includes/db/DatabaseMssql.php

   1 <?php
   2 /**
   3  * This is the MS SQL Server Native database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  * @author Joel Penner <a-joelpe at microsoft dot com>
  23  * @author Chris Pucci <a-cpucci at microsoft dot com>
  24  * @author Ryan Biesemeyer <v-ryanbi at microsoft dot com>
  25  * @author Ryan Schmidt <skizzerz at gmail dot com>
  26  */
  27
  28 /**
  29  * @ingroup Database
  30  */
  31 class DatabaseMssql extends DatabaseBase {
  32         protected $mInsertId = null;
  33         protected $mLastResult = null;
  34         protected $mAffectedRows = null;
  35         protected $mSubqueryId = 0;
  36         protected $mScrollableCursor = true;
  37         protected $mPrepareStatements = true;
  38         protected $mBinaryColumnCache = null;
  39         protected $mBitColumnCache = null;
  40         protected $mIgnoreDupKeyErrors = false;
  41
  42         protected $mPort;
  43
  44         public function cascadingDeletes() {
  45                 return true;
  46         }
  47
  48         public function cleanupTriggers() {
  49                 return false;
  50         }
  51
  52         public function strictIPs() {
  53                 return false;
  54         }
  55
  56         public function realTimestamps() {
  57                 return false;
  58         }
  59
  60         public function implicitGroupby() {
  61                 return false;
  62         }
  63
  64         public function implicitOrderby() {
  65                 return false;
  66         }
  67
  68         public function functionalIndexes() {
  69                 return true;
  70         }
  71
  72         public function unionSupportsOrderAndLimit() {
  73                 return false;
  74         }
  75
  76         /**
  77          * Usually aborts on failure
  78          * @param string $server
  79          * @param string $user
  80          * @param string $password
  81          * @param string $dbName
  82          * @throws DBConnectionError
  83          * @return bool|DatabaseBase|null
  84          */
  85         public function open( $server, $user, $password, $dbName ) {
  86                 # Test for driver support, to avoid suppressed fatal error
  87                 if ( !function_exists( 'sqlsrv_connect' ) ) {
  88                         throw new DBConnectionError(
  89                                 $this,
  90                                 "Microsoft SQL Server Native (sqlsrv) functions missing.
  91                                 You can download the driver from: http://go.microsoft.com/fwlink/?LinkId=123470\n"
  92                         );
  93                 }
  94
  95                 global $wgDBport, $wgDBWindowsAuthentication;
  96
  97                 # e.g. the class is being loaded
  98                 if ( !strlen( $user ) ) {
  99                         return null;
 100                 }
 101
 102                 $this->close();
 103                 $this->mServer = $server;
 104                 $this->mPort = $wgDBport;
 105                 $this->mUser = $user;
 106                 $this->mPassword = $password;
 107                 $this->mDBname = $dbName;
 108
 109                 $connectionInfo = array();
 110
 111                 if ( $dbName ) {
 112                         $connectionInfo['Database'] = $dbName;
 113                 }
 114
 115                 // Decide which auth scenerio to use
 116                 // if we are using Windows auth, don't add credentials to $connectionInfo
 117                 if ( !$wgDBWindowsAuthentication ) {
 118                         $connectionInfo['UID'] = $user;
 119                         $connectionInfo['PWD'] = $password;
 120                 }
 121
 122                 wfSuppressWarnings();
 123                 $this->mConn = sqlsrv_connect( $server, $connectionInfo );
 124                 wfRestoreWarnings();
 125
 126                 if ( $this->mConn === false ) {
 127                         throw new DBConnectionError( $this, $this->lastError() );
 128                 }
 129
 130                 $this->mOpened = true;
 131
 132                 return $this->mConn;
 133         }
 134
 135         /**
 136          * Closes a database connection, if it is open
 137          * Returns success, true if already closed
 138          * @return bool
 139          */
 140         protected function closeConnection() {
 141                 return sqlsrv_close( $this->mConn );
 142         }
 143
 144         /**
 145          * @param bool|MssqlResultWrapper|resource $result
 146          * @return bool|MssqlResultWrapper
 147          */
 148         public function resultObject( $result ) {
 149                 if ( empty( $result ) ) {
 150                         return false;
 151                 } elseif ( $result instanceof MssqlResultWrapper ) {
 152                         return $result;
 153                 } elseif ( $result === true ) {
 154                         // Successful write query
 155                         return $result;
 156                 } else {
 157                         return new MssqlResultWrapper( $this, $result );
 158                 }
 159         }
 160
 161         /**
 162          * @param string $sql
 163          * @return bool|MssqlResult
 164          * @throws DBUnexpectedError
 165          */
 166         protected function doQuery( $sql ) {
 167                 global $wgDebugDumpSql;
 168                 if ( $wgDebugDumpSql ) {
 169                         wfDebug( "SQL: [$sql]\n" );
 170                 }
 171                 $this->offset = 0;
 172
 173                 // several extensions seem to think that all databases support limits
 174                 // via LIMIT N after the WHERE clause well, MSSQL uses SELECT TOP N,
 175                 // so to catch any of those extensions we'll do a quick check for a
 176                 // LIMIT clause and pass $sql through $this->LimitToTopN() which parses
 177                 // the limit clause and passes the result to $this->limitResult();
 178                 if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) {
 179                         // massage LIMIT -> TopN
 180                         $sql = $this->LimitToTopN( $sql );
 181                 }
 182
 183                 // MSSQL doesn't have EXTRACT(epoch FROM XXX)
 184                 if ( preg_match( '#\bEXTRACT\s*?\(\s*?EPOCH\s+FROM\b#i', $sql, $matches ) ) {
 185                         // This is same as UNIX_TIMESTAMP, we need to calc # of seconds from 1970
 186                         $sql = str_replace( $matches[0], "DATEDIFF(s,CONVERT(datetime,'1/1/1970'),", $sql );
 187                 }
 188
 189                 // perform query
 190
 191                 // SQLSRV_CURSOR_STATIC is slower than SQLSRV_CURSOR_CLIENT_BUFFERED (one of the two is
 192                 // needed if we want to be able to seek around the result set), however CLIENT_BUFFERED
 193                 // has a bug in the sqlsrv driver where wchar_t types (such as nvarchar) that are empty
 194                 // strings make php throw a fatal error "Severe error translating Unicode"
 195                 if ( $this->mScrollableCursor ) {
 196                         $scrollArr = array( 'Scrollable' => SQLSRV_CURSOR_STATIC );
 197                 } else {
 198                         $scrollArr = array();
 199                 }
 200
 201                 if ( $this->mPrepareStatements ) {
 202                         // we do prepare + execute so we can get its field metadata for later usage if desired
 203                         $stmt = sqlsrv_prepare( $this->mConn, $sql, array(), $scrollArr );
 204                         $success = sqlsrv_execute( $stmt );
 205                 } else {
 206                         $stmt = sqlsrv_query( $this->mConn, $sql, array(), $scrollArr );
 207                         $success = (bool)$stmt;
 208                 }
 209
 210                 if ( $this->mIgnoreDupKeyErrors ) {
 211                         // ignore duplicate key errors, but nothing else
 212                         // this emulates INSERT IGNORE in MySQL
 213                         if ( $success === false ) {
 214                                 $errors = sqlsrv_errors( SQLSRV_ERR_ERRORS );
 215                                 $success = true;
 216
 217                                 foreach ( $errors as $err ) {
 218                                         if ( $err['SQLSTATE'] == '23000' && $err['code'] == '2601' ) {
 219                                                 continue; // duplicate key error
 220                                         } elseif ( $err['SQLSTATE'] == '01000' && $err['code'] == '3621' ) {
 221                                                 continue; // generic "the statement has been terminated" error
 222                                         }
 223
 224                                         $success = false; // getting here means we got an error we weren't expecting
 225                                         break;
 226                                 }
 227
 228                                 if ( $success ) {
 229                                         $this->mAffectedRows = 0;
 230                                         return true;
 231                                 }
 232                         }
 233                 }
 234
 235                 if ( $success === false ) {
 236                         return false;
 237                 }
 238                 // remember number of rows affected
 239                 $this->mAffectedRows = sqlsrv_rows_affected( $stmt );
 240
 241                 return $stmt;
 242         }
 243
 244         public function freeResult( $res ) {
 245                 if ( $res instanceof ResultWrapper ) {
 246                         $res = $res->result;
 247                 }
 248
 249                 sqlsrv_free_stmt( $res );
 250         }
 251
 252         /**
 253          * @param MssqlResultWrapper $res
 254          * @return stdClass
 255          */
 256         public function fetchObject( $res ) {
 257                 // $res is expected to be an instance of MssqlResultWrapper here
 258                 return $res->fetchObject();
 259         }
 260
 261         /**
 262          * @param MssqlResultWrapper $res
 263          * @return array
 264          */
 265         public function fetchRow( $res ) {
 266                 return $res->fetchRow();
 267         }
 268
 269         /**
 270          * @param mixed $res
 271          * @return int
 272          */
 273         public function numRows( $res ) {
 274                 if ( $res instanceof ResultWrapper ) {
 275                         $res = $res->result;
 276                 }
 277
 278                 return sqlsrv_num_rows( $res );
 279         }
 280
 281         /**
 282          * @param mixed $res
 283          * @return int
 284          */
 285         public function numFields( $res ) {
 286                 if ( $res instanceof ResultWrapper ) {
 287                         $res = $res->result;
 288                 }
 289
 290                 return sqlsrv_num_fields( $res );
 291         }
 292
 293         /**
 294          * @param mixed $res
 295          * @param int $n
 296          * @return int
 297          */
 298         public function fieldName( $res, $n ) {
 299                 if ( $res instanceof ResultWrapper ) {
 300                         $res = $res->result;
 301                 }
 302
 303                 $metadata = sqlsrv_field_metadata( $res );
 304                 return $metadata[$n]['Name'];
 305         }
 306
 307         /**
 308          * This must be called after nextSequenceVal
 309          * @return int|null
 310          */
 311         public function insertId() {
 312                 return $this->mInsertId;
 313         }
 314
 315         /**
 316          * @param MssqlResultWrapper $res
 317          * @param int $row
 318          * @return bool
 319          */
 320         public function dataSeek( $res, $row ) {
 321                 return $res->seek( $row );
 322         }
 323
 324         /**
 325          * @return string
 326          */
 327         public function lastError() {
 328                 $strRet = '';
 329                 $retErrors = sqlsrv_errors( SQLSRV_ERR_ALL );
 330                 if ( $retErrors != null ) {
 331                         foreach ( $retErrors as $arrError ) {
 332                                 $strRet .= $this->formatError( $arrError ) . "\n";
 333                         }
 334                 } else {
 335                         $strRet = "No errors found";
 336                 }
 337
 338                 return $strRet;
 339         }
 340
 341         /**
 342          * @return string
 343          */
 344         private function formatError( $err ) {
 345                 return '[SQLSTATE ' . $err['SQLSTATE'] . '][Error Code ' . $err['code'] . ']' . $err['message'];
 346         }
 347
 348         /**
 349          * @return string
 350          */
 351         public function lastErrno() {
 352                 $err = sqlsrv_errors( SQLSRV_ERR_ALL );
 353                 if ( $err !== null && isset( $err[0] ) ) {
 354                         return $err[0]['code'];
 355                 } else {
 356                         return 0;
 357                 }
 358         }
 359
 360         /**
 361          * @return int
 362          */
 363         public function affectedRows() {
 364                 return $this->mAffectedRows;
 365         }
 366
 367         /**
 368          * SELECT wrapper
 369          *
 370          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 371          * @param mixed $vars Array or string, field name(s) to be retrieved
 372          * @param mixed $conds Array or string, condition(s) for WHERE
 373          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 374          * @param array $options Associative array of options (e.g.
