CREATE TABLE `user` ( id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, domain_id INT UNSIGNED NOT NULL, `user` VARCHAR(50) NOT NULL, password VARCHAR(32) NOT NULL, CONSTRAINT UNIQUE_EMAIL UNIQUE (domain_id,user), FOREIGN KEY (domain_id) REFERENCES domain(id) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE = InnoDB; CREATE TABLE `alias` ( id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, domain_id INT UNSIGNED NOT NULL, source VARCHAR(50) NOT NULL, destination VARCHAR(80) NOT NULL, FOREIGN KEY (domain_id) REFERENCES domain(id) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE = InnoDB;