Fixed #8485: Reordered imports in the database backends to ensure that the availability of the MySQL and Oracle backends is confirmed before any attempt is made to use the backend. Many thanks to Karen Tracey for her work in narrowing down a number of vague reports into a concrete problem.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8466 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/backends/mysql/base.py

@@ -6,12 +6,6 @@ Requires MySQLdb: http://sourceforge.net/projects/mysql-python
 
 import re
 
-from django.db.backends import *
-from django.db.backends.mysql.client import DatabaseClient
-from django.db.backends.mysql.creation import DatabaseCreation
-from django.db.backends.mysql.introspection import DatabaseIntrospection
-from django.db.backends.mysql.validation import DatabaseValidation
-
 try:
     import MySQLdb as Database
 except ImportError, e:
@@ -30,6 +24,12 @@ if (version < (1,2,1) or (version[:3] == (1, 2, 1) and
 from MySQLdb.converters import conversions
 from MySQLdb.constants import FIELD_TYPE, FLAG
 
+from django.db.backends import *
+from django.db.backends.mysql.client import DatabaseClient
+from django.db.backends.mysql.creation import DatabaseCreation
+from django.db.backends.mysql.introspection import DatabaseIntrospection
+from django.db.backends.mysql.validation import DatabaseValidation
+
 # Raise exceptions for database warnings if DEBUG is on
 from django.conf import settings
 if settings.DEBUG:

django/db/backends/oracle/base.py

@@ -8,13 +8,6 @@ import os
 import datetime
 import time
 
-from django.db.backends import *
-from django.db.backends.oracle import query
-from django.db.backends.oracle.client import DatabaseClient
-from django.db.backends.oracle.creation import DatabaseCreation
-from django.db.backends.oracle.introspection import DatabaseIntrospection
-from django.utils.encoding import smart_str, force_unicode
-
 # Oracle takes client-side character set encoding from the environment.
 os.environ['NLS_LANG'] = '.UTF8'
 try:
@@ -23,6 +16,13 @@ except ImportError, e:
     from django.core.exceptions import ImproperlyConfigured
     raise ImproperlyConfigured("Error loading cx_Oracle module: %s" % e)
 
+from django.db.backends import *
+from django.db.backends.oracle import query
+from django.db.backends.oracle.client import DatabaseClient
+from django.db.backends.oracle.creation import DatabaseCreation
+from django.db.backends.oracle.introspection import DatabaseIntrospection
+from django.utils.encoding import smart_str, force_unicode
+
 DatabaseError = Database.Error
 IntegrityError = Database.IntegrityError