if(!empty($_POST['username']) && !empty($_POST['password']))
{
    $query = "SELECT * FROM users WHERE username='".$_POST['username']."' AND binary password='".$_POST['password']."'";

$dbh = new PDO('mysql:host=localhost;dbname=example', 'user', 'password');
$sth = $dbh->prepare('SELECT * FROM users WHERE username=? AND binary password=?');
$sth->execute(array($_POST['username'], $_POST['password']));
$result = $sth->fetch_all();