includes/libs/rdbms/database/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 namespace Wikimedia\Rdbms;
  29
  30 use Exception;
  31 use RuntimeException;
  32 use stdClass;
  33 use Wikimedia\AtEase\AtEase;
  34
  35 /**
  36  * @ingroup Database
  37  */
  38 class DatabaseMssql extends Database {
  39         /** @var int */
  40         protected $serverPort;
  41         /** @var bool */
  42         protected $useWindowsAuth = false;
  43         /** @var int|null */
  44         protected $lastInsertId = null;
  45         /** @var int|null */
  46         protected $lastAffectedRowCount = null;
  47         /** @var int */
  48         protected $subqueryId = 0;
  49         /** @var bool */
  50         protected $scrollableCursor = true;
  51         /** @var bool */
  52         protected $prepareStatements = true;
  53         /** @var stdClass[][]|null */
  54         protected $binaryColumnCache = null;
  55         /** @var stdClass[][]|null */
  56         protected $bitColumnCache = null;
  57         /** @var bool */
  58         protected $ignoreDupKeyErrors = false;
  59         /** @var string[] */
  60         protected $ignoreErrors = [];
  61
  62         public function implicitGroupby() {
  63                 return false;
  64         }
  65
  66         public function implicitOrderby() {
  67                 return false;
  68         }
  69
  70         public function unionSupportsOrderAndLimit() {
  71                 return false;
  72         }
  73
  74         public function __construct( array $params ) {
  75                 $this->serverPort = $params['port'];
  76                 $this->useWindowsAuth = $params['UseWindowsAuth'];
  77
  78                 parent::__construct( $params );
  79         }
  80
  81         protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix ) {
  82                 // Test for driver support, to avoid suppressed fatal error
  83                 if ( !function_exists( 'sqlsrv_connect' ) ) {
  84                         throw new DBConnectionError(
  85                                 $this,
  86                                 "Microsoft SQL Server Native (sqlsrv) functions missing.
  87                                 You can download the driver from: http://go.microsoft.com/fwlink/?LinkId=123470\n"
  88                         );
  89                 }
  90
  91                 $this->close();
  92                 $this->server = $server;
  93                 $this->user = $user;
  94                 $this->password = $password;
  95
  96                 $connectionInfo = [];
  97
  98                 if ( $dbName != '' ) {
  99                         $connectionInfo['Database'] = $dbName;
 100                 }
 101
 102                 // Decide which auth scenerio to use
 103                 // if we are using Windows auth, then don't add credentials to $connectionInfo
 104                 if ( !$this->useWindowsAuth ) {
 105                         $connectionInfo['UID'] = $user;
 106                         $connectionInfo['PWD'] = $password;
 107                 }
 108
 109                 AtEase::suppressWarnings();
 110                 $this->conn = sqlsrv_connect( $server, $connectionInfo );
 111                 AtEase::restoreWarnings();
 112
 113                 if ( $this->conn === false ) {
 114                         $error = $this->lastError();
 115                         $this->connLogger->error(
 116                                 "Error connecting to {db_server}: {error}",
 117                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 118                         );
 119                         throw new DBConnectionError( $this, $error );
 120                 }
 121
 122                 $this->currentDomain = new DatabaseDomain(
 123                         ( $dbName != '' ) ? $dbName : null,
 124                         null,
 125                         $tablePrefix
 126                 );
 127
 128                 return (bool)$this->conn;
 129         }
 130
 131         /**
 132          * Closes a database connection, if it is open
 133          * Returns success, true if already closed
 134          * @return bool
 135          */
 136         protected function closeConnection() {
 137                 return sqlsrv_close( $this->conn );
 138         }
 139
 140         /**
 141          * @param bool|MssqlResultWrapper|resource $result
 142          * @return bool|MssqlResultWrapper
 143          */
 144         protected function resultObject( $result ) {
 145                 if ( !$result ) {
 146                         return false;
 147                 } elseif ( $result instanceof MssqlResultWrapper ) {
 148                         return $result;
 149                 } elseif ( $result === true ) {
 150                         // Successful write query
 151                         return $result;
 152                 } else {
 153                         return new MssqlResultWrapper( $this, $result );
 154                 }
 155         }
 156
 157         /**
 158          * @param string $sql
 159          * @return bool|MssqlResultWrapper|resource
 160          */
 161         protected function doQuery( $sql ) {
 162                 // several extensions seem to think that all databases support limits
 163                 // via LIMIT N after the WHERE clause, but  MSSQL uses SELECT TOP N,
 164                 // so to catch any of those extensions we'll do a quick check for a
 165                 // LIMIT clause and pass $sql through $this->LimitToTopN() which parses
 166                 // the LIMIT clause and passes the result to $this->limitResult();
 167                 if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) {
 168                         // massage LIMIT -> TopN
 169                         $sql = $this->LimitToTopN( $sql );
 170                 }
 171
 172                 // MSSQL doesn't have EXTRACT(epoch FROM XXX)
 173                 if ( preg_match( '#\bEXTRACT\s*?\(\s*?EPOCH\s+FROM\b#i', $sql, $matches ) ) {
 174                         // This is same as UNIX_TIMESTAMP, we need to calc # of seconds from 1970
 175                         $sql = str_replace( $matches[0], "DATEDIFF(s,CONVERT(datetime,'1/1/1970'),", $sql );
 176                 }
 177
 178                 // perform query
 179
 180                 // SQLSRV_CURSOR_STATIC is slower than SQLSRV_CURSOR_CLIENT_BUFFERED (one of the two is
 181                 // needed if we want to be able to seek around the result set), however CLIENT_BUFFERED
 182                 // has a bug in the sqlsrv driver where wchar_t types (such as nvarchar) that are empty
 183                 // strings make php throw a fatal error "Severe error translating Unicode"
 184                 if ( $this->scrollableCursor ) {
 185                         $scrollArr = [ 'Scrollable' => SQLSRV_CURSOR_STATIC ];
 186                 } else {
 187                         $scrollArr = [];
 188                 }
 189
 190                 if ( $this->prepareStatements ) {
 191                         // we do prepare + execute so we can get its field metadata for later usage if desired
 192                         $stmt = sqlsrv_prepare( $this->conn, $sql, [], $scrollArr );
 193                         $success = sqlsrv_execute( $stmt );
 194                 } else {
 195                         $stmt = sqlsrv_query( $this->conn, $sql, [], $scrollArr );
 196                         $success = (bool)$stmt;
