One-to-Many: New child not showing up when parent retrieved

Question

I have a one to many relationship. The parent contains a collection of children in a arraylist.
A new child record is added independent of the parent, via a uow.
The parent is retrieved.
The new child doesn't show up.
So the question is Does the parent first have to be retrieved and the child added to the parent. The child is not and should not be privately owned. The child is not dependent. If the parent goes away the child should still exist.

Answer 1

"This last part" (as you describe it) is necessary. In a nutshell, you manage the object model (including both directions of a bi-directional relationship) and TopLink updates the database accordingly.
This usually isn't a big issue. I.e., if you have a "addB(ClassB b)" method that looks like this, then you don't have to worry about managing the whole relationship all over the place:
public void addB(ClassB b){
bs.add(b);
b.setA(this);
At commit time the cache and database should be updated properly when you add a "b" to an "a".
I have seen cases where the developer actually ended up not mapping the 1-M relationship in the model and had a "virtual" 1-M relationship. They would add a target to the "virtual" 1-M as you describe (just set the owner, i.e., tell the "b" it belongs to a particular "a". Then, they created a QueryKey in the Mapping Workbench in the Class "A" called "bs". Then they could build expressions and queries using "anyOf" through the "bs", even though it wasn't really mapped! I guess the point is that if you don't want to have to maintain that collection in code, and if it's not used in the application, then don't map it! Just create a QueryKey from A to B so that you can build the expressions as if it was there.
- Don