Forced to use set instead of map

Trevor Harrison · **Joined:** Tue Jan 17, 2006 5:22 pm **Posts:** 3

Converting an existing non-hibernate app to Hibernate. (3.0)

I need to re-use a column for both the index and as a property in a composite element (see the ObjName column/property in this example):

Mapping documents:

Code:

<hibernate-mapping default-lazy="false">
   <class name="MyClass" table="MYCLASSTABLE">
      <id name="id" column="ID">
         <generator class="native"/>
      </id>
      <property ..../>
      <map name="MySubObj" table="SUBOBJ">
         <key column="MYCLASSID"/>
         <index column="OBJNAME" type="string"/>
         <composite-element class="MySubObj">
            <property name="ObjName" column="OBJNAME"/>
            <property ..../>
            <property ..../>
            <property ..../>
         </composite-element>
      </map>
   </class>
</hibernate-mapping>

Hibernate gives an exception when processing the mapping docs:

Code:

org.hibernate.MappingException: Repeated column in mapping for collection: MyClass.MySubObj column: OBJNAME
   at org.hibernate.mapping.Collection.checkColumnDuplication(Collection.java:290)
   at org.hibernate.mapping.Collection.checkColumnDuplication(Collection.java:313)
   at org.hibernate.mapping.Collection.validate(Collection.java:270)
   at org.hibernate.mapping.IndexedCollection.validate(IndexedCollection.java:67)
   at org.hibernate.cfg.Configuration.validate(Configuration.java:987)
   at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1147)
   at <my app>

So as a work-around, I change the map to a set and have taken out the <index column="OBJNAME".../> line from the mapping file.

Is there anyway to keep this as a map? In my workaround, I'm converting to/from a map in the [get/set]MySubObj( Set set) getter/setter pair.
This works kinda okay, but I'm getting a lot of re-writing of the set in the SUBOBJ db table that I'm assuming is caused by me not preserving Hibernate's original set.

-Trevor

kgignatyev · **Posted:** Tue Jan 24, 2006 12:26 pm

The following mapping allows you to do what you want (at least in 3.1.1):

<class table="map_holders" name="mapmap.MapHolder" lazy="false">
<id name="id">
<generator class="assigned"/>
</id>

<map name="elements" table="map_elements" >
<key column="mh_id"/>
<map-key type="java.lang.String" formula="name"/>
<composite-element class="mapmap.MapElement">
<property name="name" column="name"/>
<property name="label" column="label"/>
</composite-element>
</map>

</class>