I'm using NHibernate 2 and with the typical Hashtable cache provider. I'm noticing a strange thing.

When I query an entity via Session.Get<T> I get an object back that is fully fleshed. If I change a property of that object and NOT call SaveOrUpdate but query the same entity and get another reference back the property that was changed on the first is the same on the second.

pseudo code:

SomeObject obj = Session.Get<SomeObject>(1);

// success
AssertEqual(obj.Description, "foo");

obj.Description = "bar";

SomeObject obj2 = Session.Get<SomeObject>(1);

// this fails b/c some reason the two are equal
AsssertNotEquals(obj.Description, obj2.Description);

The assumption I'm making is that SessionImpl is proxying an interface to the same cached object by key. And b/c I'm using the Hashtable cache provider the memory reference is the same within the heap of the AppDomain.

Is this correct? Does anyone have any clue what is going on here?

I don't know a bout NHibernate but this is expected behavior in the Java version of Hibernate. In a single session there is never more than one instance of an entity with a given ID. So, obj and obj2 are actually referring to the same instance. I would be very surprised if the same wasn't true for NHibernate since there is a lengthy discussion about this in the Hibernate docs: http://www.hibernate.org/hib_docs/v3/re ... s-identity