Is it possible to do a multiple id request?

[Nestor Manrique]

Hi! I'm kind of new working with rest and I wonder how I can support a multiple id request like '/albums/1,2,3,4,5'. I'm working with backbone and backbone-relational and it would be nice if I could retrieve multiple models at once. I've read the docs but haven't seen it around.

Thanks in advance!

Nestor

[Tom Christie]

Hi Nestor,

  Take a look through the filtering documentation...

django-rest-framework.org/api-guide/filtering.html

There's various examples of how to filter querysets, hopefully that'll put you on the right track to getting this particular use-case working.  If there's anything that isn't sufficiently explained, please do follow up on this thread.

All the best,

  Tom

[Scott White]

Hi Nestor,

I think something like the following view would work:

class SomeList(generics.ListAPIView):

    """

    API endpoint representing a list of somethings.

    """

    model = SomeModel

    serializer_class = SomeModelSerializer

    filter_fields = ('id',)

    def get_queryset(self):

        """

        Override get_queryset() to filter on multiple values for 'id'

        """

        id_value = self.request.QUERY_PARAMS.get('id', None)

        if id_value:

            id_list = id_value.split(',')

            queryset = queryset.filter(id__in=id_list)

        return queryset

I guess this will work even without 'id' in the filter_fields, but it's probably a good idea to include it. The URL would then be something like 'www.example.com/api/albums/?id=1,2,3,4,5'

Regards,

Scott

[Scott White]

Oops, this:

queryset = queryset.filter(id__in=id_list)

should be this:

queryset = SomeModel.objects.filter(id__in=id_list)

Google groups, y u no let me edit post?

[Nestor Manrique]

Thank you very much both of you, it worked perfectly!

Nestor

[Miguel Fiandor Gutiérrez]

I am having big problems here to make it work. It is a very similar case, but my filter field is a foreign field.

I am following up Scott's example, and another approach defining a FilterSet, but none of them works. 

It returns an exception: EmptyResultSet, which is kind of funny because the queryset is returned perfectly.

--------------------------------

1st approach

class PublicAdministrationIndicatorPaginated(CacheResponseMixin, CustomReadOnlyModelPaginatedViewSet):

    """

    API endpoint that allows to: view, filter, search and order.

    Formats allowed: json, api, csv, xml

    """

    queryset = PublicAdministrationIndicator.objects.all()

    serializer_class = PublicAdministrationIndicatorSerializer

    renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES + [PaginatedCSVRenderer, XMLRenderer]

    filter_backends = (filters.DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter,)

    filter_fields = ('public_administration', 'public_administration__ine_code', 'public_administration__size', 'public_administration__type', 'public_administration__territory', 'indicator', 'indicator__year', 'has_value')

    search_fields = ('public_administration', 'indicator')

    ordering_fields = ('public_administration', 'indicator', 'absolute_cons')

    def get_queryset(self):

        """

        Override get_queryset() to filter on multiple values for 'PublicAdministrationIndicator_indicator__year'

        """

        queryset = PublicAdministrationIndicator.objects.all()

        years_value = self.request.QUERY_PARAMS.get('indicator__year', None)

        if years_value:

            year_list = years_value.split(',')

            print year_list

            queryset = PublicAdministrationIndicator.objects.filter(indicator__year__in=year_list)

            print queryset.count()  # actually prints a length of queryset of 525917

        return queryset

------------------------

2nd approach:

class PublicAdministrationIndicatorFilter(django_filters.FilterSet):

    indicator__year = django_filters.ModelMultipleChoiceFilter(

            name="indicator_id__year",

            queryset=PublicAdministrationIndicator.objects.all(),

            lookup_type='in'

    )

    class Meta:

        model = PublicAdministrationIndicator

        fields = ('indicator', 'indicator__year',)

class PublicAdministrationIndicatorPaginated(CacheResponseMixin, CustomReadOnlyModelPaginatedViewSet):

    """

    API endpoint that allows to: view, filter, search and order.

    Formats allowed: json, api, csv, xml

    """

    queryset = PublicAdministrationIndicator.objects.all()

    serializer_class = PublicAdministrationIndicatorSerializer

    renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES + [PaginatedCSVRenderer, XMLRenderer]

    filter_backends = (filters.DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter,)

    filter_class = PublicAdministrationIndicatorFilter

    search_fields = ('public_administration', 'indicator')

    ordering_fields = ('public_administration', 'indicator', 'absolute_cons')

Please, I need to know why is raising that error when the queryset seems to be well computed, and all results are on it.

Cheers,

Miguel

[Miguel Fiandor Gutiérrez]

I hate when I spend hours with a problem and right after asking for help I find out what is wrong...

Anyway, I found out that in the first approach that I wrote, the one of Scott's code example, it was just a matter of removing the line: 

filter_fields = (.....) 

Since, seems to not get alone well with the queryset definition that comes after. Just removing it, it worked like a charm :-)