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(read_num) /sum(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 and a.fans_id = c.fans_id