题解 | #异常的邮件概率#简单题
异常的邮件概率
https://www.nowcoder.com/practice/d6dd656483b545159d3aa89b4c26004e
# 先查找出正常用户的id
with t1 as (
select id
from user
where is_blacklist = 0
)
# 找到正常用户发送给正常用户的邮件记录
select date, ROUND(sum(type='no_completed')/count(id), 3) as p
from email
where send_id in (select id from t1)
and receive_id in (select id from t1)
group by date
order by date;
