# 1

# (I don't know which module you're using for your $query->Dump expression,
#  so I'll simply be using the old school CGI.pm here)

use CGI 'param';
use DBI;
my $dbh = DBI->connect(...) or die ...;
my $id = param 'id';

# Hit the database with an UPDATE for every parameter
for my $p (param) {
    next if $p eq 'id';
    my $sql = sprintf("UPDATE mytable SET %s = ? WHERE id = ?", $p)
    $dbh->do($sql, undef, param($p), $id);
}