题解 | #计算用户8月每天的练题数量#

# 常见的日期数据格式有两种：'yyyy-MM-dd' 和 'yyyyMMdd'
# 现在运营想要计算出2021年8月每天用户练习题目的数量
# select  if((year(date) = 2021 and month(date) = 8), day(date)) as day,
# count(question_id) as qusetion_cnt
# from question_practice_detail
# group by day;
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 day;