OOP - jak hromadně inicializovat objekty tříd?

<?php


class NavItem
{

    /** @var integer */
    public $id_nav_item;
    
    /** @var integer */
    public $id_parent;
    
    /** @var string */
    public $name;
    
    /** @var string */
    public $url_name;
    
    /** @var integer */
    public $position;
    
    /** @var bool */
    public $active;
    
    
    function __construct($id_nav_item)
    {
        global $db;
        
        $stm = $db->prepare('SELECT id_parent, name, url_name, position, active FROM cz_nav_item WHERE id_nav_item = ? LIMIT 1');
        $stm->execute(array(intval($id_nav_item)));
        $row = $stm->fetch(PDO::FETCH_ASSOC);
        
        $this->id_nav_item = intval($id_nav_item);
        $this->id_parent = intval($row['id_parent']);
        $this->name = $row['name'];
        $this->url_name = $row['url_name'];
        $this->position = intval($row['position']);
        $this->active = (bool)$row['active'];
    }
    
    
    static function getNavItems()
    {
        global $db;
        
        $navItems = array();
        $res = $db->query('SELECT id_nav_item FROM cz_nav_item ORDER BY position ASC');
        
        while ($row = $res->fetch(PDO::FETCH_ASSOC))
            $navItems[] = new NavItem(intval($row['id_nav_item']));
        
        return $navItems;
    }
    
}

?>