CakePHP - 调用另一个导致“SQLSTATE [42000]：语法错误或访问冲突”的模型

I'm new to cakePHP and i have looked everywhere for an answer, but couldn't find the reason for this. I'm trying to call a function in distant model, if i run the model directly, it works fine, but if i run it from another model, it cause 'Syntax error or access violation' error.

Here's the code:

Cpanel Controller

class CpanelController extends AppController {

    var $uses = array('Client');

    public function index() {
        $this->Client->index();
    }

}

Client Model

class Client extends AppModel {
    public $useTable = 'users';
}

Client Controller

class ClientController extends AppController {
    public function index() {
        echo "running";
    }
}

When i run it from mysite/Client , it runs just fine. But if i try to load it from mysite/Cpanel , it throws:

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'index' at line 1

Thank you,

You dont' have a index function in your User Model.

maybe you what you intended to do was

public function index() {
        $this->Client->find('all');
    }

otherwise you have to create a index function inside the model

class Client extends AppModel {

    public $useTable = 'users';

    public function index() {
       // Do Something;
    }
}

If you want to use UserController inside CpanelController here's the code

App::uses('UserController', 'Controller');
$UserController= ClassRegistry::init('UserController');
$UserController->index();