CODEWITHSUNDEEP
javahibernatejpa
Ashish Thukral
Ashish Thukral

Reputation: 1485

Disable update to many to one entity in hibernate

I have a Parent and Child entity. Child has a Manytoone annotation to reference Parent. The use case is that when i load a child by findById and get the parent out using the getter. then If I update the parent, I am able to save the parent. I do not want the parent to be updatable which is pulled out from a child.

  1. I want only to update parent if I directly find it by id and change attribute and save.

  2. I know hibernate has no info when i do getParent() from child that it got it from child and not find by id and makes an update to parent.

  3. I tried Immutable annotation on ManytoOne on Parent but it does not prevent an update to be fired.

Is there any way that I can make the parent pulled out from a child non-updatable?

feel free to ask any clarifications.

Upvotes: 2

Views: 4778

Answers (2)

David Levesque
David Levesque

Reputation: 22451

You can call EntityManager.detach() on the parent that you obtain through the getter. Any change made to the detached entity will not be synchronized to the database.

Upvotes: 1

Radim Köhler
Radim Köhler

Reputation: 123901

The problem you are experiencing, in fact belongs to the Hibernate Session. It has nothing with Cascading. Because the session is designed to be a unit-of-work for us.

Whenever you access an object 1) by ID or 2) by reference, this object is (from that moment) "cached" in the Session. It is one instance shared accross all the handling during the Session life-time.

So, once, the Parent is loaded into session, and you are amending it anyhow, and later Session is flushed - any changes to Parent are persisted.

You can call session.evict(parent) explicitly, to avoid changes propagation during the Flush.

But It seems to me a bit weird, that you are changing the Parent (accidently...maybe) while working with child and not willing to store these changes. Other words, maybe solution is to change the approach.

Upvotes: 3

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