X-Git-Url: https://scripts.mit.edu/gitweb/autoinstallsdev/mediawiki.git/blobdiff_plain/19e297c21b10b1b8a3acad5e73fc71dcb35db44a..6932310fd58ebef145fa01eb76edf7150284d8ea:/includes/libs/rdbms/database/DatabaseMssql.php diff --git a/includes/libs/rdbms/database/DatabaseMssql.php b/includes/libs/rdbms/database/DatabaseMssql.php new file mode 100644 index 00000000..8a69eec4 --- /dev/null +++ b/includes/libs/rdbms/database/DatabaseMssql.php @@ -0,0 +1,1351 @@ + + * @author Chris Pucci + * @author Ryan Biesemeyer + * @author Ryan Schmidt + */ + +namespace Wikimedia\Rdbms; + +use MediaWiki; +use Exception; +use stdClass; + +/** + * @ingroup Database + */ +class DatabaseMssql extends Database { + protected $mPort; + protected $mUseWindowsAuth = false; + + protected $mInsertId = null; + protected $mLastResult = null; + protected $mAffectedRows = null; + protected $mSubqueryId = 0; + protected $mScrollableCursor = true; + protected $mPrepareStatements = true; + protected $mBinaryColumnCache = null; + protected $mBitColumnCache = null; + protected $mIgnoreDupKeyErrors = false; + protected $mIgnoreErrors = []; + + public function implicitGroupby() { + return false; + } + + public function implicitOrderby() { + return false; + } + + public function unionSupportsOrderAndLimit() { + return false; + } + + public function __construct( array $params ) { + $this->mPort = $params['port']; + $this->mUseWindowsAuth = $params['UseWindowsAuth']; + + parent::__construct( $params ); + } + + /** + * Usually aborts on failure + * @param string $server + * @param string $user + * @param string $password + * @param string $dbName + * @throws DBConnectionError + * @return bool|resource|null + */ + public function open( $server, $user, $password, $dbName ) { + # Test for driver support, to avoid suppressed fatal error + if ( !function_exists( 'sqlsrv_connect' ) ) { + throw new DBConnectionError( + $this, + "Microsoft SQL Server Native (sqlsrv) functions missing. + You can download the driver from: http://go.microsoft.com/fwlink/?LinkId=123470\n" + ); + } + + # e.g. the class is being loaded + if ( !strlen( $user ) ) { + return null; + } + + $this->close(); + $this->mServer = $server; + $this->mUser = $user; + $this->mPassword = $password; + $this->mDBname = $dbName; + + $connectionInfo = []; + + if ( $dbName ) { + $connectionInfo['Database'] = $dbName; + } + + // Decide which auth scenerio to use + // if we are using Windows auth, then don't add credentials to $connectionInfo + if ( !$this->mUseWindowsAuth ) { + $connectionInfo['UID'] = $user; + $connectionInfo['PWD'] = $password; + } + + MediaWiki\suppressWarnings(); + $this->mConn = sqlsrv_connect( $server, $connectionInfo ); + MediaWiki\restoreWarnings(); + + if ( $this->mConn === false ) { + throw new DBConnectionError( $this, $this->lastError() ); + } + + $this->mOpened = true; + + return $this->mConn; + } + + /** + * Closes a database connection, if it is open + * Returns success, true if already closed + * @return bool + */ + protected function closeConnection() { + return sqlsrv_close( $this->mConn ); + } + + /** + * @param bool|MssqlResultWrapper|resource $result + * @return bool|MssqlResultWrapper + */ + protected function resultObject( $result ) { + if ( !$result ) { + return false; + } elseif ( $result instanceof MssqlResultWrapper ) { + return $result; + } elseif ( $result === true ) { + // Successful write query + return $result; + } else { + return new MssqlResultWrapper( $this, $result ); + } + } + + /** + * @param string $sql + * @return bool|MssqlResultWrapper|resource + * @throws DBUnexpectedError + */ + protected function doQuery( $sql ) { + // several extensions seem to think that all databases support limits + // via LIMIT N after the WHERE clause, but MSSQL uses SELECT TOP N, + // so to catch any of those extensions we'll do a quick check for a + // LIMIT clause and pass $sql through $this->LimitToTopN() which parses + // the LIMIT clause and passes the result to $this->limitResult(); + if ( preg_match( '/\bLIMIT\s*/i', $sql ) ) { + // massage LIMIT -> TopN + $sql = $this->LimitToTopN( $sql ); + } + + // MSSQL doesn't have EXTRACT(epoch FROM XXX) + if ( preg_match( '#\bEXTRACT\s*?\(\s*?EPOCH\s+FROM\b#i', $sql, $matches ) ) { + // This is same as UNIX_TIMESTAMP, we need to calc # of seconds from 1970 + $sql = str_replace( $matches[0], "DATEDIFF(s,CONVERT(datetime,'1/1/1970'),", $sql ); + } + + // perform query + + // SQLSRV_CURSOR_STATIC is slower than SQLSRV_CURSOR_CLIENT_BUFFERED (one of the two is + // needed if we want to be able to seek around the result set), however CLIENT_BUFFERED + // has a bug in the sqlsrv driver where wchar_t types (such as nvarchar) that are empty + // strings make php throw a fatal error "Severe error translating Unicode" + if ( $this->mScrollableCursor ) { + $scrollArr = [ 'Scrollable' => SQLSRV_CURSOR_STATIC ]; + } else { + $scrollArr = []; + } + + if ( $this->mPrepareStatements ) { + // we do prepare + execute so we can get its field metadata for later usage if desired + $stmt = sqlsrv_prepare( $this->mConn, $sql, [], $scrollArr ); + $success = sqlsrv_execute( $stmt ); + } else { + $stmt = sqlsrv_query( $this->mConn, $sql, [], $scrollArr ); + $success = (bool)$stmt; + } + + // Make a copy to ensure what we add below does not get reflected in future queries + $ignoreErrors = $this->mIgnoreErrors; + + if ( $this->mIgnoreDupKeyErrors ) { + // ignore duplicate key errors + // this emulates INSERT IGNORE in MySQL + $ignoreErrors[] = '2601'; // duplicate key error caused by unique index + $ignoreErrors[] = '2627'; // duplicate key error caused by primary key + $ignoreErrors[] = '3621'; // generic "the statement has been terminated" error + } + + if ( $success === false ) { + $errors = sqlsrv_errors(); + $success = true; + + foreach ( $errors as $err ) { + if ( !in_array( $err['code'], $ignoreErrors ) ) { + $success = false; + break; + } + } + + if ( $success === false ) { + return false; + } + } + // remember number of rows affected + $this->mAffectedRows = sqlsrv_rows_affected( $stmt ); + + return $stmt; + } + + public function freeResult( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + sqlsrv_free_stmt( $res ); + } + + /** + * @param MssqlResultWrapper $res + * @return stdClass + */ + public function fetchObject( $res ) { + // $res is expected to be an instance of MssqlResultWrapper here + return $res->fetchObject(); + } + + /** + * @param MssqlResultWrapper $res + * @return array + */ + public function fetchRow( $res ) { + return $res->fetchRow(); + } + + /** + * @param mixed $res + * @return int + */ + public function numRows( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + $ret = sqlsrv_num_rows( $res ); + + if ( $ret === false ) { + // we cannot get an amount of rows from this cursor type + // has_rows returns bool true/false if the result has rows + $ret = (int)sqlsrv_has_rows( $res ); + } + + return $ret; + } + + /** + * @param mixed $res + * @return int + */ + public function numFields( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + return sqlsrv_num_fields( $res ); + } + + /** + * @param mixed $res + * @param int $n + * @return int + */ + public function fieldName( $res, $n ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + return sqlsrv_field_metadata( $res )[$n]['Name']; + } + + /** + * This must be called after nextSequenceVal + * @return int|null + */ + public function insertId() { + return $this->mInsertId; + } + + /** + * @param MssqlResultWrapper $res + * @param int $row + * @return bool + */ + public function dataSeek( $res, $row ) { + return $res->seek( $row ); + } + + /** + * @return string + */ + public function lastError() { + $strRet = ''; + $retErrors = sqlsrv_errors( SQLSRV_ERR_ALL ); + if ( $retErrors != null ) { + foreach ( $retErrors as $arrError ) { + $strRet .= $this->formatError( $arrError ) . "\n"; + } + } else { + $strRet = "No errors found"; + } + + return $strRet; + } + + /** + * @param array $err + * @return string + */ + private function formatError( $err ) { + return '[SQLSTATE ' . + $err['SQLSTATE'] . '][Error Code ' . $err['code'] . ']' . $err['message']; + } + + /** + * @return string|int + */ + public function lastErrno() { + $err = sqlsrv_errors( SQLSRV_ERR_ALL ); + if ( $err !== null && isset( $err[0] ) ) { + return $err[0]['code']; + } else { + return 0; + } + } + + /** + * @return int + */ + public function affectedRows() { + return $this->mAffectedRows; + } + + /** + * SELECT wrapper + * + * @param mixed $table Array or string, table name(s) (prefix auto-added) + * @param mixed $vars Array or string, field name(s) to be retrieved + * @param mixed $conds Array or string, condition(s) for WHERE + * @param string $fname Calling function name (use __METHOD__) for logs/profiling + * @param array $options Associative array of options (e.g. + * [ 'GROUP BY' => 'page_title' ]), see Database::makeSelectOptions + * code for list of supported stuff + * @param array $join_conds Associative array of table join conditions + * (optional) (e.g. [ 'page' => [ 'LEFT JOIN','page_latest=rev_id' ] ] + * @return mixed Database result resource (feed to Database::fetchObject + * or