Registration with PDO/PHP doesn't work - php

Question

I've got a problem through build a registration system. I don't know where is the problem, because I'm a beginner in PHP OOP.
Here's my registration class:
<?php
/*
*=======================
* REGISTRATION CLASS !!!
* ======================
*/
include_once '/../core/registration.php';
include_once '/../core/db_connect.php';
class registration {
private $db;
function __construct() { /* Connecting with MySQL */
$this->db = new db_connect();
$this->db = $this->db->connect();
} /* End of connection */
function registration($username, $password1, $password2, $email, $date) {
if(!empty($username) && !empty($password1) && !empty($password2) && !empty($email)) {
$q = $this->db->prepare("INSERT INTO users(username, password, email, date, logged, admin) VALUES (?, ?, ?, ?, ?, ?)");
$q->bindParam(1, $username);
$q->bindParam(2, $password1);
$q->bindParam(3, $email);
$q->bindParam(4, $date);
$q->bindParam(5, '0');
$q->bindParam(6, '0');
$q->execute();
}
}
}
?>
Here is a file, that is running, when user clicks on 'register' button:
<?php
include_once '/../classes/registration.php';
if(isset($_POST['regUser'])) {
$username = $_POST['regUsername'];
$pass1 = $_POST['regPassword1'];
$pass2 = $_POST['regPassword2'];
$email = $_POST['regEmail'];
$date = date("Y-m-d H:i:s");
$obj = new registration();
$obj->registration($username, $password1, $password2, $email, $date);
}
?>
For safety, I'll put also a connection file:
<?php
class db_connect {
function connect() {
return new PDO("mysql:host=127.0.0.1;dbname=oop", "root", "");
}
}
?>

Answer 1

It's one of the most common "error" with PDO.
With bindParam, you can only pass variables, not values.
In your registration() method, replace:
$q->bindParam(5, '0');
$q->bindParam(6, '0');
By:
$q->bindValue(5, '0');
$q->bindValue(6, '0');
With bindValue you can pass values and variables.
You can read the PHP manual for more info (here and here).