How can i store PDO objects

What if you make a config.php file that you include at the top of your page. You only need to create the object once, and all queries on the page can reference the same object:

function connection(){ $host = 'localhost'; $user = 'user'; $pass = 'password'; $dbName = 'db_name'; new PDO("mysql:host=$host; dbname=$dbName", $user, $pass); } $db = connection(); $query = 'Statement #1'; $stmt = $db->prepare($query); $stmt->execute(); $query = 'Statement #2'; $stmt = $db->prepare($query); $stmt->execute(); $query = 'Statement #3'; $stmt = $db->prepare($query); $stmt->execute(); $query = 'Statement #4'; $stmt = $db->prepare($query); $stmt->execute(); 

Several people has mentioned static and the Singleton pattern. This is what the code would look like, keeping only one instance of the PDO object around at one time:

class DB{ private static $_instance; private $_pdo; public static function getInstance(){ if(self::$_instance === NULL) { $dsn = 'mysql:dbname=dbname;host=host'; $user = 'user'; $password = 'password'; // call constructor and assign instance self::$_instance = new self($dsn, $user, $password); } return self::$_instance; } /** * Creates new DB wrapping a PDO instance * * Constructor is private because this class can't be instantiated. * */ private function __construct($dsn, $user, $password){ try { $this->_pdo = new PDO($dsn, $user, $password); } catch (PDOException $e) { echo 'Connection failed: ' . $e->getMessage(); } } /** * Singletons may not be cloned */ private function __clone() {} /** * Delegate every method call to PDO instance * * @param String $method * @param Array $args * @return Mixed */ public function __call($method, $args) { return call_user_func_array(array($this->_pdo, $method), $args); } } // To instantiate: $db = DB::getInstance();