Hi all collaborators,
Based on the example I need from table orders

order_ID Cod_art Cost
-------- ------- ----
1 1 10
2 2 20
3 1 15
4 3 20
5 3 22

this from the query

Cod_art MinCost order_ID
------- -------- ---------
1 10 1
2 20 2
3 20 4

Thank very much
Bye