$userDB = 'loginDB';
    $passwordDB = 'passwordDB';

    try {
      $DBH = new PDO('mssql:dbname=spr_bank;host=srv-back', $userDB, $passwordDB);
      $DBH->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );

    }
    catch(PDOException $e) {
        echo "<h1 style='font-weight:bold; color:red;'>Error. Can not connect to Database</h1>";
        file_put_contents('PDOErrors.log', date("Y-m-d H:i:s")." - ".$e->getMessage()."\n", FILE_APPEND);
        exit();
    }

$query = $DBH->prepare(" SELECT name FROM spr_sotrudnik WHERE login = :login AND password = :password");

        $login = (isset($_POST['login']) === true) ? $_POST['login'] : '' ; // ? : shorthand for if else
        $password = (isset($_POST['password']) === true) ? md5($_POST['password']) : '' ; // ? : shorthand for if else

        $query->bindValue(':login', $login);
        $query->bindValue(':password', $password);

        try {
            // run the query
            $query->execute();

            $rows = $query->fetchAll(PDO::FETCH_ASSOC);
            echo '<pre>', print_r($rows, true),'</pre>';
        }
        catch (PDOException $e){
            echo $e->getMessage(), $e->getFile(), $e->getLine();
        }

$query = $DBH->prepare(" SELECT CONVERT(NVARCHAR(10),name) AS s FROM spr_sotrudnik WHERE login = :login AND password = :password");