thinkphp模型没继承model报的错

Call to undefined method RoleModel::query()

错误位置

FILE: H:\www\tpsmarty\shop\Lib\Model\RoleModel.class.php 　LINE: 17

错误的代码

class RoleModel extends Model{
    //put your code here
    function giveAuth($auth_ids){
        $sql="select auth_c,auth_a from sw_auth where auth_id in ($auth_ids)";
        $info=$this->query($sql);
        show($info);
    }
}