Question

I’m using a database to store results of an election with the columns id, candidate, post_time and result. Results are put in the database during ‘counting the votes’. When a new update is available, a new entry will be inserted.

From this database, I would like to create a table with the most recent results (MAX post_time) per candidate (GROUP BY candidate), ordered by result (ORDER BY result).

How can I translate this to a working SQL-statement?

(I’ve tried mysql order and groupby without success)

I’ve tried:

SELECT *, MAX(time_post) 
FROM [database] 
GROUP BY candidate 
HAVING MAX(time_post) = time_post 
ORDER BY result

Answer 1

Assuming that you don’t have multiple results per candidate at same time, next should work:

select r.candiate, r.result
from results r
inner join (
    select candidate, max(post_time) as ptime
    from results
    group by candidate 
) r2 on r2.candiate=r.candidate and r2.ptime=r.post_time
order by r.result