#!/perl/bin/perl
use strict;
use warnings;
use Data::Dumper;
use SQL::Abstract;

my %fd = (
    txtName    => 'OK',
    txtCreated => '',
    txtDateren => '', # will use NOW() function 
    txtOldname => 'NOT OK',
    txtDel     => '',
);
my $id = 1234;

# column name mapping
my %cols = (
  txtName    => 'Listname', 
  txtCreated => 'DateCreated',
  txtDateren => 'DateRenamed', 
  txtOldname => 'OldListname',
  txtDel     => 'DateDeleted',
);

# which column to update?
my %column = map { $cols{$_} => $fd{$_} } grep { $fd{$_} } keys %fd;
$column{DateRenamed} = \'NOW()';

my $sql = SQL::Abstract->new;
my($query, @binds) = $sql->update('table', \%column, { id => id });
print Data::Dumper::Dumper($query, \@binds);

##</code><code>##

$VAR1 = 'UPDATE table SET DateRenamed = NOW(), Listname = ?, OldListname = ? WHERE ( id = ? )';
$VAR2 = [
          'OK',
          'NOT OK',
          1234
        ];