Object-Oriented or at least broken into function call libraries
There are certainly more items for that list, but those are the
biggest points I can think of. Maybe you can point out others.
Let's examine each of those in detail.
1. Database Independence.
Well you never know where your site is
going. Certainly when you build it, you hope it's going to get
huge and highly-trafficked. So with that in mind, you
don't want to tie yourself irreparably to MS Access or some other
cheesy, lightweight database. You will never be able to instantly
plug in different databases, but you can make the transition as
smooth as possible.
There are several different options that have cropped up to help
you abstract your database calls. One of the odd things about PHP
is that you have to code for a specific database, as all the function
calls are different for each database. To get around this, you can
use the a database abstraction layer, like those found in PHPLib,
the forthcoming PEAR, and the
we developed for SourceForge.