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                 if ( $this->debug() ) {
 168                         wfDebug( "SQL: [$sql]\n" );
 169                 }
 170                 $this->offset = 0;
 171
 172                 // several extensions seem to think that all databases support limits
 173                 // via LIMIT N after the WHERE clause well, MSSQL uses SELECT TOP N,
 174                 // so to catch any of those extensions we'll do a quick check for a
 175                 // LIMIT clause and pass $sql through $this->LimitToTopN() which parses
 176                 // the limit clause and passes the result to $this->limitResult();
 177                 if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) {
 178                         // massage LIMIT -> TopN
 179                         $sql = $this->LimitToTopN( $sql );
 180                 }
 181
 182                 // MSSQL doesn't have EXTRACT(epoch FROM XXX)
 183                 if ( preg_match( '#\bEXTRACT\s*?\(\s*?EPOCH\s+FROM\b#i', $sql, $matches ) ) {
 184                         // This is same as UNIX_TIMESTAMP, we need to calc # of seconds from 1970
 185                         $sql = str_replace( $matches[0], "DATEDIFF(s,CONVERT(datetime,'1/1/1970'),", $sql );
 186                 }
 187
 188                 // perform query
 189
 190                 // SQLSRV_CURSOR_STATIC is slower than SQLSRV_CURSOR_CLIENT_BUFFERED (one of the two is
 191                 // needed if we want to be able to seek around the result set), however CLIENT_BUFFERED
 192                 // has a bug in the sqlsrv driver where wchar_t types (such as nvarchar) that are empty
 193                 // strings make php throw a fatal error "Severe error translating Unicode"
 194                 if ( $this->mScrollableCursor ) {
 195                         $scrollArr = array( 'Scrollable' => SQLSRV_CURSOR_STATIC );
 196                 } else {
 197                         $scrollArr = array();
 198                 }
 199
 200                 if ( $this->mPrepareStatements ) {
 201                         // we do prepare + execute so we can get its field metadata for later usage if desired
 202                         $stmt = sqlsrv_prepare( $this->mConn, $sql, array(), $scrollArr );
 203                         $success = sqlsrv_execute( $stmt );
 204                 } else {
 205                         $stmt = sqlsrv_query( $this->mConn, $sql, array(), $scrollArr );
 206                         $success = (bool)$stmt;
 207                 }
 208
 209                 if ( $this->mIgnoreDupKeyErrors ) {
 210                         // ignore duplicate key errors, but nothing else
 211                         // this emulates INSERT IGNORE in MySQL
 212                         if ( $success === false ) {
 213                                 $errors = sqlsrv_errors( SQLSRV_ERR_ERRORS );
 214                                 $success = true;
 215
 216                                 foreach ( $errors as $err ) {
 217                                         if ( $err['SQLSTATE'] == '23000' && $err['code'] == '2601' ) {
 218                                                 continue; // duplicate key error caused by unique index
 219                                         } elseif ( $err['SQLSTATE'] == '23000' && $err['code'] == '2627' ) {
 220                                                 continue; // duplicate key error caused by primary key
 221                                         } elseif ( $err['SQLSTATE'] == '01000' && $err['code'] == '3621' ) {
 222                                                 continue; // generic "the statement has been terminated" error
 223                                         }
 224
 225                                         $success = false; // getting here means we got an error we weren't expecting
 226                                         break;
 227                                 }
 228
 229                                 if ( $success ) {
 230                                         $this->mAffectedRows = 0;
 231                                         return true;
 232                                 }
 233                         }
 234                 }
 235
 236                 if ( $success === false ) {
 237                         return false;
 238                 }
 239                 // remember number of rows affected
 240                 $this->mAffectedRows = sqlsrv_rows_affected( $stmt );
 241
 242                 return $stmt;
 243         }
 244
 245         public function freeResult( $res ) {
 246                 if ( $res instanceof ResultWrapper ) {
 247                         $res = $res->result;
 248                 }
 249
 250                 sqlsrv_free_stmt( $res );
 251         }
 252
 253         /**
 254          * @param MssqlResultWrapper $res
 255          * @return stdClass
 256          */
 257         public function fetchObject( $res ) {
 258                 // $res is expected to be an instance of MssqlResultWrapper here
 259                 return $res->fetchObject();
 260         }
 261
 262         /**
 263          * @param MssqlResultWrapper $res
 264          * @return array
 265          */
 266         public function fetchRow( $res ) {
 267                 return $res->fetchRow();
 268         }
 269
 270         /**
 271          * @param mixed $res
 272          * @return int
 273          */
 274         public function numRows( $res ) {
 275                 if ( $res instanceof ResultWrapper ) {
 276                         $res = $res->result;
 277                 }
 278
 279                 return sqlsrv_num_rows( $res );
 280         }
 281
 282         /**
 283          * @param mixed $res
 284          * @return int
 285          */
 286         public function numFields( $res ) {
 287                 if ( $res instanceof ResultWrapper ) {
 288                         $res = $res->result;
 289                 }
 290
 291                 return sqlsrv_num_fields( $res );
 292         }
 293
 294         /**
 295          * @param mixed $res
 296          * @param int $n
 297          * @return int
 298          */
 299         public function fieldName( $res, $n ) {
 300                 if ( $res instanceof ResultWrapper ) {
 301                         $res = $res->result;
 302                 }
 303
 304                 $metadata = sqlsrv_field_metadata( $res );
 305                 return $metadata[$n]['Name'];
 306         }
 307
 308         /**
 309          * This must be called after nextSequenceVal
 310          * @return int|null
 311          */
 312         public function insertId() {
 313                 return $this->mInsertId;
 314         }
 315
 316         /**
 317          * @param MssqlResultWrapper $res
 318          * @param int $row
 319          * @return bool
 320          */
 321         public function dataSeek( $res, $row ) {
 322                 return $res->seek( $row );
 323         }
 324
 325         /**
 326          * @return string
 327          */
 328         public function lastError() {
 329                 $strRet = '';
 330                 $retErrors = sqlsrv_errors( SQLSRV_ERR_ALL );
 331                 if ( $retErrors != null ) {
 332                         foreach ( $retErrors as $arrError ) {
 333                                 $strRet .= $this->formatError( $arrError ) . "\n";
 334                         }
 335                 } else {
 336                         $strRet = "No errors found";
 337                 }
 338
 339                 return $strRet;
 340         }
 341
 342         /**
 343          * @param array $err
 344          * @return string
 345          */
 346         private function formatError( $err ) {
 347                 return '[SQLSTATE ' . $err['SQLSTATE'] . '][Error Code ' . $err['code'] . ']' . $err['message'];
 348         }
 349
 350         /**
 351          * @return string
 352          */
 353         public function lastErrno() {
 354                 $err = sqlsrv_errors( SQLSRV_ERR_ALL );
 355                 if ( $err !== null && isset( $err[0] ) ) {
 356                         return $err[0]['code'];
 357                 } else {
 358                         return 0;
 359                 }
 360         }
 361
 362         /**
 363          * @return int
 364          */
 365         public function affectedRows() {
 366                 return $this->mAffectedRows;
 367         }
 368
 369         /**
 370          * SELECT wrapper
 371          *
 372          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 373          * @param mixed $vars Array or string, field name(s) to be retrieved
 374          * @param mixed $conds Array or string, condition(s) for WHERE
 375          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 376          * @param array $options Associative array of options (e.g.
