Fixed #36122 -- Raised FieldError when updating with composite reference value.

Thanks Jacob Walls for the report and test.

2 files changed, 14 insertions, 0 deletions

diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 6f90f11f1b..04372c509e 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -2019,6 +2019,11 @@ class SQLUpdateCompiler(SQLCompiler):
                         "Window expressions are not allowed in this query "
                         "(%s=%r)." % (field.name, val)
                     )
+                if isinstance(val, ColPairs):
+                    raise FieldError(
+                        "Composite primary keys expressions are not allowed "
+                        "in this query (%s=F('pk'))." % field.name
+                    )
             elif hasattr(val, "prepare_database_save"):
                 if field.remote_field:
                     val = val.prepare_database_save(field)
diff --git a/tests/composite_pk/test_update.py b/tests/composite_pk/test_update.py
index 5bc53f1fe1..697383b007 100644
--- a/tests/composite_pk/test_update.py
+++ b/tests/composite_pk/test_update.py
@@ -1,5 +1,6 @@
 from django.core.exceptions import FieldError
 from django.db import connection
+from django.db.models import F
 from django.test import TestCase
 
 from .models import Comment, Tenant, TimeStamped, Token, User
@@ -182,3 +183,11 @@ class CompositePKUpdateTests(TestCase):
         msg = "Composite primary key fields must be updated individually."
         with self.assertRaisesMessage(FieldError, msg):
             qs.update(pk=(1, 10))
+
+    def test_update_value_not_composite(self):
+        msg = (
+            "Composite primary keys expressions are not allowed in this "
+            "query (text=F('pk'))."
+        )
+        with self.assertRaisesMessage(FieldError, msg):
+            Comment.objects.update(text=F("pk"))