IF statements can be nested so that alternative IF statements can be invoked after it is determined whether the conditional of an outer IF statement is TRUE or FALSE.
In the following example, the outer IF-THEN-ELSE statement tests whether an employee has a commission. The inner IF-THEN-ELSE statements then test whether the total compensation of the employee exceeds or is less than the company average.
DECLARE
v_empno emp.empno%TYPE;
v_sal emp.sal%TYPE;
v_comm emp.comm%TYPE;
v_avg NUMBER(7,2);
CURSOR emp_cursor IS SELECT empno, sal, comm FROM emp;
BEGIN
--
-- Calculate the average yearly compensation in the company
--
SELECT AVG((sal + NVL(comm,0)) * 24) INTO v_avg FROM emp;
DBMS_OUTPUT.PUT_LINE('Average Yearly Compensation: ' ||
TO_CHAR(v_avg,'$999,999.99'));
OPEN emp_cursor;
DBMS_OUTPUT.PUT_LINE('EMPNO YEARLY COMP');
DBMS_OUTPUT.PUT_LINE('----- -----------');
LOOP
FETCH emp_cursor INTO v_empno, v_sal, v_comm;
EXIT WHEN emp_cursor%NOTFOUND;
--
-- Test whether or not the employee gets a commission
--
IF v_comm IS NOT NULL AND v_comm > 0 THEN
--
-- Test if the employee's compensation with commission exceeds the average
--
IF (v_sal + v_comm) * 24 > v_avg THEN
DBMS_OUTPUT.PUT_LINE(v_empno || ' ' ||
TO_CHAR((v_sal + v_comm) * 24,'$999,999.99') ||
' Exceeds Average');
ELSE
DBMS_OUTPUT.PUT_LINE(v_empno || ' ' ||
TO_CHAR((v_sal + v_comm) * 24,'$999,999.99') ||
' Below Average');
END IF;
ELSE
--
-- Test if the employee's compensation without commission exceeds the average
--
IF v_sal * 24 > v_avg THEN
DBMS_OUTPUT.PUT_LINE(v_empno || ' ' ||
TO_CHAR(v_sal * 24,'$999,999.99') || ' Exceeds Average');
ELSE
DBMS_OUTPUT.PUT_LINE(v_empno || ' ' ||
TO_CHAR(v_sal * 24,'$999,999.99') || ' Below Average');
END IF;
END IF;
END LOOP;
CLOSE emp_cursor;
END;
The following output is generated from this program:
Average Yearly Compensation: $ 53,528.57
EMPNO YEARLY COMP
----- -----------
7369 $ 19,200.00 Below Average
7499 $ 45,600.00 Below Average
7521 $ 42,000.00 Below Average
7566 $ 71,400.00 Exceeds Average
7654 $ 63,600.00 Exceeds Average
7698 $ 68,400.00 Exceeds Average
7782 $ 58,800.00 Exceeds Average
7788 $ 72,000.00 Exceeds Average
7839 $ 120,000.00 Exceeds Average
7844 $ 36,000.00 Below Average
7876 $ 26,400.00 Below Average
7900 $ 22,800.00 Below Average
7902 $ 72,000.00 Exceeds Average
7934 $ 31,200.00 Below Average
When you use this form, you are actually nesting an IF statement inside the ELSE part of an outer IF statement. Therefore, you need one END IF statement for each nested IF statement and one for the parent IF-ELSE statement.