我正在为我居住的公寓写一个简单的数据库,其中包含人员,单位,单位类型(家庭与停车位)和单位持有人的列表(连接表,用于人与人之间的多对多关系)单位) - 一个人在租用停车位时可以是单位类型“房屋”的所有者。
这是我的模特:
class Person(models.Model):
first_name = models.CharField(max_length=30, null=False)
last_name = models.CharField(max_length=30, null=False)
phone = models.CharField(max_length=20)
email = models.EmailField(max_length=20)
class UnitType(models.Model):
description = models.CharField(max_length=30)
class Unit(models.Model):
unit_number = models.IntegerField(null=False, unique=True)
unit_type = models.ForeignKey(UnitType, null=False)
unitholders = models.ManyToManyField(Person, through='UnitHolder')
class UnitHolderType(models.Model):
description = models.CharField(max_length=30)
class UnitHolder(models.Model):
person = models.ForeignKey(Person)
unit = models.ForeignKey(Unit)
unitholder_type = models.ForeignKey(UnitHolderType)
这是我的观点:
class PersonViewSet(viewsets.ModelViewSet):
queryset = Person.objects.all()
serializer_class = PersonSerializer
class UnitHolderTypeViewSet(viewsets.ModelViewSet):
queryset = UnitHolderType.objects.all()
serializer_class = UnitHolderTypeSerializer
class UnitViewSet(viewsets.ModelViewSet):
queryset = Unit.objects.all()
serializer_class = UnitSerializer
class UnitHolderViewSet(viewsets.ModelViewSet):
queryset = UnitHolder.objects.all()
serializer_class = UnitHolderSerializer
class UnitTypeViewSet(viewsets.ModelViewSet):
queryset = UnitType.objects.all()
serializer_class = UnitTypeSerializer
这是我的序列化器:
class UnitSerializer(serializers.ModelSerializer):
unit_type = serializers.SlugRelatedField(
queryset=UnitType.objects.all(), slug_field='description'
)
class Meta:
model = Unit
fields = ('unit_number', 'unit_type', 'unitholders')
class UnitTypeSerializer(serializers.ModelSerializer):
class Meta:
model = UnitType
class PersonSerializer(serializers.ModelSerializer):
class Meta:
model = Person
class UnitHolderSerializer(serializers.ModelSerializer):
person = serializers.PrimaryKeyRelatedField(many=False, read_only=True)
unit = serializers.PrimaryKeyRelatedField(many=False, read_only=True)
class Meta:
model = UnitHolder
fields = ('person', 'unit', 'unitholder_type')
class UnitHolderTypeSerializer(serializers.ModelSerializer):
class Meta:
model = UnitHolderType
问题:
当我查询/ units端点时,如下所示:
u = requests.get('http://localhost:8000/units').json()
我的回答如下:
[{'unit_type': 'Home', 'unit_number': 614, 'unitholders': [1]}]
我想要的是这样的:
[
{
'unit_type': 'Home',
'unit_number': 614,
'unitholders': [
{
'id: 1,
'first_name': 'myfirstname',
'last_name': 'mylastname',
'unitholder_type': 'renter'
}
]
}
]
我很确定我的问题出现在我的UnitSerializer中,但我是DRF的新手并通过文档阅读但仍然无法弄明白。
答案 0 :(得分:4)
一个简单的解决方案是使用depth
选项:
class UnitSerializer(serializers.ModelSerializer):
unit_type = serializers.SlugRelatedField(
queryset=UnitType.objects.all(), slug_field='description'
)
class Meta:
model = Unit
fields = ('unit_number', 'unit_type', 'unitholders')
depth = 1
这会将所有嵌套关系序列化为1级深度。如果要对每个嵌套字段的序列化方式进行精确控制,可以明确列出其序列化程序:
class UnitSerializer(serializers.ModelSerializer):
unit_type = serializers.SlugRelatedField(
queryset=UnitType.objects.all(), slug_field='description'
)
unitholders = UnitHolderSerializer(many=True)
class Meta:
model = Unit
fields = ('unit_number', 'unit_type', 'unitholders')
另外作为旁注,您需要考虑将视图中的查询集修改为prefetch related objects,否则您将非常快速地破坏应用程序性能(使用类似django-debug-toolbar的内容来监视生成的查询非常方便):
class UnitViewSet(viewsets.ModelViewSet):
queryset = Unit.objects.all().select_related('unit_type').prefetch_related('unitholders')
serializer_class = UnitSerializer
答案 1 :(得分:0)
也许你必须这样做:
class UnitHolderViewSet(viewsets.ModelViewSet):
queryset = UnitHolder.objects.all()
unitholders = UnitHolderSerializer(read_only=True, many=True)