題解 | #21年8月份練題總數(shù)#
21年8月份練題總數(shù)
http://www.fangfengwang8.cn/practice/b8f30b239b454ed490367b53ea95607d
select count(distinct device_id) as did_cnt, count(question_id) as question_cut from question_practice_detail where date like '2021-08%'
group by添加在聚合函數(shù)后面,日期還可以用like‘’表示。只寫了月份要08,怪不得答案不對(duì)哈哈哈哈哈