查询返回具有重复项的记录的1个实例 [英] Query to return 1 instance of a record with duplicates

问题描述

INFO：我正在使用Microsoft SQL。

标题很混乱，下面是我使用的表格示例：

INFO: I am working with Microsoft SQL.
Ok the title is confusing but here is an example of the table I'm working with:

ID    Value    Signal    Read    Firmware    Date           Time
5     123      656       444       217       3/30/2009     11:00:00 AM
5     123      421       333       217       3/30/2009     04:00:00 PM
5     123      111       666       217       3/30/2009     05:00:00 PM
9     321      231       551       216       3/30/2009     09:00:00 AM
9     321      599       887       216       3/30/2009     09:30:00 AM

希望查询返回：

ID    Value    Signal    Read    Firmware    Date           Time
5     123      111       666       217       3/30/2009     05:00:00 PM
9     321      599       887       216       3/30/2009     09:30:00 AM

我试过：

SELECT DISTINCT ID, Value, Signal, Read, Firmware, Date, Time FROM ....

但这会返回所有结果。我也试过SELECT TOP 1 ...但我不能让它工作。我知道这很简单，但我很困惑如何让它只显示一个唯一的行。

感谢您的帮助。

But this returns all of the results. I have also tried SELECT TOP 1... but I couldn't get that to work. I know this is simple, but I'm confused on how to get this to display only 1 single unique row.
Thanks for the help.

推荐答案

您尝试过吗？

SELECT id, value, MIN(Signal), MIN(Read), MIN(Firmware), MIN(Date), MIN(Time)
FROM
  ...
GROUP BY
  ID, Value

这篇关于查询返回具有重复项的记录的1个实例的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！