Oracle on the Web Part 5 – More on HTML DB

In this final part of the
series, we will look at some additional resources for HTML DB, which are freely
available. The resources include training documentation, blogs and news feeds,
a free workspace (hosted by Oracle), and a user forum. Oracle Corporation
typically posts a statement of direction on the OTN Web site, and we will take
a look at that as well.

Free Training Course

One of the examples used in
a previous article came from the Oracle HTML DB 2 Day Developer guide (Part No.
B14377-01, March 2005), available here.
The "course" covers the following topics.

  • How to Create a Tabular Form

  • How to Create a Parameterized
    Report

  • How to Create a Drill Down Report

  • How to Control Form Layout

  • How to Work with Check Boxes

  • How to Implement a Web Service

  • How to Create a Stacked Bar Chart

  • How to Incorporate JavaScript
    into an Application

  • How to Build and Deploy an Issue
    Tracking Application

The 2 Day Developer course
is similar to the 10g 2 Day DBA course. If you know nothing about the Oracle
RDBMS, reading the 10g course and expecting to be fully up to speed is not
going to happen. With HTML DB, you are a little better off with the Web
development aspects, but without knowing anything about Web design (basic HTML,
CSS and JavaScript), your development ability is going to be limited. Acquiring
several Web design books and bookmarking several "how to" Web sites for
JavaScript will make your life much easier. In addition, you get a bonus:
chances are pretty good you are going to enjoy Web page design, and it
certainly is a break from resetting passwords in SQL*Plus.

JavaScript can do many neat
things on a Web page, but it is not very forgiving when compared to HTML. For
example, (most) HTML will let a missing "</td>" tag slide. In
JavaScript, if you reference an object that does not exist, your page will fail
to load or submit properly. There is a difference between an element ID (for a
button) value of Submit and SUBMIT. It helps to make JavaScript "code safe"
(test for existence of an object before trying to do anything with it). Finally,
not all browsers treat HTML and JavaScript the same (thanks a lot, Microsoft).
If a user’s browser does not support JavaScript, do not forget to add in an
alert or page handling.

Shown below is what you see
when trying to sign in at Hotmail when JavaScript has been disabled.

Blogs and Newsfeeds

RSS generally stands for "Really
Simple Syndication," but you may see other definitions. Blogs and
newsfeeds are booming in popularity. Getting an RSS reader installed and
configured is very easy. Knowing this process helps you in two ways when it
comes to HTML DB. The first is that Oracle provides several feeds related to
HTML DB news, tips, and features at OTN. The second is that you, in turn, can
incorporate RSS into your Web applications.

Installing and adding a few
feeds to RSSReader takes less than two minutes.

Open the reader, click on
the Add button, paste in your Web site of interest, and you are done. Shown
below is an example of the HTML DB headlines.

There are three HTML DB
experts who maintain blogs at OTN. The blogs include tips, suggestions, and
other useful information. Drop the RSS link into your RSS reader and read away.
Interestingly enough, when trying to demo one of the blogs for this article,
clicking on a few of the links resulted in the error message shown below. Is
someone still using dictionary managed tablespaces? Ouch.

errm:ORA-01654: unable to extend index STUDIO.RSS_LOG_PK by 128 in tablespace FLOW_4217,
 sqlcode:-1654

The RSS links for headlines
and blogs can be found near the bottom right of the page at HTML
DB
.

Requesting a Free Workspace

Oracle Corporation provides
free workspaces. There is no guarantee this will always be so, and you are
cautioned not to develop or host "real" applications using this
service. Two advantages of using this free service are 1) it saves your disk
space, and 2) you can send users/developers to this site to learn and practice
rapid application development without them cluttering up your environment. Your
choice of workspace size is 2 and 5 MB.

The process of requesting a
workspace looks just like what you would see in your own installation of HTML
DB.

Overall, it is a very simple
process. It may take a day or so before your workspace is provisioned. The
email from [email protected] will
contain the name of your workspace, your username (which is your email
address), a password, and a link to the HTML DB Web site at http://htmldb.oracle.com/pls/otn/htmldb.
After logging on, the page looks similar to what we have seen before.

HTML DB User Forums at OTN

The forum here is an
excellent place to see the problems (and solutions) other users have
experienced, and some of the situations are quite sophisticated. The nature of
these questions is indicative of a maturing user base. In other words, if you
are just starting out with HTML DB, you have some catching up to do in terms of
experience and expertise. Questions are quickly answered and the quality of what
is posted by Oracle employees is yet another sign of Oracle’s commitment to
this product. The answers are much better than "Thanks for using
MetaLink, closing thread" answer. The HTML DB forum is at http://forums.oracle.com/forums/forum.jsp?forum=137.

The Future of HTML DB

According to Oracle, expect
a new version (2.0) in the second half of 2005, codenamed Columbus (just like
the way Microsoft codenames everything?). The new features in Columbus include
the following:

  • Building queries using a
    graphical designer

  • Browsing and creating managing
    database objects

  • Viewing data

  • Running scripts

  • Running ad hoc SQL and PL/SQL

  • Editing PL/SQL packages, procedures,
    and functions.

The notable shift or
addition to functionality is being able to interact more directly with database
objects and data (as opposed to using only forms). You can be one of the first
to find out when Columbus is released by using an RSS feed. Other RSS feeds
from Oracle include these sites.

In Closing

HTML DB is a powerful tool
for rapid application development. In very little time at all, developers can
prototype an application and then make changes that are immediately available
to and for users. With more direct object and data access in version 2.0, DBAs
and users may choose to totally skip iSQL*Plus. Being able to connect to a
database (or application) via your standard Web browser is a huge advantage
over performing hundreds of client installs or upgrades found in the
traditional client-server architecture environment. My guess is that there will
be many significant improvements in HTML DB in the years to come. It is not too
late to get on board!

»


See All Articles by Columnist
Steve Callan

Steve Callan
Steve Callan
Steve is an Oracle DBA (OCP 8i and 9i)/developer working in Denver. His Oracle experience also includes Forms and Reports, Oracle9iAS and Oracle9iDS.

Latest Articles