TSQL计算最旧和最新行之间的差异

Question

我试图显示用户的分数在他们最旧的条目和最近的条目之间发生了多少变化。

给定数据：

Timestamp           |    Score    |  User 
2021-08-25 10:22:00 |    1300     |   A
2021-08-24 09:38:00 |    1451     |   A
2021-08-21 21:53:00 |    1381     |   B
2021-08-21 17:17:00 |    1129     |   B
2021-08-24 14:32:00 |    1278     |   A
2021-08-21 13:21:00 |    1401     |   B  

我想生成如下所示的输出：

User  | CurrentScore |    Change   |   Timestamp
  A   |     1300     |     -151    |   2021-08-25 10:22:00
  B   |     1381     |     -19     |   2021-08-21 21:53:00

我可以显示最旧的行和最新的行，但我很难将两者放在一个带有计算列的输出行中。任何帮助表示赞赏。

Answer 1

请检查这是否符合您的需求，请下次不要描述表格，而是提供 DDL+DML（创建表格和插入一些示例数据的查询）

DDL+DML : 应该由 OP 提供！

CREATE TABLE QQ(
    [Timestamp] DATETIME2,
    Score INT,
    [User] VARCHAR(10)
)

INSERT QQ([Timestamp],Score,[User]) VALUES
('2021-08-25 10:22:00',1300,'A'),
('2021-08-24 09:38:00',1451,'A'),
('2021-08-21 21:53:00',1381,'B'),
('2021-08-21 17:17:00',1129,'B'),
('2021-08-24 14:32:00',1278,'A'),
('2021-08-21 13:21:00',1401,'B')
GO

解决方案

;With MyCTE as (
    SELECT [user], Score, 
        [Timestamp] = FIRST_VALUE ([Timestamp]) OVER (PARTITION BY [user] ORDER BY [Timestamp] DESC), 
        FirstScore = FIRST_VALUE (Score) OVER (PARTITION BY [user] ORDER BY [Timestamp]), 
        CurrentScore = FIRST_VALUE (Score) OVER (PARTITION BY [user] ORDER BY [Timestamp] DESC)
    FROM QQ
) 
SELECT DISTINCT [user], CurrentScore, Change = CurrentScore - FirstScore, [Timestamp]
FROM MyCTE
GO

结果