如何用django rest框架从一个GET请求的查询参数中过滤出多个id？

Question 1

我正在尝试制作一个网络应用程序的API。我想做一个API请求，可以提交多个ID。

The django rest框架教程展示了如何从一个模型中获取所有记录。比如说 http://127.0.0.1:8000/snippets/ 将返回所有片段记录。该教程还展示了如何从一个模型中检索一个单项。 http://127.0.0.1:8000/snippets/2/ will return only snippet record with pk=2.

我希望能够申请多个记录，但不是所有记录。

我怎样才能改变这段代码，以便我可以请求多个片段？

snippets/urls.py

from django.conf.urls import url
from snippets import views
urlpatterns = [
    url(r'^snippets/$', views.snippet_list),
    url(r'^snippets/(?P<pk>[0-9]+)/$', views.snippet_detail),
snippets/views.py
def snippet_detail(request, *pk):
        snippet = Snippet.objects.filter(pk__in=pk)
    except Snippet.DoesNotExist:
        return HttpResponse(status=404)
    if request.method == 'GET':
        serializer = SnippetSerializer(snippet)
        return JSONResponse(serializer.data)

Question 2


          
           
            根据你的评论，你可以通过URL发送ID。
           
           127.0.0.1:8000/snippets/?ids=2,3,4
而在你看来
ids = request.GET.get('ids')  # u'2,3,4' <- this is unicode
ids = ids.split(',')  # [u'2',u'3',u'4'] <- this is a list of unicodes with ids values
然后你可以查询到Snippet模型。
Snippet.objects.filter(pk__in=ids)
如果url中的id之间有空格，这可能会给你带来一些问题。
127.0.0.1:8000/snippets/?ids=2, 3 , 4
你可能需要在执行查询之前处理每个值

Question 3


          
           
            
             
              
               我发现这个方法是可行的，按照Django REST框架的主要教程，然后是关于Django REST框架的文档。
               
                根据查询参数进行过滤
               
               ，稍作调整。  这允许一个网址从两个GET请求中返回数据：一个返回id与参数相符的对象，另一个返回所有对象，当没有提供参数时。
              
              
               
                http://127.0.0.1:8000/snippets/
               
               returns all snippets
              
              
               
                http://127.0.0.1:8000/snippets/?ids=2,3,7
               
               returns only snippets with id 2, 3 and 7
              
              
               snippets/urls.py
              
              from django.conf.urls import url
from snippets import views
urlpatterns = [
   .... (code for other urls here)
   url(r'^snippets/$', views.SnippetList.as_view(), name='snippet-list'),
snippets/views.py
from snippet.serializers import SnippetSerializer
class SnippetList(generics.ListCreateAPIView):
    serializer_class = SnippetSerializer
    def get_queryset(self):
        # Get URL parameter as a string, if exists 
        ids = self.request.query_params.get('ids', None)
        # Get snippets for ids if they exist
        if ids is not None:
            # Convert parameter string to list of integers
            ids = [ int(x) for x in ids.split(',') ]
            # Get objects for all parameter ids 
            queryset = Product.objects.filter(pk__in=ids)
        else:
            # Else no parameters, return all objects
            queryset = Product.objects.all()
        return queryset
片段/序列化器.py
class SnippetSerializer(serializers.ModelSerializer):
    class Meta:
        model = Snippet
        fields = ('url', 'id', 'title', 'code', 'linenos', 'language', 'style')

Question 4


          
           
            
             
              
               
                你可以使用
                
                 django-filter
                
                并将其设置为一个过滤器，避免在viewset上的get_queryset方法上过度使用。
               
               
                Given this request
               
               /api/snippets/?ids=1,2,3,4
然后写一个django过滤器集和方法
import django_filters
def filter_by_ids(queryset, name, value):
    values = value.split(',')
    return queryset.filter(id__in=values)
class SnippetFilterSet(django_filters.FilterSet):
   ids = django_filters.CharFilter(method=filter_by_ids)
   class Meta:
      model = Snippet
      fields = ['ids']
然后在你的ModelViewSet中
from rest_framework.viewsets import ModelViewSet
from app.snippets.models import Snippet
from app.snippets.filters import SnippetFilterSet # path to filterset
class SnippetView(ModelViewSet):
    queryset = Snippet.objects.all()
    serializer_class = SnippetSerializer
    filterset_class = SnippetFilterSet

Question 5


          
           
            
             
              
               
                
                 
                  
                   一个可能的方法是将pk(s)的清单作为GET请求数据发送，类似这样。
                  
                  
                   
                    GET request to "/snippets"
                   
                  
                  
                   
                    Request body: {"list_of_pk": [1,2,3...]}
                   
                  
                  
                   snippets/urls.py
                  
                  from django.conf.urls import url
from snippets import views
urlpatterns = [
    url(r'^snippets/$', views.snippet_list),
    url(r'^snippets/(?P<pk>[0-9]+)/$', views.snippet_detail),
snippets/views.py
def snippet_list(request):
    if request.method == 'GET':
        pk_list = request.GET.get('list_of_pk')
        if pk_list:
            snippets = Snippet.objects.filter(pk__in=pk_list)
        else:
            snippets = Snippet.objects.all()
        #the serialization...

Question 6


          
           
            
             
              
               
                
                 
                  
                   
                    
                     这就是我最后的选择。
                    
                    snippet/urls.py
                    
                    
                    from django.conf.urls import url
from snippets import views
urlpatterns = [
    url(r'^snippets/$', views.snippet_list),
    url(r'^snippets/(?P<pk>[0-9]+)/$', views.snippet_detail),
http://127.0.0.1:8000/snippets/?ids=2,3,4 is received by
snippet/views.py
from rest_framework.decorators import api_view
@api_view(['GET', 'POST'])    
def snippet_list(request):
    if request.method == 'GET':
        ids = request.query_params.get('ids')  # u'2,3,4' <- this is unicode
        ids = ids.split(',')
        snippets = Snippet.objects.filter(pk__in=ids)
        serializer = SnippetSerializer(snippet, many=True)
        return JSONResponse(serializer.data)

Question 7


          
           
            
             
              
               
                
                 
                  
                   
                    
                     
                      
                       While there is no definitive standard, most web frameworks allow multiple values to be associated with a single field (e.g. field1=value1&field1=value2&field2=value3).
                      
                      
                       Django也支持这一点。
要获得数值的列表，你可以使用。
                       
                        ids = request.GET.getlist('ids')
                       
                       。
更多的例子来自
                       
                        MultiValueDict
                       
                       文档。
                      
                          >>> d = MultiValueDict({'name': ['Adrian', 'Simon'], 'position': ['Developer']})
    >>> d['name']
    'Simon'
    >>> d.getlist('name')
    ['Adrian', 'Simon']
    >>> d.getlist('doesnotexist')
    >>> d.getlist('doesnotexist', ['Adrian', 'Simon'])
    ['Adrian', 'Simon']
    >>> d.get('lastname', 'nonexistent')
    'nonexistent'
    >>> d.setlist('lastname', ['Holovaty', 'Willison'])

Question 8


          
           
            
             
              
               
                
                 
                  
                   
                    
                     
                      
                       
                        django-filter文档给出了一个很好的例子，如何做到这一点。
                        
                         https://django-filter.readthedocs.io/en/stable/ref/filters.html?highlight=ids#baseinfilter
                        
                       
                       
                        对于你的情况。
                       
                       class SnippetFilterSet(BaseInFilter, NumberFilter):
class F(FilterSet):