Hi,
I have a website in which i sell PIN numbers of telephone cards.
Telephone cards will be added to the shopping cart by the user. After payment he will be emailed the PIN number of the card he bought

I need to solve two issues
1) How to make sure that a unsold product is in the database after payment. example: suppose there is only 1 product in the database. Two users selected the product. Two of them made the payment. But only one will get the product (What i can do here?)

2) How i can block access to a record in the database when other process is using it? Suppose 2 users bought a card , how can i prevent issuing same PIN to two different users?

I AM USING SQL SERVER 2005 with ASP.net

Please help.
Thanks in advance.


Regards,
John.

my understand is

I would look at

In the Product table put Flag Sold in the Feild.


I think you mike have to have a PIN Table

PINID
ProductID
PinCODE
UserID

then when a Pin number is sold it get add the the PINtable along with the USERID