Question

我一直在尝试为Model创建一个序列化程序，其中一个字段是ManytoManyField，通过一个添加更多字段的Model。问题是中间序列化程序无法识别已添加字段。为什么我会做错？

这是我的代码：

models.py：

class Product(models.Model):
    name = models.CharField(max_length=30, unique=True)

class Movement(models.Model):
    date = models.DateTimeField(auto_now_add=True)
    products = models.ManyToManyField(Product, through='Movement_Product')

class Movement_Product(models.Model):
    movement = models.ForeignKey(Movement)
    product = models.ForeignKey(Product)
    amount = models.IntegerField()
    price = models.DecimalField(max_digits=9, decimal_places=2)

class Input(Movement):
    invoice_number = models.CharField(max_length=30, null=True)

serializers.py：

class ProductSerializer(serializers.ModelSerializer):

    class Meta:
        model = Product

class MovementProductSerializer(serializers.ModelSerializer):
    product = ProductSerializer()
    price = serializers.DecimalField(max_digits=9, decimal_places=2)
    amount = serializers.IntegerField()

    class Meta:
        model = Movement_Product

class InputSerializer(serializers.ModelSerializer):
    date = serializers.DateTimeField()
    products = MovementProductSerializer(many=True)

    class Meta:
        model = Input

views.py：

class InputViewSet(viewsets.ModelViewSet):
    queryset = Input.objects.order_by('-date')
    serializer_class = InputSerializer

urls.py：

router = routers.DefaultRouter()
router.register(r'input', views.InputViewSet)

urlpatterns = [
    url(r'^api/', include(router.urls)),
    url(r'^admin/', admin.site.urls),
]

我尝试在浏览器http://127.0.0.1:8000/api/input/中的URL路径上呈现InputSerializer时遇到的错误：

/ api / input /
的属性错误
尝试在序列化程序product上获取字段MovementProductSerializer的值时出现AttributeError。

序列化程序字段可能名称不正确，与Product实例上的任何属性或键都不匹配。

原始异常文本是：'Product'对象没有属性'product'。

Answer 1

试试这个：

class Movement(models.Model):
    date = models.DateTimeField(auto_now_add=True)
    products = models.ManyToManyField(Product, through='Movement_Product')

    @property
    def movement_product(self):
        return Movement_Product.objects.filter(movement=self)

class InputSerializer(serializers.ModelSerializer):
    date = serializers.DateTimeField()
    products = serializers.ListField(child=MovementProductSerializer(), source='movement_product')

    class Meta:
        model = Input

使用中间模型时，串行器上的Django属性错误

1 个答案: