this->reportConnectionError();
 127                         $this->close();
 128                 }
 129                 $this->mOpened = $success;
 130                 return $success;
 131         }
 132
 133         # Closes a database connection, if it is open
 134         # Returns success, true if already closed
 135         function close()
 136         {
 137                 $this->mOpened = false;
 138                 if ( $this->mConn ) {
 139                         return mysql_close( $this->mConn );
 140                 } else {
 141                         return true;
 142                 }
 143         }
 144
 145         /* private */ function reportConnectionError( $msg = "")
 146         {
 147                 if ( $this->mFailFunction ) {
 148                         if ( !is_int( $this->mFailFunction ) ) {
 149                                 $ff = $this->mFailFunction;
 150                                 $ff( $this, mysql_error() );
 151                         }
 152                 } else {
 153                         wfEmergencyAbort( $this, mysql_error() );
 154                 }
 155         }
 156
 157         # Usually aborts on failure
 158         # If errors are explicitly ignored, returns success
 159         function query( $sql, $fname = "", $tempIgnore = false )
 160         {
 161                 global $wgProfiling, $wgCommandLineMode;
 162
 163                 if ( $wgProfiling ) {
 164                         # generalizeSQL will probably cut down the query to reasonable
 165                         # logging size most of the time. The substr is really just a sanity check.
 166                         $profName = "query: " . substr( Database::generalizeSQL( $sql ), 0, 255 );
 167                         wfProfileIn( $profName );
 168                 }
 169
 170                 $this->mLastQuery = $sql;
 171
 172                 if ( $this->mDebug ) {
 173                         $sqlx = substr( $sql, 0, 500 );
 174                         $sqlx = wordwrap(strtr($sqlx,"\t\n","  "));
 175                         wfDebug( "SQL: $sqlx\n" );
 176                 }
 177                 # Add a comment for easy SHOW PROCESSLIST interpretation
 178                 if ( $fname ) {
 179                         $commentedSql = "/* $fname */ $sql";
 180                 } else {
 181                         $commentedSql = $sql;
 182                 }
 183
 184                 if( $this->mBufferResults ) {
 185                         $ret = mysql_query( $commentedSql, $this->mConn );
 186                 } else {
 187                         $ret = mysql_unbuffered_query( $commentedSql, $this->mConn );
 188                 }
 189
 190                 if ( false === $ret ) {
 191                         # Ignore errors during error handling to avoid infinite recursion
 192                         $ignore = $this->setIgnoreErrors( true );
 193
 194                         $error = mysql_error( $this->mConn );
 195                         $errno = mysql_errno( $this->mConn );
 196                         if( $ignore || $tempIgnore ) {
 197                                 wfDebug("SQL ERROR (ignored): " . $error . "\n");
 198                         } else {
 199                                 $sql1line = str_replace( "\n", "\\n", $sql );
 200                                 wfLogDBError("$fname\t$errno\t$error\t$sql1line\n");
 201                                 wfDebug("SQL ERROR: " . $error . "\n");
 202                                 if ( $wgCommandLineMode ) {
 203                                         wfDebugDieBacktrace( "A database error has occurred\n" .
 204                                           "Query: $sql\n" .
 205                                           "Function: $fname\n" .
 206                                           "Error: $errno $error\n"
 207                                         );
 208                                 } elseif ( $this->mOut ) {
 209                                         // this calls wfAbruptExit()
 210                                         $this->mOut->databaseError( $fname, $sql, $error, $errno );
 211                                 }
 212                         }
 213                         $this->setIgnoreErrors( $ignore );
 214                 }
 215
 216                 if ( $wgProfiling ) {
 217                         wfProfileOut( $profName );
 218                 }
 219                 return $ret;
 220         }
 221
 222         function freeResult( $res ) {
 223                 if ( !@mysql_free_result( $res ) ) {
 224                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 225                 }
 226         }
 227         function fetchObject( $res ) {
 228                 @$row = mysql_fetch_object( $res );
 229                 # FIXME: HACK HACK HACK HACK debug
 230                 if( mysql_errno() ) {
 231                         wfDebugDieBacktrace( "Error in fetchObject(): " . htmlspecialchars( mysql_error() ) );
 232                 }
 233                 return $row;
 234         }
 235
 236         function fetchRow( $res ) {
 237                 @$row = mysql_fetch_array( $res );
 238                 if (mysql_errno() ) {
 239                         wfDebugDieBacktrace( "Error in fetchRow(): " . htmlspecialchars( mysql_error() ) );
 240                 }
 241                 return $row;
 242         }
 243
 244         function numRows( $res ) {
 245                 @$n = mysql_num_rows( $res );
 246                 if( mysql_errno() ) {
 247                         wfDebugDieBacktrace( "Error in numRows(): " . htmlspecialchars( mysql_error() ) );
 248                 }
 249                 return $n;
 250         }
 251         function numFields( $res ) { return mysql_num_fields( $res ); }
 252         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 253         function insertId() { return mysql_insert_id( $this->mConn ); }
 254         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 255         function lastErrno() { return mysql_errno(); }
 256         function lastError() { return mysql_error(); }
 257         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 258
 259         # Simple UPDATE wrapper
 260         # Usually aborts on failure
 261         # If errors are explicitly ignored, returns success
 262         function set( $table, $var, $value, $cond, $fname = "Database::set" )
 263         {
 264                 $table = $this->tableName( $table );
 265                 $sql = "UPDATE $table SET $var = '" .
 266                   wfStrencode( $value ) . "' WHERE ($cond)";
 267                 return !!$this->query( $sql, DB_WRITE, $fname );
 268         }
 269
 270         # Simple SELECT wrapper, returns a single field, input must be encoded
 271         # Usually aborts on failure
 272         # If errors are explicitly ignored, returns FALSE on failure
 273         function getField( $table, $var, $cond, $fname = "Database::get" )
 274         {
 275                 $table = $this->tableName( $table );
 276                 $from = $table?" FROM $table ":"";
 277                 if ( is_array( $cond ) ) {
 278                         $where = ' WHERE ' . $this->makeList( $cond, LIST_AND );
 279                 } elseif ( $cond ) {
 280                         $where = " WHERE ($cond)";
 281                 } else {
 282                         $where = '';
 283                 }
 284                 $sql = "SELECT $var $from $where LIMIT 1";
 285                 $result = $this->query( $sql, $fname );
 286
 287                 $ret = false;
 288                 if ( $this->numRows( $result ) > 0 ) {
 289                         $s = $this->fetchRow( $result );
 290                         $ret = $s[0];
 291                         $this->freeResult( $result );
 292                 }
 293                 return $ret;
 294         }
 295
 296         # SELECT wrapper
 297         function select( $table, $vars, $conds, $fname = "Database::select", $options = array() )
 298         {
 299                 $vars = implode( ",", $vars );
 300                 $table = $this->tableName( $table );
 301                 if ( !is_array( $options ) ) {
 302                         $options = array( $options );
 303                 }
 304
 305                 $tailOpts = '';
 306
 307                 if ( isset( $options['ORDER BY'] ) ) {
 308                         $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 309                 }
 310                 if ( isset( $options['LIMIT'] ) ) {
 311                         $tailOpts .= " LIMIT {$options['LIMIT']}";
 312                 }
 313
 314                 if ( is_numeric( array_search( 'FOR UPDATE', $options ) ) ) {
 315                         $tailOpts .= ' FOR UPDATE';
 316                 }
 317
 318                 if ( is_numeric( array_search( 'LOCK IN SHARE MODE', $options ) ) ) {
 319                         $tailOpts .= ' LOCK IN SHARE MODE';
 320                 }
 321
 322                 if ( isset( $options['USE INDEX'] ) ) {
 323                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 324                 } else {
 325                         $useIndex = '';
 326                 }
 327
 328                 if ( $conds !== false ) {
 329                         $where = $this->makeList( $conds, LIST_AND );
 330                         $sql = "SELECT $vars FROM $table $useIndex WHERE $where $tailOpts";
 331                 } else {
 332                         $sql = "SELECT $vars FROM $table $useIndex $tailOpts";
 333                 }
 334                 return $this->query( $sql, $fname );
 335         }
 336
 337         # Single row SELECT wrapper
 338         # Aborts or returns FALSE on error
 339         #
 340         # $vars: the selected variables
 341         # $conds: a condition map, terms are ANDed together.
