public function convertDbConfig($db)
    {
        $connectionOptions = [];

        if ($db['dbdriver'] === 'pdo') {
            return $this->convertDbConfigPdo($db);
        } elseif ($db['dbdriver'] === 'mysqli') {
            $connectionOptions = [
                'driver'   => $db['dbdriver'],
                'user'     => $db['username'],
                'password' => $db['password'],
                'host'     => $db['hostname'],
                'dbname'   => $db['database'],
                'charset'  => $db['char_set'],
            ];
        } else {
            throw new Exception('Your Database Configuration is not confirmed by CodeIgniter Doctrine');
        }

        return $connectionOptions;
    }