Question

DETAILS

I want to find the difference between start and stop times(duration) for each test taken then rank users according to the highest score and lowest duration for each test. Ultimately I will use PDO to do this in mysql. So far though I’ve just been working on the sql. I think I’m pretty close now, but am unsure how to combine the information into one query.

WHAT I’VE GOT(untested).

I have the following table called testresults

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| index | id |         start         |          stop        | score| 
--------------------------------------------------------------------
|   1   | 23 |   2012-06-06 07:30:20 | 2012-06-06 07:30:34  | 100  |
--------------------------------------------------------------------

In my select statement I want to get the id and the score along with the calculated duration.

I can get duration for any test taken today with the below query.

SELECT TIMESTAMPDIFF(SECOND,stop,start) AS duration
FROM testresults WHERE `start` >= DATE(NOW())

Then I sort the results based on rank. Rank is determined according to score and duration. Top place goes to the highest score with the shortest duration.I believe I can do that with something like this:

ORDER BY score DESC, duration ASC

I only want maybe 100 entries so,

LIMIT 100

QUESTION

How can I combine the above information into 1 query?

Answer 1

SELECT `id`, `score`,
    TIMESTAMPDIFF( SECOND, start, stop ) AS `duration`
FROM `testresults`
WHERE `start` >= DATE(NOW())
ORDER BY `score` DESC, `duration` ASC
LIMIT 100;

This will work pretty good. You’ll also need to put id & score in SELECT statement.