没有数据，添加，有数据，修改

 $values = $db->fetchRow("SELECT uid FROM ew_username_config WHERE uid=".$_SESSION['business']['uid']);
   if($values){
    $returnid = $db->update('ew_username_config',$data,"uid=".$_SESSION['business']['uid']);
    }
   else{
    
    $data['uid'] = $_SESSION['business']['uid'];
    $returnid = $db->insert('ew_username_config',$data);
   }
   if($returnid > 0){
    $view->url = 'user.php?action=system_add';
    $view->msg = '更新成功！';
    echo $view->render('business/public/header.php');
    exit;
   }