whatever), or false on failure + * @throws DBQueryError + * @throws DBUnexpectedError + * @throws Exception + */ + public function select( $table, $vars, $conds = '', $fname = __METHOD__, + $options = [], $join_conds = [] + ) { + $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds ); + if ( isset( $options['EXPLAIN'] ) ) { + try { + $this->mScrollableCursor = false; + $this->mPrepareStatements = false; + $this->query( "SET SHOWPLAN_ALL ON" ); + $ret = $this->query( $sql, $fname ); + $this->query( "SET SHOWPLAN_ALL OFF" ); + } catch ( DBQueryError $dqe ) { + if ( isset( $options['FOR COUNT'] ) ) { + // likely don't have privs for SHOWPLAN, so run a select count instead + $this->query( "SET SHOWPLAN_ALL OFF" ); + unset( $options['EXPLAIN'] ); + $ret = $this->select( + $table, + 'COUNT(*) AS EstimateRows', + $conds, + $fname, + $options, + $join_conds + ); + } else { + // someone actually wanted the query plan instead of an est row count + // let them know of the error + $this->mScrollableCursor = true; + $this->mPrepareStatements = true; + throw $dqe; + } + } + $this->mScrollableCursor = true; + $this->mPrepareStatements = true; + return $ret; + } + return $this->query( $sql, $fname ); + } + + /** + * SELECT wrapper + * + * @param mixed $table Array or string, table name(s) (prefix auto-added) + * @param mixed $vars Array or string, field name(s) to be retrieved + * @param mixed $conds Array or string, condition(s) for WHERE + * @param string $fname Calling function name (use __METHOD__) for logs/profiling + * @param array $options Associative array of options (e.g. [ 'GROUP BY' => 'page_title' ]), + * see Database::makeSelectOptions code for list of supported stuff + * @param array $join_conds Associative array of table join conditions (optional) + * (e.g. [ 'page' => [ 'LEFT JOIN','page_latest=rev_id' ] ] + * @return string The SQL text + */ + public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__, + $options = [], $join_conds = [] + ) { + if ( isset( $options['EXPLAIN'] ) ) { + unset( $options['EXPLAIN'] ); + } + + $sql = parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds ); + + // try to rewrite aggregations of bit columns (currently MAX and MIN) + if ( strpos( $sql, 'MAX(' ) !== false || strpos( $sql, 'MIN(' ) !== false ) { + $bitColumns = []; + if ( is_array( $table ) ) { + foreach ( $table as $t ) { + $bitColumns += $this->getBitColumns( $this->tableName( $t ) ); + } + } else { + $bitColumns = $this->getBitColumns( $this->tableName( $table ) ); + } + + foreach ( $bitColumns as $col => $info ) { + $replace = [ + "MAX({$col})" => "MAX(CAST({$col} AS tinyint))", + "MIN({$col})" => "MIN(CAST({$col} AS tinyint))", + ]; + $sql = str_replace( array_keys( $replace ), array_values( $replace ), $sql ); + } + } + + return $sql; + } + + public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, + $fname = __METHOD__ + ) { + $this->mScrollableCursor = false; + try { + parent::deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname ); + } catch ( Exception $e ) { + $this->mScrollableCursor = true; + throw $e; + } + $this->mScrollableCursor = true; + } + + public function delete( $table, $conds, $fname = __METHOD__ ) { + $this->mScrollableCursor = false; + try { + parent::delete( $table, $conds, $fname ); + } catch ( Exception $e ) { + $this->mScrollableCursor = true; + throw $e; + } + $this->mScrollableCursor = true; + } + + /** + * Estimate rows in dataset + * Returns estimated count, based on SHOWPLAN_ALL output + * This is not necessarily an accurate estimate, so use sparingly + * Returns -1 if count cannot be found + * Takes same arguments as Database::select() + * @param string $table + * @param string $vars + * @param string $conds + * @param string $fname + * @param array $options + * @return int + */ + public function estimateRowCount( $table, $vars = '*', $conds = '', + $fname = __METHOD__, $options = [] + ) { + // http://msdn2.microsoft.com/en-us/library/aa259203.aspx + $options['EXPLAIN'] = true; + $options['FOR COUNT'] = true; + $res = $this->select( $table, $vars, $conds, $fname, $options ); + + $rows = -1; + if ( $res ) { + $row = $this->fetchRow( $res ); + + if ( isset( $row['EstimateRows'] ) ) { + $rows = (int)$row['EstimateRows']; + } + } + + return $rows; + } + + /** + * Returns information about an index + * If errors are explicitly ignored, returns NULL on failure + * @param string $table + * @param string $index + * @param string $fname + * @return array|bool|null + */ + public function indexInfo( $table, $index, $fname = __METHOD__ ) { + # This does not return the same info as MYSQL would, but that's OK + # because MediaWiki never uses the returned value except to check for + # the existence of indexes. + $sql = "sp_helpindex '" . $this->tableName( $table ) . "'"; + $res = $this->query( $sql, $fname ); + + if ( !$res ) { + return null; + } + + $result = []; + foreach ( $res as $row ) { + if ( $row->index_name == $index ) { + $row->Non_unique = !stristr( $row->index_description, "unique" ); + $cols = explode( ", ", $row->index_keys ); + foreach ( $cols as $col ) { + $row->Column_name = trim( $col ); + $result[] = clone $row; + } + } elseif ( $index == 'PRIMARY' && stristr( $row->index_description, 'PRIMARY' ) ) { + $row->Non_unique = 0; + $cols = explode( ", ", $row->index_keys ); + foreach ( $cols as $col ) { + $row->Column_name = trim( $col ); + $result[] = clone $row; + } + } + } + + return empty( $result ) ? false : $result; + } + + /** + * INSERT wrapper, inserts an array into a table + * + * $arrToInsert may be a single associative array, or an array of these with numeric keys, for + * multi-row insert. + * + * Usually aborts on failure + * If errors are explicitly ignored, returns success + * @param string $table + * @param array $arrToInsert + * @param string $fname + * @param array $options + * @return bool + * @throws Exception + */ + public function insert( $table, $arrToInsert, $fname = __METHOD__, $options = [] ) { + # No rows to insert, easy just return now + if ( !count( $arrToInsert ) ) { + return true; + } + + if ( !is_array( $options ) ) { + $options = [ $options ]; + } + + $table = $this->tableName( $table ); + + if ( !( isset( $arrToInsert[0] ) && is_array( $arrToInsert[0] ) ) ) { // Not multi row + $arrToInsert = [ 0 => $arrToInsert ]; // make everything multi row compatible + } + + // We know the table we're inserting into, get its identity column + $identity = null; + // strip matching square brackets and the db/schema from table name + $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) ); + $tableRaw = array_pop( $tableRawArr ); + $res = $this->doQuery( + "SELECT NAME AS idColumn FROM SYS.IDENTITY_COLUMNS " . + "WHERE OBJECT_NAME(OBJECT_ID)='{$tableRaw}'" + ); + if ( $res && sqlsrv_has_rows( $res ) ) { + // There is an identity for this table. + $identityArr = sqlsrv_fetch_array( $res, SQLSRV_FETCH_ASSOC ); + $identity = array_pop( $identityArr ); + } + sqlsrv_free_stmt( $res ); + + // Determine binary/varbinary fields so we can encode data as a hex string like 0xABCDEF + $binaryColumns = $this->getBinaryColumns( $table ); + + // INSERT IGNORE is not supported by SQL Server + // remove IGNORE from options list and set ignore flag to true + if ( in_array( 'IGNORE', $options ) ) { + $options = array_diff( $options, [ 'IGNORE' ] ); + $this->mIgnoreDupKeyErrors = true; + } + + $ret = null; + foreach ( $arrToInsert as $a ) { + // start out with empty identity column, this is so we can return + // it as a result of the INSERT logic + $sqlPre = ''; + $sqlPost = ''; + $identityClause = ''; + + // if we have an identity column + if ( $identity ) { + // iterate through + foreach ( $a as $k => $v ) { + if ( $k == $identity ) { + if ( !is_null( $v ) ) { + // there is a value being passed to us, + // we need to turn on and off inserted identity + $sqlPre = "SET IDENTITY_INSERT $table ON;"; + $sqlPost = ";SET IDENTITY_INSERT $table OFF;"; + } else { + // we can't insert NULL into an identity column, + // so remove the column from the insert. + unset( $a[$k] ); + } + } + } + + // we want to output an identity column as result + $identityClause = "OUTPUT INSERTED.$identity "; + } + + $keys = array_keys( $a ); + + // Build the actual query + $sql = $sqlPre . 'INSERT ' . implode( ' ', $options ) . + " INTO $table (" . implode( ',', $keys ) . ") $identityClause VALUES ("; + + $first = true; + foreach ( $a as $key => $value ) { + if ( isset( $binaryColumns[$key] ) ) { + $value = new MssqlBlob( $value ); + } + if ( $first ) { + $first = false; + } else { + $sql .= ','; + } + if ( is_null( $value ) ) { + $sql .= 'null'; + } elseif ( is_array( $value ) || is_object( $value ) ) { + if ( is_object( $value ) && $value instanceof Blob ) { + $sql .= $this->addQuotes( $value ); + } else { + $sql .= $this->addQuotes( serialize( $value ) ); + } + } else { + $sql .= $this->addQuotes( $value ); + } + } + $sql .= ')' . $sqlPost; + + // Run the query + $this->mScrollableCursor = false; + try { + $ret = $this->query( $sql ); + } catch ( Exception $e ) { + $this->mScrollableCursor = true; + $this->mIgnoreDupKeyErrors = false; + throw $e; + } + $this->mScrollableCursor = true; + + if ( $ret instanceof ResultWrapper && !is_null( $identity ) ) { + // Then we want to get the identity column value we were assigned and save it off + $row = $ret->fetchObject(); + if ( is_object( $row ) ) { + $this->mInsertId = $row->$identity; + // It seems that mAffectedRows is -1 sometimes when OUTPUT INSERTED.identity is + // used if we got an identity back, we know for sure a row was affected, so + // adjust that here + if ( $this->mAffectedRows == -1 ) { + $this->mAffectedRows = 1; + } + } + } + } + + $this->mIgnoreDupKeyErrors = false; + + return $ret; + } + + /** + * INSERT SELECT wrapper + * $varMap must be an associative array of the form [ 'dest1' => 'source1', ... ] + * Source items may be literals rather than field names, but strings should + * be quoted with Database::addQuotes(). + * @param string $destTable + * @param array|string $srcTable May be an array of tables. + * @param array $varMap + * @param array $conds May be "*" to copy the whole table. + * @param string $fname + * @param array $insertOptions + * @param array $selectOptions + * @param array $selectJoinConds + * @return null|ResultWrapper + * @throws Exception + */ + public function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__, + $insertOptions = [], $selectOptions = [], $selectJoinConds = [] + ) { + $this->mScrollableCursor = false; + try { + $ret = parent::nativeInsertSelect( + $destTable, + $srcTable, + $varMap, + $conds, + $fname, + $insertOptions, + $selectOptions, + $selectJoinConds + ); + } catch ( Exception $e ) { + $this->mScrollableCursor = true; + throw $e; + } + $this->mScrollableCursor = true; + + return $ret; + } + + /** + * UPDATE wrapper. Takes a condition array and a SET array. + * + * @param string $table Name of the table to UPDATE. This will be passed through + * Database::tableName(). + * + * @param array $values An array of values to SET. For each array element, + * the key gives the field name, and the value gives the data + * to set that field to. The data will be quoted by + * Database::addQuotes(). + * + * @param array $conds An array of conditions (WHERE). See + * Database::select() for the details of the format of + * condition arrays. Use '*' to update all rows. + * + * @param string $fname The function name of the caller (from __METHOD__), + * for logging and profiling. + * + * @param array $options An array of UPDATE options, can be: + * - IGNORE: Ignore unique key conflicts + * - LOW_PRIORITY: MySQL-specific, see MySQL manual. + * @return bool + * @throws DBUnexpectedError + * @throws Exception + */ + function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) { + $table = $this->tableName( $table ); + $binaryColumns = $this->getBinaryColumns( $table ); + + $opts = $this->makeUpdateOptions( $options ); + $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET, $binaryColumns ); + + if ( $conds !== [] && $conds !== '*' ) { + $sql .= " WHERE " . $this->makeList( $conds, LIST_AND, $binaryColumns ); + } + + $this->mScrollableCursor = false; + try { + $this->query( $sql ); + } catch ( Exception $e ) { + $this->mScrollableCursor = true; + throw $e; + } + $this->mScrollableCursor = true; + return true; + } + + /** + * Makes an encoded list of strings from an array + * @param array $a Containing the data + * @param int $mode Constant + * - LIST_COMMA: comma separated, no field names + * - LIST_AND: ANDed WHERE clause (without the WHERE). See + * the documentation for $conds in Database::select(). + * - LIST_OR: ORed WHERE clause (without the WHERE) + * - LIST_SET: comma separated with field names, like a SET clause + * - LIST_NAMES: comma separated field names + * @param array $binaryColumns Contains a list of column names that are binary types + * This is a custom parameter only present for MS SQL. + * + * @throws DBUnexpectedError + * @return string + */ + public function makeList( $a, $mode = LIST_COMMA, $binaryColumns = [] ) { + if ( !is_array( $a ) ) { + throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' ); + } + + if ( $mode != LIST_NAMES ) { + // In MS SQL, values need to be specially encoded when they are + // inserted into binary fields. Perform this necessary encoding + // for the specified set of columns. + foreach ( array_keys( $a ) as $field ) { + if ( !isset( $binaryColumns[$field] ) ) { + continue; + } + + if ( is_array( $a[$field] ) ) { + foreach ( $a[$field] as &$v ) { + $v = new MssqlBlob( $v ); + } + unset( $v ); + } else { + $a[$field] = new MssqlBlob( $a[$field] ); + } + } + } + + return parent::makeList( $a, $mode ); + } + + /** + * @param string $table + * @param string $field + * @return int Returns the size of a text field, or -1 for "unlimited" + */ + public function textFieldSize( $table, $field ) { + $table = $this->tableName( $table ); + $sql = "SELECT CHARACTER_MAXIMUM_LENGTH,DATA_TYPE FROM INFORMATION_SCHEMA.Columns + WHERE TABLE_NAME = '$table' AND COLUMN_NAME = '$field'"; + $res = $this->query( $sql ); + $row = $this->fetchRow( $res ); + $size = -1; + if ( strtolower( $row['DATA_TYPE'] ) != 'text' ) { + $size = $row['CHARACTER_MAXIMUM_LENGTH']; + } + + return $size; + } + + /** + * Construct a LIMIT query with optional offset + * This is used for query pages + * + * @param string $sql SQL query we will append the limit too + * @param int $limit The SQL limit + * @param bool|int $offset The SQL offset (default false) + * @return array|string + * @throws DBUnexpectedError + */ + public function limitResult( $sql, $limit, $offset = false ) { + if ( $offset === false || $offset == 0 ) { + if ( strpos( $sql, "SELECT" ) === false ) { + return "TOP {$limit} " . $sql; + } else { + return preg_replace( '/\bSELECT(\s+DISTINCT)?\b/Dsi', + 'SELECT$1 TOP ' . $limit, $sql, 1 ); + } + } else { + // This one is fun, we need to pull out the select list as well as any ORDER BY clause + $select = $orderby = []; + $s1 = preg_match( '#SELECT\s+(.+?)\s+FROM#Dis', $sql, $select ); + $s2 = preg_match( '#(ORDER BY\s+.+?)(\s*FOR XML .*)?$#Dis', $sql, $orderby ); + $postOrder = ''; + $first = $offset + 1; + $last = $offset + $limit; + $sub1 = 'sub_' . $this->mSubqueryId; + $sub2 = 'sub_' . ( $this->mSubqueryId + 1 ); + $this->mSubqueryId += 2; + if ( !$s1 ) { + // wat + throw new DBUnexpectedError( $this, "Attempting to LIMIT a non-SELECT query\n" ); + } + if ( !$s2 ) { + // no ORDER BY + $overOrder = 'ORDER BY (SELECT 1)'; + } else { + if ( !isset( $orderby[2] ) || !$orderby[2] ) { + // don't need to strip it out if we're using a FOR XML clause + $sql = str_replace( $orderby[1], '', $sql ); + } + $overOrder = $orderby[1]; + $postOrder = ' ' . $overOrder; + } + $sql = "SELECT {$select[1]} + FROM ( + SELECT ROW_NUMBER() OVER({$overOrder}) AS rowNumber, * + FROM ({$sql}) {$sub1} + ) {$sub2} + WHERE rowNumber BETWEEN {$first} AND {$last}{$postOrder}"; + + return $sql; + } + } + + /** + * If there is a limit clause, parse it, strip it, and pass the remaining + * SQL through limitResult() with the appropriate parameters. Not the + * prettiest solution, but better than building a whole new parser. This + * exists becase there are still too many extensions that don't use dynamic + * sql generation. + * + * @param string $sql + * @return array|mixed|string + */ + public function LimitToTopN( $sql ) { + // Matches: LIMIT {[offset,] row_count | row_count OFFSET offset} + $pattern = '/\bLIMIT\s+((([0-9]+)\s*,\s*)?([0-9]+)(\s+OFFSET\s+([0-9]+))?)/i'; + if ( preg_match( $pattern, $sql, $matches ) ) { + $row_count = $matches[4]; + $offset = $matches[3] ?: $matches[6] ?: false; + + // strip the matching LIMIT clause out + $sql = str_replace( $matches[0], '', $sql ); + + return $this->limitResult( $sql, $row_count, $offset ); + } + + return $sql; + } + + /** + * @return string Wikitext of a link to the server software's web site + */ + public function getSoftwareLink() { + return "[{{int:version-db-mssql-url}} MS SQL Server]"; + } + + /** + * @return string Version information from the database + */ + public function getServerVersion() { + $server_info = sqlsrv_server_info( $this->mConn ); + $version = 'Error'; + if ( isset( $server_info['SQLServerVersion'] ) ) { + $version = $server_info['SQLServerVersion']; + } + + return $version; + } + + /** + * @param string $table + * @param string $fname + * @return bool + */ + public function tableExists( $table, $fname = __METHOD__ ) { + list( $db, $schema, $table ) = $this->tableName( $table, 'split' ); + + if ( $db !== false ) { + // remote database + $this->queryLogger->error( "Attempting to call tableExists on a remote table" ); + return false; + } + + if ( $schema === false ) { + $schema = $this->mSchema; + } + + $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.TABLES + WHERE TABLE_TYPE = 'BASE TABLE' + AND TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table'" ); + + if ( $res->numRows() ) { + return true; + } else { + return false; + } + } + + /** + * Query whether a given column exists in the mediawiki schema + * @param string $table + * @param string $field + * @param string $fname + * @return bool + */ + public function fieldExists( $table, $field, $fname = __METHOD__ ) { + list( $db, $schema, $table ) = $this->tableName( $table, 'split' ); + + if ( $db !