SET FOREIGN_KEY_CHECKS=0; CREATE TABLE staff ( staff_id TINYINT UNSIGNED NOT NULL AUTO_INCREMENT, store_id TINYINT UNSIGNED NOT NULL, PRIMARY KEY (staff_id), KEY idx_fk_store_id (store_id), CONSTRAINT fk_staff_store FOREIGN KEY (store_id) REFERENCES store (store_id) ON DELETE RESTRICT ON UPDATE CASCADE ) ENGINE=InnoDB; CREATE TABLE store ( store_id TINYINT UNSIGNED NOT NULL AUTO_INCREMENT, manager_staff_id TINYINT UNSIGNED NOT NULL, PRIMARY KEY (store_id), UNIQUE KEY idx_unique_manager (manager_staff_id), CONSTRAINT fk_store_staff FOREIGN KEY (manager_staff_id) REFERENCES staff (staff_id) ON DELETE RESTRICT ON UPDATE CASCADE ) ENGINE=InnoDB; SET FOREIGN_KEY_CHECKS=DEFAULT; LOCK TABLE staff WRITE; UNLOCK TABLES; DROP TABLES staff, store;