From 52545e788d664040abf4f1a5d77cdfc61152ffca Mon Sep 17 00:00:00 2001
From: can <cansarigol@derinbilgi.com.tr>
Date: Wed, 10 Jul 2019 15:07:48 +0300
Subject: [PATCH] Fixed #28289 -- Fixed crash of RawSQL annotations on
 inherited model fields.

---
 django/db/models/expressions.py | 10 ++++++++++
 tests/annotations/models.py     |  1 +
 tests/annotations/tests.py      | 22 ++++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index b757426440..bef93d36a2 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -699,6 +699,16 @@ class RawSQL(Expression):
     def get_group_by_cols(self, alias=None):
         return [self]
 
+    def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
+        # Resolve parents fields used in raw SQL.
+        for parent in query.model._meta.get_parent_list():
+            for parent_field in parent._meta.local_fields:
+                _, column_name = parent_field.get_attname_column()
+                if column_name.lower() in self.sql.lower():
+                    query.resolve_ref(parent_field.name, allow_joins, reuse, summarize)
+                    break
+        return super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
+
 
 class Star(Expression):
     def __repr__(self):
diff --git a/tests/annotations/models.py b/tests/annotations/models.py
index 4aeda3c093..cd3d6ddb87 100644
--- a/tests/annotations/models.py
+++ b/tests/annotations/models.py
@@ -38,6 +38,7 @@ class Store(models.Model):
     books = models.ManyToManyField(Book)
     original_opening = models.DateTimeField()
     friday_night_closing = models.TimeField()
+    area = models.IntegerField(null=True, db_column='surface')
 
     def __str__(self):
         return self.name
diff --git a/tests/annotations/tests.py b/tests/annotations/tests.py
index af13915312..c39e8d3fbe 100644
--- a/tests/annotations/tests.py
+++ b/tests/annotations/tests.py
@@ -405,6 +405,28 @@ class NonAggregateAnnotationTestCase(TestCase):
             lambda a: (a['age'], a['age_count'])
         )
 
+    def test_raw_sql_with_inherited_field(self):
+        DepartmentStore.objects.create(
+            name='Angus & Robinson',
+            original_opening=datetime.date(2014, 3, 8),
+            friday_night_closing=datetime.time(21),
+            chain='Westfield',
+            area=123,
+        )
+        tests = (
+            ('name', 'Angus & Robinson'),
+            ('surface', 123),
+            ("case when name='Angus & Robinson' then chain else name end", 'Westfield'),
+        )
+        for sql, expected_result in tests:
+            with self.subTest(sql=sql):
+                self.assertSequenceEqual(
+                    DepartmentStore.objects.annotate(
+                        annotation=RawSQL(sql, ()),
+                    ).values_list('annotation', flat=True),
+                    [expected_result],
+                )
+
     def test_annotate_exists(self):
         authors = Author.objects.annotate(c=Count('id')).filter(c__gt=1)
         self.assertFalse(authors.exists())