Question

I have a MySQL table with 5 rows:

email
message_id
date
time

And I would like to count the number of emails there is per days.

So far I have this

SELECT Date,COUNT(*) AS Num FROM mail2_mailing_log WHERE Id_message=@Id GROUP BY Date ORDER BY Date DESC

But we found out that there was a problem with a script and many data got multiplied (Which have since been fixed), but I would like to be able to use the data I have.

So basically I would want to “merge” all the rows that match per email, date and time and then group by date and count the number of items.

Answer 1

SELECT q.date, COUNT(*)
    FROM (SELECT DISTINCT email, date, time
              FROM mail2_mailing_log
              WHERE Id_Message = @Id) q
    GROUP BY q.date
    ORDER BY q.date DESC