define("_HOST",    "localhost");
define("_DBNAME",  "database");
define("_DBUSER",  "root");
define("_DBPASS",  "password");

try {

    $db = new PDO("mysql:host="._HOST.";dbname="._DBNAME."", _DBUSER, _DBPASS);
    $db -> exec("SET NAMES 'utf8'; SET CHARSET 'utf8'");

} catch (PDOException $ex) {
    echo $ex -> getMessage();
}