Handling collection updates with JPA
collections, hibernate, java, jpa
Solution
If you are looking for something in `EntityManager` which will save or update a collection, the answer is no. You will have to loop and do a save or update.
If you use `EntityManager.merge()` API it will update if record is existing or else will insert a new record.
As far as delete is concerned, how will JPA or any other ORM determine that you want to delete that instance, if its a soft delete like updating a column like `is_active` to `true/false`, then yes by calling merge it can be done, but if you want a hard delete then JPA won't be able to determine by itself, you will have to do it manually.
Problem
I have a collection of custom objects and I'd like to persist it in the easiest way using JPA. My `CustomObject` class is mapped to a table. Now I'm wondering if JPA provides some kind of utility to handle object collection. In particular I'd like to add or remove objects to/from my collection and then pass to a `save(Collection<CustomObject> cco)` method without checking which objects have changed (which of them I need to add and which to remove...) Is it possible?