题解 | #21年8月份练题总数#
21年8月份练题总数
https://www.nowcoder.com/practice/b8f30b239b454ed490367b53ea95607d
select count(distinct device_id) as did_cnt, count(question_id) as question_cnt from question_practice_detail where date like "2021-08%"
count(参数) 获得数量,其中distinct去重
as起别名
like “参数%”模糊匹配