In the MSDN (link) it is clearly stated that EDMGen.exe is not generating the StoreGeneratedPattern attribute. So I have to add this attribute manually. I can live with that.
The problem that I have is that the properties of the EntityTypes get overwritten on every “update my model from the database”. So I have to undo these changes on every type in my model after an update.
Is there a way to prevent this automatic update of my model?
Try this fix. It was initially fixed in VS 2010 SP1 but the fix wasn’t complete because many people still had this problem. This fix should solve the problem.