SQLSTATE[42S02]: Base table or view not found [ 2.0 版本 ]

$update = Yii::$app->getDb(\Yii::$app->db_act)
    ->createCommand()
    ->update('college',array(
        'pay_status'=>3,
        'order_status'=>7
    ),['ap_id'=>$id])->execute();

message: "SQLSTATE[42S02]: Base table or view not found: 1146 Table 'rcenter_dev.college' doesn't exist↵T

这个表明明是有的啊，为什么说找不到呢？