python - 类型对象 'Users' 没有属性 '_meta'

Question

我正在使用 cassandra 数据库和 django，我想使用 Django-rest-frame work 中的序列化程序序列化数据。

模型.py

import uuid
from cassandra.cqlengine import columns
from cassandra.cqlengine.models import Model

class Users(Model):
    read_repair_chance = 0.05 # optional - defaults to 0.1
    uid      = columns.UUID(primary_key=True, default=uuid.uuid4)
    age    = columns.Integer(index=True)
    phno    = columns.Text(required=True)
    uname     = columns.Text(required=True)

    class Meta:
        verbose_name_plural = "user_details"

序列化程序.py

from rest_framework import serializers
from user_details.models import Users

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = Users
        fields = ('uid','uname','age','phno')

View .py

from user_details.models import Users
from django.http import Http404
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from user_details.serializers import UserSerializer

class UserList(APIView):
    def get(self, request , format = None):
        users = Users.objects.all()
        serializer = UserSerializer(users,many = True)
        return Response(serializer.data)

错误

AttributeError at /show_details/
type object 'Users' has no attribute '_meta'
Request Method: GET
Request URL:    http://127.0.0.1:8000/show_details/
Django Version: 1.8.5
Exception Type: AttributeError
Exception Value:    
type object 'Users' has no attribute '_meta'

我应该进行哪些更改才能以序列化 json 格式显示数据。我已经尝试使用类似的带有 MySQL 数据的 serializer.py 文件来显示它，因为它工作正常。我的理解是当我调用 Users.objects.all() 时它会显示

>>> from user_details.models import Users
>>> Users.objects.all()
<cassandra.cqlengine.query.ModelQuerySet object at 0x045614F0>
>>>

那么如何检索数据并将其序列化。

Answer 1

我有同样的问题，但在进行以下修改后，它工作得很好。

serializers.py

而不是使用serializers.ModelSerializer，使用serializers.Serializer。

class UserSerializer(serializers.Serializer):
    uid = serializers.UUIDField()
    age = serializers.IntegerField()
    phno = serializers.CharField()
    uname = serializers.CharField()

    def create(self, validated_data):
        return Users.objects.create(validated_data)

    def update(self, instance, validated_data):
        instance.uid = validated_data.get('uid', instance.uid)
        instance.age = validated_data.get('age', instance.age)
        instance.phno = validated_data.get('phno', instance.phno)
        instance.uname = validated_data.get('uname', instance.uname)
        instance.save()
        return instance