题解 | 网易云音乐推荐(网易校招笔试真题)

select music_name
from (select distinct b.music_id,c.music_name
from follow a join music_likes b on a.follower_id=b.user_id join music c on b.music_id=c.id
where a.user_id=1 and b.music_id not in (select music_id from music_likes where user_id =1))  as t1
order by music_id

关键点一：a.follower_id=b.user_id 以id=1用户关注的人喜欢的歌曲为主

关键点二：distinct 防止输出同一首歌曲