 342         #    Items with numeric keys are taken to be literal conditions
 343         # Takes an array of selected variables, and a condition map, which is ANDed
 344         # e.g. getArray( "cur", array( "cur_id" ), array( "cur_namespace" => 0, "cur_title" => "Astronomy" ) )
 345         #   would return an object where $obj->cur_id is the ID of the Astronomy article
 346         function getArray( $table, $vars, $conds, $fname = "Database::getArray", $options = array() ) {
 347                 $options['LIMIT'] = 1;
 348                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 349                 if ( $res === false || !$this->numRows( $res ) ) {
 350                         return false;
 351                 }
 352                 $obj = $this->fetchObject( $res );
 353                 $this->freeResult( $res );
 354                 return $obj;
 355
 356         }
 357
 358         # Removes most variables from an SQL query and replaces them with X or N for numbers.
 359         # It's only slightly flawed. Don't use for anything important.
 360         /* static */ function generalizeSQL( $sql )
 361         {
 362                 # This does the same as the regexp below would do, but in such a way
 363                 # as to avoid crashing php on some large strings.
 364                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 365
 366                 $sql = str_replace ( "\\\\", "", $sql);
 367                 $sql = str_replace ( "\\'", "", $sql);
 368                 $sql = str_replace ( "\\\"", "", $sql);
 369                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 370                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 371
 372                 # All newlines, tabs, etc replaced by single space
 373                 $sql = preg_replace ( "/\s+/", " ", $sql);
 374
 375                 # All numbers => N
 376                 $sql = preg_replace ('/-?[0-9]+/s', "N", $sql);
 377
 378                 return $sql;
 379         }
 380
 381         # Determines whether a field exists in a table
 382         # Usually aborts on failure
 383         # If errors are explicitly ignored, returns NULL on failure
 384         function fieldExists( $table, $field, $fname = "Database::fieldExists" )
 385         {
 386                 $table = $this->tableName( $table );
 387                 $res = $this->query( "DESCRIBE $table", DB_READ, $fname );
 388                 if ( !$res ) {
 389                         return NULL;
 390                 }
 391
 392                 $found = false;
 393
 394                 while ( $row = $this->fetchObject( $res ) ) {
 395                         if ( $row->Field == $field ) {
 396                                 $found = true;
 397                                 break;
 398                         }
 399                 }
 400                 return $found;
 401         }
 402
 403         # Determines whether an index exists
 404         # Usually aborts on failure
 405         # If errors are explicitly ignored, returns NULL on failure
 406         function indexExists( $table, $index, $fname = "Database::indexExists" )
 407         {
 408                 $info = $this->indexInfo( $table, $index, $fname );
 409                 if ( is_null( $info ) ) {
 410                         return NULL;
 411                 } else {
 412                         return $info !== false;
 413                 }
 414         }
 415
 416         function indexInfo( $table, $index, $fname = "Database::indexInfo" ) {
 417                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 418                 # SHOW INDEX should work for 3.x and up:
 419                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 420                 $table = $this->tableName( $table );
 421                 $sql = "SHOW INDEX FROM $table";
 422                 $res = $this->query( $sql, $fname );
 423                 if ( !$res ) {
 424                         return NULL;
 425                 }
 426
 427                 while ( $row = $this->fetchObject( $res ) ) {
 428                         if ( $row->Key_name == $index ) {
 429                                 return $row;
 430                         }
 431                 }
 432                 return false;
 433         }
 434         function tableExists( $table )
 435         {
 436                 $table = $this->tableName( $table );
 437                 $old = $this->mIgnoreErrors;
 438                 $this->mIgnoreErrors = true;
 439                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 440                 $this->mIgnoreErrors = $old;
 441                 if( $res ) {
 442                         $this->freeResult( $res );
 443                         return true;
 444                 } else {
 445                         return false;
 446                 }
 447         }
 448
 449         function fieldInfo( $table, $field )
 450         {
 451                 $table = $this->tableName( $table );
 452                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 453                 $n = mysql_num_fields( $res );
 454                 for( $i = 0; $i < $n; $i++ ) {
 455                         $meta = mysql_fetch_field( $res, $i );
 456                         if( $field == $meta->name ) {
 457                                 return $meta;
 458                         }
 459                 }
 460                 return false;
 461         }
 462
 463         # INSERT wrapper, inserts an array into a table
 464         #
 465         # $a may be a single associative array, or an array of these with numeric keys, for
 466         # multi-row insert.
 467         #
 468         # Usually aborts on failure
 469         # If errors are explicitly ignored, returns success
 470         function insertArray( $table, $a, $fname = "Database::insertArray", $options = array() )
 471         {
 472                 $table = $this->tableName( $table );
 473                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 474                         $multi = true;
 475                         $keys = array_keys( $a[0] );
 476                 } else {
 477                         $multi = false;
 478                         $keys = array_keys( $a );
 479                 }
 480
 481                 $sql = 'INSERT ' . implode( ' ', $options ) .
 482                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 483
 484                 if ( $multi ) {
 485                         $first = true;
 486                         foreach ( $a as $row ) {
 487                                 if ( $first ) {
 488                                         $first = false;
 489                                 } else {
 490                                         $sql .= ",";
 491                                 }
 492                                 $sql .= '(' . $this->makeList( $row ) . ')';
 493                         }
 494                 } else {
 495                         $sql .= '(' . $this->makeList( $a ) . ')';
 496                 }
 497                 return !!$this->query( $sql, $fname );
 498         }
 499
 500         # UPDATE wrapper, takes a condition array and a SET array
 501         function updateArray( $table, $values, $conds, $fname = "Database::updateArray" )
 502         {
 503                 $table = $this->tableName( $table );
 504                 $sql = "UPDATE $table SET " . $this->makeList( $values, LIST_SET );
 505                 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 506                 $this->query( $sql, $fname );
 507         }
 508
 509         # Makes a wfStrencoded list from an array
 510         # $mode: LIST_COMMA         - comma separated, no field names
 511         #        LIST_AND           - ANDed WHERE clause (without the WHERE)
 512         #        LIST_SET           - comma separated with field names, like a SET clause
 513         function makeList( $a, $mode = LIST_COMMA )
 514         {
 515                 if ( !is_array( $a ) ) {
 516                         wfDebugDieBacktrace( 'Database::makeList called with incorrect parameters' );
 517                 }
 518
 519                 $first = true;
 520                 $list = "";
 521                 foreach ( $a as $field => $value ) {
 522                         if ( !$first ) {
 523                                 if ( $mode == LIST_AND ) {
 524                                         $list .= " AND ";
 525                                 } else {
 526                                         $list .= ",";
 527                                 }
 528                         } else {
 529                                 $first = false;
 530                         }
 531                         if ( $mode == LIST_AND && is_numeric( $field ) ) {
 532                                 $list .= "($value)";
 533                         } else {
 534                                 if ( $mode == LIST_AND || $mode == LIST_SET ) {
 535                                         $list .= "$field=";
 536                                 }
 537                                 $list .= $this->addQuotes( $value );
 538                         }
 539                 }
 540                 return $list;
 541         }
 542
 543         function selectDB( $db )
 544         {
 545                 $this->mDBname = $db;
 546                 mysql_select_db( $db, $this->mConn );
 547         }
 548
 549         function startTimer( $timeout )
 550         {
 551                 global $IP;
 552
 553                 $tid = mysql_thread_id( $this->mConn );
 554                 exec( "php $IP/killthread.php $timeout $tid &>/dev/null &" );
 555         }
 556
 557         function stopTimer()
 558         {
 559         }
 560
 561         function tableName( $name ) {
 562                 return $name;
 563         }
 564
 565         function strencode( $s ) {
 566                 return addslashes( $s );
 567         }
 568
 569         # If it's a string, adds quotes and backslashes
 570         # Otherwise returns as-is
 571         function addQuotes( $s ) {
 572                 if ( !is_numeric( $s ) ) {
 573                         $s = "'" . $this->strencode( $s ) . "'";
 574                 } else if ( is_null( $s ) ) {
 575                         $s = 'NULL';
 576                 }
 577                 return $s;
 578         }
 579
 580         # Returns an appropriately quoted sequence value for inserting a new row.
 581         # MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
 582         # subclass will return an integer, and save the value for insertId()
 583         function nextSequenceValue( $seqName ) {
 584                 return NULL;
 585         }
 586
 587         # USE INDEX clause
 588         # PostgreSQL doesn't have them and returns ""
 589         function useIndexClause( $index ) {
 590                 return "USE INDEX ($index)";
 591         }
 592
 593         # REPLACE query wrapper
 594         # PostgreSQL simulates this with a DELETE followed by INSERT
 595         # $row is the row to insert, an associative array
 596         # $uniqueIndexes is an array of indexes. Each element may be either a
 597         # field name or an array of field names
 598         #
 599         # It may be more efficient to leave off unique indexes which are unlikely to collide.
 600         # However if you do this, you run the risk of encountering errors which wouldn't have
 601         # occurred in MySQL
 602         function replace( $table, $uniqueIndexes, $rows, $fname = "Database::replace" ) {
 603                 $table = $this->tableName( $table );
 604
 605                 # Single row case
 606                 if ( !is_array( reset( $rows ) ) ) {
 607                         $rows = array( $rows );
 608                 }
 609
 610                 $sql = "REPLACE INTO $table (" . implode( ',', array_flip( $rows[0] ) ) .") VALUES ";
 611                 $first = true;
 612                 foreach ( $rows as $row ) {
 613                         if ( $first ) {
 614                                 $first = false;
 615                         } else {
 616                                 $sql .= ",";
 617                         }
 618                         $sql .= "(" . $this->makeList( $row ) . ")";
 619                 }
 620                 return $this->query( $sql, $fname );
 621         }
 622
 623         # DELETE where the condition is a join
 624         # MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
 625         #
 626         # $delTable is the table to delete from
 627         # $joinTable is the other table
 628         # $delVar is the variable to join on, in the first table
 629         # $joinVar is the variable to join on, in the second table
 630         # $conds is a condition array of field names mapped to variables, ANDed together in the WHERE clause
 631         #
 632         # For safety, an empty $conds will not delete everything. If you want to delete all rows where the
 633         # join condition matches, set $conds='*'
 634         #
 635         # DO NOT put the join condition in $conds
 636         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = "Database::deleteJoin" ) {
 637                 if ( !$conds ) {
 638                         wfDebugDieBacktrace( 'Database::deleteJoin() called with empty $conds' );
 639                 }
 640
 641                 $delTable = $this->tableName( $delTable );
 642                 $joinTable = $this->tableName( $joinTable );
 643                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 644                 if ( $conds != '*' ) {
 645                         $sql .= " AND " . $this->makeList( $conds, LIST_AND );
 646                 }
 647
 648                 return $this->query( $sql, $fname );
 649         }
 650
 651         # Returns the size of a text field, or -1 for "unlimited"
 652         function textFieldSize( $table, $field ) {
 653                 $table = $this->tableName( $table );
 654                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
 655                 $res = $this->query( $sql, "Database::textFieldSize" );
 656                 $row = wfFetchObject( $res );
 657                 $this->freeResult( $res );
 658
 659                 if ( preg_match( "/\((.*)\)/", $row->Type, $m ) ) {
 660                         $size = $m[1];
 661                 } else {
 662                         $size = -1;
 663                 }
 664                 return $size;
 665         }
 666
 667         function lowPriorityOption() {
 668                 return 'LOW_PRIORITY';
 669         }
 670
