PHP PDO Encapsulation

<?php
Class DB {
private static $host = "localhost";
private static $dbname = "Bipp_new";
private static $username = "root";
private static $password = "123456";
function __construct () {
$numargs = Func_num_args ();
}

static function con () {
return new PDO (' mysql:host= '. Self:: $host. ') Dbname= '. Self:: $dbname, Self:: $username, Self:: $password,
Array (Pdo::mysql_attr_init_command => "SET NAMES UTF8"));
}


/**
/@parma $sql: SELECT name, colour, calories from fruit WHERE calories <:calories and name =:name
/@param $param _arr:array (": Calories" =>123, ": User" => "user")
**/
static function query ($sql, $param _arr) {
$stmt = Db::con ()->prepare ($sql, Array (pdo::attr_cursor => pdo::cursor_fwdonly));
$stmt->execute ($param _arr);
return $stmt->fetchall ();
}

/**
/@parma $sql: INSERT INTO ' page ' (PAGENAME) values (:p agename)
/@param $param _arr:array (":p agename" => "new test Name")
**/
static function exec ($sql, $param _arr) {
$stmt = Db::con ()->prepare ($sql, Array (pdo::attr_cursor => pdo::cursor_fwdonly));
return $stmt->execute ($param _arr);
}


}
?>