use DBI;

my $dbh = DBI->connect(...);

my $data = $dbh->selectall_arrayref(<<'__EOS__');
   SELECT id,
          name,
          parent,
          first_son,
          next_brother,
          depth
     FROM family_tree
    WHERE ...
__EOS__

my $count = @$data;

print(<<"__EOS__");
Content-Type: text/html

<applet code="family.class" width=610 height=400>
<param name="nodes" value="$count">
<!--
0=unique id (1 based)
1=text
2=parent id
3=first son id (0=none)
4=next brother id (0=none)
5=depth level (0 based)
-->
__EOS__

my $param = 1;
foreach my $fields (@$data) {
   my $name = $param++;
   my $value = join('|', @$fields);
   print("<param name=\"$param\" value=\"$value\">\n");
}

print("</applet>\n");