關於MYSQL中每個用戶取1條記錄的三種寫法(group by xxx)

今天以前的同學問我關於這方面的SQL語句，我特意記憶一下，畢竟這個也比較常見了
復制代碼 代碼如下:
select * from (select * from member_payment
                order by id desc) t group by member_id limit 10

第一種是先排序，然後group，這樣的話自然可以取到最適合的一條數據。
缺點很明顯：Using temporary; Using filesort
復制代碼 代碼如下:
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

第二種是聯合查詢
復制代碼 代碼如下:
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`
)

第三種是子查詢
竊以為第二種效率最高