sometimes, the save method of Session executes but no insert statement is displayed in console as usual although I set show_sql=true and no data is inserted into database. I'm using hibernate 3.0, Tomcat web server, Netbeans IDE.

Thanks a lot for consideration

There may be a lot of reasons, why this happens. One of the (in my opinion) less obvious reasons I encountered once was that I used declarative transaction demarcation and the surrounding transaction was marked as "read-only". This seems to prevent any updates.

But to really help you, I assume that more information on the problem is needed!?

All the best,

René

Hibernate will execute the queries when the session is flushed or closed.
So your insert query will only be displayed when any of the above happens.

Thanks a lot

Usually, when transaction.commit() is call, the query is printed out. But sometimes it doesn't and no data is insert into database. When I try again or restart server a few time, it's become good. I agree that data will insert into database when session.flush() or close() is called, but they're used to make the hibernate immediately do the query. When we don't use them, but commit(), the query must a done at certain time, When??. I see that it usually be done immediately. I beleive that hibernate don't ignore our query???

I am assuming you are using threadlocal sessions. The above statement indicates you might not be closing your sessions properly.

If you are using transactions, the commit causes the session to flush automatically.