 197                 }
 198
 199                 // Make a copy to ensure what we add below does not get reflected in future queries
 200                 $ignoreErrors = $this->ignoreErrors;
 201
 202                 if ( $this->ignoreDupKeyErrors ) {
 203                         // ignore duplicate key errors
 204                         // this emulates INSERT IGNORE in MySQL
 205                         $ignoreErrors[] = '2601'; // duplicate key error caused by unique index
 206                         $ignoreErrors[] = '2627'; // duplicate key error caused by primary key
 207                         $ignoreErrors[] = '3621'; // generic "the statement has been terminated" error
 208                 }
 209
 210                 if ( $success === false ) {
 211                         $errors = sqlsrv_errors();
 212                         $success = true;
 213
 214                         foreach ( $errors as $err ) {
 215                                 if ( !in_array( $err['code'], $ignoreErrors ) ) {
 216                                         $success = false;
 217                                         break;
 218                                 }
 219                         }
 220
 221                         if ( $success === false ) {
 222                                 return false;
 223                         }
 224                 }
 225                 // remember number of rows affected
 226                 $this->lastAffectedRowCount = sqlsrv_rows_affected( $stmt );
 227
 228                 return $stmt;
 229         }
 230
 231         public function freeResult( $res ) {
 232                 sqlsrv_free_stmt( ResultWrapper::unwrap( $res ) );
 233         }
 234
 235         /**
 236          * @param IResultWrapper $res
 237          * @return stdClass
 238          */
 239         public function fetchObject( $res ) {
 240                 // $res is expected to be an instance of MssqlResultWrapper here
 241                 return $res->fetchObject();
 242         }
 243
 244         /**
 245          * @param IResultWrapper $res
 246          * @return array
 247          */
 248         public function fetchRow( $res ) {
 249                 return $res->fetchRow();
 250         }
 251
 252         /**
 253          * @param mixed $res
 254          * @return int
 255          */
 256         public function numRows( $res ) {
 257                 $res = ResultWrapper::unwrap( $res );
 258
 259                 $ret = sqlsrv_num_rows( $res );
 260                 if ( $ret === false ) {
 261                         // we cannot get an amount of rows from this cursor type
 262                         // has_rows returns bool true/false if the result has rows
 263                         $ret = (int)sqlsrv_has_rows( $res );
 264                 }
 265
 266                 return $ret;
 267         }
 268
 269         /**
 270          * @param mixed $res
 271          * @return int
 272          */
 273         public function numFields( $res ) {
 274                 return sqlsrv_num_fields( ResultWrapper::unwrap( $res ) );
 275         }
 276
 277         /**
 278          * @param mixed $res
 279          * @param int $n
 280          * @return int
 281          */
 282         public function fieldName( $res, $n ) {
 283                 return sqlsrv_field_metadata( ResultWrapper::unwrap( $res ) )[$n]['Name'];
 284         }
 285
 286         /**
 287          * This must be called after nextSequenceVal
 288          * @return int|null
 289          */
 290         public function insertId() {
 291                 return $this->lastInsertId;
 292         }
 293
 294         /**
 295          * @param MssqlResultWrapper $res
 296          * @param int $row
 297          * @return bool
 298          */
 299         public function dataSeek( $res, $row ) {
 300                 return $res->seek( $row );
 301         }
 302
 303         /**
 304          * @return string
 305          */
 306         public function lastError() {
 307                 $strRet = '';
 308                 $retErrors = sqlsrv_errors( SQLSRV_ERR_ALL );
 309                 if ( $retErrors != null ) {
 310                         foreach ( $retErrors as $arrError ) {
 311                                 $strRet .= $this->formatError( $arrError ) . "\n";
 312                         }
 313                 } else {
 314                         $strRet = "No errors found";
 315                 }
 316
 317                 return $strRet;
 318         }
 319
 320         /**
 321          * @param array $err
 322          * @return string
 323          */
 324         private function formatError( $err ) {
 325                 return '[SQLSTATE ' .
 326                         $err['SQLSTATE'] . '][Error Code ' . $err['code'] . ']' . $err['message'];
 327         }
 328
 329         /**
 330          * @return string|int
 331          */
 332         public function lastErrno() {
 333                 $err = sqlsrv_errors( SQLSRV_ERR_ALL );
 334                 if ( $err !== null && isset( $err[0] ) ) {
 335                         return $err[0]['code'];
 336                 } else {
 337                         return 0;
 338                 }
 339         }
 340
 341         protected function wasKnownStatementRollbackError() {
 342                 $errors = sqlsrv_errors( SQLSRV_ERR_ALL );
 343                 if ( !$errors ) {
 344                         return false;
 345                 }
 346                 // The transaction vs statement rollback behavior depends on XACT_ABORT, so make sure
 347                 // that the "statement has been terminated" error (3621) is specifically present.
 348                 // https://docs.microsoft.com/en-us/sql/t-sql/statements/set-xact-abort-transact-sql
 349                 $statementOnly = false;
 350                 $codeWhitelist = [ '2601', '2627', '547' ];
 351                 foreach ( $errors as $error ) {
 352                         if ( $error['code'] == '3621' ) {
 353                                 $statementOnly = true;
 354                         } elseif ( !in_array( $error['code'], $codeWhitelist ) ) {
 355                                 $statementOnly = false;
 356                                 break;
 357                         }
 358                 }
 359
 360                 return $statementOnly;
 361         }
 362
 363         public function serverIsReadOnly() {
 364                 $encDatabase = $this->addQuotes( $this->getDBname() );
 365                 $res = $this->query(
 366                         "SELECT IS_READ_ONLY FROM SYS.DATABASES WHERE NAME = $encDatabase",
 367                         __METHOD__
 368                 );
 369                 $row = $this->fetchObject( $res );
 370
 371                 return $row ? (bool)$row->IS_READ_ONLY : false;
 372         }
 373
 374         /**
 375          * @return int
 376          */
 377         protected function fetchAffectedRowCount() {
 378                 return $this->lastAffectedRowCount;
 379         }
 380
 381         /**
 382          * SELECT wrapper
 383          *
 384          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 385          * @param mixed $vars Array or string, field name(s) to be retrieved
 386          * @param mixed $conds Array or string, condition(s) for WHERE
 387          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 388          * @param array $options Associative array of options (e.g.
 389          *   [ 'GROUP BY' => 'page_title' ]), see Database::makeSelectOptions
 390          *   code for list of supported stuff
 391          * @param array $join_conds Associative array of table join conditions
 392          *   (optional) (e.g. [ 'page' => [ 'LEFT JOIN','page_latest=rev_id' ] ]
 393          * @return mixed Database result resource (feed to Database::fetchObject
 394          *   or whatever), or false on failure
 395          * @throws DBQueryError
 396          * @throws DBUnexpectedError
 397          * @throws Exception
 398          */
 399         public function select( $table, $vars, $conds = '', $fname = __METHOD__,
 400                 $options = [], $join_conds = []
 401         ) {
 402                 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 403                 if ( isset( $options['EXPLAIN'] ) ) {
 404                         try {
 405                                 $this->scrollableCursor = false;
 406                                 $this->prepareStatements = false;
 407                                 $this->query( "SET SHOWPLAN_ALL ON" );
 408                                 $ret = $this->query( $sql, $fname );
 409                                 $this->query( "SET SHOWPLAN_ALL OFF" );
 410                         } catch ( DBQueryError $dqe ) {
 411                                 if ( isset( $options['FOR COUNT'] ) ) {
 412                                         // likely don't have privs for SHOWPLAN, so run a select count instead
 413                                         $this->query( "SET SHOWPLAN_ALL OFF" );
 414                                         unset( $options['EXPLAIN'] );
 415                                         $ret = $this->select(
 416                                                 $table,
 417                                                 'COUNT(*) AS EstimateRows',
 418                                                 $conds,
 419                                                 $fname,
 420                                                 $options,
 421                                                 $join_conds
 422                                         );
 423                                 } else {
 424                                         // someone actually wanted the query plan instead of an est row count
 425                                         // let them know of the error
 426                                         $this->scrollableCursor = true;
 427                                         $this->prepareStatements = true;
 428                                         throw $dqe;
 429                                 }
 430                         }
 431                         $this->scrollableCursor = true;
 432                         $this->prepareStatements = true;
 433                         return $ret;
 434                 }
 435                 return $this->query( $sql, $fname );
 436         }
 437
 438         /**
 439          * SELECT wrapper
 440          *
 441          * @param mixed $table Array or string, table name(s) (prefix auto-added)
 442          * @param mixed $vars Array or string, field name(s) to be retrieved
 443          * @param mixed $conds Array or string, condition(s) for WHERE
 444          * @param string $fname Calling function name (use __METHOD__) for logs/profiling
 445          * @param array $options Associative array of options (e.g. [ 'GROUP BY' => 'page_title' ]),
 446          *   see Database::makeSelectOptions code for list of supported stuff
 447          * @param array $join_conds Associative array of table join conditions (optional)
 448          *    (e.g. [ 'page' => [ 'LEFT JOIN','page_latest=rev_id' ] ]
 449          * @return string The SQL text
 450          */
 451         public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
 452                 $options = [], $join_conds = []
 453         ) {
 454                 if ( isset( $options['EXPLAIN'] ) ) {
 455                         unset( $options['EXPLAIN'] );
 456                 }
 457
 458                 $sql = parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 459
 460                 // try to rewrite aggregations of bit columns (currently MAX and MIN)
 461                 if ( strpos( $sql, 'MAX(' ) !== false || strpos( $sql, 'MIN(' ) !== false ) {
 462                         $bitColumns = [];
 463                         if ( is_array( $table ) ) {
 464                                 $tables = $table;
 465                                 while ( $tables ) {
 466                                         $t = array_pop( $tables );
 467                                         if ( is_array( $t ) ) {
 468                                                 $tables = array_merge( $tables, $t );
 469                                         } else {
 470                                                 $bitColumns += $this->getBitColumns( $this->tableName( $t ) );
 471                                         }
 472                                 }
 473                         } else {
 474                                 $bitColumns = $this->getBitColumns( $this->tableName( $table ) );
 475                         }
 476
 477                         foreach ( $bitColumns as $col => $info ) {
 478                                 $replace = [
 479                                         "MAX({$col})" => "MAX(CAST({$col} AS tinyint))",
 480                                         "MIN({$col})" => "MIN(CAST({$col} AS tinyint))",
 481                                 ];
 482                                 $sql = str_replace( array_keys( $replace ), array_values( $replace ), $sql );
 483                         }
 484                 }
 485
 486                 return $sql;
 487         }
 488
 489         public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
 490                 $fname = __METHOD__
 491         ) {
 492                 $this->scrollableCursor = false;
 493                 try {
 494                         parent::deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname );
 495                 } catch ( Exception $e ) {
 496                         $this->scrollableCursor = true;
 497                         throw $e;
 498                 }
 499                 $this->scrollableCursor = true;
 500         }
 501
 502         public function delete( $table, $conds, $fname = __METHOD__ ) {
 503                 $this->scrollableCursor = false;
 504                 try {
 505                         parent::delete( $table, $conds, $fname );
 506                 } catch ( Exception $e ) {
 507                         $this->scrollableCursor = true;
 508                         throw $e;
 509                 }
 510                 $this->scrollableCursor = true;
 511
 512                 return true;
 513         }
 514
 515         /**
 516          * Estimate rows in dataset
 517          * Returns estimated count, based on SHOWPLAN_ALL output
 518          * This is not necessarily an accurate estimate, so use sparingly
 519          * Returns -1 if count cannot be found
 520          * Takes same arguments as Database::select()
 521          * @param string $table
 522          * @param string $var
 523          * @param string $conds
 524          * @param string $fname
 525          * @param array $options
 526          * @param array $join_conds
 527          * @return int
 528          */
 529         public function estimateRowCount( $table, $var = '*', $conds = '',
 530                 $fname = __METHOD__, $options = [], $join_conds = []
 531         ) {
 532                 $conds = $this->normalizeConditions( $conds, $fname );
 533                 $column = $this->extractSingleFieldFromList( $var );
 534                 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
 535                         $conds[] = "$column IS NOT NULL";
 536                 }
 537
 538                 // http://msdn2.microsoft.com/en-us/library/aa259203.aspx
 539                 $options['EXPLAIN'] = true;
 540                 $options['FOR COUNT'] = true;
 541                 $res = $this->select( $table, $var, $conds, $fname, $options, $join_conds );
 542
 543                 $rows = -1;
 544                 if ( $res ) {
 545                         $row = $this->fetchRow( $res );
 546
 547                         if ( isset( $row['EstimateRows'] ) ) {
 548                                 $rows = (int)$row['EstimateRows'];
 549                         }
 550                 }
 551
 552                 return $rows;
 553         }
 554
 555         /**
 556          * Returns information about an index
 557          * If errors are explicitly ignored, returns NULL on failure
 558          * @param string $table
 559          * @param string $index
 560          * @param string $fname
 561          * @return array|bool|null
 562          */
 563         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 564                 # This does not return the same info as MYSQL would, but that's OK
 565                 # because MediaWiki never uses the returned value except to check for
 566                 # the existence of indexes.
