ASP.NET

AhmedNisar82 wrote:

my application runs on server not on the client side

AhmedNisar82 wrote:

Now i want to compare with existing records and remove them if a duplicate Entry Exists.

IF EXISTS (SELECT * FROM MyTable WHERE Email = @newEmail)
BEGIN
    -- Perform action based on email address already existsin
END
ELSE
BEGIN
    -- Perform action based on email address not existing.
END

SELECT MAX(PrimaryKey), COUNT(*)
FROM MyEmailTable
GROUP BY EmailAddress
HAVING COUNT(*) >= 2

DELETE FROM MyEmailTable
WHERE PrimaryKey IN
(
    SELECT MAX(PrimaryKey)
    FROM MyEmailTable
    GROUP BY EmailAddress
    HAVING COUNT(*) >= 2
)