mysql group by 与 order by 同时使用order by 先执行处理方法

select t.*,count(*)from (select * from t_chat_record order by create_time desc limit 99999999) tGROUP BY receive_user_id,send_user_id

上面的子查询里的limit必不可少,且设置值非常大就可以查询所有数据