题解 | #牛客直播转换率#

• 注意group by 要按course_id和course_name;
• group by 只用course_id的话，使用any_value。

select 
course_id,
course_name,
round(sum(if_sign)/sum(if_vw)*100,2) as rate
from  behavior_tb 
join course_tb  using(course_id)
group by course_id,course_name
order by course_id

select
    course_id,
    any_value(course_name),
    round(sum(if_sign)/sum(if_vw)*100,2) as sign_rate
from course_tb
left join behavior_tb using(course_id)
group by course_id
order by course_id