题解 | 网易云音乐推荐(网易校招笔试真题)

with t1 as (
	# 其关注的人喜欢的音乐
	select music_id from music_likes where user_id in ( select follower_id from `follow` where user_id = 1 )
),
t2 as (
	select music_id music_id_1 from music_likes where user_id = 1 
),
t3 as(
	select * from t1 left join t2 on t1.music_id = t2.music_id_1
),
t4 as (
select   id, music_name from t3 left join music on t3.music_id = music.id where music_id_1 is null
order by music.id  asc
)
select  music_name from t4 group by music_name,id order by id asc