Question

I am building an online shop and I have a problem.
I will have products which have a direct price (for example HTC Touch 2 Smartphone: $299.00 ), but in the same time I will have products which have prices for combinations based on specifications:

In this image you can see the database diagram, which I think would be ok for the multiple-price products:

THE MAIN PROBLEM:
Since this is a webshop, people will put items in the shopping cart. I think the items inserted into the shopping cart should be from the same table (in our case it would be the [combinations] table, since there are the prices stored).

Here are some data for these tables, just to be more clear:

[products]

productid   |   productName
1           |   Nike T-Shirt
2           |   HTC Touch 2 Smartphone

[specifications]

specId   |   productId   |   specName
1        |   1           |   Size
2        |   1           |   Color

[specvalues]

specValueId   |   specId   |   svValue
1             |   1        |   L
2             |   1        |   XL
3             |   2        |   white
4             |   2        |   blue
5             |   2        |   red

[combinations] (items into the cart)

combinationId   |   price   |   description
1               |   10      |   White L Nike T-Shirt
2               |   15      |   White XL Nike T-Shirt
3               |   11      |   Blue L Nike T-Shirt
4               |   16      |   Blue XL Nike T-Shirt
5               |   18      |   Red XL Nike T-Shirt

[combinationParts]

nmid   |   combinationId   |   specValueId
1      |   1               |   1
2      |   1               |   3
3      |   2               |   2
4      |   2               |   3
5      |   3               |   1
1      |   3               |   4
2      |   4               |   2
3      |   4               |   4
4      |   5               |   2
5      |   5               |   5

I hope my diagram and database population does make sense 🙂 .

So the question is how can I store the single price products (HTC Touch 2 Smartphone) so it can be added to shopping cart just like the multiple price products.

Answer 1

You might want to take a look at OpenCarts database.. It actually does a good job of this…

Essentially:

Create a tables for:
Products
Product Options (your ‘spcifications’)
Product Option Values (your ‘specvalues’)

Each product would be listed in the ‘Product Table’ and have a price
In the ‘Product Options’ table, you essentially list the different ‘specifications’ to a product…
The Product Option Values table lists the actual options and the change to the base price (+/-)…

To store the completed orders, OpenCart has essentially the same tables… (with order id associated)

Recetly I ripped out the cart feature to handle player registrations for a tournament…

The base ‘product’ is a player registration – $25
The ‘product_option’ Simply lists the ‘specification’ / “registration type”

For the ‘Registration Type’ the values are stored in the ‘product_option_value’ table…
They can either register as pay or pay & play (pay & play enters into minigames)
The pay is just the default option with no change to the price…
Pay and Play adds $15 to the price ($40 total)

I could easily add multiple “Product_options” and “product_option_value” sets to the product… Each either adding or subtracting from the products running total…

As for the script side, it just takes a couple loops to query and build the array with products array with product option as an sub array of products, and product option values as a sub array of each product option array

The ‘product_option_value’ table

--
-- Table structure for table `product`
--

CREATE TABLE IF NOT EXISTS `product` (
  `product_id` int(11) NOT NULL auto_increment,
  `site_id` int(11) NOT NULL,
  `name` varchar(255) character set utf8 collate utf8_unicode_ci NOT NULL,
  `description` text character set utf8 collate utf8_unicode_ci NOT NULL,
  `price` decimal(15,2) NOT NULL default '0.00',
  `date_available` date NOT NULL,
  `date_unavailable` date NOT NULL,
  `status` int(1) NOT NULL default '0',
  `date_added` datetime NOT NULL default '0000-00-00 00:00:00',
  `date_modified` datetime NOT NULL default '0000-00-00 00:00:00',
  PRIMARY KEY  (`product_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_bin AUTO_INCREMENT=2 ;

--
-- Dumping data for table `product`
--

INSERT INTO `product` (`product_id`, `site_id`, `name`, `description`, `price`, `date_available`, `date_unavailable`, `status`, `date_added`, `date_modified`) VALUES
(1, 2, 'Player Registration', 'This year we have two options:  Pay or Pay &amp; Play.<br />Pay &amp; Play allows you to enroll in the Flights Minigames for the weekend (Master''s Marks and Flights Doubles) and gives you twenty dollars worth of prize raffles.  <br />Pay &amp; Play is a $60.00 value and is only avalible during pre-registration.', 25.00, '2011-03-01', '2011-03-31', 1, '2011-03-01 00:00:00', '2011-03-01 00:00:00');

-- --------------------------------------------------------

--
-- Table structure for table `product_option`
--

CREATE TABLE IF NOT EXISTS `product_option` (
  `product_option_id` int(11) NOT NULL auto_increment,
  `product_id` int(11) NOT NULL,
  `sort_order` int(3) NOT NULL default '0',
  `name` varchar(255) character set utf8 collate utf8_unicode_ci NOT NULL,
  PRIMARY KEY  (`product_option_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_bin AUTO_INCREMENT=2 ;

--
-- Dumping data for table `product_option`
--

INSERT INTO `product_option` (`product_option_id`, `product_id`, `sort_order`, `name`) VALUES
(1, 1, 1, 'Registration Type');

-- --------------------------------------------------------

--
-- Table structure for table `product_option_value`
--

CREATE TABLE IF NOT EXISTS `product_option_value` (
  `product_option_value_id` int(11) NOT NULL auto_increment,
  `product_option_id` int(11) NOT NULL,
  `product_id` int(11) NOT NULL,
  `price` decimal(15,2) NOT NULL,
  `prefix` char(1) collate utf8_bin NOT NULL,
  `sort_order` int(3) NOT NULL,
  `name` varchar(255) character set utf8 collate utf8_unicode_ci NOT NULL,
  PRIMARY KEY  (`product_option_value_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_bin AUTO_INCREMENT=3 ;

--
-- Dumping data for table `product_option_value`
--

INSERT INTO `product_option_value` (`product_option_value_id`, `product_option_id`, `product_id`, `price`, `prefix`, `sort_order`, `name`) VALUES
(1, 1, 1, 15.00, '+', 1, 'Pay &amp; Play'),
(2, 1, 1, 0.00, '', 2, 'Pay');