将对象重新附加到会话时出现 NHibernate NonUniqueObjectException（使用 Lock）

发布于 2024-07-30 18:34:17 字数 803 浏览 3 评论 0原文

基本执行顺序：

查询PersistentObjects 集合，然后将其与会话分开缓存。
该集合被传递到一个模块，该模块需要将它们重新附加到会话，以便延迟加载某些属性（使用 session.Lock(obj, LockMode.None)）。
模块完成处理后，另一个模块会尝试 SaveOrUpdate 一个 UserSetting 对象，其中包含初始化操作的用户的一些使用统计信息。
在 session.Flush() 上，NHibernate 会抛出 NonUniqueObjectException。

我发现解决此问题的一种方法是使用以下命令获取对象的新副本：

obj = session.Get(obj.GetType(), (obj as PersistentObject).Id);

而不是使用 session.Lock 重新附加。然而，这不是最佳的，因为某些记录集可能非常大，并且单独重新获取每个对象可能会拖累性能。

非唯一对象是仅存在于 PersistentObject 类中的引用对象，而不存在于 UserSetting 类中。所以我不明白为什么刷新会导致这个异常。

我尝试在模块使用完缓存的对象后逐出它们，但这没有帮助。

有谁知道将对象附加到会话可以避免此问题的更好方法？

原文

Basic order of execution:

A collection of PersistentObjects is queried then cached separately from the session.
The collection is passed to a module that needs to reattach them to the session in order to lazily load some of the properties (using session.Lock(obj, LockMode.None)).
After the module has completed processing, another module attempts to SaveOrUpdate a UserSetting object with some usage statistics for the user who initialized the action.
On session.Flush() NHibernate throws a NonUniqueObjectException.

I've found that one way of working around this issue is to get new copies of the objects with:

obj = session.Get(obj.GetType(), (obj as PersistentObject).Id);

instead of reattaching with session.Lock. However, this is non-optimal as some of the record sets are potentially quite large, and re-getting each object individually could become a performance drag.

The object which is non-unique is a referenced object that exists only on the PersistentObject class, and not the UserSetting class. So I cannot understand why a flush would cause this exception.

I've tried evicting the cached objects after the module is done with them, but this does not help.

Does anyone know of a better way to attach objects to the session that could avoid this problem?

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