First off I'd like to apologise if this question has been answered elsewhere. I've looked on the forums but nothing doing.

I am trying a prototype out which has a many-to-many relationship. I have two tables Roles and Principals and a join table role_principals.

My mapping is as follows:

<hibernate-mapping
package="liquid">

<class name="Principal" table="principals">
<id name="id" column="id">
<generator class="uuid.hex"/>
</id>

<property name="firstName" column="FIRST_NAME" not-null="false"/>
<property name="lastName" column="LAST_NAME" not-null="false"/>

<set name="roles" table="role_principals" lazy="true">
<key>
<column name="principal_id" not-null="true"/>
</key>
<many-to-many class="Role">
<column name="role_id" not-null="true"/>
</many-to-many>
</set>
</class>

</hibernate-mapping>

<hibernate-mapping
package="liquid">

<class name="Role" table="roles">
<id name="id" column="id">
<generator class="uuid.hex"/>
</id>

<property name="name" column="name" not-null="false"/>

<many-to-one name="ruleset" class="Ruleset" cascade="all" not-null="true" column="ruleset_id"/>

<set name="principals" table="role_principals" lazy="true">
<key>
<column name="role_id" not-null="true"/>
</key>
<many-to-many class="Principal">
<column name="principal_id" not-null="true"/>
</many-to-many>
</set>
</class>

</hibernate-mapping>

The problem that I'm having is that when I set the 'principals' on the Role and AND set the 'roles' on the Principal end I get two identical records in the role_principals table.

I can update it only on one end but then I can't navigate from both objects.


Any help would be very gratefully received.

Ian.

Set one side of the association inverse="true", which <set> doesn't matter in your case.

Christian,

That did it. Thanks very much.

Ian.