Constructs a Connection object.
Overrides Connection::__construct
public function __construct(PDO $connection, array $connection_options = array()) {
parent::__construct($connection, $connection_options);
// 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;
}