 377          *   array('GROUP BY' => 'page_title')), see Database::makeSelectOptions
 378          *   code for list of supported stuff
 379          * @param array $join_conds Associative array of table join conditions
 380          *   (optional) (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 381          * @return mixed Database result resource (feed to Database::fetchObject
 382          *   or whatever), or false on failure
 383          */
 384         public function select( $table, $vars, $conds = '', $fname = __METHOD__,
 385                 $options = array(), $join_conds = array()
 386         ) {
 387                 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 388                 if ( isset( $options['EXPLAIN'] ) ) {
 389                         try {
 390                                 $this->mScrollableCursor = false;
 391                                 $this->mPrepareStatements = false;
 392                                 $this->query( "SET SHOWPLAN_ALL ON" );
 393                                 $ret = $this->query( $sql, $fname );
 394                                 $this->query( "SET SHOWPLAN_ALL OFF" );
 395                         } catch ( DBQueryError $dqe ) {
 396                                 if ( isset( $options['FOR COUNT'] ) ) {
 397                                         // likely don't have privs for SHOWPLAN, so run a select count instead
 398                                         $this->query( "SET SHOWPLAN_ALL OFF" );
 399                                         unset( $options['EXPLAIN'] );
 400                                         $ret = $this->select(
 401                                                 $table,
 402                                                 'COUNT(*) AS EstimateRows',
 403                                                 $conds,
 404                                                 $fname,
 405                                                 $options,
 406                                                 $join_conds
 407                                         );
 408                                 } else {
 409                                         // someone actually wanted the query plan instead of an est row count
 410                                         // let them know of the error
 411                                         $this->mScrollableCursor = true;
 412                                         $this->mPrepareStatements = true;
 413                                         throw $dqe;
 414                                 }
 415                         }
 416                         $this->mScrollableCursor = true;
 417                         $this->mPrepareStatements = true;
 418
 419                         return $ret;
 420                 }
 421
 422                 return $this->query( $sql, $fname );
 423         }
 424
 425         /**
 426          * SELECT wrapper
 427          *
 428          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 429          * @param mixed $vars Array or string, field name(s) to be retrieved
 430          * @param mixed $conds Array or string, condition(s) for WHERE
 431          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 432          * @param array $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 433          *   see Database::makeSelectOptions code for list of supported stuff
 434          * @param array $join_conds Associative array of table join conditions (optional)
 435          *    (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 436          * @return string The SQL text
 437          */
 438         public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
 439                 $options = array(), $join_conds = array()
 440         ) {
 441                 if ( isset( $options['EXPLAIN'] ) ) {
 442                         unset( $options['EXPLAIN'] );
 443                 }
 444
 445                 $sql = parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 446
 447                 // try to rewrite aggregations of bit columns (currently MAX and MIN)
 448                 if ( strpos( $sql, 'MAX(' ) !== false || strpos( $sql, 'MIN(' ) !== false ) {
 449                         $bitColumns = array();
 450                         if ( is_array( $table ) ) {
 451                                 foreach ( $table as $t ) {
 452                                         $bitColumns += $this->getBitColumns( $this->tableName( $t ) );
 453                                 }
 454                         } else {
 455                                 $bitColumns = $this->getBitColumns( $this->tableName( $table ) );
 456                         }
 457
 458                         foreach ( $bitColumns as $col => $info ) {
 459                                 $replace = array(
 460                                         "MAX({$col})" => "MAX(CAST({$col} AS tinyint))",
 461                                         "MIN({$col})" => "MIN(CAST({$col} AS tinyint))",
 462                                 );
 463                                 $sql = str_replace( array_keys( $replace ), array_values( $replace ), $sql );
 464                         }
 465                 }
 466
 467                 return $sql;
 468         }
 469
 470         public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
 471                 $fname = __METHOD__
 472         ) {
 473                 $this->mScrollableCursor = false;
 474                 try {
 475                         parent::deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname );
 476                 } catch ( Exception $e ) {
 477                         $this->mScrollableCursor = true;
 478                         throw $e;
 479                 }
 480                 $this->mScrollableCursor = true;
 481         }
 482
 483         public function delete( $table, $conds, $fname = __METHOD__ ) {
 484                 $this->mScrollableCursor = false;
 485                 try {
 486                         parent::delete( $table, $conds, $fname );
 487                 } catch ( Exception $e ) {
 488                         $this->mScrollableCursor = true;
 489                         throw $e;
 490                 }
 491                 $this->mScrollableCursor = true;
 492         }
 493
 494         /**
 495          * Estimate rows in dataset
 496          * Returns estimated count, based on SHOWPLAN_ALL output
 497          * This is not necessarily an accurate estimate, so use sparingly
 498          * Returns -1 if count cannot be found
 499          * Takes same arguments as Database::select()
 500          * @param string $table
 501          * @param string $vars
 502          * @param string $conds
 503          * @param string $fname
 504          * @param array $options
 505          * @return int
 506          */
 507         public function estimateRowCount( $table, $vars = '*', $conds = '',
 508                 $fname = __METHOD__, $options = array()
 509         ) {
 510                 // http://msdn2.microsoft.com/en-us/library/aa259203.aspx
 511                 $options['EXPLAIN'] = true;
 512                 $options['FOR COUNT'] = true;
 513                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 514
 515                 $rows = -1;
 516                 if ( $res ) {
 517                         $row = $this->fetchRow( $res );
 518
 519                         if ( isset( $row['EstimateRows'] ) ) {
 520                                 $rows = $row['EstimateRows'];
 521                         }
 522                 }
 523
 524                 return $rows;
 525         }
 526
 527         /**
 528          * Returns information about an index
 529          * If errors are explicitly ignored, returns NULL on failure
 530          * @param string $table
 531          * @param string $index
 532          * @param string $fname
 533          * @return array|bool|null
 534          */
 535         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 536                 # This does not return the same info as MYSQL would, but that's OK
 537                 # because MediaWiki never uses the returned value except to check for
 538                 # the existance of indexes.
