Hi,

If I run a query on a table that has a field with a foriegn key (although it can be of value null), NHibernate tries to issue an UPDATE statement.

If I do a Load of the same record it works fine. However, the Criteria.List gives me an error with could not update.

I'm not modifying the results. I'm just using a search condition. If I take the record and assign a value to the foreign key, then it works. But surely this shouldn't be necessary. My mapping files doesn't reference any one-to-one relationships and my property in question is:

<property name="SalesPersonId"/>

Again, Load works. Criteria.List does not, with the same exact data.

There is not enough information to do a complete troubleshoot for you. However, try making the SalesPersonId property in your C#/VB class a Nullable<int> (or "int?" in C#). When NHibernate retrieves the row from database, it gets a NULL. When the session is flushed, NHibernate sees a zero; therefore, it thinks that you have changed it, thus issues an update. The reason Load() does not cause the same problem is Load() creates a lazy proxy; and it does not actually hit the database until you access the object's properties. If the proxy has not been initialized, then NHibernate concludes that it has not been updated.

At any rate, all of the above are speculations. Please include more information if it does not solve your problem.