class DatabaseConnection_sqlsrv in Drupal driver for SQL Server and SQL Azure 7.3

Same name and namespace in other branches

7 sqlsrv/database.inc \DatabaseConnection_sqlsrv
7.2 sqlsrv/database.inc \DatabaseConnection_sqlsrv

Summary of DatabaseConnection_sqlsrv

Temporary tables: temporary table support is done by means of global temporary tables (#) to avoid the use of DIRECT QUERIES. You can enable and disable the use of direct queries with $conn->directQuery = TRUE|FALSE. http://blogs.msdn.com/b/brian_swan/archive/2010/06/15/ctp2-of-microsoft-...

Hierarchy

class \DatabaseConnection
- class \DatabaseConnection_sqlsrv

Expanded class hierarchy of DatabaseConnection_sqlsrv

1 file declares its use of DatabaseConnection_sqlsrv

sqlsrv.install in ./sqlsrv.install

File

sqlsrv/database.inc, line 28: Database interface code for Microsoft SQL Server.

View source

class DatabaseConnection_sqlsrv extends DatabaseConnection {

  // Do not preprocess the query before execution.
  public $bypassQueryPreprocess = FALSE;

  // Prepare statements with SQLSRV_ATTR_DIRECT_QUERY = TRUE.
  public $directQuery = FALSE;

  // Wether to have or not statement caching.
  public $statementCaching = FALSE;

  /**
   * Override of DatabaseConnection::driver().
   *
   * @status tested
   */
  public function driver() {
    return 'sqlsrv';
  }

  /**
   * Override of DatabaseConnection::databaseType().
   *
   * @status tested
   */
  public function databaseType() {
    return 'sqlsrv';
  }
  public function utf8mb4IsActive() {
    return TRUE;
  }
  public function utf8mb4IsSupported() {
    return TRUE;
  }

  /**
   * The PDO constants do not matcc the actual isolation names
   * used in SQL.
   */
  private static function DefaultTransactionIsolationLevelInStatement() {
    return str_replace('_', ' ', DatabaseUtils::GetConfigConstant('MSSQL_DEFAULT_ISOLATION_LEVEL', FALSE));
  }

  /**
   * Override of DatabaseConnection::databaseType().
   *
   * @status complete
   */
  public function __construct(array $connection_options = array()) {
    global $conf;

    // Store connection options for future reference.
    $this->connectionOptions =& $connection_options;

    // Set our custom statement class.
    $this->statementClass = 'DatabaseStatement_sqlsrv';

    // This driver defaults to transaction support, except if explicitly passed FALSE.
    $this->transactionSupport = !isset($connection_options['transactions']) || $connection_options['transactions'] !== FALSE;
    $this->transactionalDDLSupport = $this->transactionSupport;

    // Build the DSN.
    $options = array();
    $options['Server'] = $connection_options['host'];

    // If a port is specified and this is NOT a named instance
    if (!empty($connection_options['port']) && stripos($connection_options['host'], '\\') === false) {
      $options['Server'] .= ',' . $connection_options['port'];
    }

    // We might not have a database in the
    // connection options, for example, during
    // database creation in Install.
    if (!empty($connection_options['database'])) {
      $options['Database'] = $connection_options['database'];
    }

    // Set isolation level if specified.
    if ($level = DatabaseUtils::GetConfigConstant('MSSQL_DEFAULT_ISOLATION_LEVEL', FALSE)) {
      $options['TransactionIsolation'] = $level;
    }
    $options['MultipleActiveResultSets'] = 'false';

    // Set default direct query behaviour
    $this->directQuery = DatabaseUtils::GetConfigBoolean('MSSQL_DEFAULT_DIRECTQUERY');
    $this->statementCaching = DatabaseUtils::GetConfigBoolean('MSSQL_STATEMENT_CACHING');

    // Build the DSN
    $dsn = 'sqlsrv:';
    foreach ($options as $key => $value) {
      $dsn .= (empty($key) ? '' : "{$key}=") . $value . ';';
    }

    // PDO Options are set at a connection level.
    // and apply to all statements.
    // Allow PDO options to be overridden.
    $connection_options += array(
      'pdo' => array(),
    );
    $connection_options['pdo'] += array(
      PDO::SQLSRV_ATTR_FETCHES_NUMERIC_TYPE => TRUE,
      // Do not convert numeric values to strings when fetching.
      // This is set for legacy reasons. Core tests prefer it to be TRUE.
      PDO::ATTR_STRINGIFY_FETCHES => FALSE,
      // Set proper error mode for all statements
      PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    );

    // Set a Statement class, unless the driver opted out.
    if (!empty($this->statementClass)) {
      $connection_options['pdo'][PDO::ATTR_STATEMENT_CLASS] = array(
        $this->statementClass,
        array(
          $this,
        ),
      );
    }

    // Initialize and prepare the connection prefix.
    $this
      ->setPrefix(isset($this->connectionOptions['prefix']) ? $this->connectionOptions['prefix'] : '');

    // Set the connection.
    $this->connection = new PDO($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);
  }

  /**
   * Prepared PDO statements only makes sense if we cache them...
   *
   * @var mixed
   */
  private $statement_cache = array();

  /**
   * Temporary override of DatabaseConnection::prepareQuery().
   *
   * @todo: remove that when DatabaseConnection::prepareQuery() is fixed to call
   *   $this->prepare() and not parent::prepare().
   * @status: tested, temporary
   *
   * @param mixed $query
   * @param mixed $insecure
   * @return PDOStatement
   */
  public function prepareQuery($query, array $options = array()) {

    // Merge default statement options. These options are
    // only specific for this preparation and will only override
    // the global configuration if set to different than NULL.
    $options = array_merge(array(
      'insecure' => FALSE,
      'statement_caching' => $this->statementCaching,
      'direct_query' => $this->directQuery,
      'prefix_tables' => TRUE,
    ), $options);

    // Prefix tables. There is no global setting for this.
    if ($options['prefix_tables'] !== FALSE) {
      $query = $this
        ->prefixTables($query);
    }

    // The statement caching settings only affect the storage
    // in the cache, but if a statement is already available
    // why not reuse it!
    if (isset($this->statement_cache[$query])) {
      return $this->statement_cache[$query];
    }

    #region PDO Options
    $pdo_options = array();

    // Set insecure options if requested so. There is no global
    // setting for this, only at the statement level.
    if ($options['insecure'] === TRUE) {

      // We have to log this, prepared statements are a security RISK.
      // watchdog('SQL Server Driver', 'An insecure query has been executed against the database. This is not critical, but worth looking into: %query', array('%query' => $query));
      // These are defined in class Connection.
      // This PDO options are INSECURE, but will overcome the following issues:
      // (1) Duplicate placeholders
      // (2) > 2100 parameter limit
      // (3) Using expressions for group by with parameters are not detected as equal.
      // This options are not applied by default, they are just stored in the connection
      // options and applied when needed. See {Statement} class.
      // We ask PDO to perform the placeholders replacement itself because
      // SQL Server is not able to detect duplicated placeholders in
      // complex statements.
      // E.g. This query is going to fail because SQL Server cannot
      // detect that length1 and length2 are equals.
      // SELECT SUBSTRING(title, 1, :length1)
      // FROM node
      // GROUP BY SUBSTRING(title, 1, :length2
      // This is only going to work in PDO 3 but doesn't hurt in PDO 2.
      // The security of parameterized queries is not in effect when you use PDO::ATTR_EMULATE_PREPARES => true.
      // Your application should ensure that the data that is bound to the parameter(s) does not contain malicious
      // Transact-SQL code.
      // Never use this when you need special column binding.
      // THIS ONLY WORKS IF SET AT THE STATEMENT LEVEL.
      $pdo_options[PDO::ATTR_EMULATE_PREPARES] = TRUE;
    }

    // We run the statements in "direct mode" because the way PDO prepares
    // statement in non-direct mode cause temporary tables to be destroyed
    // at the end of the statement.
    // If you are using the PDO_SQLSRV driver and you want to execute a query that
    // changes a database setting (e.g. SET NOCOUNT ON), use the PDO::query method with
    // the PDO::SQLSRV_ATTR_DIRECT_QUERY attribute.
    // http://blogs.iis.net/bswan/archive/2010/12/09/how-to-change-database-settings-with-the-pdo-sqlsrv-driver.aspx
    // If a query requires the context that was set in a previous query,
    // you should execute your queries with PDO::SQLSRV_ATTR_DIRECT_QUERY set to True.
    // For example, if you use temporary tables in your queries, PDO::SQLSRV_ATTR_DIRECT_QUERY must be set
    // to True.
    // If we are not going to cache prepared statements, always use direct queries!
    // There is no point in preparing the statement if you are not going to cache it.
    if (!$this->statementCaching || $options['direct_query'] == TRUE) {
      $pdo_options[PDO::SQLSRV_ATTR_DIRECT_QUERY] = TRUE;
    }

    // It creates a cursor for the query, which allows you to iterate over the result set
    // without fetching the whole result at once. A scrollable cursor, specifically, is one that allows
    // iterating backwards.
    // https://msdn.microsoft.com/en-us/library/hh487158%28v=sql.105%29.aspx
    $pdo_options[PDO::ATTR_CURSOR] = PDO::CURSOR_SCROLL;

    // Lets you access rows in any order. Creates a client-side cursor query.
    $pdo_options[PDO::SQLSRV_ATTR_CURSOR_SCROLL_TYPE] = PDO::SQLSRV_CURSOR_BUFFERED;

    #endregion

    // Call our overriden prepare.
    $stmt = $this
      ->PDOPrepare($query, $pdo_options);

    // If statement caching is enabled, store current statement for reuse
    if ($options['statement_caching'] === TRUE) {
      $this->statement_cache[$query] = $stmt;
    }
    return $stmt;
  }

  /**
   * Internal function: prepare a query by calling PDO directly.
   *
   * This function has to be public because it is called by other parts of the
   * database layer, but do not call it directly, as you risk locking down the
   * PHP process.
   */
  public function PDOPrepare($query, array $options = array()) {

    // Preprocess the query.
    if (!$this->bypassQueryPreprocess) {
      $query = $this
        ->preprocessQuery($query);
    }

    // You can set the MSSQL_APPEND_CALLSTACK_COMMENT to TRUE
    // to append to each query, in the form of comments, the current
    // backtrace plus other details that aid in debugging deadlocks
    // or long standing locks. Use in combination with MSSQL profiler.
    global $conf;
    if (DatabaseUtils::GetConfigBoolean('MSSQL_APPEND_CALLSTACK_COMMENT') == TRUE) {
      global $user;
      $trim = strlen(DRUPAL_ROOT);
      $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
      static $request_id;
      if (empty($request_id)) {
        $request_id = uniqid('', TRUE);
      }

