Any vs Where clause in LINQ - linq

Question

I always thought LINQ to SQL equivalent for an exists query is to use Any(). But i recently wrote a query in LINQ , which basically is trying to find if duplicate records exists in single table.
Anycontext.Contacts.Any(c => ((c.FirstName == contact.FirstName && c.LastName == contact.LastName && c.AddressLine1 == contact.AddressLine1 && c.Zip == contact.Zip)||
(!String.IsNullOrEmpty(contact.Email) && c.Email == contact.Email)))
matching criteria is simple to find contacts with same FirstName, LastName and AddressLine1 or same Email. This query times out in 30 sec(default), there are just 500K rows in this table.
Wherecontext.Contacts.Where(c => ((c.FirstName == contact.FirstName && c.LastName == contact.LastName && c.AddressLine1 == contact.AddressLine1 && c.Zip == contact.Zip)||
(!String.IsNullOrEmpty(contact.Email) && c.Email == contact.Email))).Count()>0
I was forced to use Where clause and then do count greater than 0 to find if any duplicate exists in the set. What i can not understand is, why LINQ to SQL on simple Any clause timing out.
Any explanation will be really great here.
EDIT
SQL From from LINQ Pad
ANY
SELECT
(CASE
WHEN EXISTS(
SELECT NULL AS [EMPTY]
FROM [Accounts].[Contacts] AS [t0]
WHERE ([t0].[CompanyID] = #p0) AND ((([t0].[FirstName] = #p1) AND ([t0].[LastName] = #p2) AND ([t0].[AddressLine1] = #p3) AND ([t0].[Zip] = #p4)) OR (([t0].[FirstName] = #p5) AND ([t0].[LastName] = #p6) AND (EXISTS(
SELECT NULL AS [EMPTY]
FROM [Accounts].[PhoneNumbers] AS [t1]
WHERE ([t1].[ContactNumber] = #p7) AND ([t1].[ContactID] = [t0].[ContactID])
))))
) THEN 1
ELSE 0
END) AS [value]
Where
SELECT [t0].[ContactID]
,[t0].[CompanyID]
,[t0].[CompanyTitle]
,[t0].[FirstName]
,[t0].[LastName]
,[t0].[AddressLine1]
,[t0].[AddressLine2]
,[t0].[City]
,[t0].[State]
,[t0].[Zip]
,[t0].[Email]
,[t0].[Salutation]
,[t0].[IsActive]
FROM [Accounts].[Contacts] AS [t0]
WHERE ([t0].[CompanyID] = #p0)
AND (
(
([t0].[FirstName] = #p1)
AND ([t0].[LastName] = #p2)
AND ([t0].[AddressLine1] = #p3)
AND ([t0].[Zip] = #p4)
)
OR (
([t0].[FirstName] = #p5)
AND ([t0].[LastName] = #p6)
AND (
EXISTS (
SELECT NULL AS [EMPTY]
FROM [Accounts].[PhoneNumbers] AS [t1]
WHERE ([t1].[ContactNumber] = #p7)
AND ([t1].[ContactID] = [t0].[ContactID])
)
)
)
)

Answer 1

Not completely sure if this is what you want, but you could compare, I'm guessing you wont run the test often, as it would be better to test for existence before you input the data to the DB.
If you want to find the duplicates then
var queryA = from a in db.someTable
select a.value;
foreach(var row in queryA){
Console.Write(queryA.Where(b => b == row).Count() > 1 ? row: "");
}
If you just want to test if it exist then.
var queryA = from a in db.someTable
select a.value;
var queryB = queryA;
queryB.Distinct();
Console.Write(queryB.Count() != queryA.Count() ? "Yes" : "No");