问我应该添加1或计数来从DB获取预订号码吗？

EN

CREATE TABLE IF NOT EXISTS `omc_bookings` (
  `booking_id` int(11) NOT NULL AUTO_INCREMENT,
  `customer_id` int(11) NOT NULL,
  `course_id` int(11) NOT NULL,
  `date_enroll` date NOT NULL,
  PRIMARY KEY (`booking_id`)
) .... ;

    CREATE TABLE IF NOT EXISTS `omc_courses` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `date_id` int(10) DEFAULT NULL,
  `time` time NOT NULL,
  `course_name` varchar(255) DEFAULT NULL,
  `trainer_id` int(11) DEFAULT NULL,
  `desc` varchar(255) DEFAULT NULL,
  `capacity` int(11) DEFAULT NULL,
  `active` tinyint(1) NOT NULL DEFAULT '1',
  `order` int(11) DEFAULT NULL,
  `booked` int(5) DEFAULT NULL,
  `type` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ..... ;

  there are more like omc_date, omc_week etc.