 567                 $sql = "sp_helpindex '" . $this->tableName( $table ) . "'";
 568                 $res = $this->query( $sql, $fname );
 569
 570                 if ( !$res ) {
 571                         return null;
 572                 }
 573
 574                 $result = [];
 575                 foreach ( $res as $row ) {
 576                         if ( $row->index_name == $index ) {
 577                                 $row->Non_unique = !stristr( $row->index_description, "unique" );
 578                                 $cols = explode( ", ", $row->index_keys );
 579                                 foreach ( $cols as $col ) {
 580                                         $row->Column_name = trim( $col );
 581                                         $result[] = clone $row;
 582                                 }
 583                         } elseif ( $index == 'PRIMARY' && stristr( $row->index_description, 'PRIMARY' ) ) {
 584                                 $row->Non_unique = 0;
 585                                 $cols = explode( ", ", $row->index_keys );
 586                                 foreach ( $cols as $col ) {
 587                                         $row->Column_name = trim( $col );
 588                                         $result[] = clone $row;
 589                                 }
 590                         }
 591                 }
 592
 593                 return $result ?: false;
 594         }
 595
 596         /**
 597          * INSERT wrapper, inserts an array into a table
 598          *
 599          * $arrToInsert may be a single associative array, or an array of these with numeric keys, for
 600          * multi-row insert.
 601          *
 602          * Usually aborts on failure
 603          * If errors are explicitly ignored, returns success
 604          * @param string $table
 605          * @param array $arrToInsert
 606          * @param string $fname
 607          * @param array $options
 608          * @return bool
 609          * @throws Exception
 610          */
 611         public function insert( $table, $arrToInsert, $fname = __METHOD__, $options = [] ) {
 612                 # No rows to insert, easy just return now
 613                 if ( !count( $arrToInsert ) ) {
 614                         return true;
 615                 }
 616
 617                 if ( !is_array( $options ) ) {
 618                         $options = [ $options ];
 619                 }
 620
 621                 $table = $this->tableName( $table );
 622
 623                 if ( !( isset( $arrToInsert[0] ) && is_array( $arrToInsert[0] ) ) ) { // Not multi row
 624                         $arrToInsert = [ 0 => $arrToInsert ]; // make everything multi row compatible
 625                 }
 626
 627                 // We know the table we're inserting into, get its identity column
 628                 $identity = null;
 629                 // strip matching square brackets and the db/schema from table name
 630                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
 631                 $tableRaw = array_pop( $tableRawArr );
 632                 $res = $this->doQuery(
 633                         "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS " .
 634                                 "WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'"
 635                 );
 636                 if ( $res && sqlsrv_has_rows( $res ) ) {
 637                         // There is an identity for this table.
 638                         $identityArr = sqlsrv_fetch_array( $res, SQLSRV_FETCH_ASSOC );
 639                         $identity = array_pop( $identityArr );
 640                 }
 641                 sqlsrv_free_stmt( $res );
 642
 643                 // Determine binary/varbinary fields so we can encode data as a hex string like 0xABCDEF
 644                 $binaryColumns = $this->getBinaryColumns( $table );
 645
 646                 // INSERT IGNORE is not supported by SQL Server
 647                 // remove IGNORE from options list and set ignore flag to true
 648                 if ( in_array( 'IGNORE', $options ) ) {
 649                         $options = array_diff( $options, [ 'IGNORE' ] );
 650                         $this->ignoreDupKeyErrors = true;
 651                 }
 652
 653                 $ret = null;
 654                 foreach ( $arrToInsert as $a ) {
 655                         // start out with empty identity column, this is so we can return
 656                         // it as a result of the INSERT logic
 657                         $sqlPre = '';
 658                         $sqlPost = '';
 659                         $identityClause = '';
 660
 661                         // if we have an identity column
 662                         if ( $identity ) {
 663                                 // iterate through
 664                                 foreach ( $a as $k => $v ) {
 665                                         if ( $k == $identity ) {
 666                                                 if ( !is_null( $v ) ) {
 667                                                         // there is a value being passed to us,
 668                                                         // we need to turn on and off inserted identity
 669                                                         $sqlPre = "SET IDENTITY_INSERT $table ON;";
 670                                                         $sqlPost = ";SET IDENTITY_INSERT $table OFF;";
 671                                                 } else {
 672                                                         // we can't insert NULL into an identity column,
 673                                                         // so remove the column from the insert.
 674                                                         unset( $a[$k] );
 675                                                 }
 676                                         }
 677                                 }
 678
 679                                 // we want to output an identity column as result
 680                                 $identityClause = "OUTPUT INSERTED.$identity ";
 681                         }
 682
 683                         $keys = array_keys( $a );
 684
 685                         // Build the actual query
 686                         $sql = $sqlPre . 'INSERT ' . implode( ' ', $options ) .
 687                                 " INTO $table (" . implode( ',', $keys ) . ") $identityClause VALUES (";
 688
 689                         $first = true;
 690                         foreach ( $a as $key => $value ) {
 691                                 if ( isset( $binaryColumns[$key] ) ) {
 692                                         $value = new MssqlBlob( $value );
 693                                 }
 694                                 if ( $first ) {
 695                                         $first = false;
 696                                 } else {
 697                                         $sql .= ',';
 698                                 }
 699                                 if ( is_null( $value ) ) {
 700                                         $sql .= 'null';
 701                                 } else {
 702                                         $sql .= $this->addQuotes( $value );
 703                                 }
 704                         }
 705                         $sql .= ')' . $sqlPost;
 706
 707                         // Run the query
 708                         $this->scrollableCursor = false;
 709                         try {
 710                                 $ret = $this->query( $sql );
 711                         } catch ( Exception $e ) {
 712                                 $this->scrollableCursor = true;
 713                                 $this->ignoreDupKeyErrors = false;
 714                                 throw $e;
 715                         }
 716                         $this->scrollableCursor = true;
 717
 718                         if ( $ret instanceof IResultWrapper && !is_null( $identity ) ) {
 719                                 // Then we want to get the identity column value we were assigned and save it off
 720                                 $row = $ret->fetchObject();
 721                                 if ( is_object( $row ) ) {
 722                                         $this->lastInsertId = $row->$identity;
 723                                         // It seems that mAffectedRows is -1 sometimes when OUTPUT INSERTED.identity is
 724                                         // used if we got an identity back, we know for sure a row was affected, so
 725                                         // adjust that here
 726                                         if ( $this->lastAffectedRowCount == -1 ) {
 727                                                 $this->lastAffectedRowCount = 1;
 728                                         }
 729                                 }
 730                         }
 731                 }
 732
 733                 $this->ignoreDupKeyErrors = false;
 734
 735                 return true;
 736         }
 737
 738         /**
 739          * INSERT SELECT wrapper
 740          * $varMap must be an associative array of the form [ 'dest1' => 'source1', ... ]
 741          * Source items may be literals rather than field names, but strings should
 742          * be quoted with Database::addQuotes().
