diff --git a/django/db/utils.py b/django/db/utils.py index 41ad6df728..3f5b86ee12 100644 --- a/django/db/utils.py +++ b/django/db/utils.py @@ -32,16 +32,26 @@ def load_backend(backend_name): and not f.startswith('.')] except EnvironmentError: available_backends = [] - if backend_name.startswith('django.db.backends.'): + full_notation = backend_name.startswith('django.db.backends.') + if full_notation: backend_name = backend_name[19:] # See #15621. if backend_name not in available_backends: - error_msg = ("%r isn't an available database backend. \n" + - "Try using django.db.backends.XXX, where XXX is one of:\n %s\n" + - "Error was: %s") % \ - (backend_name, ", ".join(map(repr, sorted(available_backends))), e_user) + backend_reprs = map(repr, sorted(available_backends)) + error_msg = ("%r isn't an available database backend.\n" + "Try using django.db.backends.XXX, where XXX " + "is one of:\n %s\nError was: %s" % + (backend_name, ", ".join(backend_reprs), e_user)) + raise ImproperlyConfigured(error_msg) + elif not full_notation: + # user tried to use the old notation for the database backend + error_msg = ("%r isn't an available database backend.\n" + "Try using django.db.backends.%s instead.\n" + "Error was: %s" % + (backend_name, backend_name, e_user)) raise ImproperlyConfigured(error_msg) else: - raise # If there's some other error, this must be an error in Django itself. + # If there's some other error, this must be an error in Django + raise class ConnectionDoesNotExist(Exception): diff --git a/tests/regressiontests/backends/tests.py b/tests/regressiontests/backends/tests.py index bda604e00b..b561b4eb2d 100644 --- a/tests/regressiontests/backends/tests.py +++ b/tests/regressiontests/backends/tests.py @@ -7,11 +7,12 @@ import threading from django.conf import settings from django.core.management.color import no_style +from django.core.exceptions import ImproperlyConfigured from django.db import (backend, connection, connections, DEFAULT_DB_ALIAS, IntegrityError, transaction) from django.db.backends.signals import connection_created from django.db.backends.postgresql_psycopg2 import version as pg_version -from django.db.utils import ConnectionHandler, DatabaseError +from django.db.utils import ConnectionHandler, DatabaseError, load_backend from django.test import TestCase, skipUnlessDBFeature, TransactionTestCase from django.utils import unittest @@ -582,4 +583,11 @@ class ThreadTests(TestCase): t1.start() t1.join() # No exception was raised - self.assertEqual(len(exceptions), 0) \ No newline at end of file + self.assertEqual(len(exceptions), 0) + + +class BackendLoadingTests(TestCase): + def test_old_style_backends_raise_useful_exception(self): + self.assertRaisesRegexp(ImproperlyConfigured, + "Try using django.db.backends.sqlite3 instead", + load_backend, 'sqlite3')