Question

我有一个用django rest框架构建的API。这是代码：

models.py

class Ingredient(models.Model):
    barcode = models.CharField(max_length=13, primary_key=True)
    name = models.CharField(max_length=255)
    image = models.CharField(max_length=255)

class Recipe(models.Model):
    name = models.CharField(max_length=255)
    favorite = models.BooleanField()
    owner = models.ForeignKey(
        'auth.User', related_name="recipes", on_delete=models.CASCADE)

class Component(models.Model):
    ingredient = models.ForeignKey(Ingredient, on_delete=models.CASCADE)
    recipe = models.ForeignKey( Recipe, related_name='components', on_delete=models.CASCADE)
    quantity = models.FloatField()

serializers.py

class IngredientSerializer(serializers.ModelSerializer):
    name = serializers.CharField(read_only=True)
    image = serializers.CharField(read_only=True)

    class Meta:
        model = Ingredient
        fields = '__all__'

class ComponentSerializer(serializers.ModelSerializer):
    ingredient = serializers.PrimaryKeyRelatedField(queryset=Ingredient.objects.all())
    # ingredient = IngredientSerializer()
    class Meta:
        model = Component
        fields='__all__'

class RecipeSerializer(serializers.ModelSerializer):
    components = ComponentSerializer(many=True)
    owner = serializers.ReadOnlyField(source='owner.username')

    class Meta:
        model = Recipe
        fields = '__all__'

使用此状态的代码，我可以通过选择现有成分，现有配方和输入数量来创建新组件。但是，组件的序列化不是嵌套的：

    {
        "id": 8,
        "quantity": 123.0,
        "ingredient": "3218930313023"
    },

当我在ComponentSerializer类中将代码更改为ingredient = IngredientSerializer()时，表示按预期嵌套：

{
    "id": 9,
    "ingredient": {
        "barcode": "3218930313023",
        "name": "Crêpes L'Authentique",
        "image": "https://static.openfoodfacts.org/images/products/321/893/031/3023/front_fr.16.400.jpg",
    },
    "quantity": 123.0
}

但是当我尝试添加具有现有配方和现有成分的组件时，我收到错误400，并显示以下消息：

{
    "ingredient": {
        "barcode": [
            "ingredient with this barcode already exists."
        ]
    }
}

在第一个代码中添加组件时，获得相同行为的最佳方法是什么，但是在第二个代码中使用嵌套表示？

非常感谢你的帮助。

Django rest Framework：具有嵌套表示的PrimaryKeyRelatedField的行为

0 个答案: