SELECT max(date) as lastdt,name,col1  FROM `consumption` group by name


在上面的查询中,col1max(date)name的值是否来自同一行?

最佳答案

MySQL允许非聚合列出现在查询的SELECT子句中。但是,这些列的值不确定。

如果要获取与具有最大col1值的记录相对应的date值,那么您将不得不执行其他联接:

SELECT t1.*
FROM `consumption` AS t1
JOIN (SELECT max(`date`) as lastdt, name
      FROM `consumption`
      group by name) AS t2
ON t1.name = t2.name AND t1.`date` = t2.lastdt

关于mysql - SQL-列是否始终对应?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/36922516/

10-11 02:49
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