NHibernate: Reasons for overriding Equals and GetHashCode

Question

Are there any reasons why Equals or GetHashCode should be overriden in entities when using NHibernate? And in which scenarios are these reasons valid?

Some reasons t

Answer 1

Overloading the Equals and GetHashCode methods is important if you are working with multiple sessions, detached entities, stateless sessions or collections (see Sixto Saez's answer for an example!).

In the same session scope identity map will ensure that you only have a single instance of the same entity. However, there is the possibility of comparing an entity with a proxy of the same entity (see below).