Find duplicate with Linq

This small tips discussed about how to get list of duplicate items for the collection that we do in sql.
For example I have to get list of the email id which is get entered in user table more than one time.
[sourcecode language="csharp"]
SELECT email,
COUNT(email) AS NumOccurrences
FROM users
GROUP BY email
HAVING ( COUNT(email) > 1 )

[/sourcecode]
Linq query work same as on the set of collection and which make use of count

[sourcecode language="csharp"]
DataClassesDataContext db = new DataClassesDataContext();
var duplicates = db.Users
.GroupBy(i => i.emailid)
.Where(g => g.Count() > 1)
.Select(g => g.emailid);
foreach (var d in duplicates)
Console.WriteLine(d);
[/sourcecode]

So by using above query you can easily achieve task of finding duplicate for your set of collection.