Ticket #17047: 17047.patch

django/db/utils.py

@@ -32 +32 @@
                     and not f.startswith('.')]
         except EnvironmentError:
             available_backends = []
-        if backend_name.startswith('django.db.backends.'):
+        new_style_import = backend_name.startswith('django.db.backends.')
+        if new_style_import:
             backend_name = backend_name[19:] # See #15621.
         if backend_name not in available_backends:
             error_msg = ("%r isn't an available database backend. \n" +
@@ -40 +41 @@
                 "Error was: %s") % \
                 (backend_name, ", ".join(map(repr, sorted(available_backends))), e_user)
             raise ImproperlyConfigured(error_msg)
+        elif not new_style_import:
+            # user tried to use database backend using old-school non-qualified
+            # import path (eg 'sqlite3' instead of 'django.db.backends.sqlite3')
+            error_msg = ("%r isn't an available database backend.\n"
+                 "The backend you are probably looking for is django.db.backends.%s\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.
 

tests/regressiontests/backends/tests.py

@@ -7 +7 @@
 
 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 +583 @@
         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.assertRaises(ImproperlyConfigured, load_backend, 'sqlite3')

django/db/utils.py

@@ -32 +32 @@
                     and not f.startswith('.')]
         except EnvironmentError:
             available_backends = []
-        new_style_import = backend_name.startswith('django.db.backends.')
-        if new_style_import:
+        new_style_backend_name = backend_name.startswith('django.db.backends.')
+        if new_style_backend_name:
             backend_name = backend_name[19:] # See #15621.
         if backend_name not in available_backends:
             error_msg = ("%r isn't an available database backend. \n" +
@@ -41 +41 @@
                 "Error was: %s") % \
                 (backend_name, ", ".join(map(repr, sorted(available_backends))), e_user)
             raise ImproperlyConfigured(error_msg)
-        elif not new_style_import:
+        elif not new_style_backend_name:
             # user tried to use database backend using old-school non-qualified
             # import path (eg 'sqlite3' instead of 'django.db.backends.sqlite3')
             error_msg = ("%r isn't an available database backend.\n"

tests/regressiontests/backends/tests.py

@@ -588 +588 @@
 
 class BackendLoadingTests(TestCase):
     def test_old_style_backends_raise_useful_exception(self):
-        self.assertRaises(ImproperlyConfigured, load_backend, 'sqlite3')
+        self.assertRaisesRegexp(ImproperlyConfigured, "The backend you are probably looking for is django.db.backends.sqlite3", load_backend, 'sqlite3')