题解 | 网易云音乐推荐(网易校招笔试真题)

关键：子查询的使用。

注意：select中为distinct时，order by中只能引用select中出现的字段，否则需要先使用子查询得到distinct字段和排序根据字段，再在外层select...order by...

select music_name
from(
    select distinct music_name,ml.music_id
    from follow f join music_likes ml on f.follower_id=ml.user_id
    join music m on ml.music_id=m.id
    where ml.music_id not in (
        select music_id
        from music_likes
        where user_id=1
    ) and f.user_id=1
) t
order by music_id