在configuration.php下，您可能需要执行以下操作：

$db['mysql']['hostname'] = "server";    #your data source
$db['mysql']['username'] = "username";  #user credentials
$db['mysql']['password'] = "p@ssword";  #user credentials
$db['mysql']['dbdriver'] = "mysql";

$db['mongodb']['hostname'] = "server";  #your data source
$db['mongodb']['username'] = "username";  #user credentials
$db['mongodb']['password'] = "p@assword";
$db['mongodb']['dbdriver'] = "mongodb";