      // Remove las item (it's alwasy PDOPrepare)
      $trace = array_splice($trace, 1);
      $comment = PHP_EOL . PHP_EOL;
      $comment .= '-- uid:' . (empty($user) ? 'null' : $user->uid) . PHP_EOL;
      $uri = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : 'none';
      $uri = preg_replace("/[^a-zA-Z0-9]/i", "_", $uri);
      $comment .= '-- url:' . $uri . PHP_EOL;

      //$comment .= '-- request_id:' . $request_id . PHP_EOL;
      foreach ($trace as $t) {
        $function = isset($t['function']) ? $t['function'] : '';
        $file = '';
        if (isset($t['file'])) {
          $len = strlen($t['file']);
          if ($len > $trim) {
            $file = substr($t['file'], $trim, $len - $trim) . " [{$t['line']}]";
          }
        }
        $comment .= '-- ' . str_pad($function, 35) . '  ' . $file . PHP_EOL;
      }
      $query = $comment . PHP_EOL . $query;
    }
    return parent::prepare($query, $options);
  }

  /**
   * This is the original replacement regexp from Microsoft.
   *
   * We could probably simplify it a lot because queries only contain
   * placeholders when we modify them.
   *
   * NOTE: removed 'escape' from the list, because it explodes
   * with LIKE xxx ESCAPE yyy syntax.
   */
  const RESERVED_REGEXP = '/\\G
    # Everything that follows a boundary that is not : or _.
    \\b(?<![:\\[_])(?:
      # Any reserved words, followed by a boundary that is not an opening parenthesis.
      (action|admin|alias|any|are|array|at|begin|boolean|class|commit|contains|current|data|date|day|depth|domain|external|file|full|function|get|go|host|input|language|last|less|local|map|min|module|new|no|object|old|open|operation|parameter|parameters|path|plan|prefix|proc|public|ref|result|returns|role|rule|save|search|second|section|session|size|state|statistics|temporary|than|time|timestamp|tran|translate|translation|trim|user|value|variable|view|without)
      (?!\\()
      |
      # Or a normal word.
      ([a-z]+)
    )\\b
    |
    \\b(
      [^a-z\'"\\\\]+
    )\\b
    |
    (?=[\'"])
    (
      "  [^\\\\"] * (?: \\\\. [^\\\\"] *) * "
      |
      \' [^\\\\\']* (?: \\\\. [^\\\\\']*) * \'
    )
  /Six';

  /**
   * This method gets called between 3,000 and 10,000 times
   * on cold caches. Make sure it is simple and fast.
   *
   * @param mixed $matches
   * @return mixed
   */
  protected function replaceReservedCallback($matches) {
    if ($matches[1] !== '') {

      // Replace reserved words. We are not calling
      // quoteIdentifier() on purpose.
      return '[' . $matches[1] . ']';
    }

    // Let other value passthru.
    // by the logic of the regex above, this will always be the last match.
    return end($matches);
  }
  public function quoteIdentifier($identifier) {
    return '[' . $identifier . ']';
  }
  public function escapeField($field) {
    if (!isset($this->escapedNames[$field])) {
      if (empty($field)) {
        $this->escapedNames[$field] = '';
      }
      else {
        $this->escapedNames[$field] = implode('.', array_map(array(
          $this,
          'quoteIdentifier',
        ), explode('.', preg_replace('/[^A-Za-z0-9_.]+/', '', $field))));
      }
    }
    return $this->escapedNames[$field];
  }
  public function quoteIdentifiers($identifiers) {
    return array_map(array(
      $this,
      'quoteIdentifier',
    ), $identifiers);
  }

  /**
   * Override of DatabaseConnection::escapeLike().
   */
  public function escapeLike($string) {
    return preg_replace('/([\\[\\]%_])/', '[$1]', $string);
  }

  /**
   * Override of DatabaseConnection::queryRange().
   */
  public function queryRange($query, $from, $count, array $args = array(), array $options = array()) {
    $query = $this
      ->addRangeToQuery($query, $from, $count);
    return $this
      ->query($query, $args, $options);
  }

  /**
   * Generates a temporary table name. Because we are using
   * global temporary tables, these are visible between
   * connections so we need to make sure that their
   * names are as unique as possible to prevent collisions.
   *
   * @return
   *   A table name.
   */
  protected function generateTemporaryTableName() {
    static $temp_key;
    if (!isset($temp_key)) {
      $temp_key = strtoupper(md5(uniqid(rand(), true)));
    }
    return "db_temp_" . $this->temporaryNameIndex++ . '_' . $temp_key;
  }

  /**
   * Override of DatabaseConnection::queryTemporary().
   *
   * @status tested
   */
  public function queryTemporary($query, array $args = array(), array $options = array()) {

    // Generate a new GLOBAL temporary table name and protect it from prefixing.
    // SQL Server requires that temporary tables to be non-qualified.
    $tablename = '##' . $this
      ->generateTemporaryTableName();
    $prefixes = $this->prefixes;
    $prefixes[$tablename] = '';
    $this
      ->setPrefix($prefixes);

