IF-THEN-ELSIF-ELSE provides a method of checking many alternatives in one statement. Formally it is equivalent to nested IF-THEN-ELSE-IF-THEN statements, but only one END IF is needed.
IF boolean-expression THEN
statements
[ ELSIF boolean-expression THEN
statements
[ ELSIF boolean-expression THEN
statements ] ...]
[ ELSE
statements ]
END IF;
The following example uses an IF-THEN-ELSIF-ELSE statement to count the number of employees by compensation range of USD 25,000.
DECLARE
v_empno emp.empno%TYPE;
v_comp NUMBER(8,2);
v_lt_25K SMALLINT := 0;
v_25K_50K SMALLINT := 0;
v_50K_75K SMALLINT := 0;
v_75K_100K SMALLINT := 0;
v_ge_100K SMALLINT := 0;
CURSOR emp_cursor IS SELECT empno, (sal + NVL(comm,0)) * 24 FROM emp;
BEGIN
OPEN emp_cursor;
LOOP
FETCH emp_cursor INTO v_empno, v_comp;
EXIT WHEN emp_cursor%NOTFOUND;
IF v_comp < 25000 THEN
v_lt_25K := v_lt_25K + 1;
ELSIF v_comp < 50000 THEN
v_25K_50K := v_25K_50K + 1;
ELSIF v_comp < 75000 THEN
v_50K_75K := v_50K_75K + 1;
ELSIF v_comp < 100000 THEN
v_75K_100K := v_75K_100K + 1;
ELSE
v_ge_100K := v_ge_100K + 1;
END IF;
END LOOP;
CLOSE emp_cursor;
DBMS_OUTPUT.PUT_LINE('Number of employees by yearly compensation');
DBMS_OUTPUT.PUT_LINE('Less than 25,000 : ' || v_lt_25K);
DBMS_OUTPUT.PUT_LINE('25,000 - 49,9999 : ' || v_25K_50K);
DBMS_OUTPUT.PUT_LINE('50,000 - 74,9999 : ' || v_50K_75K);
DBMS_OUTPUT.PUT_LINE('75,000 - 99,9999 : ' || v_75K_100K);
DBMS_OUTPUT.PUT_LINE('100,000 and over : ' || v_ge_100K);
END;
The following output is generated from this program:
Number of employees by yearly compensation
Less than 25,000 : 2
25,000 - 49,9999 : 5
50,000 - 74,9999 : 6
75,000 - 99,9999 : 0
100,000 and over : 1