From eef3ea847e12f23db9a0af8efdc9543f24b780c4 Mon Sep 17 00:00:00 2001
From: Hasan Ramezani <hasan.r67@gmail.com>
Date: Thu, 9 Jan 2020 11:10:25 +0100
Subject: [PATCH] Fixed #31148 -- Added error messages on update()/delete()
 operations following union(), intersection(), and difference().

---
 django/db/models/query.py            | 2 ++
 tests/queries/test_qs_combinators.py | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/django/db/models/query.py b/django/db/models/query.py
index 38c13584d13..f8be008a62e 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -711,6 +711,7 @@ class QuerySet:
 
     def delete(self):
         """Delete the records in the current QuerySet."""
+        self._not_support_combined_queries('delete')
         assert not self.query.is_sliced, \
             "Cannot use 'limit' or 'offset' with delete."
 
@@ -756,6 +757,7 @@ class QuerySet:
         Update all elements in the current QuerySet, setting all the given
         fields to the appropriate values.
         """
+        self._not_support_combined_queries('update')
         assert not self.query.is_sliced, \
             "Cannot update a query once a slice has been taken."
         self._for_write = True
diff --git a/tests/queries/test_qs_combinators.py b/tests/queries/test_qs_combinators.py
index 668d5e6ad6f..71309ecf1b9 100644
--- a/tests/queries/test_qs_combinators.py
+++ b/tests/queries/test_qs_combinators.py
@@ -272,12 +272,14 @@ class QuerySetSetOperationTests(TestCase):
             for operation in (
                 'annotate',
                 'defer',
+                'delete',
                 'exclude',
                 'extra',
                 'filter',
                 'only',
                 'prefetch_related',
                 'select_related',
+                'update',
             ):
                 with self.subTest(combinator=combinator, operation=operation):
                     with self.assertRaisesMessage(