题解 | 网易云音乐推荐(网易校招笔试真题)

select  
        music_name
from (
    select
            b.user_id,
            b.music_id
    from (
        select
                user_id,
                music_id
        from 
                music_likes as ml
        inner join (
            select
                follower_id as 1_follower_id
            from 
                    follow
            where 
                    user_id = 1
        )a
        on 
                ml.user_id = a.1_follower_id
    )b
    where 
            b.music_id not in (select music_id from music_likes where user_id=1)
)c
left join 
        music as m
on 
        c.music_id = m.id
group by 
        c.music_id,
        music_name
order by 
        c.music_id asc