Bags and composite IDs

dapissarenko · **Joined:** Thu May 20, 2004 7:39 am **Posts:** 12

Hello!

I'm using hibernate 2.1.3 and have following problem:

There is a class Class1, which has properties prop1, prop2, prop3 which all constitute a composite id of Class1.

I have another class Class2 and Class2 has a bag of instances of Class2.

Each instance X in that bag (X instanceof Class2) has X.prop1 = Class2.id.

Class2 has a normal ID.

I have following XML definitions:

Class1:

Code:

<!DOCTYPE hibernate-mapping PUBLIC 
   "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>

   <class name="Class1"
      table="tbl_pred_seq" discriminator-value="N">
      
      <composite-id>
           <key-property name="predSeqPos" column="pred_seq_pos"/>
           <key-property name="id" column="ID_pred_seq"/>
           <key-many-to-one name="joining" class="Class2" column="ID_joining"/>
           <key-many-to-one name="prevJoining" class="Class2" column="ID_prev_joining"/>
      </composite-id>
   </class>
</hibernate-mapping>

Class2:

Code:

<bag name="predecessorSequence" table="tbl_pred_seq"
         cascade="save-update">
         <key column="ID_joining" />
         <many-to-many
            class="Class1" />
      </bag>

With these definitions I get this exception:

Code:

net.sf.hibernate.MappingException: Foreign key (tbl_pred_seq [elt])) must have same number of columns as the referenced primary key (tbl_pred_seq [pred_seq_pos,ID_pred_seq,ID_joining,ID_prev_joining])

How can I implement the bag in Class2 without modifying the database?

TIA

Dmitri