class Connection in Drupal 10

PostgreSQL implementation of \Drupal\Core\Database\Connection.

Hierarchy

• class \Drupal\pgsql\Driver\Database\pgsql\Connection extends \Drupal\Core\Database\Connection

Related topics

Database abstraction layer

Allow the use of different database servers using the same code base.

3 files declare their use of Connection

Connection.php in core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php

Connection.php in core/modules/system/tests/modules/database_statement_monitoring_test/src/pgsql/Connection.php

Connection.php in core/modules/system/tests/modules/driver_test/src/Driver/Database/DrivertestPgsql/Connection.php

File

core/modules/pgsql/src/Driver/Database/pgsql/Connection.php, line 22

Namespace

Drupal\pgsql\Driver\Database\pgsql

class Connection extends DatabaseConnection {

  /**
   * The name by which to obtain a lock for retrieve the next insert id.
   */
  const POSTGRESQL_NEXTID_LOCK = 1000;

  /**
   * Error code for "Unknown database" error.
   */
  const DATABASE_NOT_FOUND = 7;

  /**
   * Error code for "Connection failure" errors.
   *
   * Technically this is an internal error code that will only be shown in the
   * PDOException message. It will need to get extracted.
   */
  const CONNECTION_FAILURE = '08006';

  /**
   * {@inheritdoc}
   */
  protected $statementWrapperClass = StatementWrapper::class;

  /**
   * A map of condition operators to PostgreSQL operators.
   *
   * In PostgreSQL, 'LIKE' is case-sensitive. ILIKE should be used for
   * case-insensitive statements.
   */
  protected static $postgresqlConditionOperatorMap = [
    'LIKE' => [
      'operator' => 'ILIKE',
    ],
    'LIKE BINARY' => [
      'operator' => 'LIKE',
    ],
    'NOT LIKE' => [
      'operator' => 'NOT ILIKE',
    ],
    'REGEXP' => [
      'operator' => '~*',
    ],
    'NOT REGEXP' => [
      'operator' => '!~*',
    ],
  ];

  /**
   * {@inheritdoc}
   */
  protected $transactionalDDLSupport = TRUE;

  /**
   * {@inheritdoc}
   */
  protected $identifierQuotes = [
    '"',
    '"',
  ];

  /**
   * Constructs a connection object.
   */
  public function __construct(\PDO $connection, array $connection_options) {
    parent::__construct($connection, $connection_options);

    // Force PostgreSQL to use the UTF-8 character set by default.
    $this->connection
      ->exec("SET NAMES 'UTF8'");

    // Execute PostgreSQL init_commands.
    if (isset($connection_options['init_commands'])) {
      $this->connection
        ->exec(implode('; ', $connection_options['init_commands']));
    }
  }

  /**
   * {@inheritdoc}
   */
  public static function open(array &$connection_options = []) {

    // Default to TCP connection on port 5432.
    if (empty($connection_options['port'])) {
      $connection_options['port'] = 5432;
    }

    // PostgreSQL in trust mode doesn't require a password to be supplied.
    if (empty($connection_options['password'])) {
      $connection_options['password'] = NULL;
    }
    else {
      $connection_options['password'] = str_replace('\\', '\\\\', $connection_options['password']);
    }
    $connection_options['database'] = !empty($connection_options['database']) ? $connection_options['database'] : 'template1';
    $dsn = 'pgsql:host=' . $connection_options['host'] . ' dbname=' . $connection_options['database'] . ' port=' . $connection_options['port'];

    // Allow PDO options to be overridden.
    $connection_options += [
      'pdo' => [],
    ];
    $connection_options['pdo'] += [
      \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
      // Prepared statements are most effective for performance when queries
      // are recycled (used several times). However, if they are not re-used,
      // prepared statements become inefficient. Since most of Drupal's
      // prepared queries are not re-used, it should be faster to emulate
      // the preparation than to actually ready statements for re-use. If in
      // doubt, reset to FALSE and measure performance.
      \PDO::ATTR_EMULATE_PREPARES => TRUE,
      // Convert numeric values to strings when fetching.
      \PDO::ATTR_STRINGIFY_FETCHES => TRUE,
    ];
    try {
      $pdo = new \PDO($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);
    } catch (\PDOException $e) {
      if (static::getSQLState($e) == static::CONNECTION_FAILURE) {
        if (strpos($e
          ->getMessage(), 'password authentication failed for user') !== FALSE) {
          throw new DatabaseAccessDeniedException($e
            ->getMessage(), $e
            ->getCode(), $e);
        }
        elseif (strpos($e
          ->getMessage(), 'database') !== FALSE && strpos($e
          ->getMessage(), 'does not exist') !== FALSE) {
          throw new DatabaseNotFoundException($e
            ->getMessage(), $e
            ->getCode(), $e);
        }
      }
      throw $e;
    }
    return $pdo;
  }

