Learning MySQL

Building a Web Database Application

This section gives an overview of web database applications, drawing analogies and contrasts to the conventional software that you use on your computer. As an overview, it doesn’t discuss technical details in depth; we get to the details later. How Web Software Works” briefly explains how web software works and shows you the steps that occur when a user clicks on a link in his web browser. In Three-Tier Architectures,” we discuss web database applications more formally, describing the three-tier architecture model and how MySQL, PHP, and Apache fit that model.

We’ll assume in this and the next two chapters that you’re familiar with basic programming concepts, including loops, conditionals, and expressions. We’ll also assume you’re familiar with the Web and, in particular, that you understand the basic principles of HTML markup. It doesn’t matter if you don’t know the details of the HTML standard, but we expect you’ll understand HTML when it’s shown to you. If you’ve never programmed or don’t know HTML, then we advise you to use one of the resources listed in Resources” at the end of this chapter before reading this and the next two chapters.

How Web Software Works

Web software is very different from a conventional application. To understand, consider the word processing software on your computer, an example of a traditional, conventional tool. You start the program, then interact with it: you move between typing, clicking on menus and widgets, and ...