This tutorial will help you to get the information about yii update function. I added the source code to update one or multiple records using different update function in yii framework model.
<?php
$model=User::model()->updateByPk(
$ID,
array("status"=>'DECLINED')
);
$model=User::model()->updateAll(array(
'first_name'=>"$firstname",
'email'=>"$email"
),
"UserID=$id and status IS NULL "
);
$model=User::model()->updateAll(
array('status' => 1),
'UserID ='.$userid
);
?>