Getting rows filtered by most recent time mysql

Question

I have a question of a complex query and I don\'t know how to write it. I have the next table:

+---------------+-----------+----------+--------------------------         


        

Answer 1

Try this query :-

select * from (
select * from (
SELECT     a.id, 
           nia.idaction grp_is, 
           MAX(CONCAT(nia.fecha, ' ', nia.hora)) time_is
FROM       nectar_incidencias_alarma nia 
INNER JOIN alarmas a 
        ON a.id=nia.id_alarma 
WHERE      nia.idaction IN (6,7) 
GROUP BY   a.id
) tab1
order by tab1.time_is desc) tab2
group by tab2.grp_is