如何用MySQL实现图形数据库？

Question

我想使用MySQL实现连接作为朋友的朋友

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),
);

真的那么难吗？