SQL Query for joining equivalent rows summing a column

I have two tables, articolo and saldo.

articolo is like this:

id	desc_breve	variante	taglia
338673	ANYT229	00109	XL
338674	ANYT229	00109	XL
338675	ANYT229	00109	XXL
338711	MYP506S	00002	56
338712	MYP506S	00002	58
338713	MYP506S	00002	60
338714	MYP506S	00002	60
338715	MYP506S	00002	62

saldo (omitting the primary key id) is like this:

id_articolo	giacenza
338673	12.0000
338674	13.0000
338675	23.0000
338711	2.0000
338712	5.0000
338713	1.0000
338714	8.0000
338715	8.0000

I need to join the two tables from the id field in articolo and the id_articolo field in saldo with a query that returns desc_breve, variante, taglia and giacenza.

The problem is that some rows in the first table have the same desc_breve, variante and taglia, and in that case I have to join them in a single row and SUM their respective giacenza field in the saldo table.

Is it possible to do a query for that? I’m using Microsoft SQL Server.

Answer

You seem to be describing a join with group by:

select a.desc_breve, a.variante, a.taglia, sum(s.giacenza)
from articolo a join
     saldo s
     on s.id_articolo = a.id
group by a.desc_breve, a.variante, a.taglia;