Hi All,
I'm sure this error msg is self-explanatory, but how do I fix it?

Thanks

Angus

org.hibernate.MappingException: Foreign key (FKE5A0BD21AC0BCC8B:Participation [id])) must have same number of columns as the referenced primary key (Participation [roleid,id])

Here's my mapping:

<class name="com.rose.ahr.hibernate.Role" table="Role">

<id name="id" type="int" column="id">

<generator class="native"/>

</id>

<set name="participations" table="Participation">

<key column="roleid"/>

<many-to-many column="id" class="com.rose.ahr.hibernate.Participation"/>

</set>

<property name="roledefnid" column="roledefnid"/>

<property name="classcode" column="classcode"/>

<property name="moodcode" column="moodcode"/>

<property name="code" column="code"/>

<property name="zrole" column="zrole"/>

<property name="playerentityid" column="playerentityid"/>

<property name="scoperentityid" column="scoperentityid"/>

<property name="effectivestarttime" column="effectivestarttime"/>

<property name="effectiveendtime" column="effectiveendtime"/>

<property name="msaccessid" column="msaccessid"/>

</class>



<class name="com.rose.ahr.hibernate.Participation" table="Participation" >

<id name="id" type="int" column="id">

<generator class="native"/>

</id>

<property name="moodcode" column="moodcode"/>

<property name="classcode" column="classcode"/>

<property name="typecode" column="typecode"/>

<property name="roleid" column="roleid"/>

<property name="actid" column="actid"/>

<property name="quantity" column="quantity"/>

<property name="zdescription" column="zdescription"/>

<property name="functioncode" column="functioncode"/>

<property name="participation" column="participation"/>

<property name="conceptid" column="conceptid"/>

<property name="msaccessid" column="msaccessid"/>

</class>

If you want to map a many to many relationship you have to provide a mapping column to the collection mapping, not the column of participation.

<set name="participations" table="ParticipationRoles">

<key column="roleid"/>

<many-to-many column="id" class="com.rose.ahr.hibernate.Participation"/>

</set>

Is this really a many-to-many association or is it a one-to-many association?

I guess I need it to be a one-to-many mapping then as I may not be permitted to add tables How would I do this? Would I still be able to use the SET approach?

That ist fairly straight forward...

<set name="participations">
<key column="roleid"/>
<one-to-many class="com.rose.ahr.hibernate.Participation"/>
</set>

In this case you have to consider if you want to navigate from Participation to role. Then you have to map a many-to-one relationship into Participation and mark the set participations in Role as inverse="true"

I strongly recommend you to read chapters 6 and 7 from the reference documentation since collection / association mappings aren't trivial