如何嵌套這些SQL語句而沒有group by子句錯誤？

Question

我想查詢具有這些PARAMS數據庫：

交易日期，用戶電子郵件地址

我所做的就是用這個查詢：

SELECT [User Email Address], COUNT(*) AS 'count' 
    FROM 
     [DATABASE].[TABLE] 
    GROUP BY [User Email Address] 

，顯示使用參數表：

郵箱地址，算上

在這種情況下，數列顯示的賦存數量在原始表中的用戶電子郵件的es。

接下來我要做的是查看截至今天的最後一年的交易日期列，並將該子集的計數列與原始計數列（可追溯大約3年）進行比較。具體來說，我希望我的最終結果表是：

用戶用戶電子郵件地址，countDiff

其中countDiff是從1年子集和原來的子集數的差異。

我曾嘗試：

SELECT [User Email Address], [Transaction Date], [count - COUNT(*)] AS 'countdDifference' 

FROM (

    SELECT [User Email Address], COUNT(*) AS 'count' 
    FROM 
     [DATABASE].[TABLE] 
    GROUP BY [User Email Address] 


) a 

WHERE a.[Transaction Date] >= '2011-08-07 00:00:00.000' 


ORDER BY [count] DESC 

但我得到的錯誤[Transaction Date]不是在GROUP BY子句或集合。如果我把它放在[User Email Address]旁邊，它會混淆數據。

這實際上是我遇到的一個常見問題。任何方法來規避這一點？

Answer 1

您需要使用兩個不同的子查詢：一個計數滿條目和另一個計數去年的條目。

也許這將幫助你：

SELECT a.*, a.[count] - Coalesce(b.[count], 0) as 'countDif' 
FROM 
    (
     SELECT [User Email Address], COUNT(*) AS 'count' 
     FROM [DATABASE].[TABLE] 
     GROUP BY [User Email Address] 
    ) AS a 
    LEFT JOIN (
     SELECT [User Email Address], COUNT(*) AS 'count' 
     FROM [DATABASE].[TABLE] 
     WHERE [Transaction Date] >= '2011-08-07 00:00:00.000' 
     GROUP BY [User Email Address] 
    ) AS b ON a.[User Email Address] = b.[User Email Address] 

Answer 2

您可以在一個SELECT做到這兩點：

SELECT [User Email Address], 
    SUM(CASE WHEN [Transaction Date] >= '2011-08-07' THEN 1 ELSE 0 END) AS 'FilteredCount', 
    COUNT(*) AS 'TotalCount', 
    COUNT(*) 
     - SUM(CASE WHEN [Transaction Date] >= '2011-08-07' THEN 1 ELSE 0 END) 
     AS 'CountDifference' 
    FROM 
     [DATABASE].[TABLE] 
    GROUP BY [User Email Address] 

Answer 3

您可以使用此：

SELECT [User Email Address], 
     [Transaction Date], 
     count1.count - isnull(count2.count,0) as [countdDifference] 
FROM (SELECT [User Email Address], COUNT(*) AS 'count' 
     FROM [DATABASE].[TABLE] t1 
     GROUP BY t1.[User Email Address]) as count1 
LEFT JOIN (SELECT [User Email Address], COUNT(*) AS 'count' 
     FROM [DATABASE].[TABLE] t2 
     GROUP BY [User Email Address] 
     WHERE t2.[Transaction Date] >= '2011-08-07 00:00:00.000') as count2 
ON  count2.[User Email Address] = count1.[User Email Address] 
ORDER BY 3 DESC 

，因爲它是用一堆你也應該開始考慮1）不使用count（這幾乎是一個reserved word但不完全）; 2.）不要在字段名稱中使用空格; 3.）找到一個易於閱讀的方式來組織你的SQL :)

Answer 4

，這樣的事情呢？

SELECT 
    [User Email Address], 
    count(*) AS Total, 
    sum(CASE 
      WHEN [Transaction Date] >= '2011/08/07 00:00:00.000' THEN 1 
      ELSE 0 
     END) AS WithinDateRange, 
    count(*) 
     - sum(CASE 
        WHEN [Transaction Date] >= '2011/08/07 00:00:00.000' THEN 1 
        ELSE 0 
       END) AS Difference. 
FROM [DATABASE].[TABLE] 
GROUP BY [User Email Address]