Oracle PL/SQL Language Pocket Reference

Conditional and Sequential Control

PL/SQL includes conditional (IF) structures as well as sequential control (GOTO, NULL) constructs.

Conditional Control Statements

IF-THEN combination

IF condition THEN
   executable statement(s)
END IF;

For example:

IF caller_type = 'VIP' THEN
   generate_response('GOLD');
END IF;

IF-THEN-ELSE combination

IF condition THEN
   TRUE sequence_of_executable_statement(s)
ELSE
   FALSE/NULL sequence_of_executable_statement(s)
END IF;

For example:

IF caller_type = 'VIP' THEN
   generate_response('GOLD');
ELSE
   generate_response('BRONZE');
END IF;

IF-THEN-ELSIF combination

IF condition-1 THEN
   statements-1
ELSIF condition-N THEN
   statements-N
[ELSE
   else statements]
END IF;

For example:

IF caller_type = 'VIP' THEN
   generate_response('GOLD');
ELSIF priority_client THEN
   generate_response('SILVER');
ELSE
   generate_response('BRONZE');
END IF;

Sequential Control Statements

The GOTO statement performs unconditional branching to a named label. It should be used rarely. At least one executable statement must follow the label (the NULL statement can be this necessary executable statement). The format of a GOTO statement is:

GOTO label_name;

The format of the label is:

<<label_name>>

There are a number of scope restrictions on where a GOTO can branch control. A GOTO:

• Can branch out of an IF statement, LOOP, or sub-block

• Cannot branch into an IF statement, LOOP, or sub-block

• Cannot branch from one section of an IF statement to another (from the IF/THEN section to the ELSE section is illegal)

• Cannot branch ...