Hi,

When I design my object model I try to avoid bidirectional associations. When our db guy design his database model he puts not-null constraints on foreign keys.
I see in the doc that there is a limitation with this kind of stuff. I can't use an unidirectional one-to-many link if there is a not-null constraint on the <key> element (in the reference doc).
I want to know if this is a structural problem that can't be avoided or if this is something that may be bypassed by any way or if this is a limitation that will be remove in the future

It depends if you have to keep your java model in sync (ie remove the child from the collection).
But session.delete(child); should not violate the constrains by itself