  /**
   * {@inheritdoc}
   */
  public function query($query, array $args = [], $options = []) {
    $options += $this
      ->defaultOptions();

    // The PDO PostgreSQL driver has a bug which doesn't type cast booleans
    // correctly when parameters are bound using associative arrays.
    // @see http://bugs.php.net/bug.php?id=48383
    foreach ($args as &$value) {
      if (is_bool($value)) {
        $value = (int) $value;
      }
    }

    // We need to wrap queries with a savepoint if:
    // - Currently in a transaction.
    // - A 'mimic_implicit_commit' does not exist already.
    // - The query is not a savepoint query.
    $wrap_with_savepoint = $this
      ->inTransaction() && !isset($this->transactionLayers['mimic_implicit_commit']) && !(is_string($query) && (stripos($query, 'ROLLBACK TO SAVEPOINT ') === 0 || stripos($query, 'RELEASE SAVEPOINT ') === 0 || stripos($query, 'SAVEPOINT ') === 0));
    if ($wrap_with_savepoint) {

      // Create a savepoint so we can rollback a failed query. This is so we can
      // mimic MySQL and SQLite transactions which don't fail if a single query
      // fails. This is important for tables that are created on demand. For
      // example, \Drupal\Core\Cache\DatabaseBackend.
      $this
        ->addSavepoint();
      try {
        $return = parent::query($query, $args, $options);
        $this
          ->releaseSavepoint();
      } catch (\Exception $e) {
        $this
          ->rollbackSavepoint();
        throw $e;
      }
    }
    else {
      $return = parent::query($query, $args, $options);
    }
    return $return;
  }

  /**
   * {@inheritdoc}
   */
  public function prepareStatement(string $query, array $options, bool $allow_row_count = FALSE) : StatementInterface {

    // mapConditionOperator converts some operations (LIKE, REGEXP, etc.) to
    // PostgreSQL equivalents (ILIKE, ~*, etc.). However PostgreSQL doesn't
    // automatically cast the fields to the right type for these operators,
    // so we need to alter the query and add the type-cast.
    $query = preg_replace('/ ([^ ]+) +(I*LIKE|NOT +I*LIKE|~\\*|!~\\*) /i', ' ${1}::text ${2} ', $query);
    return parent::prepareStatement($query, $options, $allow_row_count);
  }
  public function queryRange($query, $from, $count, array $args = [], array $options = []) {
    return $this
      ->query($query . ' LIMIT ' . (int) $count . ' OFFSET ' . (int) $from, $args, $options);
  }
  public function driver() {
    return 'pgsql';
  }
  public function databaseType() {
    return 'pgsql';
  }

  /**
   * Overrides \Drupal\Core\Database\Connection::createDatabase().
   *
   * @param string $database
   *   The name of the database to create.
   *
   * @throws \Drupal\Core\Database\DatabaseNotFoundException
   */
  public function createDatabase($database) {

    // Escape the database name.
    $database = Database::getConnection()
      ->escapeDatabase($database);

    // If the PECL intl extension is installed, use it to determine the proper
    // locale.  Otherwise, fall back to en_US.
    if (class_exists('Locale')) {
      $locale = \Locale::getDefault();
    }
    else {
      $locale = 'en_US';
    }
    try {

      // Create the database and set it as active.
      $this->connection
        ->exec("CREATE DATABASE {$database} WITH TEMPLATE template0 ENCODING='utf8' LC_CTYPE='{$locale}.utf8' LC_COLLATE='{$locale}.utf8'");
    } catch (\Exception $e) {
      throw new DatabaseNotFoundException($e
        ->getMessage());
    }
  }
  public function mapConditionOperator($operator) {
    return static::$postgresqlConditionOperatorMap[$operator] ?? NULL;
  }

  /**
   * Retrieve a the next id in a sequence.
   *
   * PostgreSQL has built in sequences. We'll use these instead of inserting
   * and updating a sequences table.
   */
  public function nextId($existing = 0) {

    // Retrieve the name of the sequence. This information cannot be cached
    // because the prefix may change, for example, like it does in tests.
    $sequence_name = $this
      ->makeSequenceName('sequences', 'value');

    // When PostgreSQL gets a value too small then it will lock the table,
    // retry the INSERT and if it's still too small then alter the sequence.
    $id = $this
      ->query("SELECT nextval('" . $sequence_name . "')")
      ->fetchField();
    if ($id > $existing) {
      return $id;
    }

