Hello,

I have an n:m mapping between person (Person.class) and group (Gruppe.class). The mapping class is call PersonGruppe.class, so I have a n:1 relation between person and personGruppe and an 1:n relation between personGruppe and gruppe.

Everything works fine if I add a Person to the group and store the group. The problem arises if I want to remove a person from the group.

Hibernate still updates the PersonGruppe relation, but does not remove the complete entry. It only removes the group id:

The person_group table contains the following entry before update:
id person group version
3 1 2 0

after an update of group it contains the following entry:
id person group version
3 1 NULL 0

With Version 2 the complete row were deleted!

Can anyone tell me why this is the case in hibernate3 and how I can configure hibernate to remove the complete row?

Thanks
Rene

Hibernate version: 3.0

Mapping documents:
Person.hbm.xml
<hibernate-mapping>
<class name="at.sozvers.hvb.zustellclient.model.Person"
table="person" lazy="false">
<id name="id" column="id" type="java.lang.Long"
unsaved-value="null">
<generator class="org.hibernate.id.SequenceGenerator">
<param name="sequence">hibernate_sequence</param>
</generator>
</id>
<version name="version" type="java.lang.Long" column="VERSION"
access="property" unsaved-value="undefined" />
<property name="nachname" type="java.lang.String"
column="nachname" not-null="true" />
<property name="titel" type="java.lang.String" column="titel" />
<property name="vorname" type="java.lang.String"
column="vorname" not-null="true" />
<property name="vsnr" type="java.lang.String" column="vsnr"
not-null="true" />
<set name="personGruppeSet" lazy="false"
cascade="all-delete-orphan" sort="unsorted">
<key column="person"></key>
<one-to-many
class="at.sozvers.hvb.zustellclient.model.PersonGruppe" />
</set>
</class>
</hibernate-mapping>


Gruppe.hbm.xml (Group)
<hibernate-mapping>
<class name="at.sozvers.hvb.zustellclient.model.Gruppe"
table="gruppe" lazy="false">
<id name="id" column="id" type="java.lang.Long"
unsaved-value="null">
<generator class="org.hibernate.id.SequenceGenerator">
<param name="sequence">hibernate_sequence</param>
</generator>
</id>
<version name="version" type="java.lang.Long" column="VERSION"
access="property" unsaved-value="undefined" />
<property name="beschreibung" type="java.lang.String"
column="beschreibung" />
<property name="name" type="java.lang.String" column="name"
not-null="true" />
<set name="personGruppeSet" lazy="false"
cascade="all-delete-orphan" sort="unsorted">
<key column="gruppe"></key>
<one-to-many
class="at.sozvers.hvb.zustellclient.model.PersonGruppe" />
</set>
</class>
</hibernate-mapping>

PersonGruppe (Relation between group and person)
<hibernate-mapping>
<class name="at.sozvers.hvb.zustellclient.model.PersonGruppe"
table="person_gruppe" lazy="false">
<id name="id" column="id" type="java.lang.Long"
unsaved-value="null">
<generator class="org.hibernate.id.SequenceGenerator">
<param name="sequence">hibernate_sequence</param>
</generator>
</id>
<version name="version" type="java.lang.Long" column="VERSION"
access="property" unsaved-value="undefined" />
<many-to-one name="gruppe"
class="at.sozvers.hvb.zustellclient.model.Gruppe" cascade="none"
outer-join="auto" column="gruppe" />
<many-to-one name="person"
class="at.sozvers.hvb.zustellclient.model.Person" cascade="none"
outer-join="auto" column="person" />
</class>
</hibernate-mapping>



Code between sessionFactory.openSession() and session.close():
session = getHibernateSession();
tx = session.beginTransaction();
session.saveOrUpdate(persistentObject);
tx.commit();
session.flush();
return persistentObject;


Full stack trace of any exception that occurs:

Name and version of the database you are using: PostgreSQL 8.0

The generated SQL (show_sql=true):
update person_gruppe set gruppe=null where gruppe=?

I'm getting same problem. Did you figured out what was wrong..

Yes I found a solution. You have to clear the set so Hibernate knows that it can remove the entries:

Set.clear()

Rene