为啥下面代码查询没结果呀
function edit(){
$id=$_GET['id'];
$where['id']=$id;
if(!empty($id)){
$user=new UserModel();
// $data=$user->where($where)->select();
$data=$user->field('id,username,name,email,active,role_id')->join($this->tablePrefix.'role_user on id=user_id')->getById($id);
dump($data);