Consider the following mapped classes:

public abstract class Content {}

public class Image : Content {}

Now, when trying to load an instance of an Image:

[...]
Guid imageId = GetId();
ISession sess = GetSession();
object loadedObj = sess.Load(typeof(Content), imageId);
object getObj = sess.Get(typeof(Content), imageId);
[...]

loadedObj.GetType().BaseType will be "Content" (unexpected).
getObj.GetType().BaseType will be "Image" (expected).

Why the difference between Get and Load? Is this a bug, or should I use ISession.Get to suit my needs?

With 1.0.1, ISession.Load would have returned an Image instance above.

Thanks!

Ryan

out of curiosity, what does loadedObj.GetType() return? and getObj.GetType() ? are these returning proxy classes?

Both methods seem to return proxy classes. However, it seems like loadedObj.GetType() does not extend Image; but getObj.GetType() does.

My understanding is that Load will create a proxy but will not actually hit the DB until a property is accessed. Get, however, will immediately load the object into the proxy.

If a proxy for a superclass is loaded using Load() it's not possible to know what subclass it represents until the database is hit, therefore using GetType() won't yeild the expected result.

You're better off using NHibernate.NHibernateUtil.GetClass(proxy) to find out the actual object type that a proxy represents.

Cheers,

Symon.

Ah, thanks for the explanation of the subtle differences :) It hasn't been a big deal since I've changed our code to use ISession.Get(), so I may stick with that.

Thanks again,

Ryan

Good to know, thanks for clearing that up. rduffield, make sure you give him credit for answering your question ;)

Not sure who else I've given credit to.

At any rate, I've also abstracted away NHibernate.NHibernateUtil.GetClass into our helper class for future use. This also works as expected.

Thanks,

Ryan