题解 | #异常的邮件概率#
异常的邮件概率
http://www.nowcoder.com/practice/d6dd656483b545159d3aa89b4c26004e
select date,
round(avg(case when type="no_completed" then 1 else 0 end),3) as p
from email
where send_id in (select id from user where is_blacklist=0)
and receive_id in (select id from user where is_blacklist=0)
group by date
order by date;
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