I have a mapping file parent.hbm.xml which contains set of childs.

Parent.hbm.xml
-------------------
<set name="childSet" inverse="true" lazy="true" cascade="save-update" outer-join="true">
<key column="parent_id"/>
<one-to-many class="Child"/>
</set>

Child.hbm.xml
----------------
<many-to-one name="parent" column="parent_id" not-null="true"/>

In code:
--------
Parent p = new Parent();
//set other parent properties
HashSet s = new HashSet();
Child c = new Child();
//set other child properties
c.setParent(p);
s.add(c);
p.setChildSet(c);

Session session = getSessionFactory().openSession();

Transaction t = session.beginTransaction();
session.save(p);
t.commit();
session.close();

The above code is only creating parent entry in the db not child entry? why? Do I need to set any attributes in the mapping file in order to accomodate this?

I appreciate your help.

I have exactly the same problem.
I don't understand why it does't work because it's not very complicated.
Have you found any solutions to solve this problem ?

thanks a lot

1. Please read the equals()/hasCode() wiki page, It may be related.
2. check the SQL geenrated

I had the same problem and found a solution. Discussed in two different threads if you are interested.

http://forum.hibernate.org/viewtopic.php?t=929969&highlight=
http://forum.hibernate.org/viewtopic.php?t=930119&highlight=