[b]Hibernate version:[Hibernate 2.1.6]

[b]Mapping documents:[Claw + Cat]
Cat has many Claws

[color=red]
<hibernate-mapping>
<!-- Cat root -->
<class name="Cat" table="Cat">
<id name="id" column="id">
<generator class="identity"/>
</id>
<property name="name" column="name" type="string"/>
<property name="sex" column="sex" type="char"/>
<property name="weight" column="weight" type="double"/>
<set name="claws" table="CLAW" lazy="true">
<key column="cat_id"/>
<one-to-many class="Claw"/>
</set>
</class>
</hibernate-mapping>
<hibernate-mapping>

<!-- Claw root -->
<class name="Claw" table="Claw">
<id name="id" column="claw_id">
<generator class="identity"/>
</id>
<many-to-one name="owner" column="cat_id"/>
<property name="index" column="order_no" type="int"/>
<property name="tractable" column="tractable" type="true_false"/>
<property name="length" column="length" type="int"/>
</class>
</hibernate-mapping>[/color]

My issue is from understanding Hibernate in applying referential integrity. When trying to delete Cats from the table I am noticing that even though I have a many-to-one relationship with Cat in Claw. I am still able to remove the objects without complaint from the Database. Leaving a Claws without a Cat (makes sense doesnt it :-)).The Claw Database has a single field that references the Cat table via its ID.

How can I apply this in my code?

Not in code, but you should just add a NOT NULL constraint to the CAT_ID FK column in the CLAWS table.

Thanks for the response.

Im using hsqldb as my database so Im not sure how ti make the changes you mentioned (the database manager is very simple). What I was thinking is that some changes need to made in the hbm.xml docs so that the tables can be modified.

In addition to my previous post I would like to add a question about having a one-to-one relationship with another class e.g. (Cat and Owner). How would I be able to reflect this in the xml.

The documentation has examples for all of this, please consult it.

<many-to-one name="owner" column="cat_id" not-null="true"/>