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django - 尝试在序列化程序“HealthQuotationSerializer”上获取字段“members”的值时出现 AttributeError

问题描述

尝试序列化父子模型。这是我的模型：

class HealthQuotation(models.Model):
  quotation_no = models.CharField(max_length=50)
  insuredpersons = models.IntegerField()
  mobile_no = models.CharField(max_length=10)

  def __str__(self):
      return self.quotation_no

class HealthQuotationMember(models.Model):
   premium = models.FloatField(null=True)
   suminsured = models.FloatField()
   quotation = models.ForeignKey(HealthQuotation,on_delete=models.CASCADE)

   def __str__(self):
     return str(self.quotation)

这是我的序列化程序：

class HealthQuotationMemberSerializer(serializers.ModelSerializer):
  class Meta:
    model = HealthQuotationMember
    fields= "__all__"

class HealthQuotationSerializer(serializers.ModelSerializer):
   members = HealthQuotationMemberSerializer(many=True)

   class Meta:
      model = HealthQuotation
      fields = ['id','members']

在使用父序列化程序对父模型进行序列化时，Django 在尝试获取members序列化程序上的字段值时抛出错误“Got AttributeError” HealthQuotationSerializer。序列化程序字段可能命名不正确，并且与HealthQuotation实例上的任何属性或键都不匹配。原始异常文本为：'HealthQuotation ' 对象没有属性”。

标签： djangodjango-modelsdjango-rest-frameworkdjango-viewsdjango-serializer

解决方案

您有“ HealthQuotation ”作为父级和“ HealthQuotationMember ”作为子级。

现在，您决定从父级“HealthQuotation”
及其关联子级检索数据，这些子级将来自“HealthQuotationMember”，对吗？

为此，您可以使用 Django SerializerMethodField()：

您的 serializers.py 应如下所示：

class HealthQuotationMemberSerializer(serializers.ModelSerializer):
    class Meta:
        model = HealthQuotationMember
        fields= '__all__'

class HealthQuotationSerializer(serializers.ModelSerializer):

    members = serializers.SerializerMethodField() # I am using SerializerMethodField()

    class Meta:
        model = HealthQuotation
        fields = '__all__'

    def get_members(self, quotation):
        
        q = HealthQuotationMember.objects.filter(quotation = quotation)
        
        serializer = HealthQuotationMemberSerializer(q, many=True)
        return serializer.data

你的意见.py

class GetHealthQuotationList(ListAPIView):
    
    serializer_class = HealthQuotationSerializer
    queryset = HealthQuotation.objects.all()

你的 url.py 应该是：

path('get-health-quotation-list', GetHealthQuotationList.as_view()),

注意：如果您计划从child表中检索数据并找到其关联的parent，那么您的序列化程序应该可以不用many=True参数。

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