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Hi,

I am trying to figure out a way to avoid getting the NonUniqueObjectException. Any help on this is appreciated. This is my situation.

I have an instance of a class A, A1, which I persist after users make changes to it using update(). But before I persist it, I want to find out the differences between this modified A1 and whats in the database for the same identifier as A1. This I need to do to do some change log for A1. But since I have to load the already persissted instance of A1 first, so that I can find differences between the persisted A1 and the modifed A1, when I do an update() on the modified A1, I get this NonUniqueObjectException (obvious because I am loading another instance from the db with the same identifier). My question is there any way to tell Hibernate or configure somewhere in the class A, to avoid this exception.

Thanks
Rama

Try to evict the unmodified instance A1 (session.evict(A1)) and then update the modified instance.

Reto

or use saveOrUpdateCopy()

Pardon, but I think this should be added to FAQ. I have not seen any references to these two saveOrUpdateCopy methods, neither in Hibernate reference documentation nor in "Hibernate In Action". They are only in Hibernate API javadoc, but as rule nobody reads javadocs from start to end.

Thanks

Now I must rethink my poll vote :)