BUG#37047789: Python connector does not support Django enum

SubCoder1 · SubCoder1 · commit bd24fee2401a · 2025-05-09T18:41:02.000+05:30
This patch fixes the issue where pure-python mode of Connector/Python
does not work properly while executing queries via Django ORM when
Django Enum objects or ChoiceField is being used in a django model.

Change-Id: I6f8fcfde23b34c94cdc7f4486c2c614d843389cd
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -13,6 +13,7 @@ v9.4.0
 
 - BUG#37820231: Text based django ORM filters doesn't work with Connector/Python
 - BUG#37806057: Rename extra option (when installing wheel package) to install webauthn functionality dependencies
+- BUG#37047789: Python connector does not support Django enum
 - BUG#36452514: Missing version info resources
 - BUG#34950958: MySQL Python Connector doesn't work with ssh in the same process
 - BUG#34844347: Freezes on connection via sshtunnel
diff --git a/mysql-connector-python/lib/mysql/connector/conversion.py b/mysql-connector-python/lib/mysql/connector/conversion.py
@@ -35,6 +35,7 @@
 import time
 
 from decimal import Decimal
+from enum import Enum
 from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
 
 from .constants import (
@@ -233,6 +234,8 @@ def quote(buf: Optional[Union[float, int, Decimal, HexLiteral, bytes]]) -> bytes
 
     def to_mysql(self, value: MySQLConvertibleType) -> MySQLProducedType:
         """Convert Python data type to MySQL"""
+        if isinstance(value, Enum):
+            value = value.value
         type_name = value.__class__.__name__.lower()
         try:
             converted: MySQLProducedType = getattr(self, f"_{type_name}_to_mysql")(
diff --git a/mysql-connector-python/lib/mysql/connector/types.py b/mysql-connector-python/lib/mysql/connector/types.py
@@ -33,6 +33,7 @@
 
 from datetime import date, datetime, time, timedelta
 from decimal import Decimal
+from enum import Enum
 from time import struct_time
 from typing import (
     TYPE_CHECKING,
@@ -105,7 +106,7 @@ class MySQLScriptPartition(TypedDict):
 """
 
 # pylint: disable=invalid-name
-MySQLConvertibleType = Union[BinaryProtocolType, bool, struct_time]
+MySQLConvertibleType = Union[BinaryProtocolType, Enum, bool, struct_time]
 """
 MySQL convertible Python types - Python types consumed by the built-in converter that
 can be converted to MySQL. It's a superset of `BinaryProtocolType`.
diff --git a/mysql-connector-python/tests/test_django.py b/mysql-connector-python/tests/test_django.py
@@ -105,14 +105,15 @@
 import django.db  # pylint: disable=W0611
 
 from django.core.exceptions import ImproperlyConfigured
-from django.db import connection
+from django.db import connection, models
 from django.db.backends.signals import connection_created
 from django.db.utils import DEFAULT_DB_ALIAS, load_backend
 from django.utils.safestring import SafeText
 
 import mysql.connector
 
 from mysql.connector.conversion import MySQLConverter
+from mysql.connector.django.base import CursorWrapper
 from mysql.connector.django.introspection import FieldInfo
 from mysql.connector.errors import ProgrammingError
 
@@ -627,3 +628,58 @@ def test_missing_config(self):
         cnx_params = cnx.get_connection_params()
         self.assertTrue(cnx_params["raise_on_warnings"])
         del settings.DATABASES["default"]["OPTIONS"]
+
+
+class BugOra37047789(tests.MySQLConnectorTests):
+    """BUG#37047789: Python connector does not support Django enum
+
+    Django Enumeration types are not getting converted into MySQLConvertibleType
+    thus, query execution via Django ORM using Connector/Python is failing when
+    a model field with enum choices are being used.
+
+    This patch fixes the issue by changing the Enum object being passed to the
+    conversation module to its underlying value before conversion to MySQL type
+    takes place using the built-in property `value`, which already exists in every
+    Enum objects.
+    """
+
+    table_name = "BugOra37047789"
+
+    class Priority(models.IntegerChoices):
+        LOW = 1, 'Low'
+        MEDIUM = 2, 'Medium'
+        HIGH = 3, 'High'
+
+    class Status(models.TextChoices):
+        DRAFT = 'draft', 'Draft'
+        PUBLISHED = 'published', 'Published'
+
+    dbconfig = tests.get_mysql_config()
+
+    def setUp(self):
+        with mysql.connector.connect(**self.dbconfig) as cnx:
+            cnx.cmd_query(f"""
+                CREATE TABLE {self.table_name} (
+                    priority INT NOT NULL DEFAULT 1,
+                    status varchar(10) NOT NULL DEFAULT 'draft'
+                )
+            """)
+            cnx.commit()
+
+    def tearDown(self):
+        with mysql.connector.connect(**self.dbconfig) as cnx:
+            cnx.cmd_query(f"DROP TABLE {self.table_name}")
+
+    @tests.foreach_cnx()
+    def test_django_enum_support(self):
+        cnx_cur = self.cnx.cursor()
+        django_cur = CursorWrapper(cnx_cur)
+        django_cur.execute(
+            f"INSERT INTO {self.table_name} VALUES (%s, %s)",
+            (self.Priority.HIGH, self.Status.PUBLISHED)
+        )
+        django_cur.execute(
+            f"INSERT INTO {self.table_name} VALUES (%(priority)s, %(status)s)",
+            {'priority': self.Priority.HIGH, 'status': self.Status.PUBLISHED}
+        )
+        cnx_cur.close()
