Question

Hi i have a table with the following fields ‘Site Code’ ‘Date’ ‘Hour’ ‘Quantity’ and i want in a query to take all the inputed data of the last week. But there can be more than one inputs for one date so i will have to group according to Date first and then order those groups in DESC and take the last 7. The query i am using however does not work as it should because it orders the groups but in days with multiple inputs i am getting only 1 of them.
the query is:

SELECT `Quantity` , `Hour` , `Date`
FROM (
      SELECT *
      FROM `13_trans_coffee`
      WHERE `Site Code` =103713
      GROUP BY `Date`
      ORDER BY `Date` DESC
     )days
LIMIT 0 , 7

sample data

site code  date            hour    quantity
103713     5/12/2011 0:00  21      10
103713     5/12/2011 0:00  20      11
103713     4/12/2011 0:00  14      10
103713     6/12/2011 0:00  20      10
103713     8/12/2011 0:00  23      10

notice i have 2 inputs for day 5/12/2011 but the results of the query are

quantity   hour    date
10         23      8/12/2011 0:00
10         20      6/12/2011 0:00
11         20      5/12/2011 0:00
10         14      4/12/2011 0:00

one input is missing.

Answer 1

The below one should work.

SELECT * 
FROM `13_trans_coffee`
WHERE  `Site Code` =103713 AND `Date` 
IN
(
SELECT `Date`
FROM `13_trans_coffee`
WHERE `Site Code` =103713
GROUP BY `Date`
ORDER BY `Date` DESC
LIMIT 0 , 7
) Z;