text: USE `isucon2021_prior`;
  
  DROP TABLE IF EXISTS `users`;
  CREATE TABLE `users` (
    `id`         VARCHAR(255) PRIMARY KEY NOT NULL,
    `email`      VARCHAR(255) NOT NULL DEFAULT '',
    `nickname`   VARCHAR(120) NOT NULL DEFAULT '',
    `staff`      BOOLEAN NOT NULL DEFAULT false,
    `created_at` DATETIME(6) NOT NULL
  ) ENGINE=InnoDB DEFAULT CHARACTER SET=utf8mb4;
  
  DROP TABLE IF EXISTS `schedules`;
  CREATE TABLE `schedules` (
    `id`         VARCHAR(255) PRIMARY KEY NOT NULL,
    `title`      VARCHAR(255) NOT NULL DEFAULT '',
    `capacity`   INT UNSIGNED NOT NULL DEFAULT 0,
    `created_at` DATETIME(6) NOT NULL
  ) ENGINE=InnoDB DEFAULT CHARACTER SET=utf8mb4;
  
  DROP TABLE IF EXISTS `reservations`;
  CREATE TABLE `reservations` (
    `id`          VARCHAR(255) PRIMARY KEY NOT NULL,
    `schedule_id` VARCHAR(255) NOT NULL,
    `user_id`     VARCHAR(255) NOT NULL,
    `created_at`  DATETIME(6) NOT NULL
  ) ENGINE=InnoDB DEFAULT CHARACTER SET=utf8mb4;
  