Posted by Rik on 05/28/06 14:47

Dynamo wrote:
> Hi again,
> I am constructing a site on a small scale where people can buy nik
> naks and pay for them via paypal. Everything works fine unless there
> is only one of an item left for sale. What if 2 people try to buy
> this item at the same time?
> I have partially overcome this problem by adding an extra column
> called status to my catalogue table. When somebody tries to buy the
> item I have created an interim page where the user is asked to
> confirm his purchase before sending the info to paypal and I have
> inserted an update query that changes the status from "available" to
> "pending sale" on this page.

I expect you keep the data of (to be) purchased items in some kind of
session.
If you choose to store this session in the database instead of the default
handler:
- You could check wether a product is available by looking at stock minus
the amount in the (several) session.
- Other people will immediately see that an item is out of stock, or perhaps
"reserved" if you choose to.
- As soon as their purchase is aborted or time out after a arbitrary amount
of time, items are available again.

Grtz,
--
Rik Wasmus

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