I know change tracking is a feature in the Entity Framework since day one. If this is something you should really know, I confirm you later how to use it (I'm at a customer site now).

Yes, please do. Can I just confirm that I'm talking about change tracking at an *entity* level, referring to entities created using LinQ for SQL. If you stay connected, no issue. If you pass it between layers, you lose connection to the DataContext = no change tracking. Maybe I'm using the wrong words for some of this: if so I apologise, it's new to me too.

In any case, basic change tracking (like the oldval/curval) is something you can implement on your own framework really easily. You just need to keep a private clone of the entity after you read the data.

I did say you can do it by rolling your own. But why would you *want* to adopt new technology and roll your own change management simply because the transferred data no longer knows it has been changed? Especially when existing technology already offers change tracking, and MS says it is going to add change tracking for dLinQ entities too.

In any case I'm sure the EF already does this an more.

Great, please enlighten me.