我创建了一个插件，在注册过程中添加了一个函数，用户信息也会添加到外部数据库中。问题是，当函数成功运行时，即用户可以添加到外部db，但wordpress注册过程返回并出错时，用户仍然被添加到外部db。我如何构造它，以便在Wordpress端或外部出现错误时，用户看到并出错，而不会向任何db添加任何内容。

这是我的代码：

    function add_user_to_SF($errors, $sanitized_user_login, $user_email ) {
    global $SF_USERNAME;
    global $SF_PASSWORD;

    try {
      $mySforceConnection = new SforceEnterpriseClient();
      $mySoapClient = $mySforceConnection->createConnection(CD_PLUGIN_PATH . \'Toolkit/soapclient/enterprise.wsdl.xml\');
      $mySFlogin = $mySforceConnection->login($SF_USERNAME, $SF_PASSWORD);

        $sObject = new stdclass();
        $sObject->FirstName = $_POST[\'user_login\'];
        $sObject->LastName = $_POST[\'user_login\'];
        $sObject->Email = $_POST[\'user_email\'];

        $createResponse = $mySforceConnection->create(array($sObject), \'Contact\');

        $ids = array();
            foreach ($createResponse as $createResult) {
                array_push($ids, $createResult->id);
            }

            } catch (Exception $e) {
              //echo $mySforceConnection->getLastRequest();
              //echo $e->faultstring;
              $errors->add( \'demo_error\', __(\'<strong>ERROR</strong>: There is a Salesforce problem.\',\'mydomain\') );
              return $errors;
        }
              return $errors;
    }

    add_filter( \'registration_errors\', \'add_user_to_SF\', 10, 3 );