#21410: Error when trying to ignore reverse relationships with related_name
using
the "+"
----------------------------------------------+---------------------------
Reporter: troygrosfield | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.6
Severity: Normal | Keywords: related_name,
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
----------------------------------------------+---------------------------
The setup and failing test can be seen below. It's trying to use the
related name as an actual field. I didn't see this issue until I just
upgraded to django 1.6 yesterday. Am I missing something here?
{{{
# models.py
from django.db import models
from django.contrib.auth.models import User
class ModelA(models.Model):
created_user = models.ForeignKey(
User,
related_name='%(app_label)s_%(class)s_created_user+')
last_modified_user = models.ForeignKey(
User,
related_name='%(app_label)s_%(class)s_last_modified_user+')
}}}
{{{
# tests.py
from tests.models import ModelA
from django.contrib.auth.models import User
class Django16PrefetchBug(TestCase):
def test_prefetch_bug(self):
u1 = User.objects.get_or_create(username='hello1',
email='he...@world.com',
password='hi')[0]
u2 = User.objects.get_or_create(username='hello2',
email='he...@world.com',
password='hi')[0]
u3 = User.objects.get_or_create(username='hello3',
email='he...@world.com',
password='hi')[0]
m1 = ModelA.objects.create(created_user=u1,
last_modified_user=u2)
m2 = ModelA.objects.create(created_user=u2,
last_modified_user=u3)
m3 = ModelA.objects.create(created_user=u3,
last_modified_user=u2)
x = ModelA.objects.all().prefetch_related('created_user')
# The line below fails when evaluating the query.
y = list(x)
}}}
{{{
======================================================================
ERROR: test_prefetch_bug (tests.prefetch_bug.Django16PrefetchBug)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/troy/github/django-recurrence/tests/prefetch_bug.py", line
249, in test_prefetch_bug
y = list(x)
File "/path/to/site-packages/django/db/models/query.py", line 96, in
__iter__
self._fetch_all()
File "/path/to/site-packages/django/db/models/query.py", line 856, in
_fetch_all
self._prefetch_related_objects()
File "/path/to/site-packages/django/db/models/query.py", line 517, in
_prefetch_related_objects
prefetch_related_objects(self._result_cache,
self._prefetch_related_lookups)
File "/path/to/site-packages/django/db/models/query.py", line 1598, in
prefetch_related_objects
obj_list, additional_prl = prefetch_one_level(obj_list, prefetcher,
attr)
File "/path/to/site-packages/django/db/models/query.py", line 1697, in
prefetch_one_level
prefetcher.get_prefetch_queryset(instances)
File "/path/to/site-packages/django/db/models/fields/related.py", line
277, in get_prefetch_queryset
qs = self.get_queryset(instance=instances[0]).filter(**query)
File "/path/to/site-packages/django/db/models/query.py", line 590, in
filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/path/to/site-packages/django/db/models/query.py", line 608, in
_filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/path/to/site-packages/django/db/models/sql/query.py", line 1198,
in add_q
clause = self._add_q(where_part, used_aliases)
File "/path/to/site-packages/django/db/models/sql/query.py", line 1232,
in _add_q
current_negated=current_negated)
File "/path/to/site-packages/django/db/models/sql/query.py", line 1100,
in build_filter
allow_explicit_fk=True)
File "/path/to/site-packages/django/db/models/sql/query.py", line 1351,
in setup_joins
names, opts, allow_many, allow_explicit_fk)
File "/path/to/site-packages/django/db/models/sql/query.py", line 1274,
in names_to_path
"Choices are: %s" % (name, ", ".join(available)))
FieldError: Cannot resolve keyword u'tests_modela_created_user+' into
field. Choices are: date_joined, email, first_name, groups, id, is_active,
is_staff, is_superuser, last_login, last_name, password, user_permissions,
username
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/21410>
Django <https://code.djangoproject.com/>
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