public function __construct() { $this->pdo = DatabasePDO::getInstance(); }
private static function initializeConnection() { if (is_null(self::$dbConn)) { self::$dbConn = DatabasePDO::getInstance(); } }
` <?php $pcdSearch = DatabasePDO::getInstance(); $pcdSearch->search(); class DatabasePDO { private static $dbh = null; protected $pdoDB; /* __construct() Set to private so that no one can create objects using new */ private function __construct() { try { $this->pdoDB = new PDO("mysql:host=", '', ''); $this->pdoDB->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch (PDOException $pe) { die('Connection error: ' . $pe->getMessage()); } } public static function getInstance() { if (!self::$dbh) { self::$dbh = new DatabasePDO(); } return self::$dbh; } /* Like the constructor, we make __clone private so nobody can clone the instance */