**** User *****
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="User" table="Users" >
    <id column="UserId" name="Id" >
      <generator class="native"/>
    </id>

    <property name="Email"/>
    <bag name="Ads" table="Ad" inverse="true" cascade="save-update">
      <key column="UserId" />
      <one-to-many class="Ad"/>
    </bag>
  </class>
</hibernate-mapping>

**** Ad  *****
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="Ad" table="Ad" >
    <id column="AdId" name="Id">
      <generator class="native"/>
    </id>
   
    <many-to-one column="UserId" name="User" class="User"/>
    <property name="CreatedUTC" not-null="true"/>

    <bag name="Attributes" inverse="true" cascade="all">
      <key column="AdId"/>
      <one-to-many class="AttributeValue"/>
    </bag>
    <bag name="Preferences" inverse="true" cascade="all">
      <key column="AdId"/>
      <one-to-many class="PreferenceValue"/>
    </bag>     
  </class>
</hibernate-mapping>

**** Attribute Value *****
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="AttributeValue" table="AttributeValue">
    <id column="AttributeValueId" name="Id">
      <generator class="native"/>
    </id>

    <many-to-one class="Ad" column="AdId" name="Ad"/>
   
    <property name="Value" type="String"/>
    <many-to-one name="AttributeDefinition" column="AttributeDefinitionId" class="AttributeDefinition" />
  </class>
</hibernate-mapping>

**** Attribute Definition *****
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class name="AttributeDefinition" table="AttributeDefinition">
    <id column="AttributeDefinitionId" name="Id">
      <generator class="native"/>
    </id>

    <property name="Name"/>
    <property name="Target"/>
    <property name="ValueType" column="ValueTypeId" type="Int32"/>
  </class>
</hibernate-mapping>

IUser user;
try
{
   NHibernateSessionManager.Instance.BeginTransaction(IsolationLevel.ReadUncommitted);
   NHibernateSessionManager.Instance.GetSession().FlushMode = FlushMode.Never;

   user = _session.Get<User>(UserId);
   LoadForDisconnectedAccess(user);
}
finally
{
   NHibernateSessionManager.Instance.RollbackTransaction();  // !! Exception !!
   NHibernateSessionManager.Instance.CloseSession();
}
 
private void LoadForDisconnectedAccess(IUser user)
{
   object o;

   foreach (IAd ad in user.Ads)
   {
      foreach (IPreferenceValue pv in ad.Preferences)
          o = pv.PreferenceDefinition.Name;

      foreach (IAttributeValue av in ad.Attributes)
          o = av.AttributeDefinition.Name;
   }
}

NHibernate.Exceptions.GenericADOException was unhandled
  Message="could not update: [Rental.Data.PreferenceDefinition#76][SQL: UPDATE PreferenceDefinition SET Name = ?, Target = ?, ValueTypeId = ? WHERE PreferenceDefinitionId = ?]"
  Source="NHibernate"
  StackTrace:
       at NHibernate.Persister.Entity.AbstractEntityPersister.Update(Object id, Object[] fields, Object[] oldFields, Object rowId, Boolean[] includeProperty, Int32 j, Object oldVersion, Object obj, SqlCommandInfo sql, ISessionImplementor session)
       at NHibernate.Persister.Entity.AbstractEntityPersister.UpdateOrInsert(Object id, Object[] fields, Object[] oldFields, Object rowId, Boolean[] includeProperty, Int32 j, Object oldVersion, Object obj, SqlCommandInfo sql, ISessionImplementor session)
       at NHibernate.Persister.Entity.AbstractEntityPersister.Update(Object id, Object[] fields, Int32[] dirtyFields, Boolean hasDirtyCollection, Object[] oldFields, Object oldVersion, Object obj, Object rowId, ISessionImplementor session)
       at NHibernate.Action.EntityUpdateAction.Execute()
       at NHibernate.Engine.ActionQueue.Execute(IExecutable executable)
       at NHibernate.Engine.ActionQueue.ExecuteActions(IList list)
       at NHibernate.Engine.ActionQueue.ExecuteActions()
       at NHibernate.Event.Default.AbstractFlushingEventListener.PerformExecutions(IEventSource session)
       at NHibernate.Event.Default.DefaultFlushEventListener.OnFlush(FlushEvent event)
       at NHibernate.Impl.SessionImpl.Flush()
       at Rental.Common.NHibernateSessionManager.RollbackTransaction() in H:\ITSoftware\Development\flatmates\trunk\Core\Rental.Common\NHibernateSessionManager.cs:line 174
       at Rental.Biz.CompatabilityEngine.Engine.Execute() in H:\ITSoftware\Development\flatmates\trunk\Core\Rental.Biz\CompatabilityEngine\Engine.cs:line 173
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.runTryCode(Object userData)
       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.Data.SqlClient.SqlException
       Message="Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.\r\nThe statement has been terminated."
       Source=".Net SqlClient Data Provider"
       ErrorCode=-2146232060
       Class=11
       LineNumber=0
       Number=-2
       Procedure=""
       Server=".\\SQLEXPRESS"
       State=0
       StackTrace:
            at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
            at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
            at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
            at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
            at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
            at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
            at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
            at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
            at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
            at NHibernate.AdoNet.AbstractBatcher.ExecuteNonQuery(IDbCommand cmd)
            at NHibernate.AdoNet.NonBatchingBatcher.AddToBatch(IExpectation expectation)
            at NHibernate.Persister.Entity.AbstractEntityPersister.Update(Object id, Object[] fields, Object[] oldFields, Object rowId, Boolean[] includeProperty, Int32 j, Object oldVersion, Object obj, SqlCommandInfo sql, ISessionImplementor session)
       InnerException: