题解 | 请写出计算粉丝ctr的sql语句
请写出计算粉丝ctr的sql语句
https://www.nowcoder.com/practice/853a6567cf524f63bab0879b8d0bfe62
select
sum(c.read_num) / sum(c.show_num) as fans_ctr
from
a
join b on a.author_id = b.author_id
join c on b.content_id = c.content_id
where
a.fans_id = c.fans_id
