JPA EntityManager why merge() does not make the instance managed?
entitymanager, jpa, openjpa
Solution
The point is that merge() is not attaching object to EntityManager context, it is returning attached objects. So, if we have:
AEntity a2 = entityManager.merge(a1);
a1 remains not managed, while a2 is managed.
This is, by the way, clever approach since merge does not cause side effects, passed object state is not changed.
Problem
When I call merge() on an object, the object does not become managed. Instead a reference to a managed instance of the same entity is returned. What is the logic behind this? Is there a way to change this behavior (and make the object managed) through some settings? I am using OpenJPA 2.2. Thank you.