如何用MySQL实现图形数据库？

Question

我想实现连接，使用MySQL

Answer 1

CREATE TABLE user (
id MEDIUMINT NOT NULL AUTO_INCREMENT, 
name VARCHAR(30) NOT NULL, 
email VARCHAR(60) NOT NULL, 
.... 
PRIMARY KEY (id) 
); 
CREATE TABLE friendof (
    user_a_id MEDIUMINT NOT NULL, 
    user_b_id MEDIUMINT NOT NULL, 
    PRIMARY KEY(user_a_id, user_b_id), 
    FOREIGN KEY(user_a_id) REFERENCES user(id), 
    FOREIGN KEY(user_b_id) REFERENCES user(id), 
    KEY reverseLookup (user_b_id), 
    KEY lookup (user_a_id), 
); 

是真的好难朋友的朋友？