PL/SQL User's Guide and Reference

Reading Syntax Definitions

This chapter is not meant to provide a formal language definition. So, it defines syntax using a BNF-style grammar less concise but more readable than BNF.

When you are unsure of the syntax to use in a PL/SQL statement, trace through its syntax definition, reading from left to right and top to bottom. You can verify or construct any PL/SQL statement that way.

Syntax definitions use the following symbols and lexical conventions:

::= This symbol means "is defined as."
[ ] Brackets enclose optional items.
{ } Braces enclose items only one of which is required.
| A vertical bar separates alternatives within brackets or braces.
... An ellipsis shows that the preceding syntactic element can be repeated.
lower case Lower case denotes a syntactic element for which you must substitute a literal, identifier, or construct, whichever is appropriate.
UPPER CASE Upper case denotes PL/SQL keywords, which must be spelled as shown but can be entered in lower or mixed case.
punctuation Punctuation other than brackets, braces, vertical bars, and ellipses must be entered as shown.

::=	This symbol means "is defined as."
[ ]	Brackets enclose optional items.
{ }	Braces enclose items only one of which is required.
\|	A vertical bar separates alternatives within brackets or braces.
...	An ellipsis shows that the preceding syntactic element can be repeated.
lower case	Lower case denotes a syntactic element for which you must substitute a literal, identifier, or construct, whichever is appropriate.
UPPER CASE	Upper case denotes PL/SQL keywords, which must be spelled as shown but can be entered in lower or mixed case.
punctuation	Punctuation other than brackets, braces, vertical bars, and ellipses must be entered as shown.