MySQL Database, establish with more fields than you think you'll need ?

I'm creating a site with user registration and a store for electronic downloads. I'm going to use WebAssists e_commerce database, as my starting point.

I also want to offer, in my store, licenses to use my online products for a period of time.

As an example, I could have a product that my users login to, which is an online flash application. The user will have purchased a license to use this product for a set period, from my store.

Do you have any suggestions as to the fields I should add to your e_commerce database to allow me to do this ?

What about a DetailLicenseExpiry value in the OrderDetails table ? or should I put it in the Products table, or should I put it in both on the basis that if I don't use that field, its no big deal, but better to have the fields in place before I start creating my PHP pages.

Any words of wisdon will be greatly appreciated.

It does not hurt to have the extra fields in case you need them but it is not the most efficient way to go about it.

Ideally you would contemplate all the data and details that you will need to make the site function in the way you desire then create or modify the db schema based on your requirements.

If you are going to offer limited licenses then how you would like to make use of them will determine how the info should be stored. If there is only ever a single licensing option then it would make sense to store that duration as part of the product, if however you could have multiple license expiration for a single product and it depends on what the user has purchases then it would make sense to hold this info in a related table that corresponds to the user.

Let us know if you have any other questions and we will be glad to help you with whatever we can.