diff options
| -rw-r--r-- | django/db/models/query.py | 6 | ||||
| -rw-r--r-- | tests/queries/test_qs_combinators.py | 5 |
2 files changed, 10 insertions, 1 deletions
diff --git a/django/db/models/query.py b/django/db/models/query.py index 50fe2cc29d..53238ed60b 100644 --- a/django/db/models/query.py +++ b/django/db/models/query.py @@ -995,7 +995,11 @@ class QuerySet: # If the query is an EmptyQuerySet, combine all nonempty querysets. if isinstance(self, EmptyQuerySet): qs = [q for q in other_qs if not isinstance(q, EmptyQuerySet)] - return qs[0]._combinator_query('union', *qs[1:], all=all) if qs else self + if not qs: + return self + if len(qs) == 1: + return qs[0] + return qs[0]._combinator_query('union', *qs[1:], all=all) return self._combinator_query('union', *other_qs, all=all) def intersection(self, *other_qs): diff --git a/tests/queries/test_qs_combinators.py b/tests/queries/test_qs_combinators.py index 5a10196da5..073f104a22 100644 --- a/tests/queries/test_qs_combinators.py +++ b/tests/queries/test_qs_combinators.py @@ -106,6 +106,11 @@ class QuerySetSetOperationTests(TestCase): self.assertEqual(len(qs2.union(qs2)), 0) self.assertEqual(len(qs3.union(qs3)), 0) + def test_empty_qs_union_with_ordered_qs(self): + qs1 = Number.objects.all().order_by('num') + qs2 = Number.objects.none().union(qs1).order_by('num') + self.assertEqual(list(qs1), list(qs2)) + def test_limits(self): qs1 = Number.objects.all() qs2 = Number.objects.all() |