 743          * @param string $destTable
 744          * @param array|string $srcTable May be an array of tables.
 745          * @param array $varMap
 746          * @param array $conds May be "*" to copy the whole table.
 747          * @param string $fname
 748          * @param array $insertOptions
 749          * @param array $selectOptions
 750          * @param array $selectJoinConds
 751          * @throws Exception
 752          */
 753         protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 754                 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
 755         ) {
 756                 $this->scrollableCursor = false;
 757                 try {
 758                         parent::nativeInsertSelect(
 759                                 $destTable,
 760                                 $srcTable,
 761                                 $varMap,
 762                                 $conds,
 763                                 $fname,
 764                                 $insertOptions,
 765                                 $selectOptions,
 766                                 $selectJoinConds
 767                         );
 768                 } catch ( Exception $e ) {
 769                         $this->scrollableCursor = true;
 770                         throw $e;
 771                 }
 772                 $this->scrollableCursor = true;
 773         }
 774
 775         /**
 776          * UPDATE wrapper. Takes a condition array and a SET array.
 777          *
 778          * @param string $table Name of the table to UPDATE. This will be passed through
 779          *                Database::tableName().
 780          *
 781          * @param array $values An array of values to SET. For each array element,
 782          *                the key gives the field name, and the value gives the data
 783          *                to set that field to. The data will be quoted by
 784          *                Database::addQuotes().
 785          *
 786          * @param array $conds An array of conditions (WHERE). See
 787          *                Database::select() for the details of the format of
 788          *                condition arrays. Use '*' to update all rows.
 789          *
 790          * @param string $fname The function name of the caller (from __METHOD__),
 791          *                for logging and profiling.
 792          *
 793          * @param array $options An array of UPDATE options, can be:
 794          *                   - IGNORE: Ignore unique key conflicts
 795          *                   - LOW_PRIORITY: MySQL-specific, see MySQL manual.
 796          * @return bool
 797          * @throws DBUnexpectedError
 798          * @throws Exception
 799          */
 800         function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
 801                 $table = $this->tableName( $table );
 802                 $binaryColumns = $this->getBinaryColumns( $table );
 803
 804                 $opts = $this->makeUpdateOptions( $options );
 805                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET, $binaryColumns );
 806
 807                 if ( $conds !== [] && $conds !== '*' ) {
 808                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND, $binaryColumns );
 809                 }
 810
 811                 $this->scrollableCursor = false;
 812                 try {
 813                         $this->query( $sql );
 814                 } catch ( Exception $e ) {
 815                         $this->scrollableCursor = true;
 816                         throw $e;
 817                 }
 818                 $this->scrollableCursor = true;
 819                 return true;
 820         }
 821
 822         /**
 823          * Makes an encoded list of strings from an array
 824          * @param array $a Containing the data
 825          * @param int $mode Constant
 826          *      - LIST_COMMA:          comma separated, no field names
 827          *      - LIST_AND:            ANDed WHERE clause (without the WHERE). See
 828          *        the documentation for $conds in Database::select().
 829          *      - LIST_OR:             ORed WHERE clause (without the WHERE)
 830          *      - LIST_SET:            comma separated with field names, like a SET clause
 831          *      - LIST_NAMES:          comma separated field names
 832          * @param array $binaryColumns Contains a list of column names that are binary types
 833          *      This is a custom parameter only present for MS SQL.
 834          *
 835          * @throws DBUnexpectedError
 836          * @return string
 837          */
 838         public function makeList( $a, $mode = LIST_COMMA, $binaryColumns = [] ) {
 839                 if ( !is_array( $a ) ) {
 840                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
 841                 }
 842
 843                 if ( $mode != LIST_NAMES ) {
 844                         // In MS SQL, values need to be specially encoded when they are
 845                         // inserted into binary fields. Perform this necessary encoding
 846                         // for the specified set of columns.
 847                         foreach ( array_keys( $a ) as $field ) {
 848                                 if ( !isset( $binaryColumns[$field] ) ) {
 849                                         continue;
 850                                 }
 851
 852                                 if ( is_array( $a[$field] ) ) {
 853                                         foreach ( $a[$field] as &$v ) {
 854                                                 $v = new MssqlBlob( $v );
 855                                         }
 856                                         unset( $v );
 857                                 } else {
 858                                         $a[$field] = new MssqlBlob( $a[$field] );
 859                                 }
 860                         }
 861                 }
 862
 863                 return parent::makeList( $a, $mode );
 864         }
 865
 866         /**
 867          * @param string $table
 868          * @param string $field
 869          * @return int Returns the size of a text field, or -1 for "unlimited"
 870          */
 871         public function textFieldSize( $table, $field ) {
 872                 $table = $this->tableName( $table );
 873                 $sql = "SELECT CHARACTER_MAXIMUM_LENGTH,DATA_TYPE FROM INFORMATION_SCHEMA.Columns
 874                         WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'";
 875                 $res = $this->query( $sql );
 876                 $row = $this->fetchRow( $res );
 877                 $size = -1;
 878                 if ( strtolower( $row['DATA_TYPE'] ) != 'text' ) {
 879                         $size = $row['CHARACTER_MAXIMUM_LENGTH'];
 880                 }
 881
 882                 return $size;
 883         }
 884
 885         /**
 886          * Construct a LIMIT query with optional offset
 887          * This is used for query pages
 888          *
 889          * @param string $sql SQL query we will append the limit too
 890          * @param int $limit The SQL limit
 891          * @param bool|int $offset The SQL offset (default false)
 892          * @return array|string
 893          * @throws DBUnexpectedError
 894          */
 895         public function limitResult( $sql, $limit, $offset = false ) {
 896                 if ( $offset === false || $offset == 0 ) {
 897                         if ( strpos( $sql, "SELECT" ) === false ) {
 898                                 return "TOP {$limit} " . $sql;
 899                         } else {
 900                                 return preg_replace( '/\bSELECT(\s+DISTINCT)?\b/Dsi',
 901                                         'SELECT$1 TOP ' . $limit, $sql, 1 );
 902                         }
 903                 } else {
 904                         // This one is fun, we need to pull out the select list as well as any ORDER BY clause
 905                         $select = $orderby = [];
 906                         $s1 = preg_match( '#SELECT\s+(.+?)\s+FROM#Dis', $sql, $select );
 907                         $s2 = preg_match( '#(ORDER BY\s+.+?)(\s*FOR XML .*)?$#Dis', $sql, $orderby );
 908                         $postOrder = '';
 909                         $first = $offset + 1;
 910                         $last = $offset + $limit;
 911                         $sub1 = 'sub_' . $this->subqueryId;
 912                         $sub2 = 'sub_' . ( $this->subqueryId + 1 );
 913                         $this->subqueryId += 2;
 914                         if ( !$s1 ) {
 915                                 // wat
 916                                 throw new DBUnexpectedError( $this, "Attempting to LIMIT a non-SELECT query\n" );
 917                         }
 918                         if ( !$s2 ) {
 919                                 // no ORDER BY
 920                                 $overOrder = 'ORDER BY (SELECT 1)';
 921                         } else {
 922                                 if ( !isset( $orderby[2] ) || !$orderby[2] ) {
 923                                         // don't need to strip it out if we're using a FOR XML clause
 924                                         $sql = str_replace( $orderby[1], '', $sql );
 925                                 }
 926                                 $overOrder = $orderby[1];
 927                                 $postOrder = ' ' . $overOrder;
 928                         }
 929                         $sql = "SELECT {$select[1]}
 930                                         FROM (
 931                                                 SELECT ROW_NUMBER() OVER({$overOrder}) AS rowNumber, *
 932                                                 FROM ({$sql}) {$sub1}
 933                                         ) {$sub2}
 934                                         WHERE rowNumber BETWEEN {$first} AND {$last}{$postOrder}";
 935
 936                         return $sql;
 937                 }
 938         }
 939
 940         /**
 941          * If there is a limit clause, parse it, strip it, and pass the remaining
 942          * SQL through limitResult() with the appropriate parameters. Not the
 943          * prettiest solution, but better than building a whole new parser. This
 944          * exists becase there are still too many extensions that don't use dynamic
 945          * sql generation.
 946          *
 947          * @param string $sql
 948          * @return array|mixed|string
 949          */
 950         public function LimitToTopN( $sql ) {
 951                 // Matches: LIMIT {[offset,] row_count | row_count OFFSET offset}
 952                 $pattern = '/\bLIMIT\s+((([0-9]+)\s*,\s*)?([0-9]+)(\s+OFFSET\s+([0-9]+))?)/i';
 953                 if ( preg_match( $pattern, $sql, $matches ) ) {
 954                         $row_count = $matches[4];
 955                         $offset = $matches[3] ?: $matches[6] ?: false;
 956
 957                         // strip the matching LIMIT clause out
 958                         $sql = str_replace( $matches[0], '', $sql );
 959
 960                         return $this->limitResult( $sql, $row_count, $offset );
 961                 }
 962
 963                 return $sql;
 964         }
 965
 966         /**
 967          * @return string Wikitext of a link to the server software's web site
 968          */
 969         public function getSoftwareLink() {
 970                 return "[{{int:version-db-mssql-url}} MS SQL Server]";
 971         }
 972
 973         /**
 974          * @return string Version information from the database
 975          */
 976         public function getServerVersion() {
 977                 $server_info = sqlsrv_server_info( $this->conn );
 978                 $version = $server_info['SQLServerVersion'] ?? 'Error';
 979
 980                 return $version;
 981         }
 982
 983         /**
 984          * @param string $table
 985          * @param string $fname
 986          * @return bool
 987          */
 988         public function tableExists( $table, $fname = __METHOD__ ) {
 989                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
 990
 991                 if ( $db !== false ) {
 992                         // remote database
 993                         $this->queryLogger->error( "Attempting to call tableExists on a remote table" );
 994                         return false;
 995                 }
 996
 997                 if ( $schema === false ) {
 998                         $schema = $this->dbSchema();
 999                 }
1000
1001                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.TABLES
1002                         WHERE TABLE_TYPE = 'BASE TABLE'
1003                         AND TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table'" );
1004
1005                 if ( $res->numRows() ) {
1006                         return true;
1007                 } else {
1008                         return false;
1009                 }
1010         }
1011
1012         /**
1013          * Query whether a given column exists in the mediawiki schema
1014          * @param string $table
1015          * @param string $field
1016          * @param string $fname
1017          * @return bool
1018          */
1019         public function fieldExists( $table, $field, $fname = __METHOD__ ) {
1020                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1021
1022                 if ( $db !== false ) {
1023                         // remote database
1024                         $this->queryLogger->error( "Attempting to call fieldExists on a remote table" );
1025                         return false;
1026                 }
1027
1028                 $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS
1029                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1030
1031                 if ( $res->numRows() ) {
1032                         return true;
1033                 } else {
1034                         return false;
1035                 }
1036         }
1037
1038         public function fieldInfo( $table, $field ) {
1039                 list( $db, $schema, $table ) = $this->tableName( $table, 'split' );
1040
1041                 if ( $db !== false ) {
1042                         // remote database
1043                         $this->queryLogger->error( "Attempting to call fieldInfo on a remote table" );
1044                         return false;
1045                 }
1046
1047                 $res = $this->query( "SELECT * FROM INFORMATION_SCHEMA.COLUMNS
1048                         WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" );
1049
1050                 $meta = $res->fetchRow();
1051                 if ( $meta ) {
1052                         return new MssqlField( $meta );
1053                 }
1054
1055                 return false;
1056         }
1057
1058         protected function doSavepoint( $identifier, $fname ) {
1059                 $this->query( 'SAVE TRANSACTION ' . $this->addIdentifierQuotes( $identifier ), $fname );
1060         }
1061
1062         protected function doReleaseSavepoint( $identifier, $fname ) {
1063                 // Not supported. Also not really needed, a new doSavepoint() for the
1064                 // same identifier will overwrite the old.
1065         }
1066
1067         protected function doRollbackToSavepoint( $identifier, $fname ) {
1068                 $this->query( 'ROLLBACK TRANSACTION ' . $this->addIdentifierQuotes( $identifier ), $fname );
1069         }
1070
1071         protected function doBegin( $fname = __METHOD__ ) {
1072                 if ( !sqlsrv_begin_transaction( $this->conn ) ) {
1073                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), 'BEGIN', $fname );
1074                 }
1075         }
1076
1077         /**
1078          * End a transaction
1079          * @param string $fname
1080          */
1081         protected function doCommit( $fname = __METHOD__ ) {
1082                 if ( !sqlsrv_commit( $this->conn ) ) {
1083                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), 'COMMIT', $fname );
1084                 }
1085         }
1086
1087         /**
1088          * Rollback a transaction.
1089          * No-op on non-transactional databases.
1090          * @param string $fname
1091          */
1092         protected function doRollback( $fname = __METHOD__ ) {
1093                 if ( !sqlsrv_rollback( $this->conn ) ) {
1094                         $this->queryLogger->error(
1095                                 "{fname}\t{db_server}\t{errno}\t{error}\t",
1096                                 $this->getLogContext( [
1097                                         'errno' => $this->lastErrno(),
1098                                         'error' => $this->lastError(),
1099                                         'fname' => $fname,
1100                                         'trace' => ( new RuntimeException() )->getTraceAsString()
1101                                 ] )
1102                         );
1103                 }
1104         }
1105
1106         /**
1107          * @param string $s
1108          * @return string
1109          */
1110         public function strencode( $s ) {
1111                 // Should not be called by us
1112                 return str_replace( "'", "''", $s );
1113         }
1114
1115         /**
1116          * @param string|int|null|bool|Blob $s
1117          * @return string|int
1118          */
1119         public function addQuotes( $s ) {
1120                 if ( $s instanceof MssqlBlob ) {
1121                         return $s->fetch();
1122                 } elseif ( $s instanceof Blob ) {
1123                         // this shouldn't really ever be called, but it's here if needed
1124                         // (and will quite possibly make the SQL error out)
1125                         $blob = new MssqlBlob( $s->fetch() );
1126                         return $blob->fetch();
1127                 } else {
1128                         if ( is_bool( $s ) ) {
1129                                 $s = $s ? 1 : 0;
1130                         }
1131                         return parent::addQuotes( $s );
1132                 }
1133         }
1134
1135         /**
1136          * @param string $s
1137          * @return string
1138          */
1139         public function addIdentifierQuotes( $s ) {
1140                 // http://msdn.microsoft.com/en-us/library/aa223962.aspx
1141                 return '[' . $s . ']';
1142         }
1143
1144         /**
1145          * @param string $name
1146          * @return bool
1147          */
1148         public function isQuotedIdentifier( $name ) {
1149                 return strlen( $name ) && $name[0] == '[' && substr( $name, -1, 1 ) == ']';
1150         }
1151
1152         /**
1153          * MS SQL supports more pattern operators than other databases (ex: [,],^)
1154          *
1155          * @param string $s
1156          * @param string $escapeChar
1157          * @return string
1158          */
1159         protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
1160                 return str_replace( [ $escapeChar, '%', '_', '[', ']', '^' ],
1161                         [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_",
1162                                 "{$escapeChar}[", "{$escapeChar}]", "{$escapeChar}^" ],
1163                         $s );
1164         }
1165
1166         protected function doSelectDomain( DatabaseDomain $domain ) {
1167                 if ( $domain->getSchema() !== null ) {
1168                         throw new DBExpectedError( $this, __CLASS__ . ": domain schemas are not supported." );
1169                 }
1170
1171                 $database = $domain->getDatabase();
1172                 if ( $database !== $this->getDBname() ) {
1173                         $sql = 'USE ' . $this->addIdentifierQuotes( $database );
1174                         list( $res, $err, $errno ) =
1175                                 $this->executeQuery( $sql, __METHOD__, self::QUERY_IGNORE_DBO_TRX );
1176
1177                         if ( $res === false ) {
1178                                 $this->reportQueryError( $err, $errno, $sql, __METHOD__ );
1179                                 return false; // unreachable
1180                         }
1181                 }
1182                 // Update that domain fields on success (no exception thrown)
1183                 $this->currentDomain = $domain;
1184
1185                 return true;
1186         }
1187
1188         /**
1189          * @param array $options An associative array of options to be turned into
1190          *   an SQL query, valid keys are listed in the function.
1191          * @return array
1192          */
1193         public function makeSelectOptions( $options ) {
1194                 $tailOpts = '';
1195                 $startOpts = '';
1196
1197                 $noKeyOptions = [];
1198                 foreach ( $options as $key => $option ) {
1199                         if ( is_numeric( $key ) ) {
1200                                 $noKeyOptions[$option] = true;
1201                         }
1202                 }
1203
1204                 $tailOpts .= $this->makeGroupByWithHaving( $options );
1205
1206                 $tailOpts .= $this->makeOrderBy( $options );
1207
1208                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1209                         $startOpts .= 'DISTINCT';
1210                 }
1211
1212                 if ( isset( $noKeyOptions['FOR XML'] ) ) {
1213                         // used in group concat field emulation
1214                         $tailOpts .= " FOR XML PATH('')";
1215                 }
1216
1217                 // we want this to be compatible with the output of parent::makeSelectOptions()
1218                 return [ $startOpts, '', $tailOpts, '', '' ];
1219         }
1220
1221         public function getType() {
1222                 return 'mssql';
1223         }
1224
1225         /**
1226          * @param array $stringList
1227          * @return string
1228          */
1229         public function buildConcat( $stringList ) {
1230                 return implode( ' + ', $stringList );
1231         }
1232
1233         /**
1234          * Build a GROUP_CONCAT or equivalent statement for a query.
1235          * MS SQL doesn't have GROUP_CONCAT so we emulate it with other stuff (and boy is it nasty)
1236          *
1237          * This is useful for combining a field for several rows into a single string.
1238          * NULL values will not appear in the output, duplicated values will appear,
1239          * and the resulting delimiter-separated values have no defined sort order.
1240          * Code using the results may need to use the PHP unique() or sort() methods.
