How to: Eliminate Duplicate Elements from a Sequence (LINQ to SQL)
Use the Distinct operator to eliminate duplicate elements from a sequence.
Example
The following example uses Distinct to select a sequence of the unique cities that have customers.
Dim cityQuery = _
(From cust In db.Customers _
Select cust.City).Distinct()
For Each cityString In cityQuery
Console.WriteLine(cityString)
Next
IQueryable<String> cityQuery =
(from cust in db.Customers
select cust.City).Distinct();
foreach (String cityString in cityQuery)
{
Console.WriteLine(cityString);
}