关于MYSQL中每个用户取1条记录的三种写法(group by xxx)

select * from (select * from member_payment
                order by id desc) t group by member_id limit 10

select s.*
from (SELECT max(id) as id FROM `member_payment` group by `member_id` limit 10) t
left join `member_payment` as s on t.id=s.id

select * from `member_payment` where EXISTS (
 select `id` from (
  SELECT max(`id`) as id FROM `member_payment` group by `member_id` limit 10) t
 where t.`id`=`member_payment`.`id`
)