我想从customer表中获取firstname

I want to fetch firstname from customer table. In my data base there is 2 table first is Customerlifecycle there is 1 column name is customer_id and secound table is customer there is 2 column 1st is id and 2nd is firstname.

 $criteria = new CDbCriteria;
            $criteria->join = 'LEFT OUTER JOIN customer AS C ON C.id = t.customer_id AND C.store_id=' . Yii::app()->session['store_id'];
            $criteria->select = 'C.firstname as firstname';
            $criteria->group = 'C.firstname';
            $criteria->condition = 'store_id=\'' . Yii::app()->session['store_id'] . '\'';

            $list = CustomerLifecycle::model()->findAll($criteria);

I can not fetch firstname please help me

please try below code

        $criteria            = new CDbCriteria;
        $criteria->select    = 'C.firstname as customer_id';
        $criteria->condition = 't.store_id= '. Yii::app()->session['store_id'];
        $criteria->join      = 'LEFT OUTER JOIN customer AS C ON C.id = t.customer_id';
        $criteria->group     = 'C.firstname';
        $list                = CustomerLifecycle::model()->findAll($criteria);