Is it possible to allow nhibernate to update only if i call update ( or saveandupdate ) befor flush for an object and not only when i call flush?

We have a large object model where we use lazy loading to prevent long loading times. Know we want to allow the users to discard changes. But every time i update another object, i have to call flush and the all changes for all object inside the session are flushed.

I can not use Evict, because this disable lazy laoding. And i can not user more the one session, but if i set this object to an object from another session i got an error beause the object are already assigned to a session.

Steve

Discard changes = rollback the transaction?

No the we evict the changed object and reload the state from db into a new instance.

I don't think i understand the problem then. My suggestion (short formulated i admit) is that if the user want to discard changes you rollback a transaction there was started when user started to change things.

If i don't understand you correctly you might look at putting detached objects back into a new session to enable lazy loading. Take a look at: http://intellect.dk/post/Detached-objects-in-nHibernate-and-Lazy-loading.aspx