try {
    $dsn = 'mysql:host=localhost;dbname=chat';
    $username = 'chat';
    $password = '1234';
    $options = array(
        PDO::MYSQL_ATTR_INIT_COMMAND = > 'SET NAMES utf8',
    );
    $dbh = new PDO($dsn, $username, $password, $options);
} catch (PDOException $e) {
    echo $e->getMessage();
}

$dsn = 'mysql:host=localhost;dbname=chat;charset=utf8';
$username = 'chat';
$password = '1234';
$options = array(
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
);
$dbh = new PDO($dsn, $username, $password, $options);

CREATE USER 'chat'@'%' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON chat.* TO 'chat'@'localhost';