Re: Shopping Cart Schema - Sessions

Jason Beebe wrote: > > Hey, > > I'm looking for little information from those who have coded their own shopping cart apps. > what would you say the best way to setup a cart would be? more specificly, the method for adding > items to the cart. > > say the user is broswing around. when they entered the website a new session was created. when > they go to add an item, what is the best way store variables (such as what they bought and quantity) > in the session. i have read that it is possible to put all of your session variables in a single > associative array. however, i have not had any luck doing this myself. Under such a method of an > array, how would i store each item (product id and quantity, possibly price as well) in the cart > into the session. obviously i don't expect anyone to write an entire app. i am comfortable > starting the session, and doing th db extraction and presentation. i just need to know how to store > a variable in a session (passed through post) and how to extract it when need be (considering it is > an array). Thanks a lot! A session cookie can be of max 4096 bytes, so there is a limit to what you can set. Also it is (I'm not sure if this is part of the cookie standard) a general standard that only the supplier sites name and the user's ID should be stored, nothing else. Instead you can use the session id as the id of tables used for storing info: session_id key value Then you could store key value pairs in say a database. The above example is, btw, a misuse of relational databases, and should not be taken as the way of doing things. You should use a databaase in the background and store info in tables, a structure might be something like: customer_history ----------- session_id cart_id cart ----- id total date cart_item ------- cart_id item_id quantity price_pr_unit item ------- id name In this structure you can give each customer a number of carts (ie, previous orders), you can let each cart have several items, you will know the quantity of each item, and the item price for this (allowing for prices which are variable with price/discounts). You should also consider that you don't want people to register until checkout (just to mention this), if they aren't registered customers from before. If you want to read more about this, take a look at http://developer.ez.no where you can learn about eZ trade which has implemented such a shopping cart system. You'll find code, examples, design documents, administration documents and discussions covering this software. The software is free under the GNU GPL. -- Paul K Egell-Johnsen Developer/PR Manager eZ systems as http://ez.no/