Oracle Forms
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Oracle Forms is an easy to use Rapid Application Development (RAD) environment for developing database applications. The language used inside is PL/SQL.
The environment notably supplies built-in record creation, query, and update modes, each with its own default data manipulations. This eliminates the need to program common and tedious operations, such as creating dynamic SQL, sensing changed fields, and locking rows.
As is normal with event driven interfaces, the software implements a complex algorithm, consisting of special functions called triggers, which occur at critical steps in the processing of records, the receipt of keyboard strokes, and the receipt of mouse movements. Different triggers are called before, during, and after each critical step.
Each function is initially a stub, containing a default action or nothing. Programming Oracle Forms therefore generally consists of modifying the contents of these triggers in order to alter the default behavior. Some triggers, if provided by the programmer, replace the default action, others augment it.
As a result of this strategy, it is possible to create a number of default form layouts which possess complete database functionality yet contain no programmer-written code at all.
Oracle Forms had its origins in a character-cell video tool called FastForms which accompanied Oracle version 4. At Oracle version 5 the tool was renamed SQL*Forms version 2. Prior to Forms version 3, Forms used its own primitive built-in language, augmented by user exits--compiled language code linked to the binary of the Oracle-provided run-time code. In version 3 this built-in language was replaced by PL/SQL, which vastly increased its power and ease of programming.
Oracle Forms version 4, which accompanied Oracle version 6, featured a common graphical interface designed to operate under Windows and X. Due to conflicting operational paradigms, Oracle Forms version 5, which accompanied Oracle version 7, featured custom graphical modes tuned especially for each of the major systems. However, its internal programmatic interface remained system independent.
In the Internet era, Oracle Forms version 6, which accompanied Oracle version 8, included a Forms Server which solved the problem of adapting Oracle Forms to a three-tier, browser-based delivery, without incurring any changes in its programmatic interface. The complex, highly interactive form interface was provided by a java applet which communicated directly with the Forms server.
The naming and numbering system applied to Oracle Forms subsequently underwent several changes due to marketing factors, without altering the essential nature of the product. The ability to code in Java, as well as PL/SQL, was added in this period.
Recent versions of Oracle Forms, from 9i onwards, no longer support the client-server or character -based interfaces, with three-tier, browser-based delivery being the only deployment choice.
External links
- Oracle FAQ (http://www.orafaq.com/faqfrm6i.htm)