Databases Reference
In-Depth Information
Chapter 1
An Introduction to APEX 4.2
Welcome to the wonderful world of Oracle Application Express (APEX). You're about to learn how to use a tool that
will revolutionize the way you think about and approach writing web-based Oracle systems. It certainly has done so
for the authors.
Prior to the advent of APEX, developing fully interactive web-based systems for data that resided within an Oracle
database almost always meant learning a new and often complex language like Java, .NET, or PHP and then figuring
out how to integrate your chosen language seamlessly with that data. Often this also meant trying to incorporate
business rules that were already coded in the form of PL/SQL program units.
In such situations, it could take months or even years just to become proficient enough with your chosen
language to begin to write a functional system. If you're like many developers, you become frustrated with the fact that
you've spent an inordinate amount of time to do what seems like a relatively easy task.
Fear not! The days of long-winded and complex web development platforms may be behind you.
What Is APEX?
APEX is a 100% browser-based rapid application development (RAD) tool that helps you to create rich interactive
Oracle-based web applications very quickly and with relatively little programming effort.
There are many RAD development tools and platforms on the market. If you're dealing with data that resides in
an Oracle database, a number of things make APEX distinctive and thus more attractive as a development platform.
First and foremost is the fact that APEX is built on and uses as its core languages SQL and PL/SQL. This is a huge
advantage for those of you who have already been working with the Oracle database because it means you can
immediately draw on what you know. Even if you don't have an Oracle background but are going to be working with
an Oracle database, you need to learn about its particular flavor of SQL and will at some point likely find a need for the
PL/SQL procedural language.
PL/SQL program units become even more beneficial when migrating from an Oracle-based system that already
has a significant amount of business logic coded into stored PL/SQL program units. In this instance, you can almost
immediately take advantage of that logic with very little effort or change to the existing code.
Another great advantage is that APEX is a declarative tool that provides a feature-rich core designed to make your
job easier. Because APEX takes care of many of the underlying functions common to all web-based applications, you
can focus on the logic specific to your application.
A large share of what you need to accomplish can be done using one of the many built-in wizards provided
as part of the APEX Application Builder. The wizards walk you through the process of defining what you want your
application to do and then store that information as metadata. Once a wizard is complete, you can edit and enhance
the functionality or even replace it with your own custom SQL and PL/SQL routines. After you become proficient
with APEX, you might even find yourself bypassing the wizards altogether and generating more complex definitions
directly.
During the course of the topic, you'll likely discover you a few other tools at your disposal, but in truth, you could
easily develop a very rich application using nothing but your web browser and what APEX provides for you.