 539                 $sql = "sp_helpindex '" . $table . "'";
 540                 $res = $this->query( $sql, $fname );
 541                 if ( !$res ) {
 542                         return null;
 543                 }
 544
 545                 $result = array();
 546                 foreach ( $res as $row ) {
 547                         if ( $row->index_name == $index ) {
 548                                 $row->Non_unique = !stristr( $row->index_description, "unique" );
 549                                 $cols = explode( ", ", $row->index_keys );
 550                                 foreach ( $cols as $col ) {
 551                                         $row->Column_name = trim( $col );
 552                                         $result[] = clone $row;
 553                                 }
 554                         } elseif ( $index == 'PRIMARY' && stristr( $row->index_description, 'PRIMARY' ) ) {
 555                                 $row->Non_unique = 0;
 556                                 $cols = explode( ", ", $row->index_keys );
 557                                 foreach ( $cols as $col ) {
 558                                         $row->Column_name = trim( $col );
 559                                         $result[] = clone $row;
 560                                 }
 561                         }
 562                 }
 563
 564                 return empty( $result ) ? false : $result;
 565         }
 566
 567         /**
 568          * INSERT wrapper, inserts an array into a table
 569          *
 570          * $arrToInsert may be a single associative array, or an array of these with numeric keys, for
 571          * multi-row insert.
 572          *
 573          * Usually aborts on failure
 574          * If errors are explicitly ignored, returns success
 575          * @param string $table
 576          * @param array $arrToInsert
 577          * @param string $fname
 578          * @param array $options
 579          * @throws DBQueryError
 580          * @return bool
 581          */
 582         public function insert( $table, $arrToInsert, $fname = __METHOD__, $options = array() ) {
 583                 # No rows to insert, easy just return now
 584                 if ( !count( $arrToInsert ) ) {
 585                         return true;
 586                 }
 587
 588                 if ( !is_array( $options ) ) {
 589                         $options = array( $options );
 590                 }
 591
 592                 $table = $this->tableName( $table );
 593
 594                 if ( !( isset( $arrToInsert[0] ) && is_array( $arrToInsert[0] ) ) ) { // Not multi row
 595                         $arrToInsert = array( 0 => $arrToInsert ); // make everything multi row compatible
 596                 }
 597
 598                 // We know the table we're inserting into, get its identity column
 599                 $identity = null;
 600                 // strip matching square brackets and the db/schema from table name
 601                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
 602                 $tableRaw = array_pop( $tableRawArr );
 603                 $res = $this->doQuery(
 604                         "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS " .
 605                                 "WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'"
 606                 );
 607                 if ( $res && sqlsrv_has_rows( $res ) ) {
 608                         // There is an identity for this table.
 609                         $identityArr = sqlsrv_fetch_array( $res, SQLSRV_FETCH_ASSOC );
 610                         $identity = array_pop( $identityArr );
 611                 }
 612                 sqlsrv_free_stmt( $res );
 613
 614                 // Determine binary/varbinary fields so we can encode data as a hex string like 0xABCDEF
 615                 $binaryColumns = $this->getBinaryColumns( $table );
 616
 617                 foreach ( $arrToInsert as $a ) {
 618                         // start out with empty identity column, this is so we can return
 619                         // it as a result of the insert logic
 620                         $sqlPre = '';
 621                         $sqlPost = '';
 622                         $identityClause = '';
 623
 624                         // if we have an identity column
 625                         if ( $identity ) {
 626                                 // iterate through
 627                                 foreach ( $a as $k => $v ) {
 628                                         if ( $k == $identity ) {
 629                                                 if ( !is_null( $v ) ) {
 630                                                         // there is a value being passed to us,
 631                                                         // we need to turn on and off inserted identity
 632                                                         $sqlPre = "SET IDENTITY_INSERT $table ON;";
 633                                                         $sqlPost = ";SET IDENTITY_INSERT $table OFF;";
 634                                                 } else {
 635                                                         // we can't insert NULL into an identity column,
 636                                                         // so remove the column from the insert.
 637                                                         unset( $a[$k] );
 638                                                 }
 639                                         }
 640                                 }
 641
 642                                 // we want to output an identity column as result
 643                                 $identityClause = "OUTPUT INSERTED.$identity ";
 644                         }
 645
 646                         $keys = array_keys( $a );
 647
 648                         // INSERT IGNORE is not supported by SQL Server
 649                         // remove IGNORE from options list and set ignore flag to true
 650                         $ignoreClause = false;
 651                         if ( in_array( 'IGNORE', $options ) ) {
 652                                 $options = array_diff( $options, array( 'IGNORE' ) );
 653                                 $this->mIgnoreDupKeyErrors = true;
 654                         }
 655
 656                         // Build the actual query
 657                         $sql = $sqlPre . 'INSERT ' . implode( ' ', $options ) .
 658                                 " INTO $table (" . implode( ',', $keys ) . ") $identityClause VALUES (";
 659
 660                         $first = true;
 661                         foreach ( $a as $key => $value ) {
 662                                 if ( isset( $binaryColumns[$key] ) ) {
 663                                         $value = new MssqlBlob( $value );
 664                                 }
 665                                 if ( $first ) {
 666                                         $first = false;
 667                                 } else {
 668                                         $sql .= ',';
 669                                 }
 670                                 if ( is_null( $value ) ) {
 671                                         $sql .= 'null';
 672                                 } elseif ( is_array( $value ) || is_object( $value ) ) {
 673                                         if ( is_object( $value ) && $value instanceof Blob ) {
 674                                                 $sql .= $this->addQuotes( $value );
 675                                         } else {
 676                                                 $sql .= $this->addQuotes( serialize( $value ) );
 677                                         }
 678                                 } else {
 679                                         $sql .= $this->addQuotes( $value );
 680                                 }
 681                         }
 682                         $sql .= ')' . $sqlPost;
 683
 684                         // Run the query
 685                         $this->mScrollableCursor = false;
 686                         try {
 687                                 $ret = $this->query( $sql );
 688                         } catch ( Exception $e ) {
 689                                 $this->mScrollableCursor = true;
 690                                 $this->mIgnoreDupKeyErrors = false;
 691                                 throw $e;
 692                         }
 693                         $this->mScrollableCursor = true;
 694                         $this->mIgnoreDupKeyErrors = false;
 695
 696                         if ( !is_null( $identity ) ) {
 697                                 // then we want to get the identity column value we were assigned and save it off
 698                                 $row = $ret->fetchObject();
 699                                 $this->mInsertId = $row->$identity;
 700                         }
 701                 }
 702
 703                 return $ret;
 704         }
 705
 706         /**
 707          * INSERT SELECT wrapper
 708          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 709          * Source items may be literals rather than field names, but strings should
 710          * be quoted with Database::addQuotes().
 711          * @param string $destTable
 712          * @param array|string $srcTable May be an array of tables.
 713          * @param array $varMap
 714          * @param array $conds May be "*" to copy the whole table.
 715          * @param string $fname
 716          * @param array $insertOptions
 717          * @param array $selectOptions
 718          * @throws DBQueryError
 719          * @return null|ResultWrapper
 720          */
 721         public function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 722                 $insertOptions = array(), $selectOptions = array()
 723         ) {
 724                 $this->mScrollableCursor = false;
 725                 try {
 726                         $ret = parent::insertSelect(
 727                                 $destTable,
 728                                 $srcTable,
 729                                 $varMap,
 730                                 $conds,
 731                                 $fname,
 732                                 $insertOptions,
 733                                 $selectOptions
 734                         );
 735                 } catch ( Exception $e ) {
 736                         $this->mScrollableCursor = true;
 737                         throw $e;
 738                 }
 739                 $this->mScrollableCursor = true;
 740
 741                 return $ret;
 742         }
 743
 744         /**
 745          * UPDATE wrapper. Takes a condition array and a SET array.
 746          *
 747          * @param string $table Name of the table to UPDATE. This will be passed through
 748          *                DatabaseBase::tableName().
 749          *
 750          * @param array $values An array of values to SET. For each array element,
 751          *                the key gives the field name, and the value gives the data
 752          *                to set that field to. The data will be quoted by
 753          *                DatabaseBase::addQuotes().
 754          *
 755          * @param array $conds An array of conditions (WHERE). See
 756          *                DatabaseBase::select() for the details of the format of
 757          *                condition arrays. Use '*' to update all rows.
 758          *
 759          * @param string $fname The function name of the caller (from __METHOD__),
 760          *                for logging and profiling.
 761          *
 762          * @param array $options An array of UPDATE options, can be:
 763          *                   - IGNORE: Ignore unique key conflicts
 764          *                   - LOW_PRIORITY: MySQL-specific, see MySQL manual.
 765          * @return bool
 766          */
 767         function update( $table, $values, $conds, $fname = __METHOD__, $options = array() ) {
 768                 $table = $this->tableName( $table );
 769                 $binaryColumns = $this->getBinaryColumns( $table );
 770
 771                 $opts = $this->makeUpdateOptions( $options );
 772                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET, $binaryColumns );
 773
 774                 if ( $conds !== array() && $conds !== '*' ) {
 775                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND, $binaryColumns );
 776                 }
 777
 778                 $this->mScrollableCursor = false;
 779                 try {
 780                         $ret = $this->query( $sql );
 781                 } catch ( Exception $e ) {
 782                         $this->mScrollableCursor = true;
 783                         throw $e;
 784                 }
 785                 $this->mScrollableCursor = true;
 786                 return true;
 787         }
 788
 789         /**
 790          * Makes an encoded list of strings from an array
 791          * @param array $a Containing the data
 792          * @param int $mode Constant
 793          *      - LIST_COMMA:          comma separated, no field names
 794          *      - LIST_AND:            ANDed WHERE clause (without the WHERE). See
 795          *        the documentation for $conds in DatabaseBase::select().
 796          *      - LIST_OR:             ORed WHERE clause (without the WHERE)
 797          *      - LIST_SET:            comma separated with field names, like a SET clause
 798          *      - LIST_NAMES:          comma separated field names
 799          * @param array $binaryColumns Contains a list of column names that are binary types
 800          *      This is a custom parameter only present for MS SQL.
 801          *
 802          * @throws MWException|DBUnexpectedError
 803          * @return string
 804          */
 805         public function makeList( $a, $mode = LIST_COMMA, $binaryColumns = array() ) {
 806                 if ( !is_array( $a ) ) {
 807                         throw new DBUnexpectedError( $this,
 808                                 'DatabaseBase::makeList called with incorrect parameters' );
 809                 }
 810
 811                 $first = true;
 812                 $list = '';
 813
 814                 foreach ( $a as $field => $value ) {
 815                         if ( $mode != LIST_NAMES && isset( $binaryColumns[$field] ) ) {
 816                                 if ( is_array( $value ) ) {
 817                                         foreach ( $value as &$v ) {
 818                                                 $v = new MssqlBlob( $v );
 819                                         }
 820                                 } else {
 821                                         $value = new MssqlBlob( $value );
 822                                 }
 823                         }
 824
 825                         if ( !$first ) {
 826                                 if ( $mode == LIST_AND ) {
 827                                         $list .= ' AND ';
 828                                 } elseif ( $mode == LIST_OR ) {
 829                                         $list .= ' OR ';
 830                                 } else {
 831                                         $list .= ',';
 832                                 }
 833                         } else {
 834                                 $first = false;
 835                         }
 836
 837                         if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
 838                                 $list .= "($value)";
 839                         } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
 840                                 $list .= "$value";
 841                         } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
 842                                 if ( count( $value ) == 0 ) {
 843                                         throw new MWException( __METHOD__ . ": empty input for field $field" );
 844                                 } elseif ( count( $value ) == 1 ) {
 845                                         // Special-case single values, as IN isn't terribly efficient
 846                                         // Don't necessarily assume the single key is 0; we don't
 847                                         // enforce linear numeric ordering on other arrays here.
 848                                         $value = array_values( $value );
 849                                         $list .= $field . " = " . $this->addQuotes( $value[0] );
 850                                 } else {
 851                                         $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
 852                                 }
 853                         } elseif ( $value === null ) {
 854                                 if ( $mode == LIST_AND || $mode == LIST_OR ) {
 855                                         $list .= "$field IS ";
 856                                 } elseif ( $mode == LIST_SET ) {
 857                                         $list .= "$field = ";
 858                                 }
 859                                 $list .= 'NULL';
 860                         } else {
 861                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
 862                                         $list .= "$field = ";
 863                                 }
 864                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
 865                         }
 866                 }
 867
 868                 return $list;
 869         }
 870
 871         /**
 872          * @param string $table
 873          * @param string $field
 874          * @return int Returns the size of a text field, or -1 for "unlimited"
 875          */
 876         public function textFieldSize( $table, $field ) {
 877                 $table = $this->tableName( $table );
 878                 $sql = "SELECT CHARACTER_MAXIMUM_LENGTH,DATA_TYPE FROM INFORMATION_SCHEMA.Columns
 879                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'";
 880                 $res = $this->query( $sql );
 881                 $row = $this->fetchRow( $res );
 882                 $size = -1;
 883                 if ( strtolower( $row['DATA_TYPE'] ) != 'text' ) {
 884                         $size = $row['CHARACTER_MAXIMUM_LENGTH'];
 885                 }
 886
 887                 return $size;
 888         }
 889
 890         /**
 891          * Construct a LIMIT query with optional offset
 892          * This is used for query pages
 893          *
 894          * @param string $sql SQL query we will append the limit too
 895          * @param int $limit The SQL limit
 896          * @param bool|int $offset The SQL offset (default false)
 897          * @return array|string
 898          */
 899         public function limitResult( $sql, $limit, $offset = false ) {
 900                 if ( $offset === false || $offset == 0 ) {
 901                         if ( strpos( $sql, "SELECT" ) === false ) {
 902                                 return "TOP {$limit} " . $sql;
 903                         } else {
 904                                 return preg_replace( '/\bSELECT(\s+DISTINCT)?\b/Dsi',
 905                                         'SELECT$1 TOP ' . $limit, $sql, 1 );
 906                         }
 907                 } else {
 908                         // This one is fun, we need to pull out the select list as well as any ORDER BY clause
 909                         $select = $orderby = array();
 910                         $s1 = preg_match( '#SELECT\s+(.+?)\s+FROM#Dis', $sql, $select );
 911                         $s2 = preg_match( '#(ORDER BY\s+.+?)(\s*FOR XML .*)?$#Dis', $sql, $orderby );
 912                         $overOrder = $postOrder = '';
 913                         $first = $offset + 1;
 914                         $last = $offset + $limit;
 915                         $sub1 = 'sub_' . $this->mSubqueryId;
 916                         $sub2 = 'sub_' . ( $this->mSubqueryId + 1 );
 917                         $this->mSubqueryId += 2;
 918                         if ( !$s1 ) {
 919                                 // wat
 920                                 throw new DBUnexpectedError( $this, "Attempting to LIMIT a non-SELECT query\n" );
 921                         }
 922                         if ( !$s2 ) {
 923                                 // no ORDER BY
 924                                 $overOrder = 'ORDER BY 1';
 925                         } else {
 926                                 if ( !isset( $orderby[2] ) || !$orderby[2] ) {
 927                                         // don't need to strip it out if we're using a FOR XML clause
 928                                         $sql = str_replace( $orderby[1], '', $sql );
 929                                 }
 930                                 $overOrder = $orderby[1];
 931                                 $postOrder = ' ' . $overOrder;
 932                         }
 933                         $sql = "SELECT {$select[1]}
 934                                         FROM (
 935                                                 SELECT ROW_NUMBER() OVER({$overOrder}) AS rowNumber, *
 936                                                 FROM ({$sql}) {$sub1}
 937                                         ) {$sub2}
 938                                         WHERE rowNumber BETWEEN {$first} AND {$last}{$postOrder}";
 939
 940                         return $sql;
 941                 }
 942         }
 943
 944         /**
 945          * If there is a limit clause, parse it, strip it, and pass the remaining
 946          * SQL through limitResult() with the appropriate parameters. Not the
 947          * prettiest solution, but better than building a whole new parser. This
 948          * exists becase there are still too many extensions that don't use dynamic
 949          * sql generation.
 950          *
 951          * @param string $sql
 952          * @return array|mixed|string
 953          */
 954         public function LimitToTopN( $sql ) {
 955                 // Matches: LIMIT {[offset,] row_count | row_count OFFSET offset}
 956                 $pattern = '/\bLIMIT\s+((([0-9]+)\s*,\s*)?([0-9]+)(\s+OFFSET\s+([0-9]+))?)/i';
 957                 if ( preg_match( $pattern, $sql, $matches ) ) {
 958                         // row_count = $matches[4]
 959                         $row_count = $matches[4];
 960                         // offset = $matches[3] OR $matches[6]
 961                         $offset = $matches[3] or
 962                         $offset = $matches[6] or
 963                         $offset = false;
 964
 965                         // strip the matching LIMIT clause out
 966                         $sql = str_replace( $matches[0], '', $sql );
 967
 968                         return $this->limitResult( $sql, $row_count, $offset );
 969                 }
 970
 971                 return $sql;
 972         }
 973
 974         /**
 975          * @return string Wikitext of a link to the server software's web site
 976          */
 977         public function getSoftwareLink() {
 978                 return "[{{int:version-db-mssql-url}} MS SQL Server]";
 979         }
 980
 981         /**
 982          * @return string Version information from the database
 983          */
 984         public function getServerVersion() {
 985                 $server_info = sqlsrv_server_info( $this->mConn );
 986                 $version = 'Error';
 987                 if ( isset( $server_info['SQLServerVersion'] ) ) {
 988                         $version = $server_info['SQLServerVersion'];
 989                 }
 990
 991                 return $version;
 992         }
 993
 994         /**
 995          * @param string $table
 996          * @param string $fname
 997          * @return bool
 998          */
 999         public function tableExists( $table, $fname = __METHOD__ ) {
1000                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1001
1002                 if ( $db !== false ) {
1003                         // remote database
1004                         wfDebug( "Attempting to call tableExists on a remote table" );
1005                         return false;
1006                 }
1007
1008                 if ( $schema === false ) {
1009                         global $wgDBmwschema;
1010                         $schema = $wgDBmwschema;
1011                 }
1012
1013                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.TABLES
1014                         WHERE TABLE_TYPE = 'BASE TABLE'
1015                         AND TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table'" );
1016
1017                 if ( $res->numRows() ) {
1018                         return true;
1019                 } else {
1020                         return false;
1021                 }
1022         }
1023
1024         /**
1025          * Query whether a given column exists in the mediawiki schema
1026          * @param string $table
1027          * @param string $field
1028          * @param string $fname
1029          * @return bool
1030          */
1031         public function fieldExists( $table, $field, $fname = __METHOD__ ) {
1032                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1033
1034                 if ( $db !== false ) {
1035                         // remote database
1036                         wfDebug( "Attempting to call fieldExists on a remote table" );
1037                         return false;
1038                 }
1039
1040                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS
1041                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1042
1043                 if ( $res->numRows() ) {
1044                         return true;
1045                 } else {
1046                         return false;
1047                 }
1048         }
1049
1050         public function fieldInfo( $table, $field ) {
1051                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1052
1053                 if ( $db !== false ) {
1054                         // remote database
1055                         wfDebug( "Attempting to call fieldInfo on a remote table" );
1056                         return false;
1057                 }
1058
1059                 $res = $this->query( "SELECT * FROM INFORMATION_SCHEMA.COLUMNS
1060                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1061
1062                 $meta = $res->fetchRow();
1063                 if ( $meta ) {
1064                         return new MssqlField( $meta );
1065                 }
1066
1067                 return false;
1068         }
1069
1070         /**
1071          * Begin a transaction, committing any previously open transaction
1072          * @param string $fname
1073          */
1074         protected function doBegin( $fname = __METHOD__ ) {
1075                 sqlsrv_begin_transaction( $this->mConn );
1076                 $this->mTrxLevel = 1;
1077         }
1078
1079         /**
1080          * End a transaction
1081          * @param string $fname
1082          */
1083         protected function doCommit( $fname = __METHOD__ ) {
1084                 sqlsrv_commit( $this->mConn );
1085                 $this->mTrxLevel = 0;
1086         }
1087
1088         /**
1089          * Rollback a transaction.
1090          * No-op on non-transactional databases.
1091          * @param string $fname
1092          */
1093         protected function doRollback( $fname = __METHOD__ ) {
1094                 sqlsrv_rollback( $this->mConn );
1095                 $this->mTrxLevel = 0;
1096         }
1097
1098         /**
1099          * Escapes a identifier for use inm SQL.
1100          * Throws an exception if it is invalid.
1101          * Reference: http://msdn.microsoft.com/en-us/library/aa224033%28v=SQL.80%29.aspx
1102          * @param string $identifier
1103          * @throws MWException
1104          * @return string
1105          */
1106         private function escapeIdentifier( $identifier ) {
1107                 if ( strlen( $identifier ) == 0 ) {
1108                         throw new MWException( "An identifier must not be empty" );
1109                 }
1110                 if ( strlen( $identifier ) > 128 ) {
1111                         throw new MWException( "The identifier '$identifier' is too long (max. 128)" );
1112                 }
1113                 if ( ( strpos( $identifier, '[' ) !== false )
1114                         || ( strpos( $identifier, ']' ) !== false )
1115                 ) {
1116                         // It may be allowed if you quoted with double quotation marks, but
1117                         // that would break if QUOTED_IDENTIFIER is OFF
1118                         throw new MWException( "Square brackets are not allowed in '$identifier'" );
1119                 }
1120
1121                 return "[$identifier]";
1122         }
1123
1124         /**
1125          * @param string $s
1126          * @return string
1127          */
1128         public function strencode( $s ) { # Should not be called by us
1129                 return str_replace( "'", "''", $s );
1130         }
1131
1132         /**
1133          * @param string $s
1134          * @return string
1135          */
1136         public function addQuotes( $s ) {
1137                 if ( $s instanceof MssqlBlob ) {
1138                         return $s->fetch();
1139                 } elseif ( $s instanceof Blob ) {
1140                         // this shouldn't really ever be called, but it's here if needed
1141                         // (and will quite possibly make the SQL error out)
1142                         $blob = new MssqlBlob( $s->fetch() );
1143                         return $blob->fetch();
1144                 } else {
1145                         if ( is_bool( $s ) ) {
1146                                 $s = $s ? 1 : 0;
1147                         }
1148                         return parent::addQuotes( $s );
1149                 }
1150         }
1151
1152         /**
1153          * @param string $s
1154          * @return string
1155          */
1156         public function addIdentifierQuotes( $s ) {
1157                 // http://msdn.microsoft.com/en-us/library/aa223962.aspx
1158                 return '[' . $s . ']';
1159         }
1160
1161         /**
1162          * @param string $name
1163          * @return bool
1164          */
1165         public function isQuotedIdentifier( $name ) {
1166                 return strlen( $name ) && $name[0] == '[' && substr( $name, -1, 1 ) == ']';
1167         }
1168
1169         /**
1170          * @param string $db
1171          * @return bool
1172          */
1173         public function selectDB( $db ) {
1174                 try {
1175                         $this->mDBname = $db;
1176                         $this->query( "USE $db" );
1177                         return true;
1178                 } catch ( Exception $e ) {
1179                         return false;
1180                 }
1181         }
1182
1183         /**
1184          * @param array $options An associative array of options to be turned into
1185          *   an SQL query, valid keys are listed in the function.
1186          * @return array
1187          */
1188         public function makeSelectOptions( $options ) {
1189                 $tailOpts = '';
1190                 $startOpts = '';
1191
1192                 $noKeyOptions = array();
1193                 foreach ( $options as $key => $option ) {
1194                         if ( is_numeric( $key ) ) {
1195                                 $noKeyOptions[$option] = true;
1196                         }
1197                 }
1198
1199                 $tailOpts .= $this->makeGroupByWithHaving( $options );
1200
1201                 $tailOpts .= $this->makeOrderBy( $options );
1202
1203                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1204                         $startOpts .= 'DISTINCT';
1205                 }
1206
1207                 if ( isset( $noKeyOptions['FOR XML'] ) ) {
1208                         // used in group concat field emulation
1209                         $tailOpts .= " FOR XML PATH('')";
1210                 }
1211
1212                 // we want this to be compatible with the output of parent::makeSelectOptions()
1213                 return array( $startOpts, '', $tailOpts, '' );
1214         }
1215
1216         /**
1217          * Get the type of the DBMS, as it appears in $wgDBtype.
1218          * @return string
1219          */
1220         public function getType() {
1221                 return 'mssql';
1222         }
1223
1224         /**
1225          * @param array $stringList
1226          * @return string
1227          */
1228         public function buildConcat( $stringList ) {
1229                 return implode( ' + ', $stringList );
1230         }
1231
1232         /**
1233          * Build a GROUP_CONCAT or equivalent statement for a query.
1234          * MS SQL doesn't have GROUP_CONCAT so we emulate it with other stuff (and boy is it nasty)
1235          *
1236          * This is useful for combining a field for several rows into a single string.
1237          * NULL values will not appear in the output, duplicated values will appear,
1238          * and the resulting delimiter-separated values have no defined sort order.
1239          * Code using the results may need to use the PHP unique() or sort() methods.
1240          *
1241          * @param string $delim Glue to bind the results together
1242          * @param string|array $table Table name
1243          * @param string $field Field name
1244          * @param string|array $conds Conditions
1245          * @param string|array $join_conds Join conditions
1246          * @return string SQL text
1247          * @since 1.23
1248          */
1249         public function buildGroupConcatField( $delim, $table, $field, $conds = '',
1250                 $join_conds = array()
1251         ) {
1252                 $gcsq = 'gcsq_' . $this->mSubqueryId;
1253                 $this->mSubqueryId++;
1254
1255                 $delimLen = strlen( $delim );
1256                 $fld = "{$field} + {$this->addQuotes( $delim )}";
1257                 $sql = "(SELECT LEFT({$field}, LEN({$field}) - {$delimLen}) FROM ("
1258                         . $this->selectSQLText( $table, $fld, $conds, null, array( 'FOR XML' ), $join_conds )
1259                         . ") {$gcsq} ({$field}))";
1260
1261                 return $sql;
1262         }
1263
1264         /**
1265          * @return string
1266          */
1267         public function getSearchEngine() {
1268                 return "SearchMssql";
1269         }
1270
1271         /**
1272          * Returns an associative array for fields that are of type varbinary, binary, or image
1273          * $table can be either a raw table name or passed through tableName() first
1274          * @param string $table
1275          * @return array
1276          */
1277         private function getBinaryColumns( $table ) {
1278                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1279                 $tableRaw = array_pop( $tableRawArr );
1280
1281                 if ( $this->mBinaryColumnCache === null ) {
1282                         $this->populateColumnCaches();
1283                 }
1284
1285                 return isset( $this->mBinaryColumnCache[$tableRaw] )
1286                         ? $this->mBinaryColumnCache[$tableRaw]
1287                         : array();
1288         }
1289
1290         /**
1291          * @param string $table
1292          * @return array
1293          */
1294         private function getBitColumns( $table ) {
1295                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1296                 $tableRaw = array_pop( $tableRawArr );
1297
1298                 if ( $this->mBitColumnCache === null ) {
1299                         $this->populateColumnCaches();
1300                 }
1301
1302                 return isset( $this->mBitColumnCache[$tableRaw] )
1303                         ? $this->mBitColumnCache[$tableRaw]
1304                         : array();
1305         }
1306
1307         private function populateColumnCaches() {
1308                 $res = $this->select( 'INFORMATION_SCHEMA.COLUMNS', '*',
1309                         array(
1310                                 'TABLE_CATALOG' => $this->mDBname,
1311                                 'TABLE_SCHEMA' => $this->mSchema,
1312                                 'DATA_TYPE' => array( 'varbinary', 'binary', 'image', 'bit' )
1313                         ) );
1314
1315                 $this->mBinaryColumnCache = array();
1316                 $this->mBitColumnCache = array();
1317                 foreach ( $res as $row ) {
1318                         if ( $row->DATA_TYPE == 'bit' ) {
1319                                 $this->mBitColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1320                         } else {
1321                                 $this->mBinaryColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1322                         }
1323                 }
1324         }
1325
1326         /**
1327          * @param string $name
1328          * @param string $format
1329          * @return string
1330          */
1331         function tableName( $name, $format = 'quoted' ) {
1332                 # Replace reserved words with better ones
1333                 switch ( $name ) {
1334                         case 'user':
1335                                 return $this->realTableName( 'mwuser', $format );
1336                         default:
1337                                 return $this->realTableName( $name, $format );
1338                 }
1339         }
1340
1341         /**
1342          * call this instead of tableName() in the updater when renaming tables
1343          * @param string $name
1344          * @param string $format One of quoted, raw, or split
1345          * @return string
1346          */
1347         function realTableName( $name, $format = 'quoted' ) {
1348                 $table = parent::tableName( $name, $format );
1349                 if ( $format == 'split' ) {
1350                         // Used internally, we want the schema split off from the table name and returned
1351                         // as a list with 3 elements (database, schema, table)
1352                         $table = explode( '.', $table );
1353                         while ( count( $table ) < 3 ) {
1354                                 array_unshift( $table, false );
1355                         }
1356                 }
1357                 return $table;
1358         }
1359
1360         /**
1361          * Called in the installer and updater.
1362          * Probably doesn't need to be called anywhere else in the codebase.
1363          * @param bool|null $value
1364          * @return bool|null
1365          */
1366         public function prepareStatements( $value = null ) {
1367                 return wfSetVar( $this->mPrepareStatements, $value );
1368         }
1369
1370         /**
1371          * Called in the installer and updater.
1372          * Probably doesn't need to be called anywhere else in the codebase.
1373          * @param bool|null $value
1374          * @return bool|null
1375          */
1376         public function scrollableCursor( $value = null ) {
1377                 return wfSetVar( $this->mScrollableCursor, $value );
1378         }
1379 } // end DatabaseMssql class
1380
1381 /**
1382  * Utility class.
1383  *
1384  * @ingroup Database
1385  */
1386 class MssqlField implements Field {
1387         private $name, $tableName, $default, $max_length, $nullable, $type;
1388
1389         function __construct( $info ) {
1390                 $this->name = $info['COLUMN_NAME'];
1391                 $this->tableName = $info['TABLE_NAME'];
1392                 $this->default = $info['COLUMN_DEFAULT'];
1393                 $this->max_length = $info['CHARACTER_MAXIMUM_LENGTH'];
1394                 $this->nullable = !( strtolower( $info['IS_NULLABLE'] ) == 'no' );
1395                 $this->type = $info['DATA_TYPE'];
1396         }
1397
1398         function name() {
1399                 return $this->name;
1400         }
1401
1402         function tableName() {
1403                 return $this->tableName;
1404         }
1405
1406         function defaultValue() {
1407                 return $this->default;
1408         }
1409
1410         function maxLength() {
1411                 return $this->max_length;
1412         }
1413
1414         function isNullable() {
1415                 return $this->nullable;
1416         }
1417
1418         function type() {
1419                 return $this->type;
1420         }
1421 }
1422
1423 class MssqlBlob extends Blob {
1424         public function __construct( $data ) {
1425                 if ( $data instanceof MssqlBlob ) {
1426                         return $data;
1427                 } elseif ( $data instanceof Blob ) {
1428                         $this->mData = $data->fetch();
1429                 } elseif ( is_array( $data ) && is_object( $data ) ) {
1430                         $this->mData = serialize( $data );
1431                 } else {
1432                         $this->mData = $data;
1433                 }
1434         }
1435
1436         /**
1437          * Returns an unquoted hex representation of a binary string
1438          * for insertion into varbinary-type fields
1439          * @return string
1440          */
1441         public function fetch() {
1442                 if ( $this->mData === null ) {
1443                         return 'null';
1444                 }
1445
1446                 $ret = '0x';
1447                 $dataLength = strlen( $this->mData );
1448                 for ( $i = 0; $i < $dataLength; $i++ ) {
1449                         $ret .= bin2hex( pack( 'C', ord( $this->mData[$i] ) ) );
1450                 }
1451
1452                 return $ret;
1453         }
1454 }
1455
1456 class MssqlResultWrapper extends ResultWrapper {
1457         private $mSeekTo = null;
1458
1459         /**
1460          * @return stdClass|bool
1461          */
1462         public function fetchObject() {
1463                 $res = $this->result;
1464
1465                 if ( $this->mSeekTo !== null ) {
1466                         $result = sqlsrv_fetch_object( $res, 'stdClass', array(),
1467                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1468                         $this->mSeekTo = null;
1469                 } else {
1470                         $result = sqlsrv_fetch_object( $res );
1471                 }
1472
1473                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1474                 if ( $result === null ) {
1475                         return false;
1476                 }
1477
1478                 return $result;
1479         }
1480
1481         /**
1482          * @return array|bool
1483          */
1484         public function fetchRow() {
1485                 $res = $this->result;
1486
1487                 if ( $this->mSeekTo !== null ) {
1488                         $result = sqlsrv_fetch_array( $res, SQLSRV_FETCH_BOTH,
1489                                 SQLSRV_SCROLL_ABSOLUTE, $this->mSeekTo );
1490                         $this->mSeekTo = null;
1491                 } else {
1492                         $result = sqlsrv_fetch_array( $res );
1493                 }
1494
1495                 // MediaWiki expects us to return boolean false when there are no more rows instead of null
1496                 if ( $result === null ) {
1497                         return false;
1498                 }
1499
1500                 return $result;
1501         }
1502
1503         /**
1504          * @param int $row
1505          * @return bool
1506          */
1507         public function seek( $row ) {
1508                 $res = $this->result;
1509
1510                 // check bounds
1511                 $numRows = $this->db->numRows( $res );
1512                 $row = intval( $row );
1513
1514                 if ( $numRows === 0 ) {
1515                         return false;
1516                 } elseif ( $row < 0 || $row > $numRows - 1 ) {
1517                         return false;
1518                 }
1519
1520                 // Unlike MySQL, the seek actually happens on the next access
1521                 $this->mSeekTo = $row;
1522                 return true;
1523         }
1524 }