题解 | #计算用户8月每天的练题数量#
计算用户8月每天的练题数量
https://www.nowcoder.com/practice/847373e2fe8d47b4a2c294bdb5bda8b6
select day(date) as day, count(question_id) as question_cnt from question_practice_detail where year(date) = '2021' and month(date) = '8' group by date;
tmd,注意分组，说的是每天的，有聚合函数的时候一定要注意要不要分组！！！
