如何在 django 或 postgres 中应用 distinct 和 group by？

Question

table production

code	part	qty	process_id
1	21	10	10
1	22	12	10
2	22	15	10
1	21	10	12
1	22	12	12

I have to extract data like based on process, every process has multiple part but I can't take every part's data, so that have to distinct on code for getting process wise summation of qty. how to get data like this in postgresql or in django

process_id	qty
10	27
12	12

I tried in this way

Production.objects.values('process').distinct('code').annotate(total_qty=Sum('quantity'))

Answer 1

The following query gets your desired result, but from your snippet I'm not sure this is the logic you had in mind. If you add more detail I can refine the answer.

SELECT process_id, SUM(qty) qty
FROM production
WHERE part=22
GROUP BY process_id