Question

我有一个名为

的表

Ship(Date datetime,name varchar(50),Type char(1)).

在表中发货＆＃34;日期＆＃34;列是datetime数据类型。我希望在Date列（Datetime数据类型）中的分钟值更改时从ship表中选择行。为此，我使用了以下查询：

;WITH x AS
(
  SELECT Name, Date,Type, rn = ROW_NUMBER() OVER 
  (PARTITION BY Date ORDER BY Date desc)
  FROM Ship
)
SELECT * FROM x WHERE rn = 1

但是期望的输出不会到来。结果是：

Date                         Name     Type

2017-05-08 14:59:13.000      sumit      A
2017-05-08 14:59:23.000      sumit      B
2017-05-08 14:59:33.000      sumit      A
2017-05-08 15:00:05.000      Ajay       B
2017-05-08 15:00:13.000      Deep       G
2017-05-08 15:01:03.000     Suri        D   
2017-05-08 15:01:13.000     Faiz        E

在上面的输出中，当Date列的第二个值发生更改时，这些行也会出现。但是我希望在Date Column的分钟值发生变化时选择行。任何人都可以解决这个问题吗？

Answer 1

您可以在datediff minute子句

上使用partition by

;WITH x AS
(
 SELECT Name, Date,Type, rn = ROW_NUMBER() OVER 
 (PARTITION BY datediff(min,0,[Date]) ORDER BY Date desc)
 FROM Ship
)
SELECT * FROM x WHERE rn = 1

或者它是更短的版本

SELECT TOP 1 WITH TIES
      Name, Date,Type
FROM Ship
ORDER BY ROW_NUMBER() OVER  (PARTITION BY datediff(min,0,[Date]) ORDER BY [date] desc)

Answer 2

您可以在PARTITION BY中添加 DATEPART ，仅在分钟部分进行更改。

;WITH x AS
(
  SELECT Name, Date,Type, rn = ROW_NUMBER() OVER 
  (PARTITION BY DATEPART(N, Date) ORDER BY Date desc)
  FROM Ship
)
SELECT * FROM x WHERE rn = 1

参阅演示：http://rextester.com/YZW84894

如何在分钟值更改时选择行

2 个答案: