题解 | #异常的邮件概率#
异常的邮件概率
https://www.nowcoder.com/practice/d6dd656483b545159d3aa89b4c26004e
select date,
round(sum(case type
when 'completed'
then 0
else 1
end) / count(type), 3) p
from email
where send_id not in (
select id
from user
where is_blacklist = 1
)
and receive_id not in (
select id
from user
where is_blacklist = 1
)
group by date
order by date
