Ordering by multiple fields

[ad-m]

Hello,

I am would like to ask about support ordering by multiple fields at once like: Entry.objects.filter(pub_date__year=2005).order_by('-pub_date', 'headline') I can see it fail:

class StaffCaseFilter(django_filters.FilterSet):
    class Meta:
        model = Case
        fields = ['status', 'client', 'name', 'created_on', 'last_send', 'last_action']
        order_by = (
            (('deadline', '-pk'), _('Dead-line')),
        )

Result:

Traceback (most recent call last):
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 111, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django/views/generic/base.py", line 69, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/braces/views/_access.py", line 64, in dispatch
    request, *args, **kwargs)
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django/views/generic/base.py", line 87, in dispatch
    return handler(request, *args, **kwargs)
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django_filters/views.py", line 61, in get
    self.object_list = self.filterset.qs
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django_filters/filterset.py", line 376, in qs
    qs = qs.order_by(*self.get_order_by(ordered_value))
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django/db/models/query.py", line 814, in order_by
    obj.query.add_ordering(*field_names)
  File "/home/adas/.virtualenvs/poradnia/local/lib/python2.7/site-packages/django/db/models/sql/query.py", line 1639, in add_ordering
    if not ORDER_PATTERN.match(item):
TypeError: expected string or buffer

Is there a easy way to obtain such a result?

Greetings,

[ad-m]

Oh, here is it:

class StaffCaseFilter(CrispyFilterMixin, django_filters.FilterSet):
    name = django_filters.CharFilter(label=_("Subject"), lookup_type='icontains')
    client = UserChoiceFilter(label=_("Client"))
    created_by = UserChoiceFilter(label=_("Created by"))
    created_on = django_filters.DateRangeFilter(label=_("Created on"))
    last_send = django_filters.DateRangeFilter(label=_("Last send"))
    last_action = django_filters.DateRangeFilter(label=_("Last action"))

    class Meta:
        model = Case
        fields = ['status', 'client', 'name', 'created_on', 'last_send', 'last_action']
        order_by = (
            ('default', _('Default')),
            ('deadline', _('Dead-line')),
            ('pk', _('ID')),
            ('client', _('Client')),
            ('created_on', _('Created on')),
            ('last_send', _('Last send')),
            ('last_action', _('Last action')),
        )

    def get_order_by(self, order_choice):
        if order_choice == 'default':
            return ['-deadline', 'status', '-last_send', '-last_action']
        return [order_choice]

[carltongibson]

👍

[sehmaschine]

why is it not possible to add multiple ordering values with the query string, similar to the OrderingFilter of DRF? See http://www.django-rest-framework.org/api-guide/filtering/#orderingfilter

Referring to the example above, I'd like to do:

?o=client,created_on

[blueyed]

@sehmaschine Just for reference: the new OrderingFilter in 0.15 should support this.

[sehmaschine]

@blueyed great, thanks.

[soldovskii]

I created OrderingFilterExtened for this purposes https://github.com/soldovskij/OrderingFilterExtened

Example:

class UserFilter(FilterSet):
    order_by = OrderingFilterExtened(
        fields_many=(
            ('full_name', ('first_name', 'last_name'), ('-first_name', '-last_name')),
        ),
        fields=(
            ('email', 'email'),  # model field name, parameter name
            ('last_login', 'last_login'),
            ('date_joined', 'date_joined'),
        ),
    )

class UserListAPIView(UsersPermissionQuerysetMixin, generics.ListAPIView):
    queryset = User.objects.all()
    permission_classes = (permissions.IsAuthenticated,)
    serializer_class = UserListSerializer
    pagination_class = LimitOffsetPagination
    filterset_class = UserFilter

Request example: api/v2/users/order_by=full_name or api/v2/users/order_by=-full_name

[oxan]

As the link above no longer works, another implementation of an extended OrderingFilter that supports ordering by multiple fields and also ordering by complex expressions:

class ExtendedOrderingFilter(OrderingFilter):
    def filter(self, qs, value):
        if value in EMPTY_VALUES:
            return qs

        ordering = []
        for param in value:
            fields = self.param_map[param.removeprefix('-')]
            if not isinstance(fields, tuple):
                fields = (fields, )
            for field in fields:
                if isinstance(field, str):
                    field = F(field)
                ordering.append(field.desc() if param.startswith('-') else field)

        return qs.order_by(*ordering)

Usage:

class UserFilter:
    sort = ExtendedOrderingFilter(fields=[
        ('email', 'email'),  # sort by regular field
        (Length('username'), 'username'),  # sort by expression
        (('first_name', 'last_name'), 'name'),   # sort by multiple fields
    ])

[fidansamet]

Thank you @oxan! Your fix has been helpful for me. Just one thing to note - when value includes "-" prefix, it considers both ordering values as descending. The same goes for ascending. So the direction of the ordering values depends on the param passed.

In my case, I have a fixed secondary ordering factor called "name". So when it orders by "email", I want to order it by "name" (ascending) as secondary ordering factor. Here is what worked for me:

class ExtendedOrderingFilter(filters.OrderingFilter):
    NAME_FIELD = "name"

    def filter(self, qs, value):
        if value in EMPTY_VALUES:
            return qs

        # If "name" is not primary ordering, order by it as secondary factor
        if self.NAME_FIELD not in value:
            value += [self.NAME_FIELD]

        return super().filter(qs, value)

class UserFilter(filters.FilterSet):
    ordering = ExtendedOrderingFilter(
        fields=(
            ("email", "email"),
            ("name", "name"),
        )
    )