如何在使用 group by 子句时从 join 返回列？

Question

我正在尝试返回 t1.firstname、t1.lastname、t1.city、t1.stateprovince，并且我想返回 t2.amount、t2.restaurantname、t2.restaurantnum、t2.datekey 和 t2.amount也是。

这是我的代码：

SELECT DISTINCT 
    t1.[FirstName] AS FirstName,
    t1.[LastName] AS LastName,
    t1.[City] AS City,
    t1.[StateProvince] AS StateProvince
FROM 
    Database.dbo.CustomerData t1
JOIN 
    (SELECT DISTINCT
         MAX(t2.[Amount]) AS Amount,
         MAX(t2.[Account]) AS Account,
         MAX(t2.[CardNumber]) AS CardNumber,
         MAX(t2.[RestaurantNum]) AS RestaurantNum,
         MAX(t2.[RestaurantName]) AS RestaurantName,
         MAX(t2.[DateKey]) AS DateKey,
         SUM([t2].[Amount]) AS Total_Spend
     FROM 
         gift.TransactionItems t2
     GROUP BY 
         t2.[Amount],
         t2.[RestaurantNum],
         t2.[RestaurantName],
         t2.[DateKey],
         t2.[AccountID],
         t2.[TransactionID]) t2 ON t1.[CardNumber] = t2.[CardNumber]
WHERE
    [FirstName] IS NOT NULL
    AND [LastName] IS NOT NULL
    AND [EmailFailed] IS NULL       
    AND [IsRegistered] = 'Yes'
    AND [DateKey] BETWEEN 20180601 AND 20181213
    AND t2.[Account] = 'Dollars_Spent_Accrued'

这可能吗？它目前只返回 t1.firstname、t1.lastname、t1.city 和 t1.stateprovince。

Answer 1

如果在添加列时查询不起作用，那么我会将 t2 查询放入临时表中，然后进行连接，看看是否效果更好。经过一定程度的复杂性后，我通常会选择临时表并将其分解：

drop table if exists #t2
SELECT DISTINCT
         MAX(t2.[Amount]) AS Amount,
         MAX(t2.[Account]) AS Account,
         MAX(t2.[CardNumber]) AS CardNumber,
         MAX(t2.[RestaurantNum]) AS RestaurantNum,
         MAX(t2.[RestaurantName]) AS RestaurantName,
         MAX(t2.[DateKey]) AS DateKey,
         SUM([t2].[Amount]) AS Total_Spend
     INTO #t2 FROM 
         gift.TransactionItems t2
     GROUP BY 
         t2.[Amount],
         t2.[RestaurantNum],
         t2.[RestaurantName],
         t2.[DateKey],
         t2.[AccountID],
         t2.[TransactionID]

Answer 2

查询的第一部分列出了将返回的值。您只列出了来自t1 的值，尽管来自t2 的列包含在查询的FROM 段中。您需要将它们显式添加到查询的 SELECT 段中。让我知道这是否适合您。

SELECT DISTINCT 
    t1.[FirstName] AS FirstName,
    t1.[LastName] AS LastName,
    t1.[City] AS City,
    t1.[StateProvince] AS StateProvince
    t2.[amount], 
    t2.[restaurantname], 
    t2.[restaurantnum], 
    t2.[datekey]
FROM 
    Database.dbo.CustomerData t1
JOIN 
    (SELECT DISTINCT
         MAX(t2.[Amount]) AS Amount,
         MAX(t2.[Account]) AS Account,
         MAX(t2.[CardNumber]) AS CardNumber,
         MAX(t2.[RestaurantNum]) AS RestaurantNum,
         MAX(t2.[RestaurantName]) AS RestaurantName,
         MAX(t2.[DateKey]) AS DateKey,
         SUM([t2].[Amount]) AS Total_Spend
     FROM 
         gift.TransactionItems
     GROUP BY 
         t2.[Amount],
         t2.[RestaurantNum],
         t2.[RestaurantName],
         t2.[DateKey],
         t2.[AccountID],
         t2.[TransactionID]) t2 ON t1.[CardNumber] = t2.[CardNumber]
WHERE
    [FirstName] IS NOT NULL
    AND [LastName] IS NOT NULL
    AND [EmailFailed] IS NULL       
    AND [IsRegistered] = 'Yes'
    AND [DateKey] BETWEEN 20180601 AND 20181213
    AND t2.[Account] = 'Dollars_Spent_Accrued'