Fixed #27170 -- Added DatabaseWrapper class attributes to ease subclassing.

1 files changed, 6 insertions, 11 deletions

diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 19afa48047..1ab05d81f6 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -10,7 +10,6 @@ from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.db import DEFAULT_DB_ALIAS
 from django.db.backends.base.base import BaseDatabaseWrapper
-from django.db.backends.base.validation import BaseDatabaseValidation
 from django.db.utils import DatabaseError as WrappedDatabaseError
 from django.utils import six
 from django.utils.encoding import force_str
@@ -141,16 +140,12 @@ class DatabaseWrapper(BaseDatabaseWrapper):
 
     Database = Database
     SchemaEditorClass = DatabaseSchemaEditor
-
-    def __init__(self, *args, **kwargs):
-        super(DatabaseWrapper, self).__init__(*args, **kwargs)
-
-        self.features = DatabaseFeatures(self)
-        self.ops = DatabaseOperations(self)
-        self.client = DatabaseClient(self)
-        self.creation = DatabaseCreation(self)
-        self.introspection = DatabaseIntrospection(self)
-        self.validation = BaseDatabaseValidation(self)
+    # Classes instantiated in __init__().
+    client_class = DatabaseClient
+    creation_class = DatabaseCreation
+    features_class = DatabaseFeatures
+    introspection_class = DatabaseIntrospection
+    ops_class = DatabaseOperations
 
     def get_connection_params(self):
         settings_dict = self.settings_dict