How to join with LinQ to (typed) dataset?
i recently upgraded VS 2005 to 2010 and am fairly new to LinQ. Maybe somebody can put me in the right way. Background : I have a typed dataset and have the standard SQLMembershipProvider extended with a Table AccessRule. So a role can have infinitely AccessRules(f.e. "Administrator" has "DeleteCustomer"). I use a custom membership provider that inherits from SqlMemberShipProvider and has an overloaded function hasAccess(one with a memory-dataset as parameter and the other uses the database directly). This is the complete Model: Now i need to know f.e. if a User with UserID= '89f9ea8d-8ae1-460b