Postgresql get the distinct values with another max value - postgresql

Question

I have a table with this values:
id - idProduction - historical - idVehicle - km
1 - 200 - 1 - 258 - 100
2 - 200 - 2 - 258 - 100
3 - 200 - 2 - 259 - 150
4 - 200 - 3 - 258 - 120
5 - 200 - 3 - 259 - 170
6 - 300 - 1 - 100 - 80
7 - 100 - 1 - 258 - 140
8 - 300 - 2 - 325 - 50
I need to get the values with the max historical, for all the distinct idProduction. In that case:
4 - 200 - 3 - 258 - 120
5 - 200 - 3 - 259 - 170
7 - 100 - 1 - 258 - 140
8 - 300 - 2 - 325 - 50
It my first work with postgresql, so I don't have to much idea on how to do it, does anyone can help me?
Thank you!

Answer 1

I think with that I can solve my problem, but I'm not sure... :
SELECT id, productions_vehicles.id_production, nu_task_number, id_historical, id_vehicle
FROM productions_vehicles
INNER JOIN
(SELECT id_production, MAX(id_historical) AS idHistorico
FROM productions_vehicles
GROUP BY id_production) topHistorico
ON productions_vehicles.id_production = topHistorico.id_production
AND productions_vehicles.id_historical = topHistorico.idHistorico;

Answer 2

You effectively need two requests, your solution looks good, you can also use the WITH clause to do the first request :
WITH topHistorico (
SELECT id_production, MAX(id_historical) SA idHistorico
FROM productions_vehicles
GROUP BY id_production)
SELECT id, pv.id_production, nu_task_number, id_historical, id_vehicle
FROM production_vehicles pv
INNER JOIN topHistorico th ON pv.id_production = th.id_production AND pv.id_historical = th.idHistorico
PostgreSQL: Documentation: 9.1: WITH Queries (Common Table Expressions)