php - Yii - Check model relation -

models: listings , auctions
relation: auctions belongs_to listings
listings pk: id
auctions fk: listings_id

problem: how can attributes(objects) of both tables in view if(slow/lost connection during save) listings pk , auction fk not same.

model(auctions)

public function relations() {      // note: may need adjust relation name , related     // class name relations automatically generated below.     return array(         'listings' => array(self::belongs_to, 'listings', 'listing_id'),     );  } 

controller

$randomlisting= new randomlistinggenerator(); $randomlisting=$randomlisting->actiongenerate(); $profile=new profile;             $this->render('index', array(                 'data' => $randomlisting,                )); 

random listing generator

class randomlistinggenerator{     public function actiongenerate(){ $criteria = new cdbcriteria();         $criteria->select = '*, rand() rand';         $criteria->order = 'rand';         $criteria->limit = 1;         $criteria->together = true;         $criteria->with=array(                 'listings'=>array('select'=>'id'),         );          return $randomlisting = auctions::model()->find($criteria);  } 

}

view

echo $data->listings->rooms;  //other attributes .... 

i got error

trying property of non-object