Even if they never give a second thought to tasks such as system design or unit testing, all PL/SQL programmers must be familiar with some basic operational tasks:
Navigate the database.
Create and edit PL/SQL source code.
Compile the PL/SQL source code, correcting any code errors (and, optionally, warnings) noted by the compiler.
Execute the compiled program from some environment.
Examine results of program execution (screen output, changes to tables, etc.).
Unlike standalone languages such as C, PL/SQL is hosted inside an Oracle execution environment (it is an “embedded language”), so there are some unexpected nuances to all of these tasks: some are pleasant surprises; others, consternations. This chapter will show you how to accomplish these tasks at the most basic level (using SQL*Plus), with a brief tour of the nuances sprinkled in. It concludes with some drive-by examples of making calls to PL/SQL from inside several common programming environments such as PHP and C. For more detailed information about compilation and other more advanced tasks, see Chapter 20.