Commit 5074c75a authored by Tim Graham's avatar Tim Graham
Browse files

Fixed #16856 - Added a way to clear select_related. 

Thanks Carl for the suggestion and David Cramer for the patch.
parent 616f3c4a

django/db/models/query.py

+5 −1
Original line number Diff line number Diff line
@@ -645,6 +645,8 @@ class QuerySet(object): 


        If fields are specified, they must be ForeignKey fields and only those

        related objects are included in the selection.



        If select_related(None) is called, the list is cleared.

        """

        if 'depth' in kwargs:

            warnings.warn('The "depth" keyword argument has been deprecated.\n'
@@ -654,7 +656,9 @@ class QuerySet(object): 
            raise TypeError('Unexpected keyword arguments to select_related: %s'

                    % (list(kwargs),))

        obj = self._clone()

        if fields:

        if fields == (None,):

            obj.query.select_related = False

        elif fields:

            if depth:

                raise TypeError('Cannot pass both "depth" and fields to select_related()')

            obj.query.add_select_related(fields)

docs/ref/models/querysets.txt

+7 −0
Original line number Diff line number Diff line
@@ -774,6 +774,13 @@ You can also refer to the reverse direction of a 
is defined. Instead of specifying the field name, use the :attr:`related_name

<django.db.models.ForeignKey.related_name>` for the field on the related object.



.. versionadded:: 1.6



If you need to clear the list of related fields added by past calls of

``select_related`` on a ``QuerySet``, you can pass ``None`` as a parameter::



   >>> without_relations = queryset.select_related(None)



.. deprecated:: 1.5

    The ``depth`` parameter to ``select_related()`` has been deprecated. You

    should replace it with the use of the ``(*fields)`` listing specific

docs/releases/1.6.txt

+5 −0
Original line number Diff line number Diff line
@@ -287,6 +287,11 @@ Minor features 
  helper for testing formset errors:

  :meth:`~django.test.SimpleTestCase.assertFormsetError`.



* The list of related fields added to a

  :class:`~django.db.models.query.QuerySet` by

  :meth:`~django.db.models.query.QuerySet.select_related` can be cleared using

  ``select_related(None)``.



Backwards incompatible changes in 1.6

=====================================

tests/select_related/tests.py

+4 −0
Original line number Diff line number Diff line
@@ -172,3 +172,7 @@ class SelectRelatedTests(TestCase): 
                Species.objects.select_related,

                'genus__family__order', depth=4

            )



    def test_none_clears_list(self):

        queryset = Species.objects.select_related('genus').select_related(None)

        self.assertEqual(queryset.query.select_related, False)