1241          *
1242          * @param string $delim Glue to bind the results together
1243          * @param string|array $table Table name
1244          * @param string $field Field name
1245          * @param string|array $conds Conditions
1246          * @param string|array $join_conds Join conditions
1247          * @return string SQL text
1248          * @since 1.23
1249          */
1250         public function buildGroupConcatField( $delim, $table, $field, $conds = '',
1251                 $join_conds = []
1252         ) {
1253                 $gcsq = 'gcsq_' . $this->subqueryId;
1254                 $this->subqueryId++;
1255
1256                 $delimLen = strlen( $delim );
1257                 $fld = "{$field} + {$this->addQuotes( $delim )}";
1258                 $sql = "(SELECT LEFT({$field}, LEN({$field}) - {$delimLen}) FROM ("
1259                         . $this->selectSQLText( $table, $fld, $conds, null, [ 'FOR XML' ], $join_conds )
1260                         . ") {$gcsq} ({$field}))";
1261
1262                 return $sql;
1263         }
1264
1265         public function buildSubstring( $input, $startPosition, $length = null ) {
1266                 $this->assertBuildSubstringParams( $startPosition, $length );
1267                 if ( $length === null ) {
1268                         /**
1269                          * MSSQL doesn't allow an empty length parameter, so when we don't want to limit the
1270                          * length returned use the default maximum size of text.
1271                          * @see https://docs.microsoft.com/en-us/sql/t-sql/statements/set-textsize-transact-sql
1272                          */
1273                         $length = 2147483647;
1274                 }
1275                 return 'SUBSTRING(' . implode( ',', [ $input, $startPosition, $length ] ) . ')';
1276         }
1277
1278         /**
1279          * Returns an associative array for fields that are of type varbinary, binary, or image
1280          * $table can be either a raw table name or passed through tableName() first
1281          * @param string $table
1282          * @return array
1283          */
1284         private function getBinaryColumns( $table ) {
1285                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1286                 $tableRaw = array_pop( $tableRawArr );
1287
1288                 if ( $this->binaryColumnCache === null ) {
1289                         $this->populateColumnCaches();
1290                 }
1291
1292                 return $this->binaryColumnCache[$tableRaw] ?? [];
1293         }
1294
1295         /**
1296          * @param string $table
1297          * @return array
1298          */
1299         private function getBitColumns( $table ) {
1300                 $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) );
1301                 $tableRaw = array_pop( $tableRawArr );
1302
1303                 if ( $this->bitColumnCache === null ) {
1304                         $this->populateColumnCaches();
1305                 }
1306
1307                 return $this->bitColumnCache[$tableRaw] ?? [];
1308         }
1309
1310         private function populateColumnCaches() {
1311                 $res = $this->select( 'INFORMATION_SCHEMA.COLUMNS', '*',
1312                         [
1313                                 'TABLE_CATALOG' => $this->getDBname(),
1314                                 'TABLE_SCHEMA' => $this->dbSchema(),
1315                                 'DATA_TYPE' => [ 'varbinary', 'binary', 'image', 'bit' ]
1316                         ] );
1317
1318                 $this->binaryColumnCache = [];
1319                 $this->bitColumnCache = [];
1320                 foreach ( $res as $row ) {
1321                         if ( $row->DATA_TYPE == 'bit' ) {
1322                                 $this->bitColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1323                         } else {
1324                                 $this->binaryColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row;
1325                         }
1326                 }
1327         }
1328
1329         /**
1330          * @param string $name
1331          * @param string $format One of "quoted" (default), "raw", or "split".
1332          * @return string|array When the requested $format is "split", a list of database, schema, and
1333          *  table name is returned. Database and schema can be `false`.
1334          */
1335         function tableName( $name, $format = 'quoted' ) {
1336                 # Replace reserved words with better ones
1337                 switch ( $name ) {
1338                         case 'user':
1339                                 return $this->realTableName( 'mwuser', $format );
1340                         default:
1341                                 return $this->realTableName( $name, $format );
1342                 }
1343         }
1344
1345         /**
1346          * call this instead of tableName() in the updater when renaming tables
1347          * @param string $name
1348          * @param string $format One of "quoted" (default), "raw", or "split".
1349          * @return string|array When the requested $format is "split", a list of database, schema, and
1350          *  table name is returned. Database and schema can be `false`.
1351          * @private
1352          */
1353         function realTableName( $name, $format = 'quoted' ) {
1354                 $table = parent::tableName( $name, $format );
1355                 if ( $format == 'split' ) {
1356                         // Used internally, we want the schema split off from the table name and returned
1357                         // as a list with 3 elements (database, schema, table)
1358                         return array_pad( explode( '.', $table, 3 ), -3, false );
1359                 }
1360                 return $table;
1361         }
1362
1363         /**
1364          * Delete a table
1365          * @param string $tableName
1366          * @param string $fName
1367          * @return bool|IResultWrapper
1368          * @since 1.18
1369          */
1370         public function dropTable( $tableName, $fName = __METHOD__ ) {
1371                 if ( !$this->tableExists( $tableName, $fName ) ) {
1372                         return false;
1373                 }
1374
1375                 // parent function incorrectly appends CASCADE, which we don't want
1376                 $sql = "DROP TABLE " . $this->tableName( $tableName );
1377
1378                 return $this->query( $sql, $fName );
1379         }
1380
1381         /**
1382          * Called in the installer and updater.
1383          * Probably doesn't need to be called anywhere else in the codebase.
1384          * @param bool|null $value
1385          * @return bool|null
1386          */
1387         public function prepareStatements( $value = null ) {
1388                 $old = $this->prepareStatements;
1389                 if ( $value !== null ) {
1390                         $this->prepareStatements = $value;
1391                 }
1392
1393                 return $old;
1394         }
1395
1396         /**
1397          * Called in the installer and updater.
1398          * Probably doesn't need to be called anywhere else in the codebase.
1399          * @param bool|null $value
1400          * @return bool|null
1401          */
1402         public function scrollableCursor( $value = null ) {
1403                 $old = $this->scrollableCursor;
1404                 if ( $value !== null ) {
1405                         $this->scrollableCursor = $value;
1406                 }
1407
1408                 return $old;
1409         }
1410
1411         public function buildStringCast( $field ) {
1412                 return "CAST( $field AS NVARCHAR )";
1413         }
1414
1415         public static function getAttributes() {
1416                 return [ self::ATTR_SCHEMAS_AS_TABLE_GROUPS => true ];
1417         }
1418 }
1419
1420 /**
1421  * @deprecated since 1.29
1422  */
1423 class_alias( DatabaseMssql::class, 'DatabaseMssql' );