I have a problem with cascade and maps.
The classes are:

Campaign.java


Ad.java


When I try to save a Campaign object with some Ads, it throws exception for not null field "campaign_id" in the ads table.
If I take optional=false it works but no reference is kept for the Ad parent (campaign_id = NULL).
I can't set the id for the parent because it doesn't exists yet.

Am I missing something?

I found the solution myself almost instantly.
You have to reference the Campaign in the Ad like:

Even though campaign was not saved yet and there's no cascade from Ad to Cascade.

The catch is that you have to do both, add the Ad to the Ads map of the Campaign and set the campaign in the Ad (quite confusing that the object is called Ad haha)

Hope it works for someone else!