将函数与辅助类分开是否合适？

Question

I'm pretty new to the MVC concept itself but I'm slowly starting to grasp it, and what it is that makes it so useful.

I have in my app different tabs which are levels in a hierarchy (I call them entities), each represented by two classes - a Binding class with all the methods to communicate with the database and a helper class which is just a skeleton of the Entity, both in same file. I wonder if this is the right way to approach the design pattern? I haven't built a Model or a Controller yet because I'm not sure where they'll come in at the moment. Also I'm not interested to use ORM right now.

class CompanyBinding extends EntityBinding {
    function __construct() {
        parent::__construct();
    }


    public function get($criteria = array()) {
        // method to retrieve an array of DB rows, each represented by the helper class

            [...]

        return $sth->fetchAll(PDO::FETCH_CLASS, 'Company');
    }

    public function get_by_id($id) {
        // method to retrieve an one single object of the helper class

        $sth->setFetchMode(PDO::FETCH_CLASS, 'Company');
        return $sth->fetch();
    }
}


class Company extends Entity {
    public $id;
    public $name;
    public $email;
    public $phone;

    // just properties. some classes have a __construct() function to manipulate some fields after retrieval

    [...]
}

Do I need a model class now? I was considering the Controller could perform the ->get function and load appropriate class, because the name of the entity is passed from the front-end with AJAX.

By the way I also am really confused. Should the controller absorb all AJAX requests or should I make a file called ajax.php that handles that, and put the Controller class above public_html so users can't access the class file?

Answer 1

Separate the classes into their own files. PHP does a decent job at caching file locations once it opens them, so you don't have to worry about IO. And generally speaking, it is bad practice to put multiple classes in one file. It won't break your application, but it may cause more seasoned developers to break-down into tears. :)

Apart from that, you are fine.