MySQL聚合查询

Question

I am currently trying to aggregate the people who visited a sports facility and how much it cost them. I have run the following code successfully but need to aggregate the people. How can I do that.

The tables used for the code is here Tables

SELECT CONCAT( members.firstname, " ", members.surname ) AS fullname,
CASE WHEN slots >0
THEN (
bookings.slots * facilities.membercost + bookings.slots * facilities.guestcost
)
ELSE NULL
END AS "cost"
FROM `Bookings` AS bookings
LEFT JOIN `Members` AS members ON bookings.memid = members.memid
LEFT JOIN Facilities AS facilities ON bookings.facid = facilities.facid
WHERE bookings.starttime LIKE '2012-09-14%'
AND (
bookings.slots * facilities.membercost + bookings.slots * facilities.guestcost
) >30
ORDER BY 1 DESC 

OutputScreenshot

Answer 1

I got throught with this.... Here is my solution:

SELECT CONCAT (members.firstname," ",members.surname) AS fullname,
    SUM(bookings.slots*facilities.membercost + bookings.slots*facilities.guestcost) AS cost

    FROM `Bookings` AS bookings
            LEFT JOIN `Members` AS members 
            ON bookings.memid = members.memid
            LEFT JOIN Facilities as facilities
            ON bookings.facid =facilities.facid
    WHERE bookings.starttime LIKE '2012-09-14%' AND (bookings.slots*facilities.membercost + bookings.slots*facilities.guestcost) >30


GROUP BY 1
ORDER BY 2 DESC