题解 | #异常的邮件概率#

select date,
       round((select count(1)
        from email
        where date = e.date
          and type = 'no_completed'
          and 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))/(select count(1)
        from email
        where date = e.date
          and 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)
        ),3) p
from (select distinct date from email) e

一步到位，通俗易懂