如何对消息日期DESC
进行此查询的[
SELECT
`u`.`username`, `u`.`id` AS `user_id`, `m`.`text`, `m`.`date`
FROM
`users` AS `u`
RIGHT JOIN(
SELECT
`from`, `to`, `text`, `date`
FROM
`messages`
WHERE
(`from` = 6 OR `to` = 6)
) AS `m` ON (IF(`m`.`from` = 6, `m`.`to`, `m`.`from`) = `u`.`id`)
GROUP BY
`u`.`id`
ORDER BY
`m`.`date` DESC
ORDER BY
在执行计划中几乎在GROUP BY
之后应用。 ORDER BY
仅影响返回的行的顺序,不影响返回的行。GROUP BY
子句使行组折叠;返回date
和text
列的值将来自该组中的
some