Question

I’m using NHibernate and I have some doubts abour how NHibernate handles null values for non-nullable fields. I would assume that NHibernate would throw an exception at the time of creating the entity, but I have found some evidence suggesting it will set the field to the default value of the type.

Which is correct?

Answer 1

From what I have experienced, it would usually assign a default value.

• If you have an entity with an DateTine property and you don’t assign anything to it, it would assign a default date, usually the oldest one the database can handle.
• If you have an entity with an Enum property, it could simply assign the first value of the Enum (e.g., Enum { Off = 0, On = 1 }, it would take 0 by default).
• Numeric types would of course get a 0 value.

This is the behaviour I have found in my applications. One could probably somehow make it throw exceptions, but I personally have no need for it.