如果effectivedate与其他行相同，则获取最新记录

Question

我尝试抓取RowID不同的指定EffectiveDate的所有行。 但是，如果我们有多个具有相同EffectiveDate的行，我想抓取所有其他行以及使用InsertDateTime列插入的最后一条记录，以获取相同的日期。

以下是示例数据：

所以在这个例子中，我正在寻找的输出是：

我们正在使用ID＆＃39; s＆amp;＆amp; 3，因为他们的InsertDateTime小于行ID 4的InsertDateTime。

我采取的方法是在datediff之间执行EffectiveDate，如果second是0，那么它们是相同的值，我应该抓住最后一条记录。但是，由于我的join。

，这种方法并没有返回我的最后一条记录

我认为这会让这个问题变得复杂。

CREATE TABLE #MyTable
(
  ID int identity(1,1),
  RowID char(10),
  EffectiveDate DateTime,
  InsertDateTime DateTime
)

INSERT INTO #MyTable(RowID, EffectiveDate, InsertDatetime) VALUES 
('55555', '2017-06-01 00:00:00.000','2017-06-01 13:19:01.000')
INSERT INTO #MyTable(RowID, EffectiveDate, InsertDatetime) VALUES 
('55555', '2017-07-01 00:00:00.000','2017-06-01 13:34:01.000')
INSERT INTO #MyTable(RowID, EffectiveDate, InsertDatetime) VALUES 
('55555', '2017-07-01 00:00:00.000','2017-06-01 13:54:01.000')
INSERT INTO #MyTable(RowID, EffectiveDate, InsertDatetime) VALUES 
('55555', '2017-07-01 00:00:00.000','2017-06-01 13:56:01.000')

--The correct output it should return
--SELECT * FROM #MyTAble WHERE ID IN (1,4) order by 4

;WITH CTE AS
(
  SELECT ID, RowID, EffectiveDate, InsertDateTime,
  ROW_Number() OVER (Order by InsertDateTime) AS rn
  FROM #MyTable
),
CTE2 AS
(
  SELECT datediff(second, mc.EffectiveDate, mp.EffectiveDate) as Sec, mc.*, 
  mp.EffectiveDate as Date2 FROM CTE mc 
  JOIN CTE mp
  ON mc.rn = mp.rn - 1
 )
 SELECT *, CASE WHEN SEC = 0 THEN 1
 ELSE 0 END AS Valid
 FROM CTE2

Stack Exchange Fiddle

有关如何解决此问题的任何建议？

Answer 1

您可以通过将EffetiveDate添加到ROW_NUMBER分区并按RowID，EffectiveDate和InsertDateTime DESC排序来简化查询

;WITH CTE AS
(
  SELECT ID, RowID, EffectiveDate, InsertDateTime,
         ROW_Number() OVER (PARTITION BY RowID, EffectiveDate ORDER BY RowID, EffectiveDate, InsertDatetime DESC) AS rn
  FROM   #MyTable
)
SELECT *
FROM   CTE
WHERE  rn = 1
GO

ID | RowID      | EffectiveDate       | InsertDateTime      | rn
-: | :--------- | :------------------ | :------------------ | :-
 1 | 55555      | 01/06/2017 00:00:00 | 01/06/2017 13:19:01 | 1 
 4 | 55555      | 01/07/2017 00:00:00 | 01/06/2017 13:56:01 | 1 

dbfiddle here

Answer 2

我认为你过度复杂化了。只需按row_number和RowID分割EffectiveDate来电，按InsertDatetime订购并选择rn = 1行：

;WITH cte AS
(
  SELECT ID, RowID, EffectiveDate, InsertDateTime,
  ROW_NUMBER() OVER (PARTITION BY RowID, EffectiveDate ORDER BY InsertDatetime DESC) AS rn
  FROM #MyTable
)
SELECT ID, RowID, EffectiveDate, InsertDateTime
FROM   cte
WHERE  rn = 1

<强> Stack Exchange Fiddle