Databases Reference
In-Depth Information
Prepare and Build
In this chapter, we will discuss different aspects of setting up an
Application
Express
(
APEX
) environment. Among others, we'll take a look at installing
APEX, performing preparational tasks before actually building applications,
and transforming the data model into initial screens. We will also discuss some
guidelines and best practices for these phases. You'll get a lot of new ideas for
structuring and building your applications.
Before doing that we will take a brief look at the history and background of APEX.
History and background
APEX is a very powerful development tool, which is used to create web-based
database-centric applications. The tool itself consists of a schema in the database
with a lot of tables, views, and PL/SQL code. It's available for every edition of the
database. The techniques that are used with this tool are PL/SQL, HTML, CSS,
and JavaScript.
Before APEX there was WebDB, which was based on the same techniques. WebDB
became part of Oracle Portal and disappeared in silence. The difference between
APEX and WebDB is that WebDB generates packages that generate the HTML pages,
while APEX generates the HTML pages at runtime from the repository. Despite this
approach APEX is amazingly fast.
Because the database is doing all the hard work, the architecture is fairly simple. We
only have to add a web server. We can choose one of the following web servers:
• Oracle HTTP Server (OHS)
• Embedded PL/SQL Gateway (EPG)
• APEX Listener
