MySQL-带ORDER DESC的GROUP BY无法正常工作 [英] MySQL - GROUP BY with ORDER DESC not working

问题描述

我的以下查询有问题.

SELECT id, user_id, cloth_id FROM `items` GROUP BY user_id ORDER BY id desc LIMIT 3 

我想要具有group by的最新记录，但不知何故它显示了旧记录.

I want the latest records with group by but somehow its showing old records.

我也经历过 MySQL-按DESC排序的分组方式但未按预期工作.

I have also gone through MySQL - Group by with Order by DESC but not working as expected.

推荐答案

尝试一下:

SELECT i.id, i.user_id, i.cloth_id FROM
(
    SELECT max(id) as id, user_id FROM `items` GROUP BY user_id
) temp
LEFT JOIN `items` i on i.user_id = temp.user_id AND i.id = temp.id

在temp中，您会获得每个具有最新ID的用户.
在i中，您将获得该组合的cloth_id

in temp you get each user with the latest id.
in i you get the cloth_id for that combination

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