刪除重複的行，如果其中一列是相同的Sql服務器

Question

我有一個查詢鏈接表一個兩個表二，並獲得結果在表一最後的評論，這工作，但是當有多個記錄從表一個與例如，它再次說明，因此這裏的同一個ID就是一個例子

的查詢結果，

ID | Machine | description | createdtime | product code | work order | qty | comment | Reson 
     No 
129 |1 | A name | 2015-01-08 07:38:41.427 | A code | 12/14/0038 | 4000 | comment | Reason 
143 |1 | A name | 2015-01-08 13:30:39.403 | A code | 12/14/0038 | 4000 | comment | Reson 
130 |4 | A name | 2015-01-08 07:38:46.540 | A code | 12/14/0045 | 12000 | comment | Reason 
131 |5 | A name | 2015-01-08 07:38:50.243 | A code | 01/15/0001 | 4000 | comment | Reason 

正如你可以看到這裏有兩個記錄與機號1，一個在上午創建一個在中午後，但我只想要最新的一個出現，這是我的查詢。

SELECT  Qualitycontrol.ID, Qualitycontrol.MachineNo, Qualitycontrol.Description,  Qualitycontrol.CreatedTime, Qualitycontrol.ProductCode, Qualitycontrol.WorkOrder, 
       Qualitycontrol.Quantity, Qc.Comment, Qc.Reason 
FROM   Qualitycontrol 
OUTER APPLY (
    SELECT TOP 1 * 
FROM QualityControl_Comments 
WHERE Qualitycontrol.ID = QCUID 
ORDER BY Qualitycontrol.ID DESC -- whatevet defines order in QualityControl_Comments 
) AS Qc     
WHERE  (Qualitycontrol.CreatedTime BETWEEN CAST(GETDATE() AS DATE) AND DATEADD(DAY, 1,  CAST(GETDATE() AS DATE))) 
ORDER BY Qualitycontrol.MachineNo 

Answer 1

也許這樣的事情會奏效。

SELECT  Qualitycontrol.ID, Qualitycontrol.MachineNo, Qualitycontrol.Description,  Qualitycontrol.CreatedTime, Qualitycontrol.ProductCode, Qualitycontrol.WorkOrder, 
       Qualitycontrol.Quantity, Qc.Comment, Qc.Reason 
FROM   Qualitycontrol 
OUTER APPLY (
    SELECT TOP 1 * 
FROM QualityControl_Comments 
WHERE Qualitycontrol.ID = QualityControl_Comments.QCUID 
ORDER BY Qualitycontrol.ID DESC -- whatevet defines order in QualityControl_Comments 
) AS Qc     
INNER JOIN 
(
    SELECT Qualitycontrol.MachineNo, MAX(Qualitycontrol.ID) MID 
    FROM Qualitycontrol 
    GROUP BY Qualitycontrol.MachineNo 
) UNQ ON UNQ.MID = Qualitycontrol.ID 
WHERE  (Qualitycontrol.CreatedTime BETWEEN CAST(GETDATE() AS DATE) AND DATEADD(DAY, 1,  CAST(GETDATE() AS DATE))) 
ORDER BY Qualitycontrol.MachineNo 

Answer 2

您可以使用類似這樣的東西。 使用row_number你可以通過machnine id對數據進行分區並按日期對數字進行排序。比你可以只使用一個簡單的地方選擇你想要的東西

;WITH CTE 
as 
(
SELECT  Qualitycontrol.ID, Qualitycontrol.MachineNo, Qualitycontrol.Description,  Qualitycontrol.CreatedTime, Qualitycontrol.ProductCode, Qualitycontrol.WorkOrder, 
       Qualitycontrol.Quantity, Qc.Comment, Qc.Reason 
FROM   Qualitycontrol 
OUTER APPLY (
    SELECT TOP 1 * 
FROM QualityControl_Comments 
WHERE Qualitycontrol.ID = QCUID 

) AS Qc     
WHERE  (Qualitycontrol.CreatedTime BETWEEN CAST(GETDATE() AS DATE) AND DATEADD(DAY, 1,  CAST(GETDATE() AS DATE))) 

), CTE2 as 
(
select *, row_number() over(partition by MachineNo order by CreatedTime desc) as 'row_index' from cte 
) 
select * from cte2 
where row_index = 1 
order by MachineNo