Fixed a potential cause of ORA-12519: TNS:no appropriate service hand…

…ler found

See https://app.continuousphp.com/git-hub/doctrine/dbal/build/8f591452-2ed1-4dcd-8bb0-cb5ab56da04e/logs/c44a55cb-96b9-4555-a053-9d18cc003e83#line-115 for an example.

tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php

@@ -11,20 +11,20 @@
 
 class OracleSchemaManagerTest extends SchemaManagerFunctionalTestCase
 {
-    protected function setUp()
+    public static function setUpBeforeClass()
     {
-        parent::setUp();
+        parent::setUpBeforeClass();
 
         if (! isset($GLOBALS['db_username'])) {
-            $this->markTestSkipped('Foo');
+            self::markTestSkipped('Username must be explicitly specified in connection parameters for this test');
         }
 
         $username = $GLOBALS['db_username'];
 
         $query = 'GRANT ALL PRIVILEGES TO ' . $username;
 
         $conn = TestUtil::getTempConnection();
-        $conn->executeUpdate($query);
+        $conn->exec($query);
     }
 
     public function testRenameTable()