<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="net.xxx.clients.xxx.vws.model.VjqValRepJobQueue" table="VJQ_VAL_REP_JOB_QUEUE" schema="VWS_OWNER">
        <id name="vjqId" type="java.lang.String">
            <column name="VJQ_ID" length="30" />
            <generator class="select" />
        </id>
        <property name="vjqVrhId" type="java.lang.String">
            <column name="VJQ_VRH_ID" length="30" not-null="true" />
        </property>
        <property name="vjqSubmittedBy" type="java.lang.String">
            <column name="VJQ_SUBMITTED_BY" length="120" not-null="true" />
        </property>
        <property name="vjqStatus" type="java.lang.String">
            <column name="VJQ_STATUS" length="10" not-null="true" />
        </property>
        <property name="vjqStarted" type="java.util.Date">
            <column name="VJQ_STARTED" length="7" />
        </property>
    </class>
</hibernate-mapping>

public void save(VjqValRepJobQueue transientInstance) {
      log.debug("saving VjqValRepJobQueue instance");
      try {
         Session session = getSession();
         Transaction transaction = session.beginTransaction();
         session.save(transientInstance); [i][b]//This is where it throws an exception[/b][/i]
         transaction.commit();
         session.disconnect();
         log.debug("save successful");
      } catch (RuntimeException re) {
         log.error("save failed", re);
         throw re;
      }
   }

org.hibernate.MappingException: unknown property: null
    at org.hibernate.persister.entity.AbstractPropertyMapping.getColumnNames(AbstractPropertyMapping.java:54)
    at org.hibernate.persister.entity.AbstractEntityPersister.getPropertyColumnNames(AbstractEntityPersister.java:1269)
    at org.hibernate.persister.entity.AbstractEntityPersister.getSelectByUniqueKeyString(AbstractEntityPersister.java:2008)
    at org.hibernate.id.SelectGenerator.getSQL(SelectGenerator.java:37)
    at org.hibernate.id.AbstractPostInsertGenerator.getGenerated(AbstractPostInsertGenerator.java:34)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:1994)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2405)
    at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:37)
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:248)
    at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:269)
    at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:167)
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:101)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java
    :186)
    at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
    at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
    at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:530)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:518)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:514)
    at net.connaught.clients.cbre.vws.dao.impl.VjqValRepJobQueueDAO.save(VjqValRepJobQueueDAO.java:45)
    at net.connaught.clients.cbre.vws.manager.impl.VjqValRepJobQueueManager.save(VjqValRepJobQueueManager.java:11)
    at net.connaught.clients.cbre.vws.view.actions.PublishDocuments.execute(PublishDocuments.java:30)
    at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
    at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:397)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher
    .java:712)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher
    .java:369)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler
    .java:865)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.HttpRequestHandler.processRequest(HttpRequestHandler
    .java:447)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler
    .java:215)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.HttpRequestHandler.run(HttpRequestHandler.java:117)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].server.http.HttpRequestHandler.run(HttpRequestHandler.java:110)
    at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:260)
    at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:239)
    at oracle.oc4j.network.ServerSocketAcceptHandler.access$700(ServerSocketAcceptHandler.java:34)
    at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:880)
    at com.evermind[Oracle Containers for J2EE 10g (10.1.3.2.0) ].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor
    .java:303)
    at java.lang.Thread.run(Thread.java:534)