Advanced Oracle PL/SQL Programming with Packages

12.1. Why PLVio?

When you use PLVio, you can step away from the details of reading to and writing from specific types of text repositories. You build programs and utilities which get lines from the source and/or put lines to the target. But your code is not necessarily tied down to any specific type of repository. Consequently, your code can work with any of these different repositories without undergoing radical change.

The PLVhlp package's use of PLVio shows the power of abstracting the concept of source and repository for PL/SQL code. PLVhlp offers an architecture for displaying online help text for your own PL/SQL programs. The default mode for PLVhlp is to display the help text to standard output or your screen. Thus, I can call PLVhlp (through a frontend procedure in the PLV package) as shown below to get high-level information about PL/Vision itself:

SQL> exec PLV.help
Help for PLV
Overview of PL/Vision

PL/Vision is a development accelerator for PL/SQL programmers.
It is made up of a set of packages which you can use as
plug-and-play components in your own applications. Here is a
quick overview of some of the available packages:

PLVdyn - performs dynamic SQL and PL/SQL operations.
PLVexc - High-level exception handling capabilities.
PLVlog - Generic log mechanism.
PLVvu - View stored code and compile errors.

What if you are not developing applications in SQL*Plus and you cannot rely on DBMS_OUTPUT.PUT_LINE to display the help text? Instead of abandoning online help, you ...