Return the Set Difference Between Two Sequences
Use the Except operator to return the set difference between two sequences.
This example uses Except to return a sequence of all countries in which Customers
live but in which no Employees live.
var infoQuery =
(from cust in db.Customers
(from emp in db.Employees
Dim infoQuery = _
(From cust In db.Customers _
Select cust.Country) _
(From emp In db.Employees _