Hi, programming newbie here - I have an architecture question regarding OOP.

So I have a "customer" class. I want to be able to create a customer object to retrieve an existing customers info, but update and existing customer and add a new one. here is an example of the fields:

First Name
Last Name
Address 1
Address 2
Email

So, what is the best way to design this class? The thing i am struggiling with is the updating the database part. How can this class make a new customer or update an existing one? I mean differentiate between the two functions - knowing which it needs to do.

Also, field definitaions and protetion levels are confusing to me. What fields are internal, and what are public, and what are get/set and what cases/notation do i assign each.

THank you for your help!

-- Jennifer Quick

Class design aside, there is a pretty simple way of determining whether to update or create data.

In many of my scenarios, I write a method to update or save class data. The first part of the method creates an UPDATE SQL query and executes it. If rows affected by the execute is 0 then I know that the update criteria was not found indicating that the record does not yet exist. So I then generate an INSERT query and execute that.

This technique saves the step of checking to see that the record exists and then running an UPDATE or INSERT based on that. In many cases you are doing an update so you'll just have the single UPDATE query to execute and all will be fine. However, in some cases you might be performing far more INSERTs than UPDATEs. For these cases you should create methods specifically for inserting data only.

-Peter