jQuery UI的自动完成：如何使用自定义索引？

I have a problem with jQuery UI. I need to autocomplete() a form with data from database. I need name, for display, and ID, for submit.

So, i can't simply use an array of string with name, i need to use array of object. My problem is this : jQuery UI autocomplete ONLY accept label or value properties to perform auto-completion. So, i have to do that :

PHP :

public function autocomp(Connection $db)
    {

        $term = $_GET['term'];

        $req = $db->prepare("SELECT name, id FROM product LIKE '%".$term."%'");
        $req->execute();

        // Because jQuery-UI's autocomplete() accept only array with 'label' for index of value,
        // We are forced to parse the data before send it to JSON...
        $array = [];
        $i = 0;
        while($data = $req->fetch())
        {
            $i++;
            $array[$i]['id'] = $data['id'];
            $array[$i]['label'] = $data['name'];

        }

        $response = new Response(json_encode($array));
        return $response;

    }

jQuery autocomplete() :

$(function () {
    $('#autotry').autocomplete({
        source: '/autocomp',
        select: function (event, ui) {
            $('#hidden').val( ui.item.id)
        }
    });
});

Do you know what i mean ? Yeah, if 'label' or 'value' is defined, i can use other properties (like 'id') for do what i want.

I just want to use custom properties, for avoid that loop... For each input. Thank you, and please excuse my english (and my JS skill.)