PHP Config class

<?php
class Config {

    private $data = Array();

    public $dbUser = 'username';
    public $dbPass = 'password';
    public $dsn = 'mysql:dbname=;host=hostname;port=3306;charset=UTF-8';
    public $debug = TRUE;

    public function __construct() {
        try {
            $this->pdo = new PDO($this->dsn, $this->dbUser, $this->dbPass, array(PDO::ATTR_PERSISTENT => true));
            $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $this->pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
        }
        catch (PDOException $e) {
            if ($this->debug) echo $e->getMessage();
        }
        $this->dbCheck();
        if ($this->debug) {
            $this->enableDebug();
        } else {
            $this->disableDebug();
        }
        $this->testObj = new ConfigObject($this->pdo, "testnavn");
    }

    function __get($name) {
        if (($name != "pdo")) {
            if (!isset($this->data[$name])) {
                $this->data[$name]=new ConfigObject($this->pdo, $name);
            }
        }
        return $this->data[$name];
    }

    function __set($name, $value) {
        if ($name != "pdo") {
            $value=new ConfigObject($this->pdo, $name);
        }
        $this->data[$name] = $value;
    }

    function __isset($name) {
        $query = $this->pdo->prepare("SELECT COUNT (*) FROM `configuration` WHERE `key`=:name");
        $query->bindValue(":name", $name, PDO::PARAM_STR);
        $query->execute();
        $count=$query->fetchColumn();
        $query->closeCursor();
        return ((bool) $count);
    }

    function __unset($name) {
        unset($this->data[$name]);
        $query = $this->pdo->prepare("DELETE FROM `configuration` WHERE `key`=:name");
        $query->bindValue(":name", $name, PDO::PARAM_STR);
        $query->execute();
        $numrows=$query->rowCount();
        return ((bool) $numrows);
    }

    private function dbCheck() {
        $query=$this->pdo->query("SHOW TABLES LIKE 'configuration'");
        $query->execute();
        if ($query->rowCount() == 0) {
            $query->closeCursor();
            $query=$this->pdo->query("CREATE TABLE IF NOT EXISTS `configuration` (".
                                      "`key` text COLLATE utf8_swedish_ci NOT NULL,".
                                      "`value` text COLLATE utf8_swedish_ci NOT NULL,".
                                      "`group` text COLLATE utf8_swedish_ci,".
                                      "`description` text COLLATE utf8_swedish_ci,".
                                      "UNIQUE KEY `key` (`key`(16))".
                                      ") ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_swedish_ci;");
            $query->execute();
        }
        $query->closeCursor();
    }

    public function enableDebug() {
        $this->debug=TRUE;
        ini_set('display_errors', 'On');
        error_reporting(2039);
    }

    public function disableDebug() {
        $this->debug=FALSE;
        ini_set('display_errors', 'Off');
    }
}

class ConfigObject {
    private $data = Array();
    private $pdo;
    private $name;

    public function __construct($pdo, $name) {
        $this->pdo=$pdo;
        $this->name=$name;
    }

    function __get($property) {
        if ($property == "pdo") return (true);
        $query = $this->pdo->prepare("SELECT `".$property."` FROM `configuration` WHERE `key`=:name");
        $query->bindValue(":name", $this->name, PDO::PARAM_STR);
        $query->execute();
        $obj = $query->fetchObject();
        $this->data[$property]=$obj->$property;
        $query->closeCursor();
        return $this->data[$property];
    }

    function __set($property, $value) {
        $this->data[$property] = $value;
        if (($property == "pdo") || ($property == "name")) return (true);
        $query = $this->pdo->prepare("SELECT COUNT(*) FROM `configuration` WHERE `key`=:name");
        $query->bindValue(":name", $this->name, PDO::PARAM_STR);
        $query->execute();
        $count=$query->fetchColumn();
        $query->closeCursor();
        if ($count == 0) {
            $query = $this->pdo->prepare("INSERT INTO `configuration` (`value`, `key`) VALUES (:value, :name)");
            $query->bindValue(":value", $value, PDO::PARAM_STR);
            $query->bindValue(":name", $this->name, PDO::PARAM_STR);
            $query->execute();
        } else {
            $query = $this->pdo->prepare("UPDATE `configuration` SET `".$property."`=:value WHERE `key`=:name");
            $query->bindValue(":value", $value, PDO::PARAM_STR);
            $query->bindValue(":name", $this->name, PDO::PARAM_STR);
            $query->execute();
        }
    }

    public function __tostring() {
        $query = $this->pdo->prepare("SELECT `value` FROM `configuration` WHERE `key`=:name");
        $query->bindValue(":name", $this->name, PDO::PARAM_STR);
        $query->execute();
        $obj = $query->fetchObject();
        $this->data['value']=$obj->value;
        $query->closeCursor();
        return $this->data['value'];
    }
}
?>