[Solved] Model Search() Filter By Relation

Hello!

I have a problem trying to filter my results in my controller.


I got 2 tables called Alumno and Proyecto, these tables are related by alumno.proyecto_id and proyecto._id as suposed to.

Most topics in the forum use the admin view from the blog example. But i can't understand how to filter the results of $model->search() (as dataprovider to a Cgridview) to show only the "Alumno" whose "proyecto.year" equals some specific value.

Controller Action:

$model = new Alumno('search');

    $model->unsetAttributes();
    if (isset($_GET['Alumno'])) {
        $model->attributes = $_GET['Alumno'];
    }
    $this->render('lista', array(
        'model' => $model,
        'year'=>$year,
    ));

View:

$this->widget('zii.widgets.grid.CGridView', array(
    'id'=>'alumnos-grid',
    'dataProvider'=>$dataProvider, //$model->search();
    'filter'=>$model,              //from the controller action
    'columns'=>array(
            '_id',
            'nombre',
            'apellido_paterno',
     ),
));

Please help me to understand how to filter these data.

Greetings