day72 作业

视图层

class UserV4APIView(APIView):
    def get(self,request,*args,**kwargs):
        pk=kwargs.get('pk')
        if pk:
            user_obj=models.Car.objects.filter(is_delete=False,pk=pk).first()
            if not user_obj:
                return Response({
                    'status':1,
                    'msg':'pk error',
                },status=400)

            user_ser=serializers.CarModelSerializer(user_obj,many=False)#将从数据库查到的数据对象传进去，many默认为False，单查，返回的也是一个类实例化的对象

            return Response({
                'status':0,
                'msg':'ok',
                'results':user_ser.data
            })
        else:
            #将对象对外提供的字段，已经整个序列化过程封装，形成序列化类
            user_query=models.Car.objects.filter(is_delete=False).all()
            user_ser=serializers.CarModelSerializer(user_query,many=True)#将从数据库查到的query对象传进去，many为True，群查，返回的也是一个类实例化的对象
            return Response({
                'status': 0,
                'msg': 'ok',
                'results': user_ser.data
            })

    def post(self,request,*args,**kwargs):
        user_ser=serializers.CarModelSerializer(data=request.data)
        if user_ser.is_valid():
            #入库
            user_obj=user_ser.save()
            return Response({
                'status':0,
                'msg':'ok',
                'results':serializers.CarModelSerializer(user_obj).data#将入库得到的user对象重新序列化的数据返回给前台
            })
        else:
            return Response({
                'status': 1,
                'msg': user_ser.errors,
            })

序列化

class CarModelSerializer(serializers.ModelSerializer):
    re_brand = serializers.CharField(min_length=3, max_length=8, write_only=True)

    class Meta:
        model = models.Car
        fields = ('name', 'car_car', 'img', 'price', 'brand', 're_brand')
        extra_kwargs = {
            'name': {
                'min_length': 3,
                'max_length': 8,
                'error_messages': {
                    'min_length': '太短',
                    'max_length': '太长'
                }
            },
            'car_car': {'read_only': True, 'required': False},
            'img': {'read_only': True},
        }

    def validated_username(self, value):
        if 'SB' in value.lower():
            raise serializers.ValidationError('名字中不能含有SB')
        return value

    def validate(self, attrs):
        brand = attrs.get('brand')
        re_brand = attrs.pop('re_brand')
        if re_brand != brand:
            raise serializers.ValidationError({'re_brand': '两次输入不一致'})
        return attrs

模型层

class Car(models.Model):
    COLOR_CHOICE = (
        (0, '银色'),
        (1, '黑色'),
        (2, '红色'),
        (3, '灰色')
    )
    name = models.CharField(max_length=64, verbose_name='名字', blank=True)
    color = models.IntegerField(choices=COLOR_CHOICE, default=0, verbose_name='颜色')
    price = models.DecimalField(max_digits=8, decimal_places=2, verbose_name='价格')
    image = models.ImageField(upload_to='img', default='img/default.png', verbose_name='图片')
    brand = models.CharField(max_length=64, verbose_name='厂商')
    create_time = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')

    # 自定义序列化字段（插拔式，官方提倡使用）
    @property
    def car_car(self):
        return self.get_color_display()

    @property
    def img(self):
        from django.conf import settings
        return '%s%s%s' % (settings.BASE_URL, settings.MEDIA_URL, self.image)

    class Meta:
        verbose_name_plural = '汽车表'

    def __str__(self):
        return self.name