问题
I'm trying to make a web app API. I want to make an API request where multiple ids can be submitted.
The django rest framework tutorial shows how to get all records from a model. For example http://127.0.0.1:8000/snippets/ will return all snippet records. The tutorial also shows how to retrieve a single item from a model. http://127.0.0.1:8000/snippets/2/ will return only snippet record with pk=2.
I'd like to be able to request multiple records, but not all records.
How could I change this code so I could request multiple snippets?
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):
try:
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)
回答1:
Based in your comment, you could send the ids via url:
127.0.0.1:8000/snippets/?ids=2,3,4
and in your view
...
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
Then you can query to Snippet model:
Snippet.objects.filter(pk__in=ids)
This could give you some problems if there's spaces between ids in url:
127.0.0.1:8000/snippets/?ids=2, 3 , 4
You could need process every value before perform a query
回答2:
I found this to work, following the Django REST Framework main tutorial and then documentation on Filtering against query parameters, adapting slightly. This allows a single url to return data from two GET requests: one returning objects whose ids match those given as a parameter, the other returning all objects, when no parameters are provided.
- 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/$', views.SnippetList.as_view(), name='snippet-list'),
....
]
snippets/views.py
....
from snippet.serializers import SnippetSerializer
....
class SnippetList(generics.ListCreateAPIView):
serializer_class = SnippetSerializer
def get_queryset(self):
# Get URL parameter as a string, if exists
ids = self.request.query_params.get('ids', None)
# Get snippets for ids if they exist
if ids is not None:
# Convert parameter string to list of integers
ids = [ int(x) for x in ids.split(',') ]
# Get objects for all parameter ids
queryset = Product.objects.filter(pk__in=ids)
else:
# Else no parameters, return all objects
queryset = Product.objects.all()
return queryset
snippets/serializers.py
....
class SnippetSerializer(serializers.ModelSerializer):
class Meta:
model = Snippet
fields = ('url', 'id', 'title', 'code', 'linenos', 'language', 'style')
回答3:
A possible way is to send the lis of pk(s) as GET request data, somthing like this:
GET request to "/snippets"
Request body: {"list_of_pk": [1,2,3...]}
And then:
snippets/urls.py
from django.conf.urls import url
from snippets import views
urlpatterns = [
url(r'^snippets/$', views.snippet_list),
url(r'^snippets/(?P<pk>[0-9]+)/$', views.snippet_detail),
]
snippets/views.py
def snippet_list(request):
if request.method == 'GET':
pk_list = request.GET.get('list_of_pk')
if pk_list:
snippets = Snippet.objects.filter(pk__in=pk_list)
else:
snippets = Snippet.objects.all()
#the serialization...
回答4:
Here's what I ended up going with:
No changes to snippet/urls.py
from django.conf.urls import url
from snippets import views
urlpatterns = [
url(r'^snippets/$', 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)
回答5:
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 also supports this.
To get list of values you can use: ids = request.GET.getlist('ids').
More examples from MultiValueDict docs:
>>> 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'])
回答6:
You can install django-filter which I believe comes with drf https://django-filter.readthedocs.io/en/master/
You can also set it up as a filter and avoid over riding the get_queryset method on the viewset
Given this request
/api/snippets/?ids=1,2,3,4
Then write a django filter set and method
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']
And then in your ModelViewSet
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
来源：https://stackoverflow.com/questions/32876275/how-to-filter-for-multiple-ids-from-a-query-param-on-a-get-request-with-django-r