Question

我有两张桌子。

Customer ID, NAME, MonthlyIncome
Orders ID, CustomerKey, TotalCost

我希望将这两张桌子加入到一起，就像在店里购买的总金额一样。

CustomerKey, MonthlyIncome, TotalCost.

我尝试按CustomerKey进行分组，但我无法包含其余列。我应该使用哪个查询？

SELECT 
    fs.CustomerKey, SUM(fs.TotalCost) as TotalBought
FROM 
    FactOnlineSales fs
INNER JOIN 
    DimCustomer c on c.CustomerKey = fs.CustomerKey
GROUP BY 
    fs.CustomerKey

Answer 1

我尝试按CustomerKey分组，但无法管理如何包含其余列。

Just do it：

SELECT fs.CustomerKey,
       c.MonthlyIncome,
       SUM(fs.TotalCost) as TotalBought
  FROM FactOnlineSales fs
       INNER JOIN DimCustomer c
         ON c.CustomerKey = fs.CustomerKey
 GROUP BY fs.CustomerKey,
          c.MonthlyIncome

大概CustomerKey是唯一的，因此按不太独特的列进行分组不会改变SUM总数。

Answer 2

您没有提到您正在使用的SQL Server的版本 - 但如果您使用的是SQL Server 2005 或更新版本，则可以使用{{ 1}}子句：

OVER()

这基本上为您提供SELECT fs.CustomerKey, c.MonthlyIncome, TotalBought = SUM(fs.TotalCost) OVER(PARTITION BY fs.CustomerKey) FROM FactOnlineSales fs INNER JOIN DimCustomer c on c.CustomerKey = fs.CustomerKey，CustomerKey，然后为每个MonthlyIncome汇总TotalCost，并在输出中显示相应的值。在这种情况下无需执行CustomerKey

Answer 3

您可能在联接的ON子句中有错误您在CustomerKey表格中使用了Customer ID代替DimCustomer。对于gouping：您必须按照您未汇总的每个列进行分组，这样您就可以添加NAME（这样您就可以拥有描述性客户）和MonthlyIncome。

SELECT 
    c."Customer ID",
    c.NAME, 
    c.MonthlyIncome,
    SUM(fs.TotalCost) as TotalBought
FROM 
    FactOnlineSales fs INNER JOIN DimCustomer c 
    on c."Customer ID" = fs.CustomerKey
GROUP BY 
    c."Customer ID",
    c.NAME,
    c.MonthlyIncome

SQL Server分组问题

3 个答案: