[英]Select every min(Date) from group of similar rows?
这是表Posts
结构(还有其他对问题不重要的列):
Verb | Object | Date
我先按动词再按对象分组,以将所有相似的行分组,这是我当前的查询:
SELECT * FROM Posts GROUP BY Verb, Object
我需要知道每个组中最早的行的日期。 如何才能做到这一点?
要获取每个组中最早的日期,请尝试以下操作:
SELECT Verb, Object, MIN(`date`) AS min_date
FROM Posts
GROUP BY Verb, Object;
如果要获取每个组中日期最早的记录,请尝试以下操作:
然后重启MySQL服务器。
SELECT a.*
FROM Posts a
INNER JOIN (SELECT Verb, Object, MIN(`Date`) AS `Date`
FROM Posts
GROUP BY Verb, Object
) b
ON a.Verb = b.Verb
AND a.Object = b.Object
AND a.`Date` = b.`Date`;
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