基於另一列的總和選擇列

Question

比方說，我有

SalesManagerId, SaleAmount, ProductId 

我想總結SaleAmount每個（SalesManagerId，ProductId）並獲取ProductId與最大sum(SaleAmount)。

這是可能的一個查詢？

例子：

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 

結果：

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

Answer 1

如果您有可用的分析功能，您可以使用RANK()

喜歡的東西：

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

非常好的問題！

試試這個：

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

或可替代

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

你不能剛落之列，得到的只是產品ID

Answer 3

使用GROUP BY和ORDER：

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

Answer 4

假設至少是SQL 2005，所以你可以使用一個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