Selezionare la colonna in base a somma di un'altra colonna

Question

Diciamo che ho

SalesManagerId, SaleAmount, ProductId 

voglio riassumere il SaleAmount per ogni (SalesManagerId, ProductId) e prendete la ProductId con la massima sum(SaleAmount).

Questo è possibile in una query?

Esempio:

1, 100, 1 
1, 200, 1 
1, 600, 1 
1, 400, 2 
2, 100, 3 
3, 100, 4 
3, 100, 4 
2, 500, 6 
3, 100, 5 

risultato:

1, 900, 1 
2, 500, 6 
3, 200, 4 

Answer 1

Se si dispone di funzioni analitiche disponibili, è possibile utilizzare un RANK()

Qualcosa di simile:

SELECT SalesManagerId, ProductId, Total 
FROM (
    SELECT SalesManagerId, 
     ProductId, 
     SUM(SaleAmount) as Total, 
     RANK() OVER(PARTITION BY SalesManagerId 
        ORDER BY SUM(SaleAmount) DESC) as R 
    FROM <Table name> 
    GROUP BY SalesManagerId, ProductId) as InnerQuery 
WHERE InnerQuery.R = 1 

Answer 2

Molto buona domanda!

Prova questo:

SELECT MAX(SUM(SaleAmount)), ProductId GROUP BY SalesManagerId, ProductId; 

Oppure, in alternativa

SELECT SUM(SaleAmount) as Sum, ProductId GROUP BY SalesManagerId, ProductId ORDER BY Sum DESC; 

Non si può semplicemente eliminare la colonna somma e ottenere solo il prodotto id

Answer 3

Usa GROUP BY e ORDER:

SELECT SalesManagerId, SUM(SaleAmount) AS SaleSum, ProductId FROM [table-name] GROUP BY SalesManagerId, ProductId ORDER BY SaleSum DESC 

Answer 4

Assumendo almeno SQL 2005 in modo da poter utilizzare un CTE:

;with cteTotalSales as (
    select SalesManagerId, ProductId, SUM(SaleAmount) as TotalSales 
     from YourSalesTable 
     group by SalesManagerId, ProductId 
), 
cteMaxSales as (
    select SalesManagerId, MAX(TotalSales) as MaxSale 
     from cteTotalSales 
     group by SalesManagerId 
) 
select ts.SalesManagerId, ms.MaxSale, ts.ProductId 
    from cteMaxSales ms 
     inner join cteTotalSales ts 
      on ms.SalesManagerId = ts.SalesManagerId 
       and ms.MaxSale = ts.TotalSales 
    order by ts.SalesManagerId