课程/api/ KeyError /2/ 'id‘

Question

我正在尝试RetrieveUpdateDeleteAPIView和my更新方法，每次更新课程对象时都会给出一个关键错误

更新方法工作

api_views.py

from rest_framework.generics import (
  RetrieveUpdateDestroyAPIView
)

from .serializers import CourseSerializer
from .models import Course

from django.core import cache

class CourseRetrieveUpdateDestroy(RetrieveUpdateDestroyAPIView):
  queryset = Course.objects.all()
  lookup_field = 'id'
  serializer_class = CourseSerializer

  def delete(self, request, *args, **kwargs):
    course_id = request.data.get('id')
    response = super().delete(request, *args, **kwargs)

    if response.status_code == 204:
      cache.delete('course_data_{}'.format(course_id))

    return response
  
  def update(self, request, *args, **kwargs):
    response = super().update(request, *args, **kwargs)

    if response.status_code == 200:
      from django.core.cache import cache
      course = response.data
      cache.set('course_data_{}'.format(course['id']), {
        'title' : course['title'],
        'description': course['description'],
        'featured': course['featured'],
      })
    
    return response

serializers.py

from rest_framework import serializers 

from .models import Course

class CourseSerializer(serializers.ModelSerializer):
  class Meta:
    model = Course
    fields = ('title', 'description', 'issued_at', )
  
  def to_representation(self, instance):
    data = super().to_representation(instance)
    data['time_passed'] = instance.time_passed()
    data['is_fresh'] = instance.is_fresh
    return data

urls.py

from django.urls import include, path

from django.conf import settings
from django.conf.urls.static import static

from .views import (
  CourseListView,
  CourseDetailView
)

from .api_views import (
  #CourseList,
  #CourseCreate,
  CourseRetrieveUpdateDestroy
)

app_name = 'courses'
urlpatterns = [
  path('', CourseListView.as_view(), name="course_list"),
  path('course/<int:pk>/', CourseDetailView.as_view(), name="course_detail"),

  #api-views
  path('api/course/<int:id>/', CourseRetrieveUpdateDestroy.as_view(), name="course_rud_api"),
  #path('api/list/', CourseList.as_view(), name="course_list_api"),
  #path('api/create/', CourseCreate.as_view(), name="course_create_api"),
] 

urlpatterns += static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)
urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

**每当我试图更新给定id的对象并点击enter时，都会返回一个KeyError at /course/api/course/2/(以id=2为例) 'id‘作为键。

为什么它给了我一个关键错误的字段，我还没有要求序列化在serializers.py？即使在将我重定向到错误页面之后，模型也会更新。如何解决此错误或避免此错误页？

Answer 1

您没有将id字段包含在序列化程序fields中，因此它不会出现在响应数据中。试试这个：

class CourseSerializer(serializers.ModelSerializer):
  class Meta:
    model = Course
    fields = ('id', 'title', 'description', 'issued_at', )

默认情况下，id将是只读字段.因此，用户在发送数据时不能覆盖它，但是它将在发送的响应数据中。