Question

我有两个表，其中一个包含代码及其对应的显示名称，另一个表包含其结果和历史记录。

表1：

code    name

101 provide

102 modify

103 cease

104 cancel

表2：

   code      result      environment     date            time

101  Pass        test           16/08/2019  06:19:35

102  Pass        acc            15/08/2019  06:19:35

101  Pass        test           16/08/2019  07:19:35

103  Fail        test           14/08/2019  06:19:35

102  Pass        test           12/08/2019  10:19:35

104  Pass        acc            13/08/2019  20:19:35

我想选择特定于环境和代码的最新记录，并显示如下，

 code    name    result          date            time

101  provide     Pass           16/08/2019  06:19:35

102  modify      Pass           12/08/2019  10:19:35

103  cease       Fail           14/08/2019  06:19:35

我对MSSQL很陌生。

可以请你帮忙。

预先感谢

Answer 1

您的查询应该是这样的：

WITH cte AS (
    SELECT t2.code, t2.name , t2.result , t2.date, t2.time

        ROW_NUMBER() (PARTITION BY t2.environment, t2.code ORDER BY date desc, time desc) rn
    FROM table1 t1
    LEFT JOIN table2 t2 ON t1.code=t2.code
)

SELECT
    *
FROM cte
WHERE rn = 1;

Answer 2

以下查询将为您提供所需的结果：

SELECT * FROM 
    (
    SELECT  code, name , environment, result , [date], [time]
            ROW_NUMBER() OVER (PARTITION BY environment, Code ORDER BY [Date] desc, [Time] desc) rn
    FROM table1 t1
    LEFT JOIN table2 t2 ON t1.code=t2.code
    ) AS T 
Where T.rn = 1

如何通过比较2个表基于日期时间获取数据库中的最新记录

2 个答案: