thinkphp自定义业务逻辑有有关问题

thinkphp自定义业务逻辑有问题?
模型:

PHP code

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class DepartmentModel extends Model{
    
    public function getIndexDepart()
    {
        return 1; 
    }
      

控制器

PHP code

 <br> class IndexAction extends Action <br> { <br>     public function index() <br>     { <br> 		$a = D('Department'); <br> 		echo " <pre class="brush:php;toolbar:false">"; <br> 		print_r($a-&gt;getIndexDepart()); <br> 		echo " 

";
        //echo THINK_PATH;
    }

}

可是TP提示:

Model:getIndexDepart您所请求的方法不存在！


求解


------解决方案--------------------

PHP code

class IndexAction extends Action
{
    public function index()
    {
        $a = D('Department');
[color=#FF0000]        get_class($a);[/color]
        echo "<pre class="brush:php;toolbar:false">";
        print_r($a-&gt;getIndexDepart());
        echo "

"; //echo THINK_PATH; } }