jpa way to see if entity or one of its relations has changed version

Question

I'm looking for a way to find out if a detached entity has changed in the database. Furthermore I want to know if any of its relations with cascade = CascadeType.MERGE has changed. The entity and some of its relations do have a version field with @Version annotation. Basically the test should report if a merge is going to throw an OptimisticLockException without trying to do the merge itself. Of course I could go through all relations and compare the version fields, but I'd like to have a more change resistant solution. So if someone adds a relation in the future the test should still work, without adopting.

Is there a standard way of doing this?

Answer 1

JPA 2.0 have Optimistic Locking and Pessimistic Locking .

I think, you already know Optimistic Locking for main entity like as below.

I'm looking for a way to find out if a detached entity has changed in the database?

The below example is Optimistic Locking handling for detached entity. It is using LockModeType.OPTIMISTIC_FORCE_INCREMENT .