From f5184ae5dc370892d1b96576f68962b2c1c6c979 Mon Sep 17 00:00:00 2001
From: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Date: Wed, 25 Oct 2017 21:52:38 +0200
Subject: [PATCH] [2.0.x] Fixed #28689 -- Fixed unquoted table names in
 Subquery SQL when using OuterRef.

Regression in f48bc7c3dbd204eefb3c19016b1e4906ac26bee3.

Backport of 81e357a7e19f35235cc998459a10213532727d4e from master
---
 django/db/models/expressions.py | 2 +-
 docs/releases/1.11.7.txt        | 3 +++
 tests/expressions/models.py     | 1 +
 tests/expressions/tests.py      | 5 +++++
 4 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index bd649736231..edc3c4fd3e1 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -997,7 +997,7 @@ class Subquery(Expression):
                 )
                 # Add table alias to the parent query's aliases to prevent
                 # quoting.
-                if hasattr(resolved, 'alias'):
+                if hasattr(resolved, 'alias') and resolved.alias != resolved.target.model._meta.db_table:
                     clone.queryset.query.external_aliases.add(resolved.alias)
                 return resolved
             return child
diff --git a/docs/releases/1.11.7.txt b/docs/releases/1.11.7.txt
index fe2cf2e300f..81334533e92 100644
--- a/docs/releases/1.11.7.txt
+++ b/docs/releases/1.11.7.txt
@@ -16,3 +16,6 @@ Bugfixes
 
 * Made ``QuerySet.reverse()`` affect ``nulls_first`` and ``nulls_last``
   (:ticket:`28722`).
+
+* Fixed unquoted table names in ``Subquery`` SQL when using ``OuterRef``
+  (:ticket:`28689`).
diff --git a/tests/expressions/models.py b/tests/expressions/models.py
index 85f18fdf0e9..34fd9dff167 100644
--- a/tests/expressions/models.py
+++ b/tests/expressions/models.py
@@ -50,6 +50,7 @@ class Experiment(models.Model):
     end = models.DateTimeField()
 
     class Meta:
+        db_table = 'expressions_ExPeRiMeNt'
         ordering = ('name',)
 
     def duration(self):
diff --git a/tests/expressions/tests.py b/tests/expressions/tests.py
index e26b3ef6d81..ca331aeb03e 100644
--- a/tests/expressions/tests.py
+++ b/tests/expressions/tests.py
@@ -545,6 +545,11 @@ class BasicExpressionsTests(TestCase):
         expr = FuncB(FuncA())
         self.assertEqual(expr.output_field, FuncA.output_field)
 
+    def test_outerref_mixed_case_table_name(self):
+        inner = Result.objects.filter(result_time__gte=OuterRef('experiment__assigned'))
+        outer = Result.objects.filter(pk__in=Subquery(inner.values('pk')))
+        self.assertFalse(outer.exists())
+
 
 class IterableLookupInnerExpressionsTests(TestCase):
     @classmethod