Question

我需要在交易表中获得最早的上一次余额和每个人的最新实际余额。

例如，我得到了这个：

+-----------------+---------------+-----------------+---------------+
| dateTransaction | idPerson      | previousBalance | actualBalance |
+-----------------+---------------+-----------------+---------------+
| 01-11-2017      |      1        |       0         |    1000       |
| 02-11-2017      |      2        |       500       |    2000       |
| 03-11-2017      |      1        |       1000      |    1500       |
| 04-11-2017      |      2        |       2000      |    2500       |
+-----------------+---------------+-----------------+---------------+

所以我需要得到这样的东西：

+---------------+-----------------+---------------+
| idPerson      | previousBalance | actualBalance |
+---------------+-----------------+---------------+
|      1        |       0         |    1500       |
|      2        |       500       |    2500       |
+---------------+-----------------+---------------+

这是创建表格的脚本：

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Transaction]
(
    [numberTransaction] [int] NOT NULL,
    [dateTransaction] [datetime] NOT NULL,
    [idPerson] [decimal](20, 0) NOT NULL,
    [transactionAmount] [decimal](18, 3) NOT NULL,
    [previousBalance] [decimal](18, 3) NOT NULL,
    [actualBalance] [decimal](18, 3) NOT NULL,

    CONSTRAINT [PK_Transaction] 
        PRIMARY KEY CLUSTERED ([numberTransaction] ASC)
) ON [PRIMARY]
GO

提前致谢...

Answer 1

使用row_number() over()，如下所示：

SELECT *
FROM (
    SELECT t.*
    , row_number() over(partition by idPerson order by dateTransaction ASC) as is_oldest
    , row_number() over(partition by idPerson order by dateTransaction DESC) as is_newest
    FROM Transaction t
     ) d
WHERE ( is_oldest = 1 OR is_newest = 1 )
ORDER BY idPerson, dateTransaction ASC

在over clause中，partition by表示row_number()分配的数字将 PER idPerson 。然后order by在最早的日期（当分类为asending时）设置1或在最新的日期设置1（当按降序排序时）。

如何通过人 - SQL Server获取最新和不同列的最新记录？

1 个答案: