not null foreign key column

superman_eddie · **Joined:** Tue Mar 27, 2007 11:34 pm **Posts:** 13

Hi all, I had a problem about the mapping the one-to-many collection to NHibernate:

Suppose I had 2 entity A and B:

create table A (id int primary key);
create table B (id int primary key, aid int not null reference A);

A.hbm.xml

Code:

<set name="Bs" lazy="true" cascade="save-update" inverse="false">
  <key column="aid"/>
  <one-to-many class="A, test"/>
</set>

B.hbm.xml

Code:

No A related mapping in B, seems it is one way association

When I insert A, it will save B also, but I found that aid will not inserted to B. So it cannot be inserted, No this kind of problem when using inverse="true".

Did anyone know how to solve this problem?[/b]

karlchu · **Posted:** Fri Aug 10, 2007 10:17 am

http://www.hibernate.org/hib_docs/nhibe ... -onetomany

Quote:

Very Important Note: If the <key> column of a <one-to-many> association is declared NOT NULL, NHibernate may cause constraint violations when it creates or updates the association. To prevent this problem, you must use a bidirectional association with the many valued end (the set or bag) marked as inverse="true". See the discussion of bidirectional associations later in this chapter.