Using <list>: problem with inverse

fabiomaulo · **Joined:** Tue May 30, 2006 1:25 am **Posts:** 29

Hibernate version: SVN

This mapping work fine

Code:

   <class name="A" table="tabA">
      <id name="Id" type="Int32">
         <generator class="native" />
      </id>

      <list name="Elements" cascade="all">
         <key column="parentId" />
         <index column="childNum"/>
         <one-to-many class="B" />
      </list>
   </class>
   
   <class name="B" table="tabB">
      <id name="Id" type="Int32">
         <generator class="native" />
      </id>
      <property name="Name"/>
   </class>

This other don't work

Code:

   <class name="A" table="tabA">
      <id name="Id" type="Int32">
         <generator class="native" />
      </id>

      <list name="Elements" inverse="true" cascade="all">
         <key column="parentId" />
         <index column="childNum"/>
         <one-to-many class="B" />
      </list>
   </class>
   
   <class name="B" table="tabB">
      <id name="Id" type="Int32">
         <generator class="native" />
      </id>
      <many-to-one name="Parent" class="A" column="parentId"/>
      <property name="Name"/>
   </class>

The problem is that the childNum column is always NULL.
Is there some special issue for this beaviour ?

Thanks.

gert · **Joined:** Thu Jan 19, 2006 4:29 pm **Posts:** 348

fabiomaulo wrote:

This other don't work

Code:

   <class name="A" table="tabA">
      <id name="Id" type="Int32">
         <generator class="native" />
      </id>

      <list name="Elements" inverse="true" cascade="all">
         <key column="parentId" />
         <index column="childNum"/>
         <one-to-many class="B" />
      </list>
   </class>
   
   <class name="B" table="tabB">
      <id name="Id" type="Int32">
         <generator class="native" />
      </id>
      <many-to-one name="Parent" class="A" column="parentId"/>
      <property name="Name"/>
   </class>

The problem is that the childNum column is always NULL.
Is there some special issue for this beaviour ?

Inverse means that the persisting is handled by the other end of association. So, the class "B" must save all values (including index) for list.

Gert

sergey · **Posted:** Thu Jan 04, 2007 3:31 am

Indexed collections (lists and maps) cannot be mapped with inverse="true".

desiguy · **Posted:** Wed Jan 17, 2007 5:03 pm

Is there a workaround for this? Or, do I need to change the object model to not have bi-directional associations. It is kind of strange that NHibernate does not support this.

Thanks in advance!