Something like this, maybe?

# Transform hash into two arrays
my @fields = keys %{$record_ref};
my @values = map { $record_ref->{$_} } @fields;

my $sql
    = "UPDATE $table SET "
    . join( '=?,', @fields )
    . "=? WHERE $clauza_where";

# print "sql=",$sql,"\n";

eval {
    $sth = $dbh->prepare($sql);
    $sth->execute(@values);
    $dbh->commit;      # commit the changes if we get this far
};

if ($@) {
    warn "Transaction aborted because $@";
    $dbh->rollback;     # undo the incomplete changes
}
[download]

Update: fixed small typo regarding unmatched right curly bracket