    // PostgreSQL advisory locks are simply locks to be used by an
    // application such as Drupal. This will prevent other Drupal processes
    // from altering the sequence while we are.
    $this
      ->query("SELECT pg_advisory_lock(" . self::POSTGRESQL_NEXTID_LOCK . ")");

    // While waiting to obtain the lock, the sequence may have been altered
    // so lets try again to obtain an adequate value.
    $id = $this
      ->query("SELECT nextval('" . $sequence_name . "')")
      ->fetchField();
    if ($id > $existing) {
      $this
        ->query("SELECT pg_advisory_unlock(" . self::POSTGRESQL_NEXTID_LOCK . ")");
      return $id;
    }

    // Reset the sequence to a higher value than the existing id.
    $this
      ->query("ALTER SEQUENCE " . $sequence_name . " RESTART WITH " . ($existing + 1));

    // Retrieve the next id. We know this will be as high as we want it.
    $id = $this
      ->query("SELECT nextval('" . $sequence_name . "')")
      ->fetchField();
    $this
      ->query("SELECT pg_advisory_unlock(" . self::POSTGRESQL_NEXTID_LOCK . ")");
    return $id;
  }

  /**
   * {@inheritdoc}
   */
  public function getFullQualifiedTableName($table) {
    $options = $this
      ->getConnectionOptions();
    $prefix = $this
      ->tablePrefix($table);

    // The fully qualified table name in PostgreSQL is in the form of
    // <database>.<schema>.<table>, so we have to include the 'public' schema in
    // the return value.
    return $options['database'] . '.public.' . $prefix . $table;
  }

  /**
   * Add a new savepoint with a unique name.
   *
   * The main use for this method is to mimic InnoDB functionality, which
   * provides an inherent savepoint before any query in a transaction.
   *
   * @param $savepoint_name
   *   A string representing the savepoint name. By default,
   *   "mimic_implicit_commit" is used.
   *
   * @see Drupal\Core\Database\Connection::pushTransaction()
   */
  public function addSavepoint($savepoint_name = 'mimic_implicit_commit') {
    if ($this
      ->inTransaction()) {
      $this
        ->pushTransaction($savepoint_name);
    }
  }

  /**
   * Release a savepoint by name.
   *
   * @param $savepoint_name
   *   A string representing the savepoint name. By default,
   *   "mimic_implicit_commit" is used.
   *
   * @see Drupal\Core\Database\Connection::popTransaction()
   */
  public function releaseSavepoint($savepoint_name = 'mimic_implicit_commit') {
    if (isset($this->transactionLayers[$savepoint_name])) {
      $this
        ->popTransaction($savepoint_name);
    }
  }

  /**
   * Rollback a savepoint by name if it exists.
   *
   * @param $savepoint_name
   *   A string representing the savepoint name. By default,
   *   "mimic_implicit_commit" is used.
   */
  public function rollbackSavepoint($savepoint_name = 'mimic_implicit_commit') {
    if (isset($this->transactionLayers[$savepoint_name])) {
      $this
        ->rollBack($savepoint_name);
    }
  }

  /**
   * {@inheritDoc}
   */
  public function hasJson() : bool {
    try {
      return (bool) $this
        ->query('SELECT JSON_TYPEOF(\'1\')');
    } catch (\Exception $e) {
      return FALSE;
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
Connection::$identifierQuotes	protected	property
Connection::$postgresqlConditionOperatorMap	protected static	property	A map of condition operators to PostgreSQL operators.
Connection::$statementWrapperClass	protected	property
Connection::$transactionalDDLSupport	protected	property
Connection::addSavepoint	public	function	Add a new savepoint with a unique name.
Connection::CONNECTION_FAILURE		constant	Error code for "Connection failure" errors.
Connection::createDatabase	public	function	Overrides \Drupal\Core\Database\Connection::createDatabase().
Connection::databaseType	public	function
Connection::DATABASE_NOT_FOUND		constant	Error code for "Unknown database" error.
Connection::driver	public	function
Connection::getFullQualifiedTableName	public	function
Connection::hasJson	public	function
Connection::mapConditionOperator	public	function
Connection::nextId	public	function	Retrieve a the next id in a sequence.
Connection::open	public static	function
Connection::POSTGRESQL_NEXTID_LOCK		constant	The name by which to obtain a lock for retrieve the next insert id.
Connection::prepareStatement	public	function
Connection::query	public	function
Connection::queryRange	public	function
Connection::releaseSavepoint	public	function	Release a savepoint by name.
Connection::rollbackSavepoint	public	function	Rollback a savepoint by name if it exists.
Connection::__construct	public	function	Constructs a connection object.