Question

Hi I have a table that list Spanish classes start and finish time as well as date and teacher.
I’m trying to write a MYSQL query that lists the that date each teacher has the most classes, the day which they are the busiest.
If there are days that tie I’d like to show both.

This is what I have so far but It only returns one date,even if there is a tie, I sense this is because I’m GROUPing on teacher at the end

SELECT teacher_no, date
FROM (
   SELECT COUNT(date)AS counted,teacher_no,date
   FROM Spanish
   GROUP BY teacher_no,date
) AS t
GROUP BY teacher_no

Answer 1

Try this:

SELECT  teacher_no, date, COUNT(date) AS counted
FROM    Spanish s
GROUP BY teacher_no, date
HAVING  COUNT(date) = (SELECT COUNT(date) AS counted
                       FROM Spanish
                       WHERE teacher_no = s.teacher_no
                       GROUP BY teacher_no, date
                       ORDER BY counted DESC
                       LIMIT 1
                      );