 375          *   array('GROUP BY' => 'page_title')), see Database::makeSelectOptions
 376          *   code for list of supported stuff
 377          * @param array $join_conds Associative array of table join conditions
 378          *   (optional) (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 379          * @return mixed Database result resource (feed to Database::fetchObject
 380          *   or whatever), or false on failure
 381          */
 382         public function select( $table, $vars, $conds = '', $fname = __METHOD__,
 383                 $options = array(), $join_conds = array()
 384         ) {
 385                 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 386                 if ( isset( $options['EXPLAIN'] ) ) {
 387                         try {
 388                                 $this->mScrollableCursor = false;
 389                                 $this->mPrepareStatements = false;
 390                                 $this->query( "SET SHOWPLAN_ALL ON" );
 391                                 $ret = $this->query( $sql, $fname );
 392                                 $this->query( "SET SHOWPLAN_ALL OFF" );
 393                         } catch ( DBQueryError $dqe ) {
 394                                 if ( isset( $options['FOR COUNT'] ) ) {
 395                                         // likely don't have privs for SHOWPLAN, so run a select count instead
 396                                         $this->query( "SET SHOWPLAN_ALL OFF" );
 397                                         unset( $options['EXPLAIN'] );
 398                                         $ret = $this->select(
 399                                                 $table,
 400                                                 'COUNT(*) AS EstimateRows',
 401                                                 $conds,
 402                                                 $fname,
 403                                                 $options,
 404                                                 $join_conds
 405                                         );
 406                                 } else {
 407                                         // someone actually wanted the query plan instead of an est row count
 408                                         // let them know of the error
 409                                         $this->mScrollableCursor = true;
 410                                         $this->mPrepareStatements = true;
 411                                         throw $dqe;
 412                                 }
 413                         }
 414                         $this->mScrollableCursor = true;
 415                         $this->mPrepareStatements = true;
 416
 417                         return $ret;
 418                 }
 419
 420                 return $this->query( $sql, $fname );
 421         }
 422
 423         /**
 424          * SELECT wrapper
 425          *
 426          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 427          * @param mixed $vars Array or string, field name(s) to be retrieved
 428          * @param mixed $conds Array or string, condition(s) for WHERE
 429          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 430          * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 431          *   see Database::makeSelectOptions code for list of supported stuff
 432          * @param array $join_conds Associative array of table join conditions (optional)
 433          *    (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 434          * @return string The SQL text
 435          */
 436         public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
 437                 $options = array(), $join_conds = array()
 438         ) {
 439                 if ( isset( $options['EXPLAIN'] ) ) {
 440                         unset( $options['EXPLAIN'] );
 441                 }
 442
 443                 $sql = parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 444
 445                 // try to rewrite aggregations of bit columns (currently MAX and MIN)
 446                 if ( strpos( $sql, 'MAX(' ) !== false || strpos( $sql, 'MIN(' ) !== false ) {
 447                         $bitColumns = array();
 448                         if ( is_array( $table ) ) {
 449                                 foreach ( $table as $t ) {
 450                                         $bitColumns += $this->getBitColumns( $this->tableName( $t ) );
 451                                 }
 452                         } else {
 453                                 $bitColumns = $this->getBitColumns( $this->tableName( $table ) );
 454                         }
 455
 456                         foreach ( $bitColumns as $col => $info ) {
 457                                 $replace = array(
 458                                         "MAX({$col})" => "MAX(CAST({$col} AS tinyint))",
 459                                         "MIN({$col})" => "MIN(CAST({$col} AS tinyint))",
 460                                 );
 461                                 $sql = str_replace( array_keys( $replace ), array_values( $replace ), $sql );
 462                         }
 463                 }
 464
 465                 return $sql;
 466         }
 467
 468         public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
 469                 $fname = __METHOD__
 470         ) {
 471                 $this->mScrollableCursor = false;
 472                 try {
 473                         parent::deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname );
 474                 } catch ( Exception $e ) {
 475                         $this->mScrollableCursor = true;
 476                         throw $e;
 477                 }
 478                 $this->mScrollableCursor = true;
 479         }
 480
 481         public function delete( $table, $conds, $fname = __METHOD__ ) {
 482                 $this->mScrollableCursor = false;
 483                 try {
 484                         parent::delete( $table, $conds, $fname );
 485                 } catch ( Exception $e ) {
 486                         $this->mScrollableCursor = true;
 487                         throw $e;
 488                 }
 489                 $this->mScrollableCursor = true;
 490         }
 491
 492         /**
 493          * Estimate rows in dataset
 494          * Returns estimated count, based on SHOWPLAN_ALL output
 495          * This is not necessarily an accurate estimate, so use sparingly
 496          * Returns -1 if count cannot be found
 497          * Takes same arguments as Database::select()
 498          * @param string $table
 499          * @param string $vars
 500          * @param string $conds
 501          * @param string $fname
 502          * @param array $options
 503          * @return int
 504          */
 505         public function estimateRowCount( $table, $vars = '*', $conds = '',
 506                 $fname = __METHOD__, $options = array()
 507         ) {
 508                 // http://msdn2.microsoft.com/en-us/library/aa259203.aspx
 509                 $options['EXPLAIN'] = true;
 510                 $options['FOR COUNT'] = true;
 511                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 512
 513                 $rows = -1;
 514                 if ( $res ) {
 515                         $row = $this->fetchRow( $res );
 516
 517                         if ( isset( $row['EstimateRows'] ) ) {
 518                                 $rows = $row['EstimateRows'];
 519                         }
 520                 }
 521
 522                 return $rows;
 523         }
 524
 525         /**
 526          * Returns information about an index
 527          * If errors are explicitly ignored, returns NULL on failure
 528          * @param string $table
 529          * @param string $index
 530          * @param string $fname
 531          * @return array|bool|null
 532          */
 533         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 534                 # This does not return the same info as MYSQL would, but that's OK
 535                 # because MediaWiki never uses the returned value except to check for
 536                 # the existance of indexes.
 537                 $sql = "sp_helpindex '" . $table . "'";
 538                 $res = $this->query( $sql, $fname );
 539                 if ( !$res ) {
 540                         return null;
 541                 }
 542
 543                 $result = array();
 544                 foreach ( $res as $row ) {
 545                         if ( $row->index_name == $index ) {
 546                                 $row->Non_unique = !stristr( $row->index_description, "unique" );
 547                                 $cols = explode( ", ", $row->index_keys );
 548                                 foreach ( $cols as $col ) {
 549                                         $row->Column_name = trim( $col );
 550                                         $result[] = clone $row;
 551                                 }
 552                         } elseif ( $index == 'PRIMARY' && stristr( $row->index_description, 'PRIMARY' ) ) {
 553                                 $row->Non_unique = 0;
 554                                 $cols = explode( ", ", $row->index_keys );
 555                                 foreach ( $cols as $col ) {
 556                                         $row->Column_name = trim( $col );
 557                                         $result[] = clone $row;
 558                                 }
 559                         }
 560                 }
 561
 562                 return empty( $result ) ? false : $result;
 563         }
 564
 565         /**
 566          * INSERT wrapper, inserts an array into a table
 567          *
 568          * $arrToInsert may be a single associative array, or an array of these with numeric keys, for
 569          * multi-row insert.
