Isntance of PDO given instead of namespace name - PSR4 Autoloading with composer

Question

I am trying to learn how to use PDO. I have a very small application that uses namespaces. I use composer to autoload the classes.

I am trying to follow PHPTheRightWay MVC approach to PDO but I am failing. I have setup my DbModel class to match their one and in my php code I create a new instance of it and parse the PDO object.

Class:

namespace Acme;

class DbModel {

    protected $db;

    public function __construct(PDO $db)
    {
        $this->db = $db;
    }

    public function getAllPlayers()
    {
        return $this->db->query('SELECT * FROM player');
    }
}

Page:

use Acme\DbModel;
use Acme\Player;
use Acme\Team;
use Acme\Match;

$db = new PDO('mysql:host=127.0.0.1;dbname=football', 'root', '');
$model = new DbModel($db);

However, I get the following error. I have no idea why this is happening.

Catchable fatal error: Argument 1 passed to Acme\\DbModel::__construct() must be an instance of Acme\\PDO, instance of PDO given, called in C:\\xampp\\htdocs\\footballMatch\\matchDay.php on line 9 and defined in C:\\xampp\\htdocs\\footballMatch\\src\\DbModel.php on line 9

After adding this class I run composer install and composer dump-autoload .

Answer 1

Add the root namespace prefix to PDO wherever it's used, eg:

public function __construct(\PDO $db)

For now, your script assumes that the class named PDO should be under the Acme namespace, which isn't the case.