Hibernate version: 2.1.6

Mapping documents:
Parent:
<hibernate-mapping package="pkg">
<class name="A" table="A_TAB">

<!-- Identity column (PK) -->
<composite-id>
<key-many-to-one name="B" class="BClass" >
<column name=".." />
<column name=".." />
<column name=".." />
</key-many-to-one>
<key-many-to-one name="C" class="CClass" >
<column name=".." />
<column name=".." />
<column name=".." />
</key-many-to-one>
</composite-id>

<!-- Properties -->
:
:
:
<!-- private Collection E -->
<set name="E" lazy="true">
<key>
<column name=".." />
<column name=".." />
<column name=".." />
<column name=".." />
<column name=".." />
<column name=".. />
</key>
<one-to-many class="EClass"/>
</set>

</class>

</hibernate-mapping>

Child:
<hibernate-mapping package="pkg">

<class name="EClass" table="E_TAB">

<!-- Identity column (PK) -->
<composite-id>
<key-many-to-one name="A" class="AClass">
<column name=".." />
<column name=".." />
<column name=".." />
<column name=".." />
<column name=".." />
<column name=".." />
</key-many-to-one>
<key-property name=".." column=".." />
<key-property name=".." column=".." />
</composite-id>
</class>
</hibernate-mapping>


The situation is as follows:

We unfortunately have a data model that relies exclusively on composite primary keys.
The references between parent and child records are bi-directional

In case of a composite id wo PK class BPK for example, the object itself is probably its onw PK, so it has to be loaded. I'm not 100% sure of that, but try to create a Bpk Epk class.

Thanks for the response. I'll give it a go.