Removed escaping test of query content

As the content of last_executed_query() is not under Django's control
for most backends, it is useless to test too specific aspects of it.

tests/regressiontests/backends/tests.py

@@ -127,28 +127,12 @@ class DateQuotingTest(TestCase):
 
 
 class LastExecutedQueryTest(TestCase):
-    # There are no escaping tests for the sqlite backend because it does not
-    # implement paramater escaping. See #14091.
-
-    @unittest.skipUnless(connection.vendor in ('oracle', 'postgresql'),
-                         "These backends use the standard parameter escaping rules")
-    @override_settings(DEBUG=True)
-    def test_parameter_escaping(self):
-        # check that both numbers and string are properly quoted
-        list(models.Tag.objects.filter(name="special:\\\"':", object_id=12))
-        sql = connection.queries[-1]['sql']
-        self.assertTrue("= 'special:\\\"'':' " in sql)
-        self.assertTrue("= 12 " in sql)
-
-    @unittest.skipUnless(connection.vendor == 'mysql',
-                         "MySQL uses backslashes to escape parameters.")
     @override_settings(DEBUG=True)
-    def test_parameter_escaping(self):
-        list(models.Tag.objects.filter(name="special:\\\"':", object_id=12))
-        sql = connection.queries[-1]['sql']
-        # only this line is different from the test above
-        self.assertTrue("= 'special:\\\\\\\"\\':' " in sql)
-        self.assertTrue("= 12 " in sql)
+    def test_debug_sql(self):
+        list(models.Tag.objects.filter(name="test"))
+        sql = connection.queries[-1]['sql'].lower()
+        self.assertTrue(sql.startswith("select"))
+        self.assertIn(models.Tag._meta.db_table, sql)
 
     def test_query_encoding(self):
         """