mysql命令和groupby

问题描述

我有一个MySQL日志表.它具有以下字段:id，status_id，object_id，已创建，已修改.

I got a MySQL table of logs. It has the following fields: id, status_id, object_id, created, modified.

我想知道获取每个对象的最新状态的最佳方法是什么?

I'm wondering what's the best way to get the latest status for each object?

提前谢谢！

我最后的解决办法是做

My last solution was to do

SELECT id, status_id, object_id, created, modified 
FROM (SELECT * FROM logs ORDER BY created DESC) AS a
GROUP BY object_id

它可以工作，但是我认为有更好的方法可以做到这一点.有人在这里启发我们吗? :)

It works but I think there's a better way of doing this. Anyone care to enlighten us here at SO? :)

推荐答案

尝试一下，我没有检查过，但应该可以使用

try this, i've not checked this but should work

select object_id, status_id, MAX(created)
from ff
group by object_id having created = MAX(created)

关键是要使用having功能，它将为每个分组的对象选择最后一个项目

the key is to use having function which will choose last item for every grouped object

我添加了status_id来选择;)

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