题解 | 计算用户8月每天的练题数量

 -- 时间限制2021年8月：WHERE date BETWEEN '2021-08-01' AND '2021-08-31'
-- 计算刷题数量：COUNT(question_id) AS question_cnt, 需要按照DAY(date)分组：GROUP BY DAY(date)
-- 返回DAY(date),question_cnt
SELECT
    DAY (date) AS day,
    COUNT(question_id) AS question_cnt
FROM
    question_practice_detail
WHERE
    date BETWEEN '2021-08-01' AND '2021-08-31'
GROUP BY
    DAY (date)