Fixed #36074 -- Excluded composite primary key fields on save() updates.

2 files changed, 8 insertions, 2 deletions

diff --git a/django/db/models/base.py b/django/db/models/base.py
index a7a26b405c..6d66080c20 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -1091,10 +1091,11 @@ class Model(AltersData, metaclass=ModelBase):
         for a single table.
         """
         meta = cls._meta
+        pk_fields = meta.pk_fields
         non_pks_non_generated = [
             f
             for f in meta.local_concrete_fields
-            if not f.primary_key and not f.generated
+            if f not in pk_fields and not f.generated
         ]
 
         if update_fields:
diff --git a/tests/composite_pk/test_update.py b/tests/composite_pk/test_update.py
index e711745447..6748aa2834 100644
--- a/tests/composite_pk/test_update.py
+++ b/tests/composite_pk/test_update.py
@@ -1,3 +1,4 @@
+from django.db import connection
 from django.test import TestCase
 
 from .models import Comment, Tenant, Token, User
@@ -45,7 +46,11 @@ class CompositePKUpdateTests(TestCase):
         email = "user9314@example.com"
         user = User.objects.get(pk=self.user_1.pk)
         user.email = email
-        user.save()
+        with self.assertNumQueries(1) as ctx:
+            user.save()
+        sql = ctx[0]["sql"]
+        self.assertEqual(sql.count(connection.ops.quote_name("tenant_id")), 1)
+        self.assertEqual(sql.count(connection.ops.quote_name("id")), 1)
         user.refresh_from_db()
         self.assertEqual(user.email, email)
         user = User.objects.get(pk=self.user_1.pk)