Conexão com PDO

gistfile1.php

function getConnection() {
    $dbhost="localhost";
    $dbuser="root";
    $dbpass="root";
    $dbname="db_name";
    $dbh = new PDO("mysql:host=$dbhost;dbname=$dbname;", $dbuser, $dbpass);
    $dbh -> exec("set names utf8");
    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    return $dbh;
}