When I delete an object (let's call it "Person") it cascade deletes all the child objects (let's call them "Order"s). This is correct. However BEFORE it deletes them it set's the Order.Person field to null. this is how my database schema works, it is not a nullable column.

Examples:

session.Delete(somePerson);
session.Flush();

this does a:

UPDATE Order SET Person = NULL WHERE Person = 1235415
DELETE FROM Order WHERE Id = 12455;
...etc.

It's the first update that is bothering me. Anyone know of a mapping that prevents this?

Have you tried playing with inverse attribute? By the way, this got me thinking... it should be rather easy to alter NH code so that if during Flush an UPDATE is followed by a DELETE, the UPDATE is ignored.

I did play with it, but also with different cascade settings. Now, with cascade="all-delete-orphan" and inverse="true" it seems ot not do the update.

I'll test more thoroughly and post something more conclusive.

I have the same problem. It's strange it's working with inverse="true" because I don't have a bidirectional relationship.

It's quite cruical issue - I hope anybody has an explanation for this behaviour or fix if it's a bug?