課程計劃排序代碼如下：

@Override

??public void orderByUpOrDown(String moveType, Long teachplanId) {

????Teachplan teachplan = teachplanMapper.selectById(teachplanId);

????Integer grade = teachplan.getGrade();

????if (moveType.equals("moveup") || moveType.equals("movedown") && (grade == 1 || grade == 2)) {

??????changePostition(teachplan, moveType);

????}

?????

??}

??private void changePostition(Teachplan teachplan, String moveType) {

//????定位上一個標題或下一個標題

????LambdaQueryWrapper<Teachplan> wrapper = new LambdaQueryWrapper<>();

????int offset = moveType.equals("moveup") ? -1 : 1;

????wrapper.eq(Teachplan::getOrderby, teachplan.getOrderby() + offset)

????????.eq(Teachplan::getCourseId, teachplan.getCourseId())

????????.eq(Teachplan::getGrade, teachplan.getGrade());

????Teachplan beforeTeachPlan = teachplanMapper.selectOne(wrapper);

????if (beforeTeachPlan == null) {

??????throw new XueChengPlusException("不能移動了");

????}

????beforeTeachPlan.setOrderby(teachplan.getOrderby());

????teachplanMapper.updateById(beforeTeachPlan);

//????定位當前標題

????Teachplan currentTachPlan = teachplanMapper.selectById(teachplan.getId());

????currentTachPlan.setOrderby(teachplan.getOrderby() + offset);

????teachplanMapper.updateById(currentTachPlan);

??}