yii - How to extend cactiverecord -

i want add aditional methods in cactiverecord, if class project_model extends cactiverecord {} error

the table "project_activerecord" active record class "project_activerecord" cannot found in database.

i want create simple structure: cactiverecord->project_activerecord (only extend methods)->table (real table).

how can this?

the error clear: don't have table named project_activerecord in db!

if project_model going base model others active record models should like:

//a base classe example has behavior shared inherited class abstract class project_model extends cactiverecord {      public function behaviors(){         return array(             'ctimestampbehavior' => array(                 'class' => 'zii.behaviors.ctimestampbehavior',                 'setupdateoncreate' => true             ),         );     }  } 

and can declare other class will have table in db:

class yourclass extends project_model {     /**      * returns static model of specified ar class.      * @param string $classname active record class name.      * @return token static model class      */     public static function model($classname=__class__)     {         return parent::model($classname);     }      /**      * @return string associated database table name      */     public function tablename()     {         return 'yourclasstable';     }     ... } 

then shoudl never call class project_model (this why put keyword abstract) in code, have call inherited classes have existing table in db!