黑馬程序員Java項目企業(yè)級微服務(wù)實戰(zhàn)《學(xué)成在線》，基于SpringCloud、SpringCloudAlibaba技術(shù)棧開發(fā)，項目搭建到選課支付學(xué)習(xí)全通關(guān)

1.刪除課程計劃

（1）controller

@ApiOperation("課程計劃刪除")
@DeleteMapping("/teachplan/{teachplanId}")
public void deleteTeachplan(@PathVariable Long teachplanId) {
? ?teachplanService.deleteTeachplan(teachplanId);
}

（2）service

/**
*?實現(xiàn)課程刪除
*?@param?courseId
*/
public void?deleteTeachplan(Long courseId);

（3）service

@Override
public void deleteTeachplan(Long teachplanId) {
? ?if (teachplanId == null)
? ? ? ?XueChengPlusException.cast("課程計劃id為空");
? ?Teachplan teachplan = teachplanMapper.selectById(teachplanId);
? ?// 判斷當(dāng)前課程計劃是章還是節(jié)
? ?Integer grade = teachplan.getGrade();
? ?// 當(dāng)前課程計劃為章
? ?if (grade == 1) {
? ? ? ?// 查詢當(dāng)前課程計劃下是否有小節(jié)
? ? ? ?LambdaQueryWrapper<Teachplan> queryWrapper = new LambdaQueryWrapper<>();
? ? ? ?// select * from teachplan where parentid = {當(dāng)前章計劃id}
? ? ? ?queryWrapper.eq(Teachplan::getParentid, teachplanId);
? ? ? ?// 獲取一下查詢的條目數(shù)
? ? ? ?Integer count = teachplanMapper.selectCount(queryWrapper);
? ? ? ?// 如果當(dāng)前章下還有小節(jié)，則拋異常
? ? ? ?if (count > 0)
? ? ? ? ? ?XueChengPlusException.cast("課程計劃信息還有子級信息，無法操作");
? ? ? ?teachplanMapper.deleteById(teachplanId);
? ?} else {
? ? ? ?// 課程計劃為節(jié)
? ? ? ?teachplanMapper.deleteById(teachplanId);
? ? ? ?LambdaQueryWrapper<TeachplanMedia> queryWrapper = new LambdaQueryWrapper<>();
? ? ? ?queryWrapper.eq(TeachplanMedia::getTeachplanId, teachplanId);
? ? ? ?teachplanMediaMapper.delete(queryWrapper);
? ?}
}

2.課程計劃排序

（1）controller

@ApiOperation("上移")
@PostMapping("/teachplan/moveup/{teachplanId}")
public void moveUp(@PathVariable Long teachplanId){
? teachplanService.moveUp(teachplanId);
}

@ApiOperation("下移")
@PostMapping("/teachplan/movedown/{teachplanId}")
public void moveDown(@PathVariable Long teachplanId){
? ?teachplanService.moveDown(teachplanId);
}

（2）service

/**
?* 實現(xiàn)上移
?* @param courseId
?*/
public void moveUp(Long courseId);

/**
?* 實現(xiàn)下移
?* @param courseId
?*/
public void moveDown(Long courseId);
}

（3）serviceImpl

@Override
public void moveUp(Long teachplanId) {
? ?Teachplan teachplan = teachplanMapper.selectById(teachplanId);
? LambdaQueryWrapper<Teachplan> queryWrapper =new LambdaQueryWrapper<>();
? queryWrapper.eq(Teachplan::getCourseId,teachplan.getCourseId())
? ? ? ? ? ? ? .eq(Teachplan::getStatus,1)
? ? ? ? ? ? ? .eq(Teachplan::getParentid,teachplan.getParentid())
? ? ? ? ? ? ? .lt(Teachplan::getOrderby,teachplan.getOrderby())//大于當(dāng)前課程id的課程進(jìn)行排序
? ? ? ? ? ? ? .orderByDesc(Teachplan::getOrderby)//限制取的數(shù)據(jù)只有一條，防止取數(shù)據(jù)時遇到相同
? ? ? ? ? ? ? .last("limit 1");
? ?one(teachplan, queryWrapper);
}

@Override
public void moveDown(Long teachplanId) {
? ?Teachplan teachplan = teachplanMapper.selectById(teachplanId);
? ?LambdaQueryWrapper<Teachplan> queryWrapper =new LambdaQueryWrapper<>();
? ?queryWrapper.eq(Teachplan::getCourseId,teachplan.getCourseId())
? ? ? ? ? ?.eq(Teachplan::getStatus,1)
? ? ? ? ? ?.eq(Teachplan::getParentid,teachplan.getParentid())
? ? ? ? ? ?.gt(Teachplan::getOrderby,teachplan.getOrderby())//大于當(dāng)前課程id的課程進(jìn)行排序
? ? ? ? ? ?.orderByDesc(Teachplan::getOrderby)
? ? ? ? ? ?.last("limit 1");//限制取的數(shù)據(jù)只有一條，防止取數(shù)據(jù)時遇到相同
? ?one(teachplan, queryWrapper);
}
//由于看著太長了，直接把判斷封裝成一個類
private void one(Teachplan teachplan, LambdaQueryWrapper<Teachplan> queryWrapper) {
? ?Teachplan first = teachplanMapper.selectOne(queryWrapper);
? ?if (first == null){
? ? ? ?XueChengPlusException.cast("已經(jīng)在第一個了，無法進(jìn)行上升");
? ?}else {
? ? ? ?Integer orderby = teachplan.getOrderby();
? ? ? ?teachplan.setOrderby(first.getOrderby());//將所選課程放入目標(biāo)課程
? ? ? ?first.setOrderby(orderby); ? ? ?//將目標(biāo)課程放在所選課程
? ? ? ?teachplanMapper.updateById(teachplan);//更新數(shù)據(jù)
? ? ? ?teachplanMapper.updateById(first);
? ?}
}