title: Yii model default values. DRY
body: <p>I am codding multiuser application.And in each model I have a field user_id, every user login and i can get him id: <code>Yii::app()-&gt;user-&gt;id</code>.</p>
  
  <p>I don't want to repeat it in every action find/update/inset condition so How can I set this in model user_id?</p>