public function DatabaseConnection_mysql::__construct in Drupal 7

Overrides DatabaseConnection::__construct

File

includes/database/mysql/database.inc, line 298

Database interface code for MySQL database servers.

Class

DatabaseConnection_mysql

Code

public function __construct(array $connection_options = array()) {

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

  // MySQL never supports transactional DDL.
  $this->transactionalDDLSupport = FALSE;
  $this->connectionOptions = $connection_options;
  $charset = 'utf8';

  // Check if the charset is overridden to utf8mb4 in settings.php.
  if ($this
    ->utf8mb4IsActive()) {
    $charset = 'utf8mb4';
  }

  // The DSN should use either a socket or a host/port.
  if (isset($connection_options['unix_socket'])) {
    $dsn = 'mysql:unix_socket=' . $connection_options['unix_socket'];
  }
  else {

    // Default to TCP connection on port 3306.
    $dsn = 'mysql:host=' . $connection_options['host'] . ';port=' . (empty($connection_options['port']) ? 3306 : $connection_options['port']);
  }

  // Character set is added to dsn to ensure PDO uses the proper character
  // set when escaping. This has security implications. See
  // https://www.drupal.org/node/1201452 for further discussion.
  $dsn .= ';charset=' . $charset;
  $dsn .= ';dbname=' . $connection_options['database'];

  // Allow PDO options to be overridden.
  $connection_options += array(
    'pdo' => array(),
  );
  $connection_options['pdo'] += array(
    // So we don't have to mess around with cursors and unbuffered queries by default.
    PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => TRUE,
    // Because MySQL's prepared statements skip the query cache, because it's dumb.
    PDO::ATTR_EMULATE_PREPARES => TRUE,
  );
  if (defined('PDO::MYSQL_ATTR_MULTI_STATEMENTS')) {

    // An added connection option in PHP 5.5.21+ to optionally limit SQL to a
    // single statement like mysqli.
    $connection_options['pdo'] += array(
      PDO::MYSQL_ATTR_MULTI_STATEMENTS => FALSE,
    );
  }
  parent::__construct($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);

  // Force MySQL to use the UTF-8 character set. Also set the collation, if a
  // certain one has been set; otherwise, MySQL defaults to 'utf8_general_ci'
  // for UTF-8.
  if (!empty($connection_options['collation'])) {
    $this->connection
      ->exec('SET NAMES ' . $charset . ' COLLATE ' . $connection_options['collation']);
  }
  else {
    $this->connection
      ->exec('SET NAMES ' . $charset);
  }

  // Set MySQL init_commands if not already defined.  Default Drupal's MySQL
  // behavior to conform more closely to SQL standards.  This allows Drupal
  // to run almost seamlessly on many different kinds of database systems.
  // These settings force MySQL to behave the same as postgresql, or sqlite
  // in regards to syntax interpretation and invalid data handling.  See
  // http://drupal.org/node/344575 for further discussion. Also, as MySQL 5.5
  // changed the meaning of TRADITIONAL we need to spell out the modes one by
  // one.
  $connection_options += array(
    'init_commands' => array(),
  );
  $sql_mode = 'REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO';

  // NO_AUTO_CREATE_USER was removed in MySQL 8.0.11
  // https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-11.html#mysqld-8-0-11-deprecation-removal
  if (version_compare($this->connection
    ->getAttribute(PDO::ATTR_SERVER_VERSION), '8.0.11', '<')) {
    $sql_mode .= ',NO_AUTO_CREATE_USER';
  }
  $connection_options['init_commands'] += array(
    'sql_mode' => "SET sql_mode = '{$sql_mode}'",
  );

  // Execute initial commands.
  foreach ($connection_options['init_commands'] as $sql) {
    $this->connection
      ->exec($sql);
  }
}