yii 下锁表

/**
* 当日单项内容状态
*/
public function getPointAready($money,$dayTime){
  $model = Balance::model()->findByAttributes(array('balance_money'=>$money,'balance_daytime'=>$dayTime));
  if(empty($model)){
    //表写锁定
    Yii::app()->db->createCommand()->setText("lock tables {{balance}} WRITE")->execute();
    $model = new Balance();
    $model->balance_money= $money;
    $model->balance_daytime= $dayTime;
    $model->save();
    //表解锁
    Yii::app()->db->createCommand()->setText("unlock tables")->execute();
  }
  return $model;
}