日期！！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)=08
GROUP BY day
或者使用substr也很好用
select DAY(date) as day, count(question_id) as question_cnt from question_practice_detail where SUBSTR(date,1,7) = '2021-08' group by day