java - 按键删除一个实体而不先在应用程序引擎中获取它(使用 JDO)

Question

有没有一种方法可以删除一个实体而不必先从数据存储中获取它？我假设我已经拥有实体的 key 或 ID。我正在考虑类似 deleteObjectById 的东西，它类似于 PersistenceManager 上的 getObjectById。

我能想到的最接近的方法是使用 Query.deletePersistentAll()(如 here 所示)并指定一个仅依赖于键的查询，但我不知道这是否是在删除之前获取实体。

谢谢

编辑:我知道如何使用低级 API 以及 python API 执行此操作。我想知道是否有一种方法可以在 JDO 层内完成。

Answer 1

datanucleus 在 google group 上回答了我的问题:

Not really. The issue is that an object can have relations and so, since these can cause cascade of operations, it typically has to be loaded into memory first. The only situation where it wouldn't need to be loaded into memory was if the class of the object to be deleted had no relations.

Going into the low level API and blasting away objects may or may not have an impact on related objects ... perhaps someone responsible for it could comment on that.