How to: Remove Duplicate Elements From Query Results
This topic provides examples of how to remove duplicate elements from query results by using Distinct.
The example in this topic is based on the Adventure Works Sales Model. To run the code in this topic, you must have already added the Adventure Works Sales Model to your project and configured your project to use the Entity Framework. For more information, see How to: Use the Entity Data Model Wizard (Entity Framework) or How to: Manually Configure an Entity Framework Project and How to: Manually Define an Entity Data Model (Entity Framework).
Example
Description
This example uses the Distinct method to return unique last names.
Code
Using context As New AdventureWorksEntities()
Dim contacts = context.Contacts
Dim contactsQuery = _
From c In contacts _
Select c.LastName
Dim distinctNames = contactsQuery.Distinct()
For Each name In distinctNames
Console.WriteLine("Name: " + name)
Next
End Using
using (AdventureWorksEntities context = new AdventureWorksEntities())
{
IQueryable<string> contactsQuery = from c in context.Contacts
select c.LastName;
IQueryable<string> distinctNames = contactsQuery.Distinct();
foreach (string name in distinctNames)
{
Console.WriteLine("Name: {0}", name);
}
}