I understand that NHibernate will at times automatically flush the session; however, IsDirty isn't the place I would expect this to happen.

It does this even with FlushMode set to Never.

If this is indeed necessary it should be documented somewhere.

Yes, I noticed this also. Seems like a place where flushing should NEVER happen ...

It doesn't perform a complete flush in IsDirty (no SQL is executed), but it does perform the preparation phase since that's how it detects whether any changes occurred.

Hi All!

Yes, it really doesn't "execute" flush but only create "insertions/deletions/updates". Unfortunately it may lead to exception if data is somehow invalid (for example there is null in not-null pproperty). So I ended with "validate before dirty check" approach - at least in my simple case it helped to solve this problem... Until we move to more correct way of handling sessions in winforms :(

I am seeing SQL executed in some instances (in particular with new items added to a collection). There is a call to "FlushEverything" that appears to do exactly as it's name implies.

public bool IsDirty()
{
CheckIsOpen();

log.Debug("checking session dirtiness");
if (insertions.Count > 0 || deletions.Count > 0)
{
log.Debug("session dirty (scheduled updates and insertions)");
return true;
}
else
{
int oldSize = collectionRemovals.Count;
try
{
FlushEverything();

Yes, there is a call to that, but it doesn't do what its name implies to you, it only fills the insertions/deletions/etc. lists.