女士访问/ SQL查询

-3

我有一个表如下。需要查询来选择用户的最后一项活动。（这里不应该是相同的用户，单用户单排多个上市）女士访问/ SQL查询

+----------------+---------+--------------------+-----------------+------------+ 
|  Date  | BOT_ID |  Process  | LastModified | Status | 
+----------------+---------+--------------------+-----------------+------------+ 
| 17/09/26 00:00 | User 1 | Interaction record | 9/19/2017 10:50 | In Process | 
| 17/09/26 00:00 | User 2 | Single Assessed | 9/26/2017 12:00 | In process | 
| 17/09/26 00:00 | User 3 | Interaction record | 9/26/2017 11:35 | Completed | 
| 17/09/26 00:00 | User 4 | Metering   | 9/26/2017 11:50 | In proce | 
| 17/09/26 00:00 | User 1 | Move In   | 9/26/2017 11:50 | In process | 
| 17/09/26 00:00 | User 4 | Interaction record | 9/26/2017 11:58 | Completed | 
| 17/09/26 00:00 | User 5 | Direct Debit  | 9/26/2017 11:10 | Completed | 
| 17/09/26 00:00 | User 17 | latest    | 9/26/2017 0:15 | In Process | 
+----------------+---------+--------------------+-----------------+------------+

来源

2017-09-26 Subash Sukumari

问题是？ –

您对Access或MySQL有疑问吗？请只使用适当的标签。 – Barmar

在MySQL中它会是：https://stackoverflow.com/questions/7745609/sql-select-only-rows-with-max-value-on-a-column?rq=1也许它在Access中类似。 – Barmar

您可以使用：

Select Max([Last Modified]) As [Last Activity] 
From YourTable 
Where BOT_ID = "User 1"

要列出所有：

Select BOT_ID, Max([Last Modified]) As [Last Activity] 
From YourTable 
Group By BOT_ID

来源

2017-09-26 07:37:41 Gustav

但是，我需要列出每个用户的最后一项活动。 –

好吧，看到扩展的答案。 – Gustav

是的！这也是有效的。感谢您的宝贵努力.. –

你可以试试这个查询。子选择使用GROUP BY为每个用户计算max（lastmodified）。结果使用BOT_ID和上次修改日期的计算日期连接到主表。如果用户最后修改了两个相同的日期，则两行都将被返回：

SELECT A.* 
FROM YOURTABLE A 
INNER JOIN (SELECT BOT_ID, MAX(LASTMODIFIED) AS LAST_ACTIVITY 
      FROM YOURTABLE 
      GROUP BY BOT_ID) B ON A.BOT_ID=B.BOT_ID AND A.LASTMODIFIED = B.LAST_ACTIVITY

来源

2017-09-26 07:42:42 etsa

Ye ..工作。感谢esta。小修改，用Last（）代替max（） –

女士访问/ SQL查询

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