== false ) { + // remote database + $this->queryLogger->error( "Attempting to call fieldExists on a remote table" ); + return false; + } + + $res = $this->query( "SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS + WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" ); + + if ( $res->numRows() ) { + return true; + } else { + return false; + } + } + + public function fieldInfo( $table, $field ) { + list( $db, $schema, $table ) = $this->tableName( $table, 'split' ); + + if ( $db !== false ) { + // remote database + $this->queryLogger->error( "Attempting to call fieldInfo on a remote table" ); + return false; + } + + $res = $this->query( "SELECT * FROM INFORMATION_SCHEMA.COLUMNS + WHERE TABLE_SCHEMA = '$schema' AND TABLE_NAME = '$table' AND COLUMN_NAME = '$field'" ); + + $meta = $res->fetchRow(); + if ( $meta ) { + return new MssqlField( $meta ); + } + + return false; + } + + /** + * Begin a transaction, committing any previously open transaction + * @param string $fname + */ + protected function doBegin( $fname = __METHOD__ ) { + sqlsrv_begin_transaction( $this->mConn ); + $this->mTrxLevel = 1; + } + + /** + * End a transaction + * @param string $fname + */ + protected function doCommit( $fname = __METHOD__ ) { + sqlsrv_commit( $this->mConn ); + $this->mTrxLevel = 0; + } + + /** + * Rollback a transaction. + * No-op on non-transactional databases. + * @param string $fname + */ + protected function doRollback( $fname = __METHOD__ ) { + sqlsrv_rollback( $this->mConn ); + $this->mTrxLevel = 0; + } + + /** + * @param string $s + * @return string + */ + public function strencode( $s ) { + // Should not be called by us + return str_replace( "'", "''", $s ); + } + + /** + * @param string|int|null|bool|Blob $s + * @return string|int + */ + public function addQuotes( $s ) { + if ( $s instanceof MssqlBlob ) { + return $s->fetch(); + } elseif ( $s instanceof Blob ) { + // this shouldn't really ever be called, but it's here if needed + // (and will quite possibly make the SQL error out) + $blob = new MssqlBlob( $s->fetch() ); + return $blob->fetch(); + } else { + if ( is_bool( $s ) ) { + $s = $s ? 1 : 0; + } + return parent::addQuotes( $s ); + } + } + + /** + * @param string $s + * @return string + */ + public function addIdentifierQuotes( $s ) { + // http://msdn.microsoft.com/en-us/library/aa223962.aspx + return '[' . $s . ']'; + } + + /** + * @param string $name + * @return bool + */ + public function isQuotedIdentifier( $name ) { + return strlen( $name ) && $name[0] == '[' && substr( $name, -1, 1 ) == ']'; + } + + /** + * MS SQL supports more pattern operators than other databases (ex: [,],^) + * + * @param string $s + * @param string $escapeChar + * @return string + */ + protected function escapeLikeInternal( $s, $escapeChar = '`' ) { + return str_replace( [ $escapeChar, '%', '_', '[', ']', '^' ], + [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_", + "{$escapeChar}[", "{$escapeChar}]", "{$escapeChar}^" ], + $s ); + } + + /** + * @param string $db + * @return bool + */ + public function selectDB( $db ) { + try { + $this->mDBname = $db; + $this->query( "USE $db" ); + return true; + } catch ( Exception $e ) { + return false; + } + } + + /** + * @param array $options An associative array of options to be turned into + * an SQL query, valid keys are listed in the function. + * @return array + */ + public function makeSelectOptions( $options ) { + $tailOpts = ''; + $startOpts = ''; + + $noKeyOptions = []; + foreach ( $options as $key => $option ) { + if ( is_numeric( $key ) ) { + $noKeyOptions[$option] = true; + } + } + + $tailOpts .= $this->makeGroupByWithHaving( $options ); + + $tailOpts .= $this->makeOrderBy( $options ); + + if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) { + $startOpts .= 'DISTINCT'; + } + + if ( isset( $noKeyOptions['FOR XML'] ) ) { + // used in group concat field emulation + $tailOpts .