如何在此查詢中使用ROW_NUMBER？

Question

我是一個新的SQL Server，並具有以下查詢：

SELECT distinct top 10 ExecuteDate 
FROM [ClubEatc].[dbo].[GetOnlineBills] 
ORDER BY ExecuteDate DESC 

我應該用在查詢Row_Number，我怎麼可以編寫查詢？

謝謝大家。

Answer 1

如果你想有一個編號爲每一行和每一ExecuteDate應該是不同的：

WITH CTE AS 
(
    SELECT DISTINCT ExecuteDate FROM [ClubEatc].[dbo].[GetOnlineBills] 
) 
SELECT TOP 10 ExecuteDate, RN = ROW_NUMBER() OVER (ORDER BY ExecuteDate DESC) 
FROM CTE 
ORDER BY ExecuteDate DESC 

或GROUP BY：

SELECT TOP 10 ExecuteDate, RN = ROW_NUMBER() OVER (ORDER BY ExecuteDate DESC) 
FROM [ClubEatc].[dbo].[GetOnlineBills] 
GROUP BY ExecuteDate 
ORDER BY ExecuteDate DESC 

---

也許你想看到整個記錄，但只有每個ExecuteDate-Group的第一個。然後，這個查詢將工作：

WITH CTE AS 
(
    SELECT ExecuteDate, 
      RN_DESC = ROW_NUMBER() OVER (PARTITION BY ExecuteDate 
             ORDER BY ExecuteDate DESC) 
    FROM [ClubEatc].[dbo].[GetOnlineBills] 
) 
SELECT TOP 10 ExecuteDate 
FROM CTE 
WHERE RN_DESC = 1 
ORDER BY ExecuteDate DESC 

而是僅列ExecuteDate你可以列出所有。但是ExecuteDate是要分組的列，並且您沒有告訴我們要將哪個列用於每個組的排序，因此您希望查看每個ExecuteDate組的哪一行。所以目前這個查詢返回每個組的任意一行。將PARTITION BY ExecuteDate ORDER BY ExecuteDate DESC更改爲f.e. PARTITION BY ExecuteDate ORDER BY AnotherDateOrIdColumn DESC以獲得更有意義的結果。

Answer 2

你的意思是這樣的：

SELECT distinct top 10 ROW_NUMBER() OVER(ORDER BY ExecuteDate DESC), ExecuteDate 
FROM [ClubEatc].[dbo].[GetOnlineBills] 
ORDER BY ExecuteDate DESC 

Answer 3

您可以使用：

SELECT TOP 10 ExecuteDate 
FROM (
    SELECT ExecuteDate, 
      ROW_NUMBER() over (PARTITION BY ExecuteDate ORDER BY ExecuteDate DESC) as RN 
    FROM [GetOnlineBills] 
) as t 
WHERE RN = 1 
ORDER BY ExecuteDate DESC 

或者：

SELECT TOP 10 ExecuteDate 
FROM (
    SELECT TOP 1 WITH TIES ExecuteDate 
    FROM [GetOnlineBills] 
    ORDER BY ROW_NUMBER() over (PARTITION BY ExecuteDate ORDER BY ExecuteDate DESC) 
) as t 
ORDER BY ExecuteDate DESC