将对象重新附加到会话时出现 NHibernate NonUniqueObjectException（使用 Lock）
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？
Basic order of execution:
- A collection of
PersistentObjectsis 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
SaveOrUpdateaUserSettingobject with some usage statistics for the user who initialized the action. - On
session.Flush()NHibernate throws aNonUniqueObjectException.
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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评论（1）
您可以使用新的会话（或事务）来处理每个项目并更新 UserSetting 吗？ 这可能会阻止 NonUniqueException。
干杯，
-马丁
Can you use a fresh session (or transaction) for processing each item and for updating the UserSetting? This would probably prevent the NonUniqueException.
Cheers,
-Maarten