问如何使用新创建的id从父表自动将id插入子表

EN

CREATE TABLE IF NOT EXISTS `users` (
  `id_user` int(10) NOT NULL AUTO_INCREMENT,
  `name` varchar(25) NOT NULL DEFAULT '',
  PRIMARY KEY (`id_user`)
) ENGINE=InnoDB;

CREATE TABLE IF NOT EXISTS  `scores` (
 `user_id` INT( 10 ) NOT NULL DEFAULT  '0',
 `score` INT( 10 ) NOT NULL DEFAULT  '0',
PRIMARY KEY (`user_id`),
CONSTRAINT FOREIGN KEY ( `user_id` ) REFERENCES  `users` ( `id_user` )
    ON UPDATE CASCADE
) ENGINE = INNODB;

INSERT INTO users (name) VALUES ('i am');

UPDATE scores SET score = '10' WHERE user_id = '1';