When to call NHibernate Rollback? - nhibernate

Question

I'm using NHibernate to insert some data into Table A. I want to update the status in Table B if the Table A transaction fails. How do I check if it has failed?
Below is my current code:
// Add userId to Receiver
Receiver receiver = new Receiver();
receiver.User = User.GetById(Convert.ToInt32(listItem.Value));
receiver.Notification = Notification.GetById(notification.NotificationId);
receiver.Save();
Where do I call the NHibernate Transaction? If it fails where do I call NHibernate Rollback and update the Table B status?

Answer 1

Take a look at the Official NHibernate documentation on Exception handling: http://nhibernate.info/doc/nh/en/index.html#manipulatingdata-exceptions
using ( ISession session = sessionFactory.OpenSession() )
{
using ( ITransaction transaction = session.BeginTransaction() )
{
try
{
// Do your save/update here for Table A
transaction.Commit();
}
catch( Exception e )
{
// Your save or update failed so this is where you
// could capture that info and update your Table B
transaction.Rollback();
}
}
}
From what I remember, you don't actually have to call tx.Rollback() because when your code leaves the using blocks, it will do that automatically but again, I can't remember exactly. Give it a try and if it doesn't behave as I just described, you can manually rollback in the catch.

Answer 2

using (ISession session = factory.OpenSession())
using (ITransaction tx = session.BeginTransaction())
{
// do some work
tx.Commit();
}
or manually
ISession session = factory.openSession();
try
{
// do some work
session.Flush();
currentTransaction.Commit();
}
catch (Exception e)
{
currentTransaction.Rollback();
throw;
}
finally
{
session.Close();
}
Take a look NHibernate transactions for more details