The IF...THEN...ELSE statement allows you to process a series of statements under ELSE if the condition is false.
The Syntax for the IF...THEN...ELSE Statement
IF
THEN
ELSE
END IF;
some_condition_evaluates_to_true, tests a BOOLEAN condition that you provide.
If true, the second parameter, perform_statements_condition_true, executes.
If the condition is false, the parameter perform_statements_condition_false executes.
SQL>
SQL> set echo on
SQL>
SQL> DECLARE
2 v_a Number := 50 ;
3 v_b Number;
4 BEGIN
5 IF v_a > 40 THEN
6 v_b := v_a - 40;
7 DBMS_OUTPUT.PUT_LINE('Hours b worked = ' || v_b);
8 ELSE
9 v_b := 0;
10 END IF;
11 END;
12 /
Hours b worked = 10
PL/SQL procedure successfully completed.
SQL>