CREATE TABLE `transaction_payees` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `transaction_id` int(10) unsigned NOT NULL,
  `user_id` int(10) unsigned DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `unique_user_for_transaction` (`transaction_id`, `user_id`),
  KEY `transaction_id` (`transaction_id`),
  KEY `user_id` (`user_id`),
  CONSTRAINT `transaction_payees_transaction_id` FOREIGN KEY (`transaction_id`) REFERENCES `transactions` (`id`),
  CONSTRAINT `transaction_payees_user_id` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;