Return the Set Difference Between Two Sequences
Use the Except operator to return the set difference between two sequences.
Example
This example uses Except to return a sequence of all countries/regions in which Customers
live but in which no Employees
live.
var infoQuery =
(from cust in db.Customers
select cust.Country)
.Except
(from emp in db.Employees
select emp.Country)
;
Dim infoQuery = _
(From cust In db.Customers _
Select cust.Country) _
.Except _
(From emp In db.Employees _
Select emp.Country)
In LINQ to SQL, the Except operation is well defined only on sets. The semantics for multisets is undefined.