题解 | #21年8月份练题总数#
21年8月份练题总数
http://www.nowcoder.com/practice/b8f30b239b454ed490367b53ea95607d
select count(distinct(device_id)) as did_cnt, count(question_id) as question_cnt from question_practice_detail where year(date) = 2021 and month(date) = 8;