} elsif ($action eq 'nextval') {
        my $oldrow = $row;
        $row = $sth->fetchrow_arrayref;
        return $oldrow->[0];
      }

##</code><code>##

  sub dbi_query_iterator {
    my ($sth, @params) = @_;

    $sth->execute(@params) or return;
    my $row = $sth->fetchrow_arrayref()

    return Iterator {
      my $action = shift() || 'nextval';

      if ($action eq 'exhausted?') {
        return ! defined $row;
      } elsif ($action eq 'nextval') {
        my $oldrow = $row;
        $row = $sth->fetchrow_arrayref;
        return $oldrow->[0];
      }
  }