Compare similarities between two result sets
问题 I am creating a music website where I would like users to be able to find users who like approximately the same artists as they. I have a 'like' table that has 2 columns 'id_user', 'id_artist'. Here is an example of how I would like it to work: User 1 likes: 1, 12 1, 13 1, 14 1, 26 1, 42 1, 44 User 2 likes: 2, 13 2, 14 2, 15 2, 26 2, 42 2, 56 Those 2 users have 4 artists in common. Is there a way, to compare those 2 results sets, to find the most similar people in the database? My first idea