Here are my mappings

PARENT OBJECT
<hibernate-mapping>
<class name="objects.Parent" table="PARENT">
<id name="parent_id" type="int" column="PARENT_ID">
<generator class="identity"/>
</id>
<property name="title" type="string">
<column name="TITLE" sql-type="TEXT" not-null="true"/>
</property>
<set name="children" table="CHILD" sort="comparators.ChildComparator" cascade="all-delete-orphan">
<key>
<column name="PARENT_ID"/>
</key>
<one-to-many class="objects.Child"/>
</set>
</class>
</hibernate-mapping>

CHILD OBJECT
<hibernate-mapping>
<class name="objects.Child" table="CHILD">
<composite-id name="child_pk" class="objects.ChildPK">
<key-property name="child_id" column="CHILD_ID" type="int"/>
<key-many-to-one name="parent" class="objects.Parent">
<column name="PARENT_ID"/>
</key-many-to-one>
</composite-id>
<property name="text" type="string">
<column name="TEXT" sql-type="TEXT" not-null="false"/>
</property>
</class>
</hibernate-mapping>


CODE TO EXECUTE
Session sess = HibernateUtil.currentSession();
sess.delete(parent);
sess.flush();
HibernateUtil.closeSession();

STUPID EXCEPTION

13:50:07,562 ERROR SessionImpl:2269 - Could not synchronize database state with session
net.sf.hibernate.HibernateException: Batch update row count wrong: 0
at net.sf.hibernate.impl.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:65)
at net.sf.hibernate.impl.BatcherImpl.executeBatch(BatcherImpl.java:118)
at net.sf.hibernate.impl.BatcherImpl.prepareStatement(BatcherImpl.java:55)
at net.sf.hibernate.impl.BatcherImpl.prepareBatchStatement(BatcherImpl.java:105)
at net.sf.hibernate.persister.EntityPersister.delete(EntityPersister.jav
a:565)
at net.sf.hibernate.impl.ScheduledDeletion.execute(ScheduledDeletion.java:29)
at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2308)
at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2266)
at net.sf.hibernate.impl.SessionImpl.flush(SessionImpl.java:2187)
at com.overalltesting.servlets.DeleteParent.doGet(Unknown Source)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:126)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:103)
at com.caucho.server.http.FilterChainServlet.doFilter(FilterChainServlet
.java:96)
at com.caucho.server.http.Invocation.service(Invocation.java:315)
at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:246
)
at com.caucho.server.http.HttpRequest.handleConnection(HttpRequest.java:
164)
at com.caucho.server.TcpConnection.run(TcpConnection.java:139)
at java.lang.Thread.run(Thread.java:534)


COMMENT
I see this exception if there are more than 0 child objects for current parent.
Any ideas ?

inverse="true" on the collection, read the wiki page talking about that.
and batch_size=0 to have a more fine grained error

More description ? Maybe URL to wiki page ?

http://www.hibernate.org/155.html and http://www.hibernate.org/hib_docs/reference/html/parent-child.html

the same exception !
inverse="true" didn't help !

Look at the log and the generated SQL.

14:48:56,890 DEBUG SQL:223 - update CHILD set PARENT_ID=null where PARENT_ID=?
14:48:56,906 DEBUG SQL:223 - delete from CHILD where CHILD_ID=? and PARENT_ID=?
EXCEPTION

Damn, where is that update from ? and why null... ???

Keep inverse="true" on the set.
Show the full code (parent retrieve by load() and parent deletion) in a simple test case and the associated logs.

Full code

then:


That is all !

It should work with inverse="true", Hibernate may be swindled by the <key-many-to-one> instead of <many-to-one not-null="true">

Please submit a bug to JIRA

No, <key-many-to-one> is no problem.

I assume that the user has not followed your instruction to add inverse="true".

Here is the final variant of Parent object (NOT WORKING):

<hibernate-mapping>
<class name="objects.Parent" table="PARENT">
<composite-id name="parent_pk" class="objects.ParentPK">
<key-property name="parent_id" column="PARENT_ID" type="int"/>
<key-many-to-one name="GRAND_PARENT" class="objects.GrandParent">
<column name="GRANDPARENT_ID"/>
</key-many-to-one>
</composite-id>
<property name="text" type="string">
<column name="TEXT" sql-type="TEXT" not-null="false"/>
</property>
<set name="children" table="CHILD" sort="comparators.ChildComparator" inverse="true" cascade="all-delete-orphan">
<key>
<column name="GRANDPARENT_ID"/>
<column name="PARENT_ID"/>
</key>
<one-to-many class="objects.Child"/>
</set>
</class>
</hibernate-mapping>

Maybe it's not working because of 2-level relationships ???
GrandParent has 0 or more Parent objects, and Parent object may has 0 or more Child objects ! Exception, while deleting Parent object !

Show the child mapping.

CHILD MAPPING

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="objects.Child" table="CHILD">
<composite-id name="child_pk" class="objects.ChildPK">
<key-property name="child_id" column="CHILD_ID" type="int"/>
<key-many-to-one name="parent" class="objects.Parent">
<column name="GRANDPARENT_ID"/>
<column name="PARENT_ID"/>
</key-many-to-one>
</composite-id>
<property name="text" type="string">
<column name="TEXT" sql-type="TEXT" not-null="false"/>
</property>
</class>
</hibernate-mapping>

I feel usafe with
delete from CHILD where CHILD_ID=? and PARENT_ID=?
It should have been the GRAND_PARENT_Id olumn. I don't know why it's not in.