I'm pretty sure Jonathan AC Roberts has is right in his original post, the iType = 1 in the NOT EXISTS subquery is what's throwing you.

You're correct that the code...

If you have a dbo.C table/view in the database the query will run ok.

Yes, you need to use the Decision1 subquery in the WHERE clause in place of Decision1. Decision1 in the query you have written is a column alias, meaning the column...