数据信息:
用户登录日志表为user_id,log_id,session_id,visit_time
要求:
用sql查询近30天每天平均登录用户数量
代码展示:
select
avg(numUser) as averageUsers
from (
select
date_format(visit_time,'%Y-%m-%d') as visit_date,
count(distinct user_id) as numUser
from table
where
datediff(curdate(),visit_date)<=30
group by visit_date
);