【发布时间】：2019-12-25 21:50:50
【问题描述】：
我是在 StackOverflow 和 Django 上提问的新手，所以如果我犯了任何错误，我很抱歉。
到目前为止，我有一个带有 Django 和 REST 框架的基本 API。我只想返回添加到数据库中的最后一个对象，这可以使用最高 ID 完成。
这是models.py：
from django.db import models
class Humidity(models.Model):
value = models.FloatField()
class Temperature(models.Model):
value = models.FloatField()
isFarenheit = models.BooleanField()
我没有任何时间字段，但如果需要，我可以添加它们。
这是serializers.py：
class HumiditySerializer(serializers.ModelSerializer):
class Meta:
model = Humidity
fields = ('id', 'value')
class TemperatureSerializer(serializers.ModelSerializer):
class Meta:
model = Temperature
fields = ('id', 'value', 'isFarenheit')
这是views.py：
from django.shortcuts import render
from rest_framework import viewsets, permissions
from .models import Humidity, Temperature
from .serializers import HumiditySerializer, TemperatureSerializer
class HumidityView(viewsets.ModelViewSet):
queryset = Humidity.objects.order_by('-id')[0]
serializer_class = HumiditySerializer
class TemperatureView(viewsets.ModelViewSet):
queryset = Temperature.objects.order_by('-id')[0]
serializer_class = TemperatureSerializer
这是错误的回溯：
Traceback (most recent call last):
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\threading.py", line 917, in _bootstrap_inner
self.run()
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\threading.py", line 865, in run
self._target(*self._args, **self._kwargs)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\utils\autoreload.py", line 54, in wrapper
fn(*args, **kwargs)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\commands\runserver.py", line 117, in inner_run
self.check(display_num_errors=True)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\base.py", line 390, in check
include_deployment_checks=include_deployment_checks,
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\management\base.py", line 377, in _run_checks
return checks.run_checks(**kwargs)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\checks\registry.py", line 72, in run_checks
new_errors = check(app_configs=app_configs)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\checks\urls.py", line 13, in check_url_config
return check_resolver(resolver)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\core\checks\urls.py", line 23, in check_resolver
return check_method()
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\resolvers.py", line 398, in check
for pattern in self.url_patterns:
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\utils\functional.py", line 80, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\resolvers.py", line 579, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\utils\functional.py", line 80, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\resolvers.py", line 572, in urlconf_module
return import_module(self.urlconf_name)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\importlib\__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "C:\Users\usuario\Desktop\Subcarpetas\iot-sensors\iot-sensors-backend\iot-sensors-backend\iotSensors\iotSensors\urls.py", line 21, in <module>
path('', include('api.urls')),
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\django\urls\conf.py", line 34, in include
urlconf_module = import_module(urlconf_module)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\importlib\__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "C:\Users\usuario\Desktop\Subcarpetas\iot-sensors\iot-sensors-backend\iot-sensors-backend\iotSensors\api\urls.py", line 6, in <module>
router.register('humidity', views.HumidityView)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\rest_framework\routers.py", line 75, in register
basename = self.get_default_basename(viewset)
File "C:\Users\usuario\AppData\Local\Programs\Python\Python37-32\lib\site-packages\rest_framework\routers.py", line 162, in get_default_basename
return queryset.model._meta.object_name.lower()
AttributeError: 'Humidity' object has no attribute 'model'
仅当我将views.py 从Humidity.objects.all() 更改为Humidity.objects.order_by('-id')[0] 并且与温度相同时才会引发此错误。
如何返回最后保存的对象？
【问题讨论】：
-
model.objects.order_by('-id')[0] -
您想要哪个
model的最新输出？ -
在views.py中？它记录“AttributeError：'Humidity'对象没有属性'model'”
-
两种型号
-
为什么要将
id作为string表示Humidity模型？
标签： django django-rest-framework