/config/includes/bdd/database.php

<?php

class Database {

    private $tokenAuth;
    private $pdo;

    private function _construct() {
        $this->tokenAuth = array(
            'bdname' => 'bd_name_xxx',
            'host' => 'localhost'
        );
    }

    /**
    * Connexion à la base de données.
    */
    private function getPDO() {
        try {
            if($this->pdo == null){
                $user = 'user_xxx';
                $password = 'xxxx';

                $pdo = new PDO('mysql:host=' . $this->tokenAuth['host'] . ';dbname=' . $this->tokenAuth['dbname'] . ';charset=UTF8', $user, $password);
                $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
                $this->pdo = $pdo;
            }
        } catch (PDOException $e) {
            echo 'Connexion bdd = false <br/>Raison = ';
            die('Erreur : ' .$e->getMessage());
        }
    }

    /**
    * Appel de la BDD
    */
    public function BDD() {
        $this->getPDO();
    }

    /**
    * Fermer la connexion à la base de données.
    */
    public function shutdownbdd() {
        $this->pdo = null;
        return true;
    }

    /**
    * Requête query à la base de données.
    */
    public function query($statement) {
        $request = $this->getPDO()->query($statement);
        $this->shutdown();
        return $result;
    }
}