题解 | 邮件发送成功概率
邮件发送成功概率
https://www.nowcoder.com/practice/5b56f63467114d19ac9c33af86d8a74e
select
a.日期,
sum(case when a.枚举类型 = 'no_completed' then 1 else 0 end) / count(a.枚举类型) as 失败率
from
邮件表 a
left join
用户表 b on a.寄信人编号 = b.用户编号
left join
邮件表 c on a.编号 = c.编号 and b.用户编号 = c.收信人编号
where
b.是否为黑名单 = '0'
group by 1
order by 1 asc
