NHibernate在.list调用期间更新我更改的记录

I've got a record I'm editing in a ASP.net web app using nhibernate and MVP. When I make the changes to the record, I need to check to see that one field is unique (see 'friendlyUrl' below). However when I so my Criteria.List call, it updates the record as well as all child records (PharmacyStoreHours) first then does the select (found this out with a SQL profile). Obviously I don't want to update the record before the validation is complete and the validation fails as the data has been updated before the select. How do I do a select without the record updating?I've got a record I'm editing in a ASP.net web