Django 如何让序列化程序从模型中的依赖字段返回数据?
我正在使用Django 2和Python 3.7。我已经把这些模型安装好了。一个(合作社)依赖于另一个(合作社类型),使用多对多Django 如何让序列化程序从模型中的依赖字段返回数据?,django,python-3.x,django-models,serialization,django-serializer,Django,Python 3.x,Django Models,Serialization,Django Serializer,我正在使用Django 2和Python 3.7。我已经把这些模型安装好了。一个(合作社)依赖于另一个(合作社类型),使用多对多 class CoopTypeManager(models.Manager): def get_by_natural_key(self, name): return self.get_or_create(name=name)[0] class CoopType(models.Model): name = models.CharFie
class CoopTypeManager(models.Manager):
def get_by_natural_key(self, name):
return self.get_or_create(name=name)[0]
class CoopType(models.Model):
name = models.CharField(max_length=200, null=False, unique=True)
objects = CoopTypeManager()
class CoopManager(models.Manager):
# Look up by coop type
def get_by_type(self, type):
qset = Coop.objects.filter(type__name=type,
enabled=True)
return qset
# Look up coops by a partial name (case insensitive)
def find_by_name(self, partial_name):
queryset = Coop.objects.filter(name__icontains=partial_name, enabled=True)
print(queryset.query)
return queryset
# Meant to look up coops case-insensitively by part of a type
def contains_type(self, types_arr):
filter = Q(
*[('type__name__icontains', type) for type in types_arr],
_connector=Q.OR
)
queryset = Coop.objects.filter(filter,
enabled=True)
return queryset
class Coop(models.Model):
objects = CoopManager()
name = models.CharField(max_length=250, null=False)
types = models.ManyToManyField(CoopType)
address = AddressField(on_delete=models.CASCADE)
enabled = models.BooleanField(default=True, null=False)
phone = PhoneNumberField(null=True)
email = models.EmailField(null=True)
web_site = models.TextField()
我设置了以下序列化程序,旨在以JSON格式返回数据
class CoopTypeField(serializers.PrimaryKeyRelatedField):
queryset = CoopType.objects
def to_internal_value(self, data):
if type(data) == dict:
cooptype, created = CoopType.objects.get_or_create(**data)
# Replace the dict with the ID of the newly obtained object
data = cooptype.pk
return super().to_internal_value(data)
...
class CoopTypeSerializer(serializers.ModelSerializer):
class Meta:
model = CoopType
fields = ['id', 'name']
def create(self, validated_data):
"""
Create and return a new `CoopType` instance, given the validated data.
"""
return CoopType.objects.create(**validated_data)
def update(self, instance, validated_data):
"""
Update and return an existing `CoopType` instance, given the validated data.
"""
instance.name = validated_data.get('name', instance.name)
instance.save()
return instance
class CoopSerializer(serializers.ModelSerializer):
types = CoopTypeSerializer(many=True)
address = AddressTypeField()
class Meta:
model = Coop
fields = ['id', 'name', 'types', 'address', 'phone', 'enabled', 'email', 'web_site']
extra_kwargs = {
'phone': {
'required': False,
'allow_blank': True
}
}
def to_representation(self, instance):
rep = super().to_representation(instance)
rep['types'] = CoopTypeSerializer(instance.types).data
rep['address'] = AddressSerializer(instance.address).data
return rep
def create(self, validated_data):
#"""
#Create and return a new `Snippet` instance, given the validated data.
coop_types = validated_data.pop('types', {})
instance = super().create(validated_data)
for item in coop_types:
coop_type, _ = CoopType.objects.get_or_create(name=item['name']) #**item)
instance.types.add(coop_type)
return instance
但是,依赖字段“type”总是返回为“null”,尽管我可以看到数据库中存在有效数据。下面是运行curl请求时发生的情况
curl -v --header "Content-type: application/json" --request GET "http://127.0.0.1:8000/coops/?contains=resource"
[{"id":348,"name":"Garden Resources of Woodlawn (GRoW)","types":{"name":null}
如何编辑序列化程序以使其返回依赖类型的值?尝试删除
rep['types']=CoopTypeSerializer(instance.types)。数据
从到_表示(…)
方法
def to_representation(self, instance):
rep = super().to_representation(instance)
rep['types'] = CoopTypeSerializer(instance.types).data
rep['address'] = AddressSerializer(instance.address).data
return rep
看起来您不需要
来表示CoopSerializer
的方法,请尝试删除它。第一个解决方案只生成了一个空数组(“[]”),第二个解决方案生成了错误,'AttributeError:在尝试获取序列化程序CoopTypeSerializer
上的字段name
的值时,获取了AttributeError。。。原始异常文本为:“QuerySet”对象没有属性“name”。“更新了第二个选项。”
def to_representation(self, instance):
rep = super().to_representation(instance)
rep['types'] = CoopTypeSerializer(instance.types.all(), many=True).data
rep['address'] = AddressSerializer(instance.address).data
return rep