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 month(date)=8 and year(date)=2021 group by date
- 限定条件:2021年8月,写法有很多种,比如用year/month函数的
year(date)=2021 and month(date)=8
,比如用date_format函数的date_format(date, "%Y-%m")="202108"
- 每天:按天分组
group by date
- 题目数量:count(question_id)