Get only latest row, grouped by a column

Question

I have a large data-set of emails sent and status-codes.

ID Recipient           Date       Status
 1 someone@example.com 01/01/2010      1
 2 someone@example.com         


        

Answer 1

SELECT
    M.Recipient,
    C.EmailCount,
    M.Status
FROM
    (
    SELECT Recipient, Count(*) EmailCount
    FROM Messages
    GROUP BY Recipient
    ) C
    JOIN
    (
    SELECT Recipient, MAX(Date) AS LastDate
    FROM Messages
    GROUP BY Recipient
    ) MD ON C.Recipient = MD.Recipient
    JOIN
    Messages M ON MD.Recipient = M.Recipient AND MD.LastDate = M.Date
ORDER BY
    Recipient

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