    // Having comments in the query can be tricky and break the SELECT FROM  -> SELECT INTO conversion
    $query = $this
      ->schema()
      ->removeSQLComments($query);

    // Replace SELECT xxx FROM table by SELECT xxx INTO #table FROM table.
    $query = preg_replace('/^SELECT(.*?)FROM/is', 'SELECT$1 INTO ' . $tablename . ' FROM', $query);
    $this
      ->query($query, $args, $options);
    return $tablename;
  }

  /**
   * {@inheritdoc}
   *
   * This method is overriden to manage the insecure (EMULATE_PREPARE)
   * behaviour to prevent some compatibility issues with SQL Server.
   */
  public function query($query, array $args = array(), $options = array()) {

    // Use default values if not already set.
    $options += $this
      ->defaultOptions();
    $stmt = NULL;
    try {

      // We allow either a pre-bound statement object or a literal string.
      // In either case, we want to end up with an executed statement object,
      // which we pass to PDOStatement::execute.
      if ($query instanceof DatabaseStatementInterface) {
        $stmt = $query;
        $stmt
          ->execute(NULL, $options);
      }
      else {
        $this
          ->expandArguments($query, $args);
        $insecure = isset($options['insecure']) ? $options['insecure'] : FALSE;

        // Try to detect duplicate place holders, this check's performance
        // is not a good addition to the driver, but does a good job preventing
        // duplicate placeholder errors.
        $argcount = count($args);
        if ($insecure === TRUE || $argcount >= 2100 || $argcount != substr_count($query, ':')) {
          $insecure = TRUE;
        }
        $stmt = $this
          ->prepareQuery($query, array(
          'insecure' => TRUE,
        ));
        $stmt
          ->execute($args, $options);
      }

      // Depending on the type of query we may need to return a different value.
      // See DatabaseConnection::defaultOptions() for a description of each
      // value.
      switch ($options['return']) {
        case Database::RETURN_STATEMENT:
          return $stmt;
        case Database::RETURN_AFFECTED:
          return $stmt
            ->rowCount();
        case Database::RETURN_INSERT_ID:
          return $this
            ->lastInsertId();
        case Database::RETURN_NULL:
          return NULL;
        default:
          throw new PDOException('Invalid return directive: ' . $options['return']);
      }
    } catch (PDOException $e) {

      // Most database drivers will return NULL here, but some of them
      // (e.g. the SQLite driver) may need to re-run the query, so the return
      // value will be the same as for static::query().
      return $this
        ->handleQueryException($e, $stmt, $args, $options);
    }
  }

  /**
   * Like query but with no insecure detection or query preprocessing.
   * The caller is sure that his query is MS SQL compatible! Used internally
   * from the schema class, but could be called from anywhere.
   *
   * @param mixed $query
   * @param array $args
   * @param mixed $options
   * @throws PDOException
   * @return mixed
   */
  public function query_direct($query, array $args = array(), $options = array()) {

    // Use default values if not already set.
    $options += $this
      ->defaultOptions();
    $stmt = NULL;
    try {

      // Bypass query preprocessing and use direct queries.
      $ctx = new \DatabaseContext($this, TRUE, TRUE);

      // Prepare the statement and execute it.
      $stmt = $this
        ->prepareQuery($query, $options);
      $stmt
        ->execute($args, $options);

      // Reset the context settings.
      unset($ctx);

      // Depending on the type of query we may need to return a different value.
      // See DatabaseConnection::defaultOptions() for a description of each
      // value.
      switch ($options['return']) {
        case Database::RETURN_STATEMENT:
          return $stmt;
        case Database::RETURN_AFFECTED:
          return $stmt
            ->rowCount();
        case Database::RETURN_INSERT_ID:
          return $this
            ->lastInsertId();
        case Database::RETURN_NULL:
          return NULL;
        default:
          throw new PDOException('Invalid return directive: ' . $options['return']);
      }
    } catch (PDOException $e) {

      // Most database drivers will return NULL here, but some of them
      // (e.g. the SQLite driver) may need to re-run the query, so the return
      // value will be the same as for static::query().
      return $this
        ->handleQueryException($e, $stmt, $args, $options);
    }
  }

  /**
   * Wraps and re-throws any PDO exception thrown by static::query().
   *
   * @param \PDOException $e
   *   The exception thrown by static::query().
   * @param $query
   *   The query executed by static::query().
   * @param array $args
   *   An array of arguments for the prepared statement.
   * @param array $options
   *   An associative array of options to control how the query is run.
   *
   * @return DatabaseStatementInterface|int|null
   *   Most database drivers will return NULL when a PDO exception is thrown for
   *   a query, but some of them may need to re-run the query, so they can also
   *   return a \Drupal\Core\Database\StatementInterface object or an integer.
   */
  public function handleQueryException(\PDOException $e, $query, array $args = array(), $options = array()) {
    if ($options['throw_exception']) {

      // Add additional debug information.
      if ($query instanceof DatabaseStatement_sqlsrv) {

        /** @var DatabaseStatement_sqlsrv $statement */
        $statement = $query;
        $e->query_string = $statement
          ->getQueryString();
        $e->args = $statement
          ->GetBoundParameters();
      }
      else {
        $e->query_string = $query;
      }
      if (empty($e->args)) {
        $e->args = $args;
      }
      throw $e;
    }
    return NULL;
  }

  /**
   * Internal function: massage a query to make it compliant with SQL Server.
   */
  public function preprocessQuery($query) {

    // Force quotes around some SQL Server reserved keywords.
    if (preg_match('/^SELECT/i', $query)) {
      $query = preg_replace_callback(self::RESERVED_REGEXP, array(
        $this,
        'replaceReservedCallback',
      ), $query);
    }

    // Last chance to modify some SQL Server-specific syntax.
    $replacements = array();

    // Add prefixes to Drupal-specific functions.
    $defaultSchema = $this
      ->schema()
      ->GetDefaultSchema();
    foreach ($this
      ->schema()
      ->DrupalSpecificFunctions() as $function) {
      $replacements['/\\b(?<![:.])(' . preg_quote($function) . ')\\(/i'] = "{$defaultSchema}.\$1(";
    }

    // Rename some functions.
    $funcs = array(
      'LENGTH' => 'LEN',
      'POW' => 'POWER',
    );
    foreach ($funcs as $function => $replacement) {
      $replacements['/\\b(?<![:.])(' . preg_quote($function) . ')\\(/i'] = $replacement . '(';
    }

    // Replace the ANSI concatenation operator with SQL Server poor one.
    $replacements['/\\|\\|/'] = '+';

    // Now do all the replacements at once.
    $query = preg_replace(array_keys($replacements), array_values($replacements), $query);
    return $query;
  }

  /**
   * Internal function: add range options to a query.
   *
   * This cannot be set protected because it is used in other parts of the
   * database engine.
   *
   * @status tested
   */
  public function addRangeToQuery($query, $from, $count) {
    if ($from == 0) {

      // Easy case: just use a TOP query if we don't have to skip any rows.
      $query = preg_replace('/^\\s*SELECT(\\s*DISTINCT)?/Dsi', 'SELECT$1 TOP(' . $count . ')', $query);
    }
    else {
      if ($this
        ->schema()
        ->EngineVersionNumber() >= 11) {

        // As of SQL Server 2012 there is an easy (and faster!) way to page results.
        $query = $query .= " OFFSET {$from} ROWS FETCH NEXT {$count} ROWS ONLY";
      }
      else {

        // More complex case: use a TOP query to retrieve $from + $count rows, and
        // filter out the first $from rows using a window function.
        $query = preg_replace('/^\\s*SELECT(\\s*DISTINCT)?/Dsi', 'SELECT$1 TOP(' . ($from + $count) . ') ', $query);
        $query = '
          SELECT * FROM (
            SELECT sub2.*, ROW_NUMBER() OVER(ORDER BY sub2.__line2) AS __line3 FROM (
              SELECT sub1.*, 1 AS __line2 FROM (' . $query . ') AS sub1
            ) as sub2
          ) AS sub3
          WHERE __line3 BETWEEN ' . ($from + 1) . ' AND ' . ($from + $count);
      }
    }
    return $query;
  }
  public function mapConditionOperator($operator) {

    // SQL Server doesn't need special escaping for the \ character in a string
    // literal, because it uses '' to escape the single quote, not \'.
    static $specials = array(
      'LIKE' => array(),
      'NOT LIKE' => array(),
    );
    return isset($specials[$operator]) ? $specials[$operator] : NULL;
  }

  /**
   * Override of DatabaseConnection::nextId().
   *
   * @status tested
   */
  public function nextId($existing = 0) {

    // If an exiting value is passed, for its insertion into the sequence table.
    if ($existing > 0) {
      try {
        $this
          ->query_direct('SET IDENTITY_INSERT {sequences} ON; INSERT INTO {sequences} (value) VALUES(:existing); SET IDENTITY_INSERT {sequences} OFF', array(
          ':existing' => $existing,
        ));
      } catch (Exception $e) {

        // Doesn't matter if this fails, it just means that this value is already
        // present in the table.
      }
    }

    // Refactored to use OUTPUT because under high concurrency LAST_INSERTED_ID does not work properly.
    return $this
      ->query_direct('INSERT INTO {sequences} OUTPUT (Inserted.[value]) DEFAULT VALUES')
      ->fetchField();
  }

  /**
   * Override DatabaseConnection::escapeTable().
   *
   * @status needswork
   */
  public function escapeTable($table) {

    // A static cache is better suited for this.
    static $tables = array();
    if (isset($tables[$table])) {
      return $tables[$table];
    }

    // Rescue the # prefix from the escaping.
    $is_temporary = $table[0] == '#';
    $is_temporary_global = $is_temporary && isset($table[1]) && $table[1] == '#';

    // Any temporary table prefix will be removed.
    $result = preg_replace('/[^A-Za-z0-9_.]+/', '', $table);

    // Restore the temporary prefix.
    if ($is_temporary) {
      if ($is_temporary_global) {
        $result = '##' . $result;
      }
      else {
        $result = '#' . $result;
      }
    }
    $tables[$table] = $result;
    return $result;
  }

  #region Transactions

  /**
   * Overriden to allow transaction settings.
   */
  public function startTransaction($name = '', DatabaseTransactionSettings $settings = NULL) {
    if ($settings == NULL) {
      $settings = DatabaseTransactionSettings::GetDefaults();
    }
    return new DatabaseTransaction_sqlsrv($this, $name, $settings);
  }

  /**
   * Overriden.
   */
  public function rollback($savepoint_name = 'drupal_transaction') {
    if (!$this
      ->supportsTransactions()) {
      return;
    }
    if (!$this
      ->inTransaction()) {
      throw new DatabaseTransactionNoActiveException();
    }

    // A previous rollback to an earlier savepoint may mean that the savepoint
    // in question has already been accidentally committed.
    if (!isset($this->transactionLayers[$savepoint_name])) {
      throw new DatabaseTransactionNoActiveException();
    }

    // We need to find the point we're rolling back to, all other savepoints
    // before are no longer needed. If we rolled back other active savepoints,
    // we need to throw an exception.
    $rolled_back_other_active_savepoints = FALSE;
    while ($savepoint = array_pop($this->transactionLayers)) {
      if ($savepoint['name'] == $savepoint_name) {

        // If it is the last the transaction in the stack, then it is not a
        // savepoint, it is the transaction itself so we will need to roll back
        // the transaction rather than a savepoint.
        if (empty($this->transactionLayers)) {
          break;
        }
        if ($savepoint['started'] == TRUE) {
          $this
            ->query_direct('ROLLBACK TRANSACTION ' . $savepoint['name']);
        }
        $this
          ->popCommittableTransactions();
        if ($rolled_back_other_active_savepoints) {
          throw new DatabaseTransactionOutOfOrderException();
        }
        return;
      }
      else {
        $rolled_back_other_active_savepoints = TRUE;
      }
    }
    $this->connection
      ->rollback();

    // Restore original transaction isolation level
    if ($level = static::DefaultTransactionIsolationLevelInStatement()) {
      if ($savepoint['settings']
        ->Get_IsolationLevel() != DatabaseTransactionIsolationLevel::Ignore()) {
        if ($level != $savepoint['settings']
          ->Get_IsolationLevel()) {
          $this
            ->query_direct("SET TRANSACTION ISOLATION LEVEL {$level}");
        }
      }
    }
    if ($rolled_back_other_active_savepoints) {
      throw new DatabaseTransactionOutOfOrderException();
    }
  }

  /**
   * Summary of pushTransaction
   * @param string $name
   * @param DatabaseTransactionSettings $settings
   * @throws DatabaseTransactionNameNonUniqueException
   * @return void
   */
  public function pushTransaction($name, $settings = NULL) {
    if (!$this
      ->supportsTransactions()) {
      return;
    }
    if (isset($this->transactionLayers[$name])) {
      throw new DatabaseTransactionNameNonUniqueException($name . " is already in use.");
    }
    $started = FALSE;

    // If we're already in a transaction.
    // TODO: Transaction scope Options is not working properly
    // for first level transactions. It assumes that - always - a first level
    // transaction must be started.
    if ($this
      ->inTransaction()) {
      switch ($settings
        ->Get_ScopeOption()) {
        case DatabaseTransactionScopeOption::RequiresNew():
          $this
            ->query_direct('SAVE TRANSACTION ' . $name);
          $started = TRUE;
          break;
        case DatabaseTransactionScopeOption::Required():

          // We are already in a transaction, do nothing.
          break;
        case DatabaseTransactionScopeOption::Supress():

          // The only way to supress the ambient transaction is to use a new connection
          // during the scope of this transaction, a bit messy to implement.
          throw new Exception('DatabaseTransactionScopeOption::Supress not implemented.');
      }
    }
    else {
      if ($settings
        ->Get_IsolationLevel() != DatabaseTransactionIsolationLevel::Ignore()) {
        $user_options = $this
          ->schema()
          ->UserOptions();
        $current_isolation_level = strtoupper($user_options['isolation level']);

        // Se what isolation level was requested.
        $level = $settings
          ->Get_IsolationLevel()
          ->__toString();
        if (strcasecmp($current_isolation_level, $level) !== 0) {
          $this
            ->query_direct("SET TRANSACTION ISOLATION LEVEL {$level}");
        }
      }

      // In order to start a transaction current statement cursors
      // must be closed.
      foreach ($this->statement_cache as $statement) {
        $statement
          ->closeCursor();
      }
      $this->connection
        ->beginTransaction();
    }

    // Store the name and settings in the stack.
    $this->transactionLayers[$name] = array(
      'settings' => $settings,
      'active' => TRUE,
      'name' => $name,
      'started' => $started,
    );
  }

  /**
   * Decreases the depth of transaction nesting.
   *
   * If we pop off the last transaction layer, then we either commit or roll
   * back the transaction as necessary. If no transaction is active, we return
   * because the transaction may have manually been rolled back.
   *
   * @param $name
   *   The name of the savepoint
   *
   * @throws DatabaseTransactionNoActiveException
   * @throws DatabaseTransactionCommitFailedException
   *
   * @see DatabaseTransaction
   */
  public function popTransaction($name) {
    if (!$this
      ->supportsTransactions()) {
      return;
    }

    // The transaction has already been committed earlier. There is nothing we
    // need to do. If this transaction was part of an earlier out-of-order
    // rollback, an exception would already have been thrown by
    // Database::rollback().
    if (!isset($this->transactionLayers[$name])) {
      return;
    }

    // Mark this layer as committable.
    $this->transactionLayers[$name]['active'] = FALSE;
    $this
      ->popCommittableTransactions();
  }

  /**
   * Internal function: commit all the transaction layers that can commit.
   */
  protected function popCommittableTransactions() {

