Yii Cdbhttpsession

I'm using mysql database to store the user session data. I redirect the user to another server with the session id as a variable (GET), and then i need to retrieve the session from the DB using the ID.

code used in my remote server:

Yii::app()->session->sessionID = $sessionID;
Yii::app()->session->open();
the result is that the session gets overridden with no data (new session is opened). how do i retrieve the session from DB? do i need to create a model for the table or can i use YII session functionality?

thanks, Danny