Oracle PL/SQL Programming, 6th Edition

Chapter 2. Creating and Running PL/SQL Code

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:

• Navigating the database

• Creating and editing PL/SQL source code

• Compiling the PL/SQL source code, and correcting any code errors (and, optionally, warnings) noted by the compiler

• Executing the compiled program from some environment

• Examining the 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.

Navigating the Database

Everybody who chooses to write PL/SQL programs does so to work with the contents of an Oracle database. It is, therefore, no surprise that you will need to know how to “get around” the Oracle database where your code is going to run. You will want to examine the data structures (tables, columns, sequences, user-defined types, etc.) in the database, ...