Django 反向关系序列化

Question

我有多对多关系，我想序列化反向关系。

这是我的模型：

class Nutrition(models.Model):
  name = models.CharField(max_length=30, blank=False)

  def __str__(self):
    return self.name

class Company(models.Model):
   name = models.CharField(max_length=30, blank=False)
   nutritions = models.ManyToManyField(Nutrition, blank=True, related_name="companyID")

   def __str__(self):
     return self.name

这是我的序列化程序：

class NutritionSerializer(serializers.ModelSerializer):
  companyID = CompanySerializer(read_only=True, many=True)

  class Meta:
    model = Nutrition
    fields=('id', 'name', 'companyID')

class CompanySerializer(serializers.ModelSerializer):
  nutritions_list = NutritionSerializer(source="nutritions", read_only=True, many=True)

  class Meta:
    model = Company
    fields = ('id', 'name', 'nutritions_list')

我收到一个错误：

NameError: name 'CompanySerializer' is not defined

Answer 1

您收到名称错误是因为您调用了 CompanySerializer:

class NutritionSerializer(serializers.ModelSerializer):
    companyID = CompanySerializer(read_only=True, many=True)
    ...

在定义它之前（下面几行）：

class CompanySerializer(serializers.ModelSerializer):
    ...

我建议做的是为 Company 添加另一个不包含 NutritionSerializer 的序列化程序，这样您就可以将它放在 NutritionSerializer 和 CompanySerializer 之上。这是它的样子：

class SimpleCompanySerializer(serializers.ModelSerializer):
    class Meta:
        model = Company
        fields = ('id', 'name')

class NutritionSerializer(serializers.ModelSerializer):
    company = SimpleCompanySerializer(read_only=True, many=True)

    class Meta:
        model = Nutrition
        fields=('id', 'name', 'company')

class CompanySerializer(serializers.ModelSerializer):
    nutritions_list = NutritionSerializer(source="nutritions", read_only=True, many=True)

    class Meta:
        model = Company
        fields = ('id', 'name', 'nutritions_list')

Django 反向关系序列化

Django reverse relations serialization

django

serialization

many-to-many

relational-database

django-rest-framework