#!/usr/bin/env perl
use strict;
use warnings;
use DBD::mysql;
(...)
my $updateStatement =
"UPDATE `<censored>_buch`
SET
        `autor` = ?,
        `titel` = ?,
        `verlag` = ?,
        `jahr` = ?,
        `ort` = ?,
        `auflage` = ?,
        `sprache` = ?,
        `einband` = ?,
        `seiten` = ?,
        `format` = ?,
        `stichwort` = ?,
        `sparteName` = ?,
        `lfdnr` = ?,
        `infotext` = ?,
        `preis_euro` = ?,
        `gewicht` = ?
WHERE
        `isbn` = ?
LIMIT 1";
(...)
my $db = DBI->connect("DBI:mysql:database=<censored>;host=localhost;port=3306", "<censored>", "<censored>");
my $update = $db->prepare($updateStatement) or die ($DBI::errstr);