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Posted Jul 27, 2005

Oracle on the Web Part 5 - More on HTML DB

By Steve Callan

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,

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 htmldb_us@oracle.com 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

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