 570          *
 571          * Usually aborts on failure
 572          * If errors are explicitly ignored, returns success
 573          * @param string $table
 574          * @param array $arrToInsert
 575          * @param string $fname
 576          * @param array $options
 577          * @throws DBQueryError
 578          * @return bool
 579          */
 580         public function insert( $table, $arrToInsert, $fname = __METHOD__, $options = array() ) {
 581                 # No rows to insert, easy just return now
 582                 if ( !count( $arrToInsert ) ) {
 583                         return true;
 584                 }
 585
 586                 if ( !is_array( $options ) ) {
 587                         $options = array( $options );
 588                 }
 589
 590                 $table = $this->tableName( $table );
 591
 592                 if ( !( isset( $arrToInsert[0] ) && is_array( $arrToInsert[0] ) ) ) { // Not multi row
 593                         $arrToInsert = array( 0 => $arrToInsert ); // make everything multi row compatible
 594                 }
 595
 596                 // We know the table we're inserting into, get its identity column
 597                 $identity = null;
 598                 // strip matching square brackets and the db/schema from table name
 599                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
 600                 $tableRaw = array_pop( $tableRawArr );
 601                 $res = $this->doQuery(
 602                         "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS " .
 603                                 "WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'"
 604                 );
 605                 if ( $res && sqlsrv_has_rows( $res ) ) {
 606                         // There is an identity for this table.
 607                         $identityArr = sqlsrv_fetch_array( $res, SQLSRV_FETCH_ASSOC );
 608                         $identity = array_pop( $identityArr );
 609                 }
 610                 sqlsrv_free_stmt( $res );
 611
 612                 // Determine binary/varbinary fields so we can encode data as a hex string like 0xABCDEF
 613                 $binaryColumns = $this->getBinaryColumns( $table );
 614
 615                 foreach ( $arrToInsert as $a ) {
 616                         // start out with empty identity column, this is so we can return
 617                         // it as a result of the insert logic
 618                         $sqlPre = '';
 619                         $sqlPost = '';
 620                         $identityClause = '';
 621
 622                         // if we have an identity column
 623                         if ( $identity ) {
 624                                 // iterate through
 625                                 foreach ( $a as $k => $v ) {
 626                                         if ( $k == $identity ) {
 627                                                 if ( !is_null( $v ) ) {
 628                                                         // there is a value being passed to us,
 629                                                         // we need to turn on and off inserted identity
 630                                                         $sqlPre = "SET IDENTITY_INSERT $table ON;";
 631                                                         $sqlPost = ";SET IDENTITY_INSERT $table OFF;";
 632                                                 } else {
 633                                                         // we can't insert NULL into an identity column,
 634                                                         // so remove the column from the insert.
 635                                                         unset( $a[$k] );
 636                                                 }
 637                                         }
 638                                 }
 639
 640                                 // we want to output an identity column as result
 641                                 $identityClause = "OUTPUT INSERTED.$identity ";
 642                         }
 643
 644                         $keys = array_keys( $a );
 645
 646                         // INSERT IGNORE is not supported by SQL Server
 647                         // remove IGNORE from options list and set ignore flag to true
 648                         $ignoreClause = false;
 649                         if ( in_array( 'IGNORE', $options ) ) {
 650                                 $options = array_diff( $options, array( 'IGNORE' ) );
 651                                 $this->mIgnoreDupKeyErrors = true;
 652                         }
 653
 654                         // Build the actual query
 655                         $sql = $sqlPre . 'INSERT ' . implode( ' ', $options ) .
 656                                 " INTO $table (" . implode( ',', $keys ) . ") $identityClause VALUES (";
 657
 658                         $first = true;
 659                         foreach ( $a as $key => $value ) {
 660                                 if ( isset( $binaryColumns[$key] ) ) {
 661                                         $value = new MssqlBlob( $value );
 662                                 }
 663                                 if ( $first ) {
 664                                         $first = false;
 665                                 } else {
 666                                         $sql .= ',';
 667                                 }
 668                                 if ( is_null( $value ) ) {
 669                                         $sql .= 'null';
 670                                 } elseif ( is_array( $value ) || is_object( $value ) ) {
 671                                         if ( is_object( $value ) && $value instanceof Blob ) {
 672                                                 $sql .= $this->addQuotes( $value );
 673                                         } else {
 674                                                 $sql .= $this->addQuotes( serialize( $value ) );
 675                                         }
 676                                 } else {
 677                                         $sql .= $this->addQuotes( $value );
 678                                 }
 679                         }
 680                         $sql .= ')' . $sqlPost;
 681
 682                         // Run the query
 683                         $this->mScrollableCursor = false;
 684                         try {
 685                                 $ret = $this->query( $sql );
 686                         } catch ( Exception $e ) {
 687                                 $this->mScrollableCursor = true;
 688                                 $this->mIgnoreDupKeyErrors = false;
 689                                 throw $e;
 690                         }
 691                         $this->mScrollableCursor = true;
 692                         $this->mIgnoreDupKeyErrors = false;
 693
 694                         if ( !is_null( $identity ) ) {
 695                                 // then we want to get the identity column value we were assigned and save it off
 696                                 $row = $ret->fetchObject();
 697                                 $this->mInsertId = $row->$identity;
 698                         }
 699                 }
 700
 701                 return $ret;
 702         }
 703
 704         /**
 705          * INSERT SELECT wrapper
 706          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 707          * Source items may be literals rather than field names, but strings should
 708          * be quoted with Database::addQuotes().
 709          * @param string $destTable
 710          * @param array|string $srcTable May be an array of tables.
 711          * @param array $varMap
 712          * @param array $conds May be "*" to copy the whole table.
 713          * @param string $fname
 714          * @param array $insertOptions
 715          * @param array $selectOptions
 716          * @throws DBQueryError
 717          * @return null|ResultWrapper
 718          */
 719         public function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 720                 $insertOptions = array(), $selectOptions = array()
 721         ) {
 722                 $this->mScrollableCursor = false;
 723                 try {
 724                         $ret = parent::insertSelect(
 725                                 $destTable,
 726                                 $srcTable,
 727                                 $varMap,
 728                                 $conds,
 729                                 $fname,
 730                                 $insertOptions,
 731                                 $selectOptions
 732                         );
 733                 } catch ( Exception $e ) {
 734                         $this->mScrollableCursor = true;
 735                         throw $e;
 736                 }
 737                 $this->mScrollableCursor = true;
 738
 739                 return $ret;
 740         }
 741
 742         /**
 743          * UPDATE wrapper. Takes a condition array and a SET array.
 744          *
 745          * @param string $table name of the table to UPDATE. This will be passed through
 746          *                DatabaseBase::tableName().
 747          *
 748          * @param array $values An array of values to SET. For each array element,
 749          *                the key gives the field name, and the value gives the data
 750          *                to set that field to. The data will be quoted by
 751          *                DatabaseBase::addQuotes().
 752          *
 753          * @param array $conds An array of conditions (WHERE). See
 754          *                DatabaseBase::select() for the details of the format of
 755          *                condition arrays. Use '*' to update all rows.
 756          *
 757          * @param string $fname The function name of the caller (from __METHOD__),
 758          *                for logging and profiling.
 759          *
 760          * @param array $options An array of UPDATE options, can be:
 761          *                   - IGNORE: Ignore unique key conflicts
 762          *                   - LOW_PRIORITY: MySQL-specific, see MySQL manual.
 763          * @return bool
 764          */
 765         function update( $table, $values, $conds, $fname = __METHOD__, $options = array() ) {
 766                 $table = $this->tableName( $table );
 767                 $binaryColumns = $this->getBinaryColumns( $table );
 768
 769                 $opts = $this->makeUpdateOptions( $options );
 770                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET, $binaryColumns );
 771
 772                 if ( $conds !== array() && $conds !== '*' ) {
 773                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND, $binaryColumns );
 774                 }
 775
 776                 $this->mScrollableCursor = false;
 777                 try {
 778                         $ret = $this->query( $sql );
 779                 } catch ( Exception $e ) {
 780                         $this->mScrollableCursor = true;
 781                         throw $e;
 782                 }
 783                 $this->mScrollableCursor = true;
 784                 return true;
 785         }
 786
 787         /**
 788          * Makes an encoded list of strings from an array
 789          * @param array $a containing the data
 790          * @param int $mode Constant
 791          *      - LIST_COMMA:          comma separated, no field names
 792          *      - LIST_AND:            ANDed WHERE clause (without the WHERE). See
 793          *        the documentation for $conds in DatabaseBase::select().
 794          *      - LIST_OR:             ORed WHERE clause (without the WHERE)
 795          *      - LIST_SET:            comma separated with field names, like a SET clause
 796          *      - LIST_NAMES:          comma separated field names
 797          * @param array $binaryColumns Contains a list of column names that are binary types
 798          *      This is a custom parameter only present for MS SQL.
 799          *
 800          * @throws MWException|DBUnexpectedError
 801          * @return string
 802          */
 803         public function makeList( $a, $mode = LIST_COMMA, $binaryColumns = array() ) {
 804                 if ( !is_array( $a ) ) {
 805                         throw new DBUnexpectedError( $this,
 806                                 'DatabaseBase::makeList called with incorrect parameters' );
 807                 }
 808
 809                 $first = true;
 810                 $list = '';
 811
 812                 foreach ( $a as $field => $value ) {
 813                         if ( $mode != LIST_NAMES && isset( $binaryColumns[$field] ) ) {
 814                                 if ( is_array( $value ) ) {
 815                                         foreach ( $value as &$v ) {
 816                                                 $v = new MssqlBlob( $v );
 817                                         }
 818                                 } else {
 819                                         $value = new MssqlBlob( $value );
 820                                 }
 821                         }
 822
 823                         if ( !$first ) {
 824                                 if ( $mode == LIST_AND ) {
 825                                         $list .= ' AND ';
 826                                 } elseif ( $mode == LIST_OR ) {
 827                                         $list .= ' OR ';
 828                                 } else {
 829                                         $list .= ',';
 830                                 }
 831                         } else {
 832                                 $first = false;
 833                         }
 834
 835                         if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
 836                                 $list .= "($value)";
 837                         } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
 838                                 $list .= "$value";
 839                         } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
 840                                 if ( count( $value ) == 0 ) {
 841                                         throw new MWException( __METHOD__ . ": empty input for field $field" );
 842                                 } elseif ( count( $value ) == 1 ) {
 843                                         // Special-case single values, as IN isn't terribly efficient
 844                                         // Don't necessarily assume the single key is 0; we don't
 845                                         // enforce linear numeric ordering on other arrays here.
 846                                         $value = array_values( $value );
 847                                         $list .= $field . " = " . $this->addQuotes( $value[0] );
 848                                 } else {
 849                                         $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
 850                                 }
 851                         } elseif ( $value === null ) {
 852                                 if ( $mode == LIST_AND || $mode == LIST_OR ) {
 853                                         $list .= "$field IS ";
 854                                 } elseif ( $mode == LIST_SET ) {
 855                                         $list .= "$field = ";
 856                                 }
 857                                 $list .= 'NULL';
 858                         } else {
 859                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
 860                                         $list .= "$field = ";
 861                                 }
 862                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
 863                         }
 864                 }
 865
 866                 return $list;
 867         }
 868
 869         /**
 870          * @param string $table
 871          * @param string $field
 872          * @return int Returns the size of a text field, or -1 for "unlimited"
 873          */
 874         public function textFieldSize( $table, $field ) {
 875                 $table = $this->tableName( $table );
 876                 $sql = "SELECT CHARACTER_MAXIMUM_LENGTH,DATA_TYPE FROM INFORMATION_SCHEMA.Columns
 877                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'";
 878                 $res = $this->query( $sql );
 879                 $row = $this->fetchRow( $res );
 880                 $size = -1;
 881                 if ( strtolower( $row['DATA_TYPE'] ) != 'text' ) {
 882                         $size = $row['CHARACTER_MAXIMUM_LENGTH'];
 883                 }
 884
 885                 return $size;
 886         }
 887
 888         /**
 889          * Construct a LIMIT query with optional offset
 890          * This is used for query pages
 891          *
 892          * @param string $sql SQL query we will append the limit too
 893          * @param int $limit The SQL limit
 894          * @param bool|int $offset The SQL offset (default false)
 895          * @return array|string
 896          */
 897         public function limitResult( $sql, $limit, $offset = false ) {
 898                 if ( $offset === false || $offset == 0 ) {
 899                         if ( strpos( $sql, "SELECT" ) === false ) {
 900                                 return "TOP {$limit} " . $sql;
 901                         } else {
 902                                 return preg_replace( '/\bSELECT(\s+DISTINCT)?\b/Dsi',
 903                                         'SELECT$1 TOP ' . $limit, $sql, 1 );
 904                         }
 905                 } else {
 906                         // This one is fun, we need to pull out the select list as well as any ORDER BY clause
 907                         $select = $orderby = array();
 908                         $s1 = preg_match( '#SELECT\s+(.+?)\s+FROM#Dis', $sql, $select );
 909                         $s2 = preg_match( '#(ORDER BY\s+.+?)(\s*FOR XML .*)?$#Dis', $sql, $orderby );
 910                         $overOrder = $postOrder = '';
 911                         $first = $offset + 1;
 912                         $last = $offset + $limit;
 913                         $sub1 = 'sub_' . $this->mSubqueryId;
 914                         $sub2 = 'sub_' . ( $this->mSubqueryId + 1 );
 915                         $this->mSubqueryId += 2;
 916                         if ( !$s1 ) {
 917                                 // wat
 918                                 throw new DBUnexpectedError( $this, "Attempting to LIMIT a non-SELECT query\n" );
 919                         }
 920                         if ( !$s2 ) {
 921                                 // no ORDER BY
 922                                 $overOrder = 'ORDER BY 1';
 923                         } else {
 924                                 if ( !isset( $orderby[2] ) || !$orderby[2] ) {
 925                                         // don't need to strip it out if we're using a FOR XML clause
 926                                         $sql = str_replace( $orderby[1], '', $sql );
 927                                 }
 928                                 $overOrder = $orderby[1];
 929                                 $postOrder = ' ' . $overOrder;
 930                         }
 931                         $sql = "SELECT {$select[1]}
 932                                         FROM (
 933                                                 SELECT ROW_NUMBER() OVER({$overOrder}) AS rowNumber, *
 934                                                 FROM ({$sql}) {$sub1}
 935                                         ) {$sub2}
 936                                         WHERE rowNumber BETWEEN {$first} AND {$last}{$postOrder}";
 937
 938                         return $sql;
 939                 }
 940         }
 941
 942         /**
 943          * If there is a limit clause, parse it, strip it, and pass the remaining
 944          * SQL through limitResult() with the appropriate parameters. Not the
 945          * prettiest solution, but better than building a whole new parser. This
 946          * exists becase there are still too many extensions that don't use dynamic
 947          * sql generation.
 948          *
 949          * @param string $sql
 950          * @return array|mixed|string
 951          */
 952         public function LimitToTopN( $sql ) {
 953                 // Matches: LIMIT {[offset,] row_count | row_count OFFSET offset}
 954                 $pattern = '/\bLIMIT\s+((([0-9]+)\s*,\s*)?([0-9]+)(\s+OFFSET\s+([0-9]+))?)/i';
 955                 if ( preg_match( $pattern, $sql, $matches ) ) {
 956                         // row_count = $matches[4]
 957                         $row_count = $matches[4];
 958                         // offset = $matches[3] OR $matches[6]
 959                         $offset = $matches[3] or
 960                         $offset = $matches[6] or
 961                         $offset = false;
 962
 963                         // strip the matching LIMIT clause out
 964                         $sql = str_replace( $matches[0], '', $sql );
 965
 966                         return $this->limitResult( $sql, $row_count, $offset );
 967                 }
 968
 969                 return $sql;
 970         }
 971
 972         /**
 973          * @return string Wikitext of a link to the server software's web site
 974          */
 975         public function getSoftwareLink() {
 976                 return "[{{int:version-db-mssql-url}} MS SQL Server]";
 977         }
 978
 979         /**
 980          * @return string Version information from the database
 981          */
 982         public function getServerVersion() {
 983                 $server_info = sqlsrv_server_info( $this->mConn );
 984                 $version = 'Error';
 985                 if ( isset( $server_info['SQLServerVersion'] ) ) {
 986                         $version = $server_info['SQLServerVersion'];
 987                 }
 988
 989                 return $version;
 990         }
 991
 992         /**
 993          * @param string $table
 994          * @param string $fname
 995          * @param bool $schema
 996          * @return bool
 997          */
 998         public function tableExists( $table, $fname = __METHOD__, $schema = false ) {
 999                 $res = sqlsrv_query( $this->mConn, "SELECT * FROM information_schema.tables
1000                         WHERE table_type='BASE TABLE' AND table_name = '$table'" );
1001                 if ( $res === false ) {
1002                         print "Error in tableExists query: " . $this->lastError();
1003
1004                         return false;
1005                 }
1006                 if ( sqlsrv_fetch( $res ) ) {
1007                         return true;
1008                 } else {
1009                         return false;
1010                 }
1011         }
1012
1013         /**
1014          * Query whether a given column exists in the mediawiki schema
1015          * @param string $table
1016          * @param string $field
1017          * @param string $fname
1018          * @return bool
1019          */
1020         public function fieldExists( $table, $field, $fname = __METHOD__ ) {
1021                 $table = $this->tableName( $table );
1022                 $res = sqlsrv_query( $this->mConn, "SELECT DATA_TYPE FROM INFORMATION_SCHEMA.Columns
1023                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1024                 if ( $res === false ) {
1025                         print "Error in fieldExists query: " . $this->lastError();
1026
1027                         return false;
1028                 }
1029                 if ( sqlsrv_fetch( $res ) ) {
1030                         return true;
1031                 } else {
1032                         return false;
1033                 }
1034         }
1035
1036         public function fieldInfo( $table, $field ) {
1037                 $table = $this->tableName( $table );
1038                 $res = sqlsrv_query( $this->mConn, "SELECT * FROM INFORMATION_SCHEMA.Columns
1039                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1040                 if ( $res === false ) {
1041                         print "Error in fieldInfo query: " . $this->lastError();
1042
1043                         return false;
1044                 }
1045                 $meta = $this->fetchRow( $res );
1046                 if ( $meta ) {
1047                         return new MssqlField( $meta );
1048                 }
1049
1050                 return false;
1051         }
1052
1053         /**
1054          * Begin a transaction, committing any previously open transaction
1055          */
1056         protected function doBegin( $fname = __METHOD__ ) {
1057                 sqlsrv_begin_transaction( $this->mConn );
1058                 $this->mTrxLevel = 1;
1059         }
1060
1061         /**
1062          * End a transaction
1063          */
1064         protected function doCommit( $fname = __METHOD__ ) {
1065                 sqlsrv_commit( $this->mConn );
1066                 $this->mTrxLevel = 0;
1067         }
1068
1069         /**
1070          * Rollback a transaction.
1071          * No-op on non-transactional databases.
1072          */
1073         protected function doRollback( $fname = __METHOD__ ) {
1074                 sqlsrv_rollback( $this->mConn );
1075                 $this->mTrxLevel = 0;
1076         }
1077
1078         /**
1079          * Escapes a identifier for use inm SQL.
1080          * Throws an exception if it is invalid.
1081          * Reference: http://msdn.microsoft.com/en-us/library/aa224033%28v=SQL.80%29.aspx
1082          * @param string $identifier
1083          * @throws MWException
1084          * @return string
1085          */
1086         private function escapeIdentifier( $identifier ) {
1087                 if ( strlen( $identifier ) == 0 ) {
1088                         throw new MWException( "An identifier must not be empty" );
1089                 }
1090                 if ( strlen( $identifier ) > 128 ) {
1091                         throw new MWException( "The identifier '$identifier' is too long (max. 128)" );
1092                 }
1093                 if ( ( strpos( $identifier, '[' ) !== false )
1094                         || ( strpos( $identifier, ']' ) !== false )
1095                 ) {
1096                         // It may be allowed if you quoted with double quotation marks, but
1097                         // that would break if QUOTED_IDENTIFIER is OFF
1098                         throw new MWException( "Square brackets are not allowed in '$identifier'" );
1099                 }
1100
1101                 return "[$identifier]";
1102         }
1103
1104         /**
1105          * @param string $s
1106          * @return string
1107          */
1108         public function strencode( $s ) { # Should not be called by us
1109                 return str_replace( "'", "''", $s );
1110         }
1111
1112         /**
1113          * @param string $s
1114          * @return string
1115          */
1116         public function addQuotes( $s ) {
1117                 if ( $s instanceof MssqlBlob ) {
1118                         return $s->fetch();
1119                 } elseif ( $s instanceof Blob ) {
1120                         // this shouldn't really ever be called, but it's here if needed
1121                         // (and will quite possibly make the SQL error out)
1122                         $blob = new MssqlBlob( $s->fetch() );
1123                         return $blob->fetch();
1124                 } else {
1125                         if ( is_bool( $s ) ) {
1126                                 $s = $s ? 1 : 0;
1127                         }
1128                         return parent::addQuotes( $s );
1129                 }
1130         }
1131
1132         /**
1133          * @param string $s
1134          * @return string
1135          */
1136         public function addIdentifierQuotes( $s ) {
1137                 // http://msdn.microsoft.com/en-us/library/aa223962.aspx
1138                 return '[' . $s . ']';
1139         }
1140
1141         /**
1142          * @param string $name
1143          * @return bool
1144          */
1145         public function isQuotedIdentifier( $name ) {
1146                 return strlen( $name ) && $name[0] == '[' && substr( $name, -1, 1 ) == ']';
1147         }
1148
1149         /**
1150          * @param string $db
1151          * @return bool
1152          */
1153         public function selectDB( $db ) {
1154                 try {
1155                         $this->mDBname = $db;
1156                         $this->query( "USE $db" );
1157                         return true;
1158                 } catch ( Exception $e ) {
1159                         return false;
1160                 }
1161         }
1162
1163         /**
1164          * @param array $options an associative array of options to be turned into
1165          *   an SQL query, valid keys are listed in the function.
1166          * @return array
1167          */
1168         public function makeSelectOptions( $options ) {
1169                 $tailOpts = '';
1170                 $startOpts = '';
1171
1172                 $noKeyOptions = array();
1173                 foreach ( $options as $key => $option ) {
1174                         if ( is_numeric( $key ) ) {
1175                                 $noKeyOptions[$option] = true;
1176                         }
1177                 }
1178
1179                 $tailOpts .= $this->makeGroupByWithHaving( $options );
1180
1181                 $tailOpts .= $this->makeOrderBy( $options );
1182
1183                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1184                         $startOpts .= 'DISTINCT';
1185                 }
1186
1187                 if ( isset( $noKeyOptions['FOR XML'] ) ) {
1188                         // used in group concat field emulation
1189                         $tailOpts .= " FOR XML PATH('')";
1190                 }
1191
1192                 // we want this to be compatible with the output of parent::makeSelectOptions()
1193                 return array( $startOpts, '', $tailOpts, '' );
1194         }
1195
1196         /**
1197          * Get the type of the DBMS, as it appears in $wgDBtype.
1198          * @return string
1199          */
1200         public function getType() {
1201                 return 'mssql';
1202         }
1203
1204         /**
1205          * @param array $stringList
1206          * @return string
1207          */
1208         public function buildConcat( $stringList ) {
1209                 return implode( ' + ', $stringList );
1210         }
1211
1212         /**
1213          * Build a GROUP_CONCAT or equivalent statement for a query.
1214          * MS SQL doesn't have GROUP_CONCAT so we emulate it with other stuff (and boy is it nasty)
1215          *
1216          * This is useful for combining a field for several rows into a single string.
1217          * NULL values will not appear in the output, duplicated values will appear,
1218          * and the resulting delimiter-separated values have no defined sort order.
1219          * Code using the results may need to use the PHP unique() or sort() methods.
1220          *
1221          * @param string $delim Glue to bind the results together
1222          * @param string|array $table Table name
1223          * @param string $field Field name
1224          * @param string|array $conds Conditions
1225          * @param string|array $join_conds Join conditions
1226          * @return String SQL text
1227          * @since 1.23
1228          */
1229         public function buildGroupConcatField( $delim, $table, $field, $conds = '',
1230                 $join_conds = array()
1231         ) {
1232                 $gcsq = 'gcsq_' . $this->mSubqueryId;
1233                 $this->mSubqueryId++;
1234
1235                 $delimLen = strlen( $delim );
1236                 $fld = "{$field} + {$this->addQuotes( $delim )}";
1237                 $sql = "(SELECT LEFT({$field}, LEN({$field}) - {$delimLen}) FROM ("
1238                         . $this->selectSQLText( $table, $fld, $conds, null, array( 'FOR XML' ), $join_conds )
1239                         . ") {$gcsq} ({$field}))";
1240
1241                 return $sql;
1242         }
1243
1244         /**
1245          * @return string
1246          */
1247         public function getSearchEngine() {
1248                 return "SearchMssql";
1249         }
1250
1251         /**
1252          * Returns an associative array for fields that are of type varbinary, binary, or image
1253          * $table can be either a raw table name or passed through tableName() first
1254          * @param string $table
1255          * @return array
1256          */
1257         private function getBinaryColumns( $table ) {
1258                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1259                 $tableRaw = array_pop( $tableRawArr );
1260
1261                 if ( $this->mBinaryColumnCache === null ) {
1262                         $this->populateColumnCaches();
1263                 }
1264
1265                 return isset( $this->mBinaryColumnCache[$tableRaw] )
1266                         ? $this->mBinaryColumnCache[$tableRaw]
1267                         : array();
1268         }
1269
1270         /**
1271          * @param string $table
1272          * @return array
1273          */
1274         private function getBitColumns( $table ) {
1275                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1276                 $tableRaw = array_pop( $tableRawArr );
1277
1278                 if ( $this->mBitColumnCache === null ) {
1279                         $this->populateColumnCaches();
1280                 }
1281
1282                 return isset( $this->mBitColumnCache[$tableRaw] )
1283                         ? $this->mBitColumnCache[$tableRaw]
1284                         : array();
1285         }
1286
1287         /**
1288          * @void
1289          */
1290         private function populateColumnCaches() {
1291                 $res = $this->select( 'INFORMATION_SCHEMA.COLUMNS', '*',
1292                         array(
1293                                 'TABLE_CATALOG' => $this->mDBname,
1294                                 'TABLE_SCHEMA' => $this->mSchema,
1295                                 'DATA_TYPE' => array( 'varbinary', 'binary', 'image', 'bit' )
1296                         ) );
1297
1298                 $this->mBinaryColumnCache = array();
1299                 $this->mBitColumnCache = array();
1300                 foreach ( $res as $row ) {
1301                         if ( $row->DATA_TYPE == 'bit' ) {
1302                                 $this->mBitColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1303                         } else {
1304                                 $this->mBinaryColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1305                         }
1306                 }
1307         }
1308
1309         /**
1310          * @param string $name
1311          * @param string $format
1312          * @return string
1313          */
1314         function tableName( $name, $format = 'quoted' ) {
1315                 # Replace reserved words with better ones
1316                 switch ( $name ) {
1317                         case 'user':
1318                                 return $this->realTableName( 'mwuser', $format );
1319                         default:
1320                                 return $this->realTableName( $name, $format );
1321                 }
1322         }
1323
1324         /**
1325          * call this instead of tableName() in the updater when renaming tables
1326          * @param string $name
1327          * @param string $format
1328          * @return string
1329          */
1330         function realTableName( $name, $format = 'quoted' ) {
1331                 return parent::tableName( $name, $format );
1332         }
1333
1334         /**
1335          * Called in the installer and updater.
1336          * Probably doesn't need to be called anywhere else in the codebase.
1337          * @param bool|null $value
1338          * @return bool|null
1339          */
1340         public function prepareStatements( $value = null ) {
1341                 return wfSetVar( $this->mPrepareStatements, $value );
1342         }
1343
1344         /**
1345          * Called in the installer and updater.
1346          * Probably doesn't need to be called anywhere else in the codebase.
1347          * @param bool|null $value
1348          * @return bool|null
1349          */
1350         public function scrollableCursor( $value = null ) {
1351                 return wfSetVar( $this->mScrollableCursor, $value );
1352         }
1353 } // end DatabaseMssql class
1354
1355 /**
1356  * Utility class.
1357  *
1358  * @ingroup Database
1359  */
1360 class MssqlField implements Field {
1361         private $name, $tableName, $default, $max_length, $nullable, $type;
1362
1363         function __construct( $info ) {
1364                 $this->name = $info['COLUMN_NAME'];
1365                 $this->tableName = $info['TABLE_NAME'];
1366                 $this->default = $info['COLUMN_DEFAULT'];
1367                 $this->max_length = $info['CHARACTER_MAXIMUM_LENGTH'];
1368                 $this->nullable = !( strtolower( $info['IS_NULLABLE'] ) == 'no' );
1369                 $this->type = $info['DATA_TYPE'];
1370         }
1371
1372         function name() {
1373                 return $this->name;
1374         }
1375
1376         function tableName() {
1377                 return $this->tableName;
1378         }
1379
1380         function defaultValue() {
1381                 return $this->default;
1382         }
1383
1384         function maxLength() {
1385                 return $this->max_length;
1386         }
1387
1388         function isNullable() {
1389                 return $this->nullable;
1390         }
1391
1392         function type() {
1393                 return $this->type;
1394         }
1395 }
1396
1397 class MssqlBlob extends Blob {
1398         public function __construct( $data ) {
1399                 if ( $data instanceof MssqlBlob ) {
1400                         return $data;
1401                 } elseif ( $data instanceof Blob ) {
1402                         $this->mData = $data->fetch();
1403                 } elseif ( is_array( $data ) && is_object( $data ) ) {
1404                         $this->mData = serialize( $data );
1405                 } else {
1406                         $this->mData = $data;
1407                 }
1408         }
1409
1410         /**
1411          * Returns an unquoted hex representation of a binary string
1412          * for insertion into varbinary-type fields
1413          * @return string
1414          */
1415         public function fetch() {
1416                 if ( $this->mData === null ) {
1417                         return 'null';
1418                 }
1419
1420                 $ret = '0x';
1421                 $dataLength = strlen( $this->mData );
1422                 for ( $i = 0; $i < $dataLength; $i++ ) {
1423                         $ret .= bin2hex( pack( 'C', ord( $this->mData[$i] ) ) );
1424                 }
1425
1426                 return $ret;
1427         }
1428 }
1429
1430 class MssqlResultWrapper extends ResultWrapper {
1431         private $mSeekTo = null;
1432
1433         /**
1434          * @return stdClass|bool
1435          */
1436         public function fetchObject() {
1437                 $res = $this->result;
1438
1439                 if ( $this->mSeekTo !== null ) {
1440                         $result = sqlsrv_fetch_object( $res, 'stdClass', array(),
1441                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1442                         $this->mSeekTo = null;
1443                 } else {
1444                         $result = sqlsrv_fetch_object( $res );
1445                 }
1446
1447                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1448                 if ( $result === null ) {
1449                         return false;
1450                 }
1451
1452                 return $result;
1453         }
1454
1455         /**
1456          * @return array|bool
1457          */
1458         public function fetchRow() {
1459                 $res = $this->result;
1460
1461                 if ( $this->mSeekTo !== null ) {
1462                         $result = sqlsrv_fetch_array( $res, SQLSRV_FETCH_BOTH,
1463                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1464                         $this->mSeekTo = null;
1465                 } else {
1466                         $result = sqlsrv_fetch_array( $res );
1467                 }
1468
1469                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1470                 if ( $result === null ) {
1471                         return false;
1472                 }
1473
1474                 return $result;
1475         }
1476
1477         /**
1478          * @param int $row
1479          * @return bool
1480          */
1481         public function seek( $row ) {
1482                 $res = $this->result;
1483
1484                 // check bounds
1485                 $numRows = $this->db->numRows( $res );
1486                 $row = intval( $row );
1487
1488                 if ( $numRows === 0 ) {
1489                         return false;
1490                 } elseif ( $row < 0 || $row > $numRows - 1 ) {
1491                         return false;
1492                 }
1493
1494                 // Unlike MySQL, the seek actually happens on the next access
1495                 $this->mSeekTo = $row;
1496                 return true;
1497         }
1498 }