From 4a9f9cc521f09c60f56024eb6688e30ab86b998f Mon Sep 17 00:00:00 2001
From: Daniel Hillier <daniel.hillier@gmail.com>
Date: Wed, 14 Dec 2016 01:06:54 +1100
Subject: [PATCH] Fixed #27594 -- Fixed select_related() with reverse
self-referential OneToOneField.
Fix definition of `klass_info['from_parent']`. The relationship between
two models shouldn't be considered as being from a parent class if the
model classes are the same.
Thanks Tim for the review.
---
django/db/models/sql/compiler.py | 2 +-
tests/select_related_onetoone/models.py | 9 +++++++++
tests/select_related_onetoone/tests.py | 12 ++++++++++--
3 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index fed4353a3a..579e289c72 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -724,7 +724,7 @@ class SQLCompiler(object):
_, _, _, joins, _ = self.query.setup_joins([related_field_name], opts, root_alias)
alias = joins[-1]
- from_parent = issubclass(model, opts.model)
+ from_parent = issubclass(model, opts.model) and model is not opts.model
klass_info = {
'model': model,
'field': f,
diff --git a/tests/select_related_onetoone/models.py b/tests/select_related_onetoone/models.py
index 9af1b3f31b..773ae65125 100644
--- a/tests/select_related_onetoone/models.py
+++ b/tests/select_related_onetoone/models.py
@@ -102,3 +102,12 @@ class Child3(Child2):
class Child4(Child1):
value4 = models.IntegerField()
+
+
+class LinkedList(models.Model):
+ name = models.CharField(max_length=50)
+ previous_item = models.OneToOneField(
+ 'self', models.CASCADE,
+ related_name="next_item", blank=True,
+ null=True,
+ )
diff --git a/tests/select_related_onetoone/tests.py b/tests/select_related_onetoone/tests.py
index 2cb17a5ba9..81b6d0e8f4 100644
--- a/tests/select_related_onetoone/tests.py
+++ b/tests/select_related_onetoone/tests.py
@@ -6,8 +6,9 @@ from django.core.exceptions import FieldError
from django.test import TestCase
from .models import (
- AdvancedUserStat, Child1, Child2, Child3, Child4, Image, Parent1, Parent2,
- Product, StatDetails, User, UserProfile, UserStat, UserStatResult,
+ AdvancedUserStat, Child1, Child2, Child3, Child4, Image, LinkedList,
+ Parent1, Parent2, Product, StatDetails, User, UserProfile, UserStat,
+ UserStatResult,
)
@@ -212,6 +213,13 @@ class ReverseSelectRelatedTestCase(TestCase):
with self.assertNumQueries(1):
self.assertEqual(p.child1.child4.name1, 'n1')
+ def test_self_relation(self):
+ item1 = LinkedList.objects.create(name='item1')
+ LinkedList.objects.create(name='item2', previous_item=item1)
+ with self.assertNumQueries(1):
+ item1_db = LinkedList.objects.select_related('next_item').get(name='item1')
+ self.assertEqual(item1_db.next_item.name, 'item2')
+
class ReverseSelectRelatedValidationTests(TestCase):
"""