I have studied up on deleting objects in "Hibernate In Action" and it seems simple enough. Yet, I am having a few issues. Basically, what it boils down to is that I will remove a RegistrationSession object from a set inside a Registration object but when it comes time to update the Registration object the deleted RegistrationSession object in the set does not get deleted. It instead gets updated.

Do I need to make sure the object being delete does not have anything depending on it? Do all objects that it references need to be dereferenced or made null?

Nothing that I try seems to work. I have a feeling that it could be a setting somewhere in my mapping documents but not sure.

Any help greatly appreciated.

Cheers
Tom

Hibernate version: The one that ships with JBoss 4.0.3. I think its now version 3 but not sure.

Mapping documents:

Registration

<class name="com.camp.common.registration.Registration" table="tblRegistration">

<cache usage="read-write"/>

<id name="registrationID" type="integer">
<column name="id_registration" sql-type="integer" not-null="true"/>
<generator class="sequence">
<param name="sequence">tblregistration_id_registration_seq</param>
</generator>
</id>

<set name="regSessions" table="tblRegSession" sort="com.camp.common.registration.RegistrationSessionComparator" order-by="id_reg_session asc" cascade="all-delete-orphan" inverse="true">
<cache usage="read-write"/>
<key column="fk_id_registration"/>
<one-to-many class="com.camp.common.registration.RegistrationSession"/>
</set>

</class>

RegistrationSession

<class name="com.camp.common.registration.RegistrationSession" table="tblRegSession">

<cache usage="read-write"/>

<id name="regSessionID" type="integer">
<column name="id_reg_session" sql-type="integer" not-null="true"/>
<generator class="sequence">
<param name="sequence">tblregsession_id_reg_session_seq</param>
</generator>
</id>

<many-to-one name="registration" column="fk_id_registration" class="com.camp.common.registration.Registration" not-null="true"/>

<many-to-one name="cabin" column="fk_id_cabin" class="com.camp.common.cabin.Cabin" not-null="true"/>

<many-to-one name="session" column="fk_id_session" class="com.camp.common.session.Session" not-null="true"/>

</class>

Do I need to remove all references to registration, cabin and session?

Code between sessionFactory.openSession() and session.close():
This is the code that I originally had which I thought would work to delete the RegistrationSession but its not working.

reg_session = (RegistrationSession) registration.getRegistrationSession(i);
reg_session.setCabin(null);
reg_session.setSession(null);
regSessions.remove(reg_session);
hib_session.update(registration);

Full stack trace of any exception that occurs:

I think this error happens because I am manually trying to delete the RegistrationSession objects and then updating the Registration and thats when things go haywire!!

org.hibernate.StaleStateException: Batch update returned unexpected row count from update: 1 actual row count: 0 expecte
d: 1
at org.hibernate.jdbc.BatchingBatcher.checkRowCount(BatchingBatcher.java:92)
at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:78)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:57)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:174)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:226)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:137)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:28
4)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:736)
at com.camp.server.entity.EntityBackEnd.modifyEntities(Unknown Source)
at com.camp.helpers.entity.EntityHelper.modifyEntities(Unknown Source)
at com.camp.actions.registration.updateRegistrationSessionsAction.execute(Unknown Source)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.securityfilter.filter.SecurityFilter.doFilter(SecurityFilter.java:188)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.camp.common.utilities.HibernateFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)

Name and version of the database you are using:
Postgres 8.0.4

The generated SQL (show_sql=true):
10:15:08,525 INFO [STDOUT] Hibernate: update tblRegSession set fk_id_registration=?, fk_id_cabin=?, fk_id_session=?, us
er_entered=? where id_reg_session=?
10:15:08,525 INFO [STDOUT] Hibernate: update tblRegSession set fk_id_registration=?, fk_id_cabin=?, fk_id_session=?, us
er_entered=? where id_reg_session=?

i think you are getting a staleobjectexception, which means your object is out-of-date. you must be using optimistic locking. make sure the version number is the same as the one in db.

Well, the StateObjectException happens because of my attempted workaround, so really I shouldn't have included it at all. The reason I get it is because I try to delete the RegistrationSession manually, and then at the end when I close the session the Registration gets updated which then tries to update the set, including the deleted object. Which causes the error.