Product Description
From the Publisher
Covers the 5 basic tools for Oracle Web application development: PL/SQL & PL/SQL Server Pages, Oracle Portal, Oracle Designer, Forms and Reports, Java Servlets and Java Server Pages
Based on Sten Vesterli's highly regarded "The 5 Ways of Building Oracle Web Applications" presentation (given at the IOUG-A Live/Anaheim, and EOUG/Madrid).
Easy-to-Use Glossary of key terms written in non-technical language
Techniques and tools for web application development are detailed with comparisons and descriptions.
Hands-on exercises (step-by-step or concept-based) interspersed throughout the book
From the Back Cover
Learn to build Web-based applications using Oracle development tools
Get step-by-step details on creating and deploying Web applications on Oracle servers.
Oracle Web Applications 101 discusses the Oracle9i Application Server architecture and explains how to build Web applications in five different ways with Java servlets and JavaServer Pages, PL/SQL and PL/SQL Server Pages, Oracle Designer, Oracle Portal, and Oracle Forms and Reports. You'll learn how and when to use an HTML-based application, a Java applet-based application, or a code generation tool to build powerful Web applications.
-Understand how the components of the Oracle9i Application Server work together
-Install all the Oracle software you need to get started building Web applications
-Design HTML-based Web applications using Java servlets or JavaServer Pages
-Build HTML applications with PL/SQL stored procedures or PL/SQL Server Pages
-Create PL/SQL Web applications quickly and easily with Oracle Designer
-Use Oracle Portal to build application components, such as dynamic Web pages
-Web-enable existing client/server applications built with Oracle Forms and Reports
Officially authorized by Oracle Corporation, this hands-on resource shows you everything you need to know to get started building Oracle Web applications right away.
About the Author
Excerpted from Oracle Web Applications by Sten Vesterli. Copyright © 2001. Reprinted by permission. All rights reserved.
Imagine a world where each TV set receives only one channel. There is no channel selector; and if you want to watch a program on another station, you need another TV set. You have to sign up for the channel with a TV station, and they send a professional TV set installer by your house to install the customized TV set for that channel. When you decide to watch another channel, yet another professional installer must come by and set up another TV set.
Ridiculous? Yes, of course!
But consider for a moment the way that client/server applications have been
built: for each application, someone has been going around installing custom clients at each client workstation; and for every new application, an IT professional has been going around to the users again to install and set up the application. Web applications are a return to the standards-based approach that works well for TV: if you want to start receiving a new channel, you simply tune in. Now, when you want to use a new Web application, you simply enter the address in your browser, and you have access.
This chapter defines Web applications and explains the difference between
intranets, extranets, and the Internet. It then describes the possible range of clients and ends with a discussion of the advantages of writing Web applications.
What Is a Web Application?
A Web application is an application based on the public standards used on the
World Wide Web (described in more detail in just a bit). The Internet, and the
World Wide Web in particular, has been such a tremendous success that it makes sense to emulate the principles used there, even if your application will never be accessible to the world via the Internet.
All multiuser applications today are client/server applications in one form or
another—each user works at a client workstation, and some central server stores the common data. Both the “old-fashioned” client/server applications developed with tools like Oracle Forms and the new Web applications are really client/server applications. To distinguish between traditional client/server applications and Web applications, we will use another measure: how many layers (or tiers) the whole architecture has.
In traditional client/server applications (using tools like Oracle Forms), a client
computer handled the user interface, and a database server stored the data. The
actual functionality ( business logic) of the application could reside on the client (as triggers in Oracle Forms) and/or in the databases (as stored procedures). This is a two-tierarchitecture.
Back in 1990, when the World Wide Web was originally conceived at CERN,
the European Laboratory for Particle Physics in Geneva, Switzerland, it was
intended to serve static files like research papers. The Web thus also originally had two tiers: a browser that needed only to display the file on the screen and a file server (or Web server) that delivered the file on request.
This was great; but after a while, Web developers wanted more. They wanted the
ability to create dynamic content by running a program that created a customized
page on the fly. The Web server was therefore extended with the possibility to call programs through the Common Gateway Interface (CGI). This was great, but it wasn’t long before Web developers wanted to let these programs access databases. This was achieved in many different ways from different programming languages; but because the databases normally resided on other servers than the Web servers, there was now a Web browser on the client side, and two or more layers of servers on the server side. This lead to the terms three-tier and
multitierapplications. A Web application is thus defined as a multitier application based on the Internet standards, using a Web browser as client.
