Many to Many Retrieval Issue

Question

While understanding the limitation of having both a child and parent both be updatable, I am having trouble getting the child (read only mapping) to retrieve the appropriate objects??? is there some trick to get this to happen? the writable mapping is able to retrieve them, but the read only one just doesn't populate?
Thanks,
Michael

Answer 1

Ok, I think I am closer to the real issue... your example provides a fremework that functions as it should.
However, what I am doing is:
(FYI: My parents can update their children in the M-M mapping)
1. Copying a child object using a copy constructor.
The constructor retains all existing relationships to it's parent and children (both many to many) by looping through them and calling the setParent and setChild appropriate methods that you recommended.
...this works properly
2. Then I assign a new (already persisted) Parent object to the newly created child. When I persist the child, I get the following error after fully validating the uow:
Exception occured: LOCAL EXCEPTION STACK:
EXCEPTION [TOPLINK-7056] (TopLink - 9.0.3.2 (Build 429)): oracle.toplink.exceptions.ValidationException
EXCEPTION DESCRIPTION: The wrong object was registered into the UnitOfWork. The object [com.wachovia.retail.dal.business.loanreview.Element@9815354] should be the object from the parent cache
Can you explain why this is happening?
FYI, if I attempt to assign a new (already persisted) child, it works fine.