my $prod_dbh = DBI->connect_cached('DBI:Sybase:database','web_','web') || die "Couldn't connect to DB!\n" . DBI->errstr;
my $parent_sth = $prod_dbh->prepare_cached('select * from table where id = ?');
$parent_sth->bind_param(1,$id);
$parent_sth->execute();
my $parent_data = $parent_sth->fetchall_arrayref();

...

my $child_sth = $prod_dbh->prepare_cached('select * from table2 where id = ?');
$child_sth->bind_param(1,$parent_data[0]);
$child_sth->execute();
my $child_data = $child_sth->fetchall_arrayref();
print Dumper($child_data->[0]);


##</code><code>##

select 
       parent.*
     , child.*
  from table parent
  join table2 child on (parent.id=child.id)
 where parent.id = ?