drf中 连表深度查询和ListSerializer类包括drf中Response二次封装

from rest_framework.response import Response
‘‘‘
return MyResponse(status=1,msg=‘error‘,results=[],token=‘a.b.c‘,http_status=400,exception=True)

Response模块的响应数据 data，最终数据results，Response模块需要向前台展示的一般有响应数据data（包括data里面的results），网络状态码status，是否异常exception

return Response(
     data={
        ‘status‘:1,
        ‘msg‘:‘error‘,
        ‘results‘:[],
        token:‘a.b.c‘
        },
        status=400,
        exception=True
‘‘‘
class APIResponse(Response):
    def __init__(self,status=0,msg=‘ok‘,results=None,http_status=None,
                 headers=None,exception=False,content_type=None,**kwargs):
        #将status、msg、results、kwargs格式化成data
        data={
            ‘status‘:status,
            ‘msg‘:msg,
        }
        #results只要不为空都是数据：False、0、‘‘都是数据==》条件不能写if results
        if results is not None:
            data[‘results‘]=results
        #将kwargs中额外的k-v数据添加data中  字典的update方法
        data.update(**kwargs)
        super().__init__(data=data,status=http_status,headers=headers,exception=exception,content_type=content_type)

#serializers.py
class BookModelSerializer(serializers.ModelSerializer):
  
    class Meta:
        list_serializer_class = BookListSerializer

        model = models.Book
        fields = [‘name‘, ‘price‘, ‘publish‘, ‘authors‘, ‘publish_info‘, ‘author_list‘]
        extra_kwargs = {
            ‘publish‘: {
                ‘write_only‘: True
            },
            ‘authors‘: {
                ‘write_only‘: True
            }
        }
        
#models.py
class Book(BaseModel):
    name = models.CharField(max_length=64)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    publish = models.ForeignKey(to=‘Publish‘, related_name=‘books‘, db_constraint=False, on_delete=models.DO_NOTHING, null=True)
    authors = models.ManyToManyField(to=‘Author‘, related_name=‘books‘, db_constraint=False)

    @property
    def publish_info(self):  #单个数据
        return {
            ‘name‘: self.publish.name,
            ‘address‘:self.publish.address,

        }

    @property
    def author_list(self):
        author_list_temp = []  # 存放所有作者格式化成数据的列表
        authors=self.authors.all()  #所有作者
        for author in authors:  #遍历处理所有作者
            author_dic={
                ‘name‘:author.name,
            }
            try: #有详情才处理详情信息
                author_dic[‘mobile‘]=author.detail.mobile
            except:
                author_dic[‘mobile‘]=‘无‘
            author_list_temp.append(author_dic)   #将处理过的数据添加到数据列表中
        return author_list_temp  #返回处理后的结果


    def __str__(self):
        return self.name

class BookAPIView(APIView):
    # 单查群查
    def get(self, request, *args, **kwargs):
        pk = kwargs.get(‘pk‘)
        if pk:
            book_obj = models.Book.objects.filter(is_delete=False, pk=pk).first()
            book_ser = serializers.BookModelSerializer(book_obj)
        else:
            book_query = models.Book.objects.filter(is_delete=False).all()
            book_ser = serializers.BookModelSerializer(book_query, many=True)

        return Response({
            ‘status‘: 0,
            ‘msg‘: ‘ok‘,
            ‘results‘: book_ser.data
        })

 # 单删群删
    def delete(self, request, *args, **kwargs):
        ‘‘‘
        单删：接口：/books/(pk)/ 数据：空
        群删：接口/books/ 数据：[pk1,...pkn]
        逻辑：修改is_delete字段，修改成功代表删除成功
        ‘‘‘
        pk = kwargs.get(‘pk‘)
        if pk:
            pks = [pk]  # 将单删格式化成群删一条
        else:
            pks = request.data  # 群删
        try:  # 数据如果有误，数据库执行会出错
            rows = models.Book.objects.filter(is_delete=False, pk__in=pks).update(is_delete=True)
        except:
            return APIResponse(1, ‘数据有误‘)
        if rows:
            return APIResponse(0, ‘删除成功‘)
        return APIResponse(1, ‘删除失败‘)

 # 单增群增
    def post(self, request, *args, **kwargs):
        ‘‘‘
        单增：接口：/books/数据：{...}
        群增：接口：/books/数据：[{...},...,{...}]
        逻辑：将数据给序列化类处理，数据的类型关系到many属性是否为True
        ‘‘‘
        if isinstance(request.data, dict):
            many = False
        elif isinstance(request.data, list):
            many = True
        else:
            return Response(data={‘detail‘: ‘数据有误‘}, status=400)

        book_ser = serializers.BookModelSerializer(data=request.data, many=many)
        book_ser.is_valid(raise_exception=True)
        book_obj_or_list = book_ser.save()
        return APIResponse(results=serializers.BookModelSerializer(book_obj_or_list, many=many).data)

class BookListSerializer(serializers.ListSerializer):
    # 自定义的群增群改辅助类，没有必要重写create方法
    def create(self, validated_data):
        return super().create(validated_data)

    def update(self, instance_list, validated_data_list):
        return [
            self.child.update(instance_list[index], attrs) for index, attrs in enumerate(validated_data_list)
        ]

# 整体单改群改
    def put(self, request, *args, **kwargs):
        """
        单改：接口：/books/(pk)/   数据：{...}
        群增：接口：/books/   数据：[{pk, ...}, ..., {pk, ...}]
        逻辑：将数据给系列化类处理，数据的类型关系到 many 属性是否为True
        """
        pk = kwargs.get(‘pk‘)
        if pk:  # 单改
            try:
                # 与增的区别在于，需要明确被修改的对象，交给序列化类
                book_instance = models.Book.objects.get(is_delete=False, pk=pk)
            except:
                return Response({‘detail‘: ‘pk error‘}, status=400)

            book_ser = serializers.BookModelSerializer(instance=book_instance, data=request.data)
            book_ser.is_valid(raise_exception=True)
            book_obj = book_ser.save()
            return APIResponse(results=serializers.BookModelSerializer(book_obj).data)
        else:  # 群改
            # 分析（重点）：
            # 1）数据是列表套字典，每个字典必须带pk，就是指定要修改的对象，如果有一条没带pk，整个数据有误
            # 2）如果pk对应的对象已被删除，或是对应的对象不存在，可以认为整个数据有误(建议)，可以认为将这些错误数据抛出即可
            request_data = request.data
            try:
                pks = []
                for dic in request_data:
                    pk = dic.pop(‘pk‘)  # 解决分析1，没有pk pop方法就会抛异常
                    pks.append(pk)

                book_query = models.Book.objects.filter(is_delete=False, pk__in=pks).all()
                if len(pks) != len(book_query):
                    raise Exception(‘pk对应的数据不存在‘)
            except Exception as e:
                return Response({‘detail‘: ‘%s‘ % e}, status=400)

            book_ser = serializers.BookModelSerializer(instance=book_query, data=request_data, many=True)
            book_ser.is_valid(raise_exception=True)
            book_list = book_ser.save()
            return APIResponse(results=serializers.BookModelSerializer(book_list, many=True).data)

# 局部单改群改
    def patch(self, request, *args, **kwargs):
        pk = kwargs.get(‘pk‘)
        if pk:  # 单改
            try:
                book_instance = models.Book.objects.get(is_delete=False, pk=pk)
            except:
                return Response({‘detail‘: ‘pk error‘}, status=400)
           
            book_ser = serializers.BookModelSerializer(instance=book_instance, data=request.data, partial=True, context={‘request‘: request})
            book_ser.is_valid(raise_exception=True)
            book_obj = book_ser.save()
            return APIResponse(results=serializers.BookModelSerializer(book_obj).data)
        else:  # 群改
            request_data = request.data
            try:
                pks = []
                for dic in request_data:
                    pk = dic.pop(‘pk‘)
                    pks.append(pk)

                book_query = models.Book.objects.filter(is_delete=False, pk__in=pks).all()
                if len(pks) != len(book_query):
                    raise Exception(‘pk对应的数据不存在‘)
            except Exception as e:
                return Response({‘detail‘: ‘%s‘ % e}, status=400)

            book_ser = serializers.BookModelSerializer(instance=book_query, data=request_data, many=True, partial=True)
            book_ser.is_valid(raise_exception=True)
            book_list = book_ser.save()
            return APIResponse(results=serializers.BookModelSerializer(book_list, many=True).data)