聊聊怎么用MySQL快速实现一个推荐算法-速讯

CREATE TABLE user_likes (    user_id INT NOT NULL,    book_id VARCHAR(10) NOT NULL,    PRIMARY KEY (user_id,book_id),    UNIQUE KEY book_id (book_id, user_id));CREATE TABLE user_likes_similar (    user_id INT NOT NULL,    liked_user_id INT NOT NULL,    rank INT NOT NULL,    KEY book_id (user_id, liked_user_id));

INSERT INTO user_likes VALUES (1, "A"), (1, "B"), (1, "C");INSERT INTO user_likes VALUES (2, "A"), (2, "B"), (2, "C"), (2,"D");INSERT INTO user_likes VALUES (3, "X"), (3, "Y"), (3, "C"), (3,"Z");INSERT INTO user_likes VALUES (4, "W"), (4, "Q"), (4, "C"), (4,"Z");

DELETE FROM user_likes_similar WHERE user_id = 1;

INSERT INTO user_likes_similarSELECT 1 AS user_id, similar.user_id AS liked_user_id, COUNT(*) AS rank    FROM user_likes target    JOIN user_likes similar ON target.book_id= similar.book_id AND target.user_id != similar.user_id    WHERE target.user_id = 1    GROUP BY similar.user_id ;

user_id, liked_user_id, rank1, 2, 21, 3, 11, 4, 1

SELECT similar.book_id, SUM(user_likes_similar.rank) AS total_rank    FROM user_likes_similar    JOIN user_likes similar ON user_likes_similar.liked_user_id = similar.user_id    LEFT JOIN user_likes target ON target.user_id = 1 AND target.book_id = similar.book_id    WHERE user_likes_similar.user_id = 1 AND target.book_id IS NULL    GROUP BY similar.book_id    ORDER BY total_rank desc    LIMIT 10;