Fixed #22603 -- Reorganized classes in django.db.backends.

1 files changed, 12 insertions, 42 deletions

diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 8b45b5d73e..34b2870773 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -5,19 +5,11 @@ Requires psycopg 2: http://initd.org/projects/psycopg2
 """
 
 from django.conf import settings
-from django.db.backends import (BaseDatabaseFeatures, BaseDatabaseWrapper,
-    BaseDatabaseValidation)
-from django.db.backends.postgresql_psycopg2.operations import DatabaseOperations
-from django.db.backends.postgresql_psycopg2.client import DatabaseClient
-from django.db.backends.postgresql_psycopg2.creation import DatabaseCreation
-from django.db.backends.postgresql_psycopg2.version import get_version
-from django.db.backends.postgresql_psycopg2.introspection import DatabaseIntrospection
-from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
-from django.db.utils import InterfaceError
+from django.db.backends.base.base import BaseDatabaseWrapper
+from django.db.backends.base.validation import BaseDatabaseValidation
 from django.utils.encoding import force_str
 from django.utils.functional import cached_property
 from django.utils.safestring import SafeText, SafeBytes
-from django.utils.timezone import utc
 
 try:
     import psycopg2 as Database
@@ -27,6 +19,16 @@ except ImportError as e:
     from django.core.exceptions import ImproperlyConfigured
     raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
 
+# Some of these import psycopg2, so import them after checking if it's installed.
+from .client import DatabaseClient
+from .creation import DatabaseCreation
+from .features import DatabaseFeatures
+from .introspection import DatabaseIntrospection
+from .operations import DatabaseOperations
+from .schema import DatabaseSchemaEditor
+from .utils import utc_tzinfo_factory
+from .version import get_version
+
 DatabaseError = Database.DatabaseError
 IntegrityError = Database.IntegrityError
 
@@ -37,38 +39,6 @@ psycopg2.extensions.register_adapter(SafeText, psycopg2.extensions.QuotedString)
 psycopg2.extras.register_uuid()
 
 
-def utc_tzinfo_factory(offset):
-    if offset != 0:
-        raise AssertionError("database connection isn't set to UTC")
-    return utc
-
-
-class DatabaseFeatures(BaseDatabaseFeatures):
-    needs_datetime_string_cast = False
-    can_return_id_from_insert = True
-    has_real_datatype = True
-    has_native_duration_field = True
-    driver_supports_timedelta_args = True
-    can_defer_constraint_checks = True
-    has_select_for_update = True
-    has_select_for_update_nowait = True
-    has_bulk_insert = True
-    uses_savepoints = True
-    can_release_savepoints = True
-    supports_tablespaces = True
-    supports_transactions = True
-    can_introspect_autofield = True
-    can_introspect_ip_address_field = True
-    can_introspect_small_integer_field = True
-    can_distinct_on_fields = True
-    can_rollback_ddl = True
-    supports_combined_alters = True
-    nulls_order_largest = True
-    closed_cursor_error_class = InterfaceError
-    has_case_insensitive_like = False
-    requires_sqlparse_for_splitting = False
-
-
 class DatabaseWrapper(BaseDatabaseWrapper):
     vendor = 'postgresql'
     # This dictionary maps Field objects to their associated PostgreSQL column