sub add_item
{
my @item_ref;
my @cart_ref;
my ($dbh, $cart_ref, $item_id, $qty, $color) = @_;
               
    # If the item isn't already in the cart, look it up from the datab
+ase
    # and store it in the cart as a new entry with a quantity of zero.
    if (!exists ($cart_ref->{$item_id}))
    {
        my $sth = $dbh->prepare ("SELECT item_id, description, categor
+y, price, picture, thumbnail, mime_type, color FROM catalog_pet
                                    WHERE item_id = ?");
        $sth->execute ($item_id);
        my $item_ref = $sth->fetchrow_arrayref ();
        $sth->finish ();
                                 
        return if !defined ($item_ref);    # this shouldn't happen...
        @cart_ref->[0] = {};    # create new entry, indexed by item ID
        @cart_ref->[1] = $item_ref->{description};
                                  @cart_ref->[3] = $item_ref->{price};
        @cart_ref->[8] = 1;
    }
    @cart_ref->[8] = $qty;    
                @cart_ref->[7] = $color;    
                push (@cart_ref, @item_ref);
}
[download]

Well, first of all you have to change ALL of your code that uses this cart structure -- not just this one sub -- if you want to switch the cart from a hash to an array. I actually think this is probably the wrong approach and you would be better off making unique item ids for every one of your colors. You could also cheat by making a generated key to use in your shopping cart: my $item_key = $item_id . '|' . $color or something like that.

Just to give you an idea of what you need to do to that code to change it to arrays, here is another take on your add_item sub:

sub add_item {
    my ($dbh, $cart_ref, $item_id, $qty, $color) = @_;
               
    # If the item isn't already in the cart, look it up from the datab
+ase
    # and store it in the cart as a new entry with a quantity of zero.
    my $saw_item = 0;
    foreach  my $item (@{$cart_ref}) {
        if (($item->{'id'} == $item_id) && $item->{'color'} eq $color)
+) {
            $saw_item = 1;
            break;
        }
    }
 
    if (!$saw_item) {
        my $sth = $dbh->prepare ("SELECT item_id, description, categor
+y, price, picture, thumbnail, mime_type, color FROM catalog_pet WHERE
+ item_id = ?");
        $sth->execute ($item_id);
        my $row = $sth->fetchrow_hashref ();
                                 
        return if !defined ($row);    # this shouldn't happen...
        my $item_ref = {};
        $item_ref->{description} = $row->{description};
        $item_ref->{price}       = $row->{price};
        $item_ref->{qty}         = 1;
        $item_ref->{color} = $color;
    }
    $item_ref->{qty} = $qty;
  
    push (@{$cart_ref}, @item_ref);
}
[download]

Note that it is no longer possible to look up a single item in the cart by ID with this structure: you have to loop through all the items.

Hi Perrin,

I understand what you're trying to tell me. I think my solution will have to be with the database structure. I don't want the script to loop through all the items all the time. I believe a lot of processing time would be required to run the script.

So, I'm going to investigate the database option. From your earlier reply to the node you mentioned a higher entity.

Here's an example of the database structures and let me see if I understand what you're trying to suggest.

Product Table:
item_id: 7
description: ball
category: toys
price: 5.69
PRIMARY KEY item_id

Color Table:
color_id: 7br
item_id: 7
color: blue

color_id: 7gr
item_id: 7
color: green

color_id: 7or
item_id: 7
color: orange

PRIMARY KEY color_id
FOREIGN KEY item_id

I would write a SQL that would join these two tables, along the lines:

SELECT product.item_id, product.description, product.category, product.price, color.color WHERE product.item_id = color.color_id GROUP BY product.item_id, product.description, product.category, product.price;

If I'm on the right track thus far, will I have a popup menu with the individual colors for a single item as well as be able to choose that item more than once with a different color?

Here's my online catalog:

Item picture, item description, item price,
a popup menu that will show me the colors: blue, green orange for this item.
To get a better idea, please visit: http://www.summitwebcrafters.com/cgi-bin/pet_shop1.cgi

Click on the Toys category and the first item on the page is the item that has colors at the moment.

With the above database structure, will I be able to achieve the look and feel of that Toys page, with the color popup menu, and the ability to add that same item with two different colors?

Do you think I'm on the right track?