text: CREATE TABLE IF NOT EXISTS users (
      id          INTEGER UNSIGNED PRIMARY KEY AUTO_INCREMENT,
      nickname    VARCHAR(128) NOT NULL,
      login_name  VARCHAR(128) NOT NULL,
      pass_hash   VARCHAR(128) NOT NULL,
      UNIQUE KEY login_name_uniq (login_name)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
  
  CREATE TABLE IF NOT EXISTS events (
      id          INTEGER UNSIGNED PRIMARY KEY AUTO_INCREMENT,
      title       VARCHAR(128)     NOT NULL,
      public_fg   TINYINT(1)       NOT NULL,
      closed_fg   TINYINT(1)       NOT NULL,
      price       INTEGER UNSIGNED NOT NULL
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
  
  CREATE TABLE IF NOT EXISTS sheets (
      id          INTEGER UNSIGNED PRIMARY KEY AUTO_INCREMENT,
      `rank`      ENUM('S', 'A', 'B', 'C'),
      num         INTEGER UNSIGNED NOT NULL,
      price       INTEGER UNSIGNED NOT NULL,
      UNIQUE KEY rank_num_uniq (`rank`, num)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
  
  CREATE TABLE IF NOT EXISTS reservations (
      id          INTEGER UNSIGNED PRIMARY KEY AUTO_INCREMENT,
      event_id    INTEGER UNSIGNED NOT NULL,
      sheet_id    INTEGER UNSIGNED NOT NULL,
      user_id     INTEGER UNSIGNED NOT NULL,
      reserved_at DATETIME         NOT NULL,
      canceled_at DATETIME         DEFAULT NULL,
      updated_at  DATETIME         NOT NULL,
      KEY event_id_idx (event_id)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
  
  CREATE TABLE IF NOT EXISTS administrators (
      id          INTEGER UNSIGNED PRIMARY KEY AUTO_INCREMENT,
      nickname    VARCHAR(128) NOT NULL,
      login_name  VARCHAR(128) NOT NULL,
      pass_hash   VARCHAR(128) NOT NULL,
      UNIQUE KEY login_name_uniq (login_name)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
  