Oracle PL/SQL Programming, 5th Edition

The PL/SQL Character Set

A PL/SQL program consists of a sequence of statements, each made up of one or more lines of text. The precise characters available to you will depend on what database character set you’re using. For example, Table 3-1 illustrates the available characters in the US7ASCII character set.

Table 3-1. Characters available to PL/SQL in the US7ASCII character set

Type	Characters
Letters	A–Z, a–z
Digits	0–9
Symbols	~ ! @ # $ % * () _ – + = | : ; " ' < > , . ? / ^
Whitespace	Tab, space, newline, carriage return

Every keyword, operator, and token in PL/SQL is made from various combinations of characters in this character set. Now you just have to figure out how to put them all together!

And now for some real PL/SQL trivia: Oracle’s documentation—as well as earlier editions of this book—list the ampersand, curly braces, and square brackets as part of the default character set:

& { } [ ]

While all characters are allowed in literal strings, Oracle does not seem to use these particular five characters anywhere in the visible portions of PL/SQL. Moreover, there is no direct way to use these characters in programmer-defined identifiers.

Regardless of your memory for such trivia, you’ll definitely want to remember that PL/SQL is a case-insensitive language. That is, it doesn’t matter how you type keywords and identifiers; uppercase letters are treated the same way as lowercase letters unless surrounded by delimiters that make them a literal string. By convention, the authors of this book ...