 671         # Use $conds == "*" to delete all rows
 672         function delete( $table, $conds, $fname = "Database::delete" ) {
 673                 if ( !$conds ) {
 674                         wfDebugDieBacktrace( "Database::delete() called with no conditions" );
 675                 }
 676                 $table = $this->tableName( $table );
 677                 $sql = "DELETE FROM $table ";
 678                 if ( $conds != '*' ) {
 679                         $sql .= "WHERE " . $this->makeList( $conds, LIST_AND );
 680                 }
 681                 return $this->query( $sql, $fname );
 682         }
 683
 684         # INSERT SELECT wrapper
 685         # $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 686         # Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
 687         # $conds may be "*" to copy the whole table
 688         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect' ) {
 689                 $destTable = $this->tableName( $destTable );
 690                 $srcTable = $this->tableName( $srcTable );
 691                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ")" .
 692                         " SELECT " . implode( ',', $varMap ) .
 693                         " FROM $srcTable";
 694                 if ( $conds != '*' ) {
 695                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 696                 }
 697                 return $this->query( $sql, $fname );
 698         }
 699 }
 700
 701 class DatabaseMysql extends Database {
 702         # Inherit all
 703 }
 704
 705 #------------------------------------------------------------------------------
 706 # Global functions
 707 #------------------------------------------------------------------------------
 708
 709 /* Standard fail function, called by default when a connection cannot be established
 710    Displays the file cache if possible */
 711 function wfEmergencyAbort( &$conn, $error ) {
 712         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgSiteNotice, $wgOutputEncoding;
 713
 714         if( !headers_sent() ) {
 715                 header( "HTTP/1.0 500 Internal Server Error" );
 716                 header( "Content-type: text/html; charset=$wgOutputEncoding" );
 717                 /* Don't cache error pages!  They cause no end of trouble... */
 718                 header( "Cache-control: none" );
 719                 header( "Pragma: nocache" );
 720         }
 721         $msg = $wgSiteNotice;
 722         if($msg == "") $msg = wfMsgNoDB( "noconnect", $error );
 723         $text = $msg;
 724
 725         if($wgUseFileCache) {
 726                 if($wgTitle) {
 727                         $t =& $wgTitle;
 728                 } else {
 729                         if($title) {
 730                                 $t = Title::newFromURL( $title );
 731                         } elseif (@$_REQUEST['search']) {
 732                                 $search = $_REQUEST['search'];
 733                                 echo wfMsgNoDB( "searchdisabled" );
 734                                 echo wfMsgNoDB( "googlesearch", htmlspecialchars( $search ), $wgInputEncoding );
 735                                 wfAbruptExit();
 736                         } else {
 737                                 $t = Title::newFromText( wfMsgNoDB( "mainpage" ) );
 738                         }
 739                 }
 740
 741                 $cache = new CacheManager( $t );
 742                 if( $cache->isFileCached() ) {
 743                         $msg = "<p style='color: red'><b>$msg<br />\n" .
 744                                 wfMsgNoDB( "cachederror" ) . "</b></p>\n";
 745
 746                         $tag = "<div id='article'>";
 747                         $text = str_replace(
 748                                 $tag,
 749                                 $tag . $msg,
 750                                 $cache->fetchPageText() );
 751                 }
 752         }
 753
 754         echo $text;
 755         wfAbruptExit();
 756 }
 757
 758 function wfLimitResult( $limit, $offset ) {
 759         return " LIMIT ".(is_numeric($offset)?"{$offset},":"")."{$limit} ";
 760 }
 761
 762
 763 ?>