    // Commit all the committable layers.
    foreach (array_reverse($this->transactionLayers) as $name => $state) {

      // Stop once we found an active transaction.
      if ($state['active']) {
        break;
      }

      // If there are no more layers left then we should commit.
      unset($this->transactionLayers[$name]);
      if (empty($this->transactionLayers)) {
        try {

          // PDO::commit() can either return FALSE or throw an exception itself
          $commit_check = $this->connection
            ->commit();
          if (!$commit_check) {
            throw new DatabaseTransactionCommitFailedException();
          }
        } finally {

          // Restore original transaction isolation level
          if ($level = static::DefaultTransactionIsolationLevelInStatement()) {
            if ($state['settings']
              ->Get_IsolationLevel() != DatabaseTransactionIsolationLevel::Ignore()) {
              if ($level != $state['settings']
                ->Get_IsolationLevel()
                ->__toString()) {
                $this
                  ->query_direct("SET TRANSACTION ISOLATION LEVEL {$level}");
              }
            }
          }
        }
      }
      else {

        // Savepoints cannot be commited, only rolled back.
      }
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DatabaseConnection::$connection	protected	property	The actual PDO connection.
DatabaseConnection::$connectionOptions	protected	property	The connection information for this connection object.
DatabaseConnection::$driverClasses	protected	property	Index of what driver-specific class to use for various operations.
DatabaseConnection::$escapedAliases	protected	property	List of escaped aliases names, keyed by unescaped aliases.
DatabaseConnection::$escapedNames	protected	property	List of escaped database, table, and field names, keyed by unescaped names.
DatabaseConnection::$key	protected	property	The key representing this connection.
DatabaseConnection::$logger	protected	property	The current database logging object for this connection.
DatabaseConnection::$prefixes	protected	property	The prefixes used by this database connection.
DatabaseConnection::$prefixReplace	protected	property	List of replacement values for use in prefixTables().
DatabaseConnection::$prefixSearch	protected	property	List of search values for use in prefixTables().
DatabaseConnection::$schema	protected	property	The schema object for this connection.
DatabaseConnection::$statementClass	protected	property	The name of the Statement class for this connection.
DatabaseConnection::$target	protected	property	The database target this connection is for.
DatabaseConnection::$temporaryNameIndex	protected	property	An index used to generate unique temporary table names.
DatabaseConnection::$transactionalDDLSupport	protected	property	Whether this database connection supports transactional DDL.
DatabaseConnection::$transactionLayers	protected	property	Tracks the number of "layers" of transactions currently active.
DatabaseConnection::$transactionSupport	protected	property	Whether this database connection supports transactions.
DatabaseConnection::$unprefixedTablesMap	protected	property	List of un-prefixed table names, keyed by prefixed table names.
DatabaseConnection::commit	public	function	Throws an exception to deny direct access to transaction commits.
DatabaseConnection::defaultOptions	protected	function	Returns the default query options for any given query.
DatabaseConnection::delete	public	function	Prepares and returns a DELETE query object.
DatabaseConnection::destroy	public	function	Destroys this Connection object.
DatabaseConnection::escapeAlias	public	function	Escapes an alias name string.	1
DatabaseConnection::expandArguments	protected	function	Expands out shorthand placeholders.
DatabaseConnection::filterComment	protected	function	Sanitize a query comment string.
DatabaseConnection::getConnectionOptions	public	function	Returns the connection information for this connection object.
DatabaseConnection::getDriverClass	public	function	Gets the driver-specific override class if any for the specified class.
DatabaseConnection::getKey	public	function	Returns the key this connection is associated with.
DatabaseConnection::getLogger	public	function	Gets the current logging object for this connection.
DatabaseConnection::getTarget	public	function	Returns the target this connection is associated with.
DatabaseConnection::getUnprefixedTablesMap	public	function	Gets a list of individually prefixed table names.
DatabaseConnection::insert	public	function	Prepares and returns an INSERT query object.
DatabaseConnection::inTransaction	public	function	Determines if there is an active transaction open.
DatabaseConnection::makeComment	public	function	Flatten an array of query comments into a single comment string.
DatabaseConnection::makeSequenceName	public	function	Creates the appropriate sequence name for a given table and serial field.
DatabaseConnection::merge	public	function	Prepares and returns a MERGE query object.
DatabaseConnection::prefixTables	public	function	Appends a database prefix to all tables in a query.
DatabaseConnection::schema	public	function	Returns a DatabaseSchema object for manipulating the schema.
DatabaseConnection::select	public	function	Prepares and returns a SELECT query object.
DatabaseConnection::setKey	public	function	Tells this connection object what its key is.
DatabaseConnection::setLogger	public	function	Associates a logging object with this connection.
DatabaseConnection::setPrefix	protected	function	Set the list of prefixes used by this database connection.	1
DatabaseConnection::setTarget	public	function	Tells this connection object what its target value is.
DatabaseConnection::supportsTransactionalDDL	public	function	Determines if this driver supports transactional DDL.
