April 1999
Intermediate to advanced
99 pages
2h 4m
English
PL/SQL includes conditional (IF) structures as well as sequential control (GOTO, NULL) constructs.
IF condition THEN executable statement(s) END IF;
For example:
IF caller_type = 'VIP' THEN
generate_response('GOLD');
END IF;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 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;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 ...