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
round(sum(c.read_num) / sum(c.show_num),4) as fans_ctr
from a
join b using (author_id)
join c using (content_id)
where a.fans_id = c.fans_id
