/**
  * 更新实体, 必须指定实体的主键值
  * @param object $entity
  */
 public function replace($entity)
 {
     $arrayId = array();
     if (is_array($entity)) {
         foreach ($entity as $object) {
             $id = DaoSupport::replaceEntity($object);
             array_push($arrayId, $id);
         }
     } else {
         return DaoSupport::replaceEntity($entity);
     }
     return $arrayId;
 }