Hibernate - How to persist only the parent, keeping the children as they are

Question

Can someone please help me understand how to configure hibernate to do what i want.

I have a parent entity \"Appartment\" with a List of \"Room\"s as children. I hav

Answer 1

Instead of using persistent entities, consider using DTOs (you can call them a page model in the case of web pages). They can give you a flexibility to depict information you want and show it in the format you want. But you should pay for this - you're adding new classes to your system and you have to come up with a way to transform entities to DTOs and backward.

Answer 2

This is really simple. No need to repopulate your children, or create separate DTO's.

If you are never going to persist the children just add insertable=false, updatable=false to your joincolumn annotation. Like this:

@OneToMany
@JoinColumn (name = "appartmentId", insertable = false, updatable = false)
@Fetch(value = FetchMode.JOIN)
private List<Room> room;

Answer 3

1. Don't disable lazy fetching in a mapping. Use fetching strategies for performance tuning.
2. Hibernate will only remove the Rooms from an Apartment if you tell it to save/update an Apartment that has no Rooms in it.