SQL语句匹配时间的用法

题目： 现在运营想要了解2021年8月份所有练习过题目的总用户数和练习过题目的总次数，请取出相应结果

• 限定条件：2021年8月份，匹配date字段即可，匹配方法主要有三种：
  （1）like语法：date like "2021-08%"
  （2）year、month函数：year(date)='2021' and month(date)='08'；
  （3）date_format函数：date_format(date, '%Y-%m')='2021-08';
• 2：总用户数：count函数计数，因为用户有重复，所以需要distinct去重，即count(distinct device_id)
• 3：总次数：count(question_id)即可

使用like

select count(distinct device_id) as did_cut,
count(question_id) as question_cut
from question_practice_detail
where date like "2021-08%"

between匹配日期

select
    count(distinct device_id) as did_cnt,
    count(question_id) as question_cnt
from question_practice_detail
where 
date between '2021-08-01' and '2021-08-30'

month函数

select
    count(DISTINCT device_id) did_cnt,
    COUNT(device_id) question_cnt
FROM question_practice_detail
WHERE MONTH(date)=8

select count(distinct device_id) as did_cnt,
       count(result) as question_cnt
from question_practice_detail
where year(date)=2021 and month(date) = 8