题解 | #异常的邮件概率#
异常的邮件概率
https://www.nowcoder.com/practice/d6dd656483b545159d3aa89b4c26004e
select date, p from ( select id, send_id, round( ( sum(if (type = 'completed', 0, 1)) over ( partition by date order by date ) ) / ( count(type) over ( partition by date order by date ) ), 3 ) as p, date 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 ) ) a group by date,p