django - 如何在 django rest 框架中存储外键字段？

Question

我想创建一个订单，我正在尝试保存用户的牛奶订单。基本上，用户必须在下订单时选择他们想要的牛奶类型。在我看来我应该怎么做？我有点困惑。下面的代码什么也没给我，数据没有保存。我该怎么办，有人可以帮忙吗？

这是我的文件。
模型.py

MILK_CHOICES = (
('C', 'COW'),
('B', 'BUFFALO'),
('FC', 'FULL CREAM')
)

class MilkType(models.Model):
    type = models.CharField(max_length = 20, choices = MILK_CHOICES, default = MILK_CHOICES[0][1])
    quantity = models.PositiveIntegerField() # Stock
    description = models.CharField(max_length = 100)

class Order(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)
    milk_choice = models.ForeignKey(MilkType)
    qty = models.PositiveIntegerField(default = 1)

序列化程序.py

class UserSerializer(serializers.ModelSerializer):
    orders = serializers.PrimaryKeyRelatedField(many=True, queryset=Order.objects.all())

    class Meta:
        model = CustomUser
        fields = ('id', 'username', 'email')

class MilkTypeSerializer(serializers.ModelSerializer):

    class Meta:
        model = MilkType
        fields = ('id', 'type', 'quantity', 'description')

class OrderSerializer(serializers.ModelSerializer):
    user = serializers.ReadOnlyField(source = 'user.username')

    class Meta:
        model = Order
        fields = ('id', 'user', 'milk_choice', 'qty')

View .py

class OrderList(APIView):

    def get(self, request, format = None):
        orders = Order.objects.all()
        serializer = OrderSerializer(orders, many = True)
        return Response(serializer.data)

    def post(self, request, format = None):
        serializer = OrderSerializer(data = request.data)

        if serializer.is_valid():
            serializer.save(user = request.user)
            return Response(serializer.data, status = status.HTTP_201_CREATED)
        return Response(serializer.errors, status = status.HTTP_400_BAD_REQUEST)

Answer 1

在您的 OrderSerializer 中，为 milk_choice 定义序列化程序字段为 MilkTypeSerializer。

class OrderSerializer(serializers.ModelSerializer):
    user = serializers.ReadOnlyField(source = 'user.username')
    milk_choice = MilkTypeSerializer()

    class Meta:
        model = Order
        fields = ('id', 'user', 'milk_choice', 'qty')