《Mysql學習關于MYSQL中每個用戶取1條記錄的三種寫法(group by xxx)》要點：
本文介紹了Mysql學習關于MYSQL中每個用戶取1條記錄的三種寫法(group by xxx)，希望對您有用。如果有疑問，可以聯系我們。
今天以前的同學問我關于這方面的SQL語句,我特意記憶一下,畢竟這個也比較常見了
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,然后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
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
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
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