public function connect() {
		$this->_isConnected = false;
		$config = $this->_config;

		if (!$config['database']) {
			throw new ConfigException('No Database configured');
		}
		if (!$config['dsn']) {
			throw new ConfigException('No DSN setup for DB Connection');
		}
		$dsn = $config['dsn'];

		$options = $config['options'] + array(
			PDO::ATTR_PERSISTENT => $config['persistent'],
			PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
		);

		try {
			$this->connection = new PDO($dsn, $config['login'], $config['password'], $options);
		} catch (PDOException $e) {
			preg_match('/SQLSTATE\[(.+?)\]/', $e->getMessage(), $code);
			$code = $code[1] ?: 0;
			switch (true) {
				case $code === 'HY000' || substr($code, 0, 2) === '08':
					$msg = "Unable to connect to host `{$config['host']}`.";
					throw new NetworkException($msg, null, $e);
				break;
				case in_array($code, array('28000', '42000')):
					$msg = "Host connected, but could not access database `{$config['database']}`.";
					throw new ConfigException($msg, null, $e);
				break;
			}
			throw new ConfigException("An unknown configuration error has occured.", null, $e);
		}
		$this->_isConnected = true;

		if ($this->_config['encoding']) {
			$this->encoding($this->_config['encoding']);
		}
		return $this->_isConnected;
	}