13
PL/SQL Language Elements

Grammar, which knows how to control even kings. --Molière

This chapter is a quick reference guide to PL/SQL syntax and semantics. It shows you how commands, parameters, and other language elements are sequenced to form PL/SQL statements. Also, to save you time and trouble, it provides usage notes and short examples.

This chapter discusses the following topics:

Assignment Statement

AUTONOMOUS_TRANSACTION Pragma

Blocks

CASE Statement

CLOSE Statement

Collection Methods

Collections

Comments

COMMIT Statement

Constants and Variables

Cursor Attributes

Cursor Variables

Cursors

DELETE Statement

EXCEPTION_INIT Pragma

Exceptions

EXECUTE IMMEDIATE Statement

EXIT Statement

Expressions

FETCH Statement

FORALL Statement

Functions

GOTO Statement

IF Statement

INSERT Statement

Literals

LOCK TABLE Statement

LOOP Statements

MERGE Statement

NULL Statement

Object Types

OPEN Statement

OPEN-FOR Statement

OPEN-FOR-USING Statement

Packages

Procedures

RAISE Statement

Records

RESTRICT_REFERENCES Pragma

RETURN Statement

ROLLBACK Statement

%ROWTYPE Attribute

SAVEPOINT Statement

SELECT INTO Statement

SERIALLY_REUSABLE Pragma

SET TRANSACTION Statement

SQL Cursor

SQLCODE Function

SQLERRM Function

%TYPE Attribute

UPDATE Statement

Reading the Syntax Diagrams

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

The diagrams are graphic representations of Backus-Naur Form (BNF) productions. Within the diagrams, keywords are enclosed in boxes, delimiters in circles, and identifiers in ovals.

Each diagram defines a syntactic element. Every path through the diagram describes a possible form of that element. Follow in the direction of the arrows. If a line loops back on itself, you can repeat the element enclosed by the loop.