Question

I ran into this problem using EF4 and a self-referential table (implementing an adjacency list hierarchy).
NOTE: not a many-to-many reference, just a one-to-many on a single table.

Attempts to resolve an intermittent InvalidOperationException (“…The ObjectContext might be in an inconsistent state…“) using Context.Refresh fail due to an apparent bug in EF4.

I saw, from following Shimmy’s connect.microsoft.com link, on the aforementioned post, that the bug is still outstanding.
Can anyone recommend a workaround?
What do you do if your database and Entity Framework get out of sync?

EDIT
Some more facts that may help:

1. When I get the InvalidOperationException and the message says “The changes to the database were committed successfully…”, it is not true. They weren’t.
   I tried to change an object’s ParentId from 1 to null (ParentId of type int?).
2. My object’s ParentId attribute is correctly changed to the expected value (null). I call Context.SaveChanges(). Then, the exception is thrown. I check the DB, and the value has not been updated. In this case, ParentId is still 1 in the database.
3. Inside the catch, if I try to requery the object via
   myObj = Context.MyObjects.SingleOrDefault(o => o.Id == id),
   the object’s ParentId remains the same. It does not get updated by the (incorrect) database value!
   Now I think, Okay, that seems weird, but maybe if I save again the db will be corrected.
4. Calling a subsequent Context.SaveChanges() from inside the catch still does not update the database. (But this time, an exception is not thrown.)
5. If I make a new call to my SetParent method,
   myObj = Context.MyObjects.SingleOrDefault(o => o.Id == id),
   correcly populates the object’s ParentId parameter to 1, the value from the database.

Additionally, for giggles, I set the object’s ParentId to it’s own Id, instead of null, to denote parentlessness. This worked fine and did not cause the InvalidOperationException. But, it’s a PITA for other reasons. E.g., the object reports having itself as an extra child.

So, the questions are:

• What is it about trying to set my self-referential int? ParentId to null that causes an exception?
• Why does the db not get updated before the exception?
• And why, inside the catch, can’t I resync?!

Answer 1

Requery the object from the database through the context…

EDIT – in response to your update, if you submit changes for an object within a context, an an error happens, using the same context most likely is the problem. Try recreating the context in the catch to requery and reupdate, and see if that works any better.