Hi;

I have a problem mapping for this design;

I used  joined-subclass  for the first level  and  subclass  for the second level .

for example I want to add a new invoice sales So the code is: I used a mapping  file for each class

Document.hbm.xml:

<hibernate-mapping>

   <class name="src.Document" table="DOCUMENT">

      <composite-id class="src.IdDocument" name="identifiant">

          <key-property column="NUM_DOC" name="numero" />

          <key-property column="TYPE_DOC" name="type" />

      </composite-id>

      <discriminator column="TYPE" type="string" />

                 ...........

                 ...........

   </class>

</hibernate-mapping>

DocumentSale.hbm.xml:

<hibernate-mapping>  
      <joined-subclass name="src.DocumentSale" extends="src.Document" table="DOCUMENT_SALE">
                      <key property-ref="identifiant">
            <column name="NUM_DOC"></column>
            <column name="TYPE_DOC"></column>
         </key>
      <property name="ref" column="REF"  type="java.lang.String"/>        
                 ...........
                 ...........
   </class>
</hibernate-mapping>

InvoiceSale.hbm.xml:

<hibernate-mapping>
   <subclass name="src.InvoiceSale" extends="src.DocumentSale"             
      discriminator-value="INVOICE_SALE">     
   </subclass>
</hibernate-mapping>

in code java

      InvoiceSale invoice = new InvoiceSale();
        //....
   Session session = service.getTheSession();
   session .saveOrUpdate(invoice );

and this is what appears in the console

   Hibernate: insert into DOCUMENT (NUM_DOC, TYPE_DOC ,TYPE,HT, TTC) values (?, ?, ?, ?, ?)
   Hibernate: insert into DOCUMENT_SALE (NUM_DOC, TYPE_DOC ,REF) values (?, ?, ?)
   Hibernate: insert into DOCUMENT_SALE (NUM_DOC, TYPE_DOC ,) values (?, ?)
    ......
   SEVERE: ORA-00001: violation  single  constraint
   ....

it insert twice in the table DOCUMENT_SALE.I do not understand where does the problem.

thank you in advance.