DatabaseConnection::supportsTransactions	public	function	Determines if this driver supports transactions.
DatabaseConnection::tablePrefix	public	function	Find the prefix for a table.
DatabaseConnection::transactionDepth	public	function	Determines current transaction depth.
DatabaseConnection::truncate	public	function	Prepares and returns a TRUNCATE query object.
DatabaseConnection::update	public	function	Prepares and returns an UPDATE query object.
DatabaseConnection::utf8mb4IsConfigurable	public	function	Checks whether utf8mb4 support is configurable in settings.php.	1
DatabaseConnection::version	public	function	Returns the version of the database server.
DatabaseConnection::__call	public	function	Proxy possible direct calls to the \PDO methods.
DatabaseConnection_sqlsrv::$bypassQueryPreprocess	public	property
DatabaseConnection_sqlsrv::$directQuery	public	property
DatabaseConnection_sqlsrv::$statementCaching	public	property
DatabaseConnection_sqlsrv::$statement_cache	private	property	Prepared PDO statements only makes sense if we cache them...
DatabaseConnection_sqlsrv::addRangeToQuery	public	function	Internal function: add range options to a query.
DatabaseConnection_sqlsrv::databaseType	public	function	Override of DatabaseConnection::databaseType(). Overrides DatabaseConnection::databaseType
DatabaseConnection_sqlsrv::DefaultTransactionIsolationLevelInStatement	private static	function	The PDO constants do not matcc the actual isolation names used in SQL.
DatabaseConnection_sqlsrv::driver	public	function	Override of DatabaseConnection::driver(). Overrides DatabaseConnection::driver
DatabaseConnection_sqlsrv::escapeField	public	function	Escapes a field name string. Overrides DatabaseConnection::escapeField
DatabaseConnection_sqlsrv::escapeLike	public	function	Override of DatabaseConnection::escapeLike(). Overrides DatabaseConnection::escapeLike
DatabaseConnection_sqlsrv::escapeTable	public	function	Override DatabaseConnection::escapeTable(). Overrides DatabaseConnection::escapeTable
DatabaseConnection_sqlsrv::generateTemporaryTableName	protected	function	Generates a temporary table name. Because we are using global temporary tables, these are visible between connections so we need to make sure that their names are as unique as possible to prevent collisions. Overrides DatabaseConnection::generateTemporaryTableName
DatabaseConnection_sqlsrv::handleQueryException	public	function	Wraps and re-throws any PDO exception thrown by static::query().
DatabaseConnection_sqlsrv::mapConditionOperator	public	function	Gets any special processing requirements for the condition operator. Overrides DatabaseConnection::mapConditionOperator
DatabaseConnection_sqlsrv::nextId	public	function	Override of DatabaseConnection::nextId(). Overrides DatabaseConnection::nextId
DatabaseConnection_sqlsrv::PDOPrepare	public	function	Internal function: prepare a query by calling PDO directly.
DatabaseConnection_sqlsrv::popCommittableTransactions	protected	function	Internal function: commit all the transaction layers that can commit. Overrides DatabaseConnection::popCommittableTransactions
DatabaseConnection_sqlsrv::popTransaction	public	function	Decreases the depth of transaction nesting. Overrides DatabaseConnection::popTransaction
DatabaseConnection_sqlsrv::prepareQuery	public	function	Temporary override of DatabaseConnection::prepareQuery(). Overrides DatabaseConnection::prepareQuery
DatabaseConnection_sqlsrv::preprocessQuery	public	function	Internal function: massage a query to make it compliant with SQL Server.
DatabaseConnection_sqlsrv::pushTransaction	public	function	Summary of pushTransaction Overrides DatabaseConnection::pushTransaction
DatabaseConnection_sqlsrv::query	public	function	This method is overriden to manage the insecure (EMULATE_PREPARE) behaviour to prevent some compatibility issues with SQL Server. Overrides DatabaseConnection::query
DatabaseConnection_sqlsrv::queryRange	public	function	Override of DatabaseConnection::queryRange(). Overrides DatabaseConnection::queryRange
DatabaseConnection_sqlsrv::queryTemporary	public	function	Override of DatabaseConnection::queryTemporary(). Overrides DatabaseConnection::queryTemporary
DatabaseConnection_sqlsrv::query_direct	public	function	Like query but with no insecure detection or query preprocessing. The caller is sure that his query is MS SQL compatible! Used internally from the schema class, but could be called from anywhere.
DatabaseConnection_sqlsrv::quoteIdentifier	public	function
DatabaseConnection_sqlsrv::quoteIdentifiers	public	function
DatabaseConnection_sqlsrv::replaceReservedCallback	protected	function	This method gets called between 3,000 and 10,000 times on cold caches. Make sure it is simple and fast.
DatabaseConnection_sqlsrv::RESERVED_REGEXP		constant	This is the original replacement regexp from Microsoft.
DatabaseConnection_sqlsrv::rollback	public	function	Overriden. Overrides DatabaseConnection::rollback
DatabaseConnection_sqlsrv::startTransaction	public	function	Overriden to allow transaction settings. Overrides DatabaseConnection::startTransaction
DatabaseConnection_sqlsrv::utf8mb4IsActive	public	function	Checks whether utf8mb4 support is currently active. Overrides DatabaseConnection::utf8mb4IsActive
DatabaseConnection_sqlsrv::utf8mb4IsSupported	public	function	Checks whether utf8mb4 support is available on the current database system. Overrides DatabaseConnection::utf8mb4IsSupported
DatabaseConnection_sqlsrv::__construct	public	function	Override of DatabaseConnection::databaseType(). Overrides DatabaseConnection::__construct

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class DatabaseConnection_sqlsrv in Drupal driver for SQL Server and SQL Azure 7.3

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