I created some code following Nick Heudecker's Introduction to Hibernate tutorial, and nothing happened with my database. The basic code idea was:

Session s = sf.openSession();
s.saveOrUpdate(team);
s.close();

However, if I wrap a Transaction around the saveOrUpdate() and commit it before the session close(), it works.

I got rid of the Transaction and put s.flush() before the s.close() and the database was updated, but in much of the introductory material scattered around the Hibernate website, there are neither Transactions nor Session flushes to be found. Is this a change from previous versions?

So, I guess my questions are:

1) Should I be using Transactions as a matter of course, even for atomic statements?

2) If the answer to (1) is no, do I have to call flush() separately from close(), and, if so, isn't this different from the way Streams and Writers work in the Java classes, and so confusing?

Thanks!

P.S. I followed the Getting Started guide at http://www.hibernate.org/152.html and almost nothing worked in the way it was advertised. I think the implementation and the documentation have parted ways. I suppose that's fine, but it does make life for newbies quite a bit more difficult.

Yes, you should ALLWAYS use transactions!

There is no SQL execution without transactions, thats a myth usually attributed to "auto commit mode". Read the reference documentation, "Ending a Session".

Can you describe _what_ didn't work?

My entry did not appear in the database is what didn't work.

So, I'm to understand that Transactions are *not* optional.

OK.

Todd

you can never avoid using *transactions* at the database level - but you can avoid using the Transaction class - just go read the docs about "ending a session".'

But if you need good control over transactions then use the Transaction class.

...and the reason for you not getting the enitty to the db is because you miss the call to flush(); which acutally is perfectly aligned with java io streams since you also can lose data on a stream if you do not close it first ;) ...

Right, but I did close the session.

With Java streams, close() automatically calls flush(). Apparently, it doesn't with Sessions. That's what had me confused.

you got it ! ;)

(...but still java streams does not call flush() on close() - only some of them do! If you are writing to a file then always remember to call flush() before closing!)