I recently changed a mapping from cascade='all' to cascade='all-delete-orphan'. Now I find that when go to save the parent object, I get the message:

net.sf.hibernate.HibernateException: You may not dereference a collection with cascade="all-delete-orphan"

I'm not sure what dereferencing a collection means. Any pointers? If it's any help, what I'm doing immediately before that is:

a) Getting a list of child records matching the parent id, 'direct' from Hibernate (i.e, not via the parent record).

b) Changing a 'position' property in them, to enable a specific sort order.

c) Loading the parent record.

d) Creating a HashSet from the list.

e) Assigning it to the collection property in the parent record.

f) Saving the parent record.

This all works fine when it's just 'cascade="all"', but not when it's 'cascade="all-delete-orphan"'.

http://www.hibernate.org/264.html

user update instead.