text: CREATE TABLE `car` (
    `id` int NOT NULL AUTO_INCREMENT,
    `car_name` varchar(100) NOT NULL,
    CONSTRAINT car_pk PRIMARY KEY (`id`)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
  /
  CREATE UNIQUE INDEX  car_car_name_IDX USING BTREE ON `car` (car_name);
  /
  CREATE TABLE `error` (
    `id` int NOT NULL,
    `error_name` varchar(100) NOT NULL,
    CONSTRAINT error_pk PRIMARY KEY (id)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
  /
  CREATE UNIQUE INDEX error_error_name_IDX USING BTREE ON `error` (error_name);
  /
  INSERT INTO `error`
  (id, error_name)
  VALUES(-1, 'Database error');
  /
  INSERT INTO `error`
  (id, error_name)
  VALUES(-100, 'Some items with specified id is not found');
  /
  CREATE TABLE `usr` (
    `id` int NOT NULL AUTO_INCREMENT,
    `usr_name` varchar(100) NOT NULL,
    `usr_password` varchar(100) NOT NULL,
    CONSTRAINT usr_pk PRIMARY KEY (`id`)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
  /
  CREATE UNIQUE INDEX usr_usr_name_IDX USING BTREE ON `usr` (usr_name);
  /
  INSERT INTO `usr`
  (usr_name, usr_password)
  VALUES('user1', 'pass1');
  /
  INSERT INTO `usr`
  (usr_name, usr_password)
  VALUES('test', '1234567890');
  /
  CREATE TABLE `subscription` (
    `id` int NOT NULL AUTO_INCREMENT,
    `object_name` varchar(100) NOT NULL,
    `event_name` varchar(100) NOT NULL,
    `call_back` varchar(100) NOT NULL,
    CONSTRAINT usr_pk PRIMARY KEY (`id`)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
  /
  CREATE UNIQUE INDEX subs_obj_env_cb_idx USING BTREE ON `subscription` (object_name, event_name, call_back);
  /