题解 | #网易云音乐推荐(网易校招笔试真题)#

• 参考答案

select music_name from music
where id in (
select music_id from music_likes
where user_id in(
    select follower_id from follow
    where user_id = 1)
and
    music_id not in (select 
    music_id from music_likes
     where user_id = 1)
)

• 答案解析

1. 找到user_id=1关注的人:

select follower_id from follow
    where user_id = 1

2. 找到他专注的人喜欢的音乐id,并且去除他喜欢的音乐id

select music_id from music_likes
where user_id in(
    select follower_id from follow
    where user_id = 1)
and
    music_id not in (select 
    music_id from music_likes
     where user_id = 1)

3.查询音乐名字,上面两步就是限制条件