Commit 9e23c3c5 authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

EmptyQuerySet classes can now be merged with normal querysets. 


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7765 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent 0e692fda

django/db/models/query.py

+10 −0
Original line number Diff line number Diff line
@@ -218,6 +218,8 @@ class QuerySet(object): 


    def __and__(self, other):

        self._merge_sanity_check(other)

        if isinstance(other, EmptyQuerySet):

            return other._clone()

        combined = self._clone()

        combined.query.combine(other.query, sql.AND)

        return combined
@@ -225,6 +227,8 @@ class QuerySet(object): 
    def __or__(self, other):

        self._merge_sanity_check(other)

        combined = self._clone()

        if isinstance(other, EmptyQuerySet):

            return combined

        combined.query.combine(other.query, sql.OR)

        return combined
@@ -705,6 +709,12 @@ class EmptyQuerySet(QuerySet): 
        super(EmptyQuerySet, self).__init__(model, query)

        self._result_cache = []



    def __and__(self, other):

        return self._clone()



    def __or__(self, other):

        return other._clone()



    def count(self):

        return 0

tests/regressiontests/queries/models.py

+10 −0
Original line number Diff line number Diff line
@@ -781,5 +781,15 @@ Bug #7107 -- this shouldn't create an infinite loop. 
>>> Valid.objects.all()

[]



Empty querysets can be merged with others.

>>> Note.objects.none() | Note.objects.all()

[<Note: n1>, <Note: n2>, <Note: n3>]

>>> Note.objects.all() | Note.objects.none()

[<Note: n1>, <Note: n2>, <Note: n3>]

>>> Note.objects.none() & Note.objects.all()

[]

>>> Note.objects.all() & Note.objects.none()

[]



"""}