= " FOR XML PATH('')"; + } + + // we want this to be compatible with the output of parent::makeSelectOptions() + return [ $startOpts, '', $tailOpts, '', '' ]; + } + + public function getType() { + return 'mssql'; + } + + /** + * @param array $stringList + * @return string + */ + public function buildConcat( $stringList ) { + return implode( ' + ', $stringList ); + } + + /** + * Build a GROUP_CONCAT or equivalent statement for a query. + * MS SQL doesn't have GROUP_CONCAT so we emulate it with other stuff (and boy is it nasty) + * + * This is useful for combining a field for several rows into a single string. + * NULL values will not appear in the output, duplicated values will appear, + * and the resulting delimiter-separated values have no defined sort order. + * Code using the results may need to use the PHP unique() or sort() methods. + * + * @param string $delim Glue to bind the results together + * @param string|array $table Table name + * @param string $field Field name + * @param string|array $conds Conditions + * @param string|array $join_conds Join conditions + * @return string SQL text + * @since 1.23 + */ + public function buildGroupConcatField( $delim, $table, $field, $conds = '', + $join_conds = [] + ) { + $gcsq = 'gcsq_' . $this->mSubqueryId; + $this->mSubqueryId++; + + $delimLen = strlen( $delim ); + $fld = "{$field} + {$this->addQuotes( $delim )}"; + $sql = "(SELECT LEFT({$field}, LEN({$field}) - {$delimLen}) FROM (" + . $this->selectSQLText( $table, $fld, $conds, null, [ 'FOR XML' ], $join_conds ) + . ") {$gcsq} ({$field}))"; + + return $sql; + } + + /** + * Returns an associative array for fields that are of type varbinary, binary, or image + * $table can be either a raw table name or passed through tableName() first + * @param string $table + * @return array + */ + private function getBinaryColumns( $table ) { + $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) ); + $tableRaw = array_pop( $tableRawArr ); + + if ( $this->mBinaryColumnCache === null ) { + $this->populateColumnCaches(); + } + + return isset( $this->mBinaryColumnCache[$tableRaw] ) + ? $this->mBinaryColumnCache[$tableRaw] + : []; + } + + /** + * @param string $table + * @return array + */ + private function getBitColumns( $table ) { + $tableRawArr = explode( '.', preg_replace( '#\[([^\]]*)\]#', '$1', $table ) ); + $tableRaw = array_pop( $tableRawArr ); + + if ( $this->mBitColumnCache === null ) { + $this->populateColumnCaches(); + } + + return isset( $this->mBitColumnCache[$tableRaw] ) + ? $this->mBitColumnCache[$tableRaw] + : []; + } + + private function populateColumnCaches() { + $res = $this->select( 'INFORMATION_SCHEMA.COLUMNS', '*', + [ + 'TABLE_CATALOG' => $this->mDBname, + 'TABLE_SCHEMA' => $this->mSchema, + 'DATA_TYPE' => [ 'varbinary', 'binary', 'image', 'bit' ] + ] ); + + $this->mBinaryColumnCache = []; + $this->mBitColumnCache = []; + foreach ( $res as $row ) { + if ( $row->DATA_TYPE == 'bit' ) { + $this->mBitColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row; + } else { + $this->mBinaryColumnCache[$row->TABLE_NAME][$row->COLUMN_NAME] = $row; + } + } + } + + /** + * @param string $name + * @param string $format + * @return string + */ + function tableName( $name, $format = 'quoted' ) { + # Replace reserved words with better ones + switch ( $name ) { + case 'user': + return $this->realTableName( 'mwuser', $format ); + default: + return $this->realTableName( $name, $format ); + } + } + + /** + * call this instead of tableName() in the updater when renaming tables + * @param string $name + * @param string $format One of quoted, raw, or split + * @return string + */ + function realTableName( $name, $format = 'quoted' ) { + $table = parent::tableName( $name, $format ); + if ( $format == 'split' ) { + // Used internally, we want the schema split off from the table name and returned + // as a list with 3 elements (database, schema, table) + $table = explode( '.', $table ); + while ( count( $table ) < 3 ) { + array_unshift( $table, false ); + } + } + return $table; + } + + /** + * Delete a table + * @param string $tableName + * @param string $fName + * @return bool|ResultWrapper + * @since 1.18 + */ + public function dropTable( $tableName, $fName = __METHOD__ ) { + if ( !$this->tableExists( $tableName, $fName ) ) { + return false; + } + + // parent function incorrectly appends CASCADE, which we don't want + $sql = "DROP TABLE " . $this->tableName( $tableName ); + + return $this->query( $sql, $fName ); + } + + /** + * Called in the installer and updater. + * Probably doesn't need to be called anywhere else in the codebase. + * @param bool|null $value + * @return bool|null + */ + public function prepareStatements( $value = null ) { + $old = $this->mPrepareStatements; + if ( $value !== null ) { + $this->mPrepareStatements = $value; + } + + return $old; + } + + /** + * Called in the installer and updater. + * Probably doesn't need to be called anywhere else in the codebase. + * @param bool|null $value + * @return bool|null + */ + public function scrollableCursor( $value = null ) { + $old = $this->mScrollableCursor; + if ( $value !== null ) { + $this->mScrollableCursor = $value; + } + + return $old; + } +} + +class_alias( DatabaseMssql::class, 'DatabaseMssql' );