package CART::user;
use base qw(CART::DBI);
__PACKAGE__->table('user');
__PACKAGE__->columns(All => qw(id name));
__PACKAGE__->has_many(items => [qw(CART::item item)]);

package CART::item;
use base qw(CART::DBI);
__PACKAGE__->table('item');
__PACKAGE__->columns(All => qw(id name));
__PACKAGE__->has_many(users => [qw(DVD::user user)]);

package CART::cart;
use base qw(CART::DBI);
__PACKAGE__->table('cart');
__PACKAGE__->columns(Primary => qw/user item/);
__PACKAGE__->has_a(user => 'DVD::user');
__PACKAGE__->has_a(item => 'DVD::item');

package main;

for my $user (CART::user->retrieve_all) {
   my $items = $user->items;
   print $user->name;
   print " has no items\n" and next unless $items;
   print "has these items:\n";
   print $_->name, "\n" for @$items;
}