mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2024-12-23 01:25:58 +00:00
Code Issues 25 Releases Wiki Activity

Fixed #27499 -- Made Prefetches pickle without evaluating their QuerySet.

Browse Source
This commit is contained in:
Adam Chainz 2016-11-16 14:49:20 +00:00 committed by Tim Graham
parent 7dd315a46f
commit e044026dce
2 changed files with 19 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
django/db/models/query.py
View File

@ -1289,6 +1289,16 @@ class Prefetch(object):
self.queryset = queryset
self.to_attr = to_attr
def __getstate__(self):
obj_dict = self.__dict__.copy()
if self.queryset is not None:
# Prevent the QuerySet from being evaluated
obj_dict['queryset'] = self.queryset._clone(
_result_cache=[],
_prefetch_done=True,
)
return obj_dict
def add_prefix(self, prefix):
self.prefetch_through = LOOKUP_SEP.join([prefix, self.prefetch_through])
self.prefetch_to = LOOKUP_SEP.join([prefix, self.prefetch_to])

9
tests/queryset_pickle/tests.py
View File

@ -134,6 +134,15 @@ class PickleabilityTestCase(TestCase):
groups2 = pickle.loads(pickle.dumps(groups))
self.assertSequenceEqual(groups2.filter(id__gte=0), [g])
def test_pickle_prefetch_queryset_not_evaluated(self):
Group.objects.create(name='foo')
groups = Group.objects.prefetch_related(
models.Prefetch('event_set', queryset=Event.objects.order_by('id'))
)
list(groups) # evaluate QuerySet
with self.assertNumQueries(0):
pickle.loads(pickle.dumps(groups))
def test_pickle_prefetch_related_with_m2m_and_objects_deletion(self):
"""
#24831 -- Cached properties on ManyToOneRel created in QuerySet.delete()