Fixed #33916 -- Added support for serialization of enum.Flag in migrations.

1 files changed, 15 insertions, 2 deletions

diff --git a/django/db/migrations/serializer.py b/django/db/migrations/serializer.py
index 38da1e6ecc..7ebc966f40 100644
--- a/django/db/migrations/serializer.py
+++ b/django/db/migrations/serializer.py
@@ -16,7 +16,7 @@ from django.db import models
 from django.db.migrations.operations.base import Operation
 from django.db.migrations.utils import COMPILED_REGEX_TYPE, RegexObject
 from django.utils.functional import LazyObject, Promise
-from django.utils.version import get_docs_version
+from django.utils.version import PY311, get_docs_version
 
 
 class BaseSerializer:
@@ -125,8 +125,21 @@ class EnumSerializer(BaseSerializer):
     def serialize(self):
         enum_class = self.value.__class__
         module = enum_class.__module__
+        if issubclass(enum_class, enum.Flag):
+            if PY311:
+                members = list(self.value)
+            else:
+                members, _ = enum._decompose(enum_class, self.value)
+                members = reversed(members)
+        else:
+            members = (self.value,)
         return (
-            "%s.%s[%r]" % (module, enum_class.__qualname__, self.value.name),
+            " | ".join(
+                [
+                    f"{module}.{enum_class.__qualname__}[{item.name!r}]"
+                    for item in members
+                ]
+            ),
             {"import %s" % module},
         )