DROP TRIGGER IF EXISTS trg_loading_pick_task_before_update;
DELIMITER $$
CREATE TRIGGER trg_loading_pick_task_before_update
BEFORE UPDATE ON fl_loading_pick_task
FOR EACH ROW
BEGIN
  IF OLD.task_status = 'COMPLETED' THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = '已完成PDA拣货任务不可修改';
  END IF;
  IF NEW.loading_plan_id <> OLD.loading_plan_id
     OR NOT (NEW.container_booking_id <=> OLD.container_booking_id)
     OR NOT (NEW.cabinet_no <=> OLD.cabinet_no) THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'PDA拣货任务稳定归属不可修改';
  END IF;
  IF NOT ((OLD.task_status = 'LOADING' AND NEW.task_status IN ('LOADING','COMPLETING'))
       OR (OLD.task_status = 'COMPLETING' AND NEW.task_status IN ('COMPLETING','COMPLETION_FAILED','COMPLETED'))
       OR (OLD.task_status = 'COMPLETION_FAILED' AND NEW.task_status = 'COMPLETING')) THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'PDA拣货任务状态流转非法';
  END IF;
END$$
DELIMITER ;