PLSQL pracs

DROP TABLE employee
CREATE TABLE employee (
    empno int primary key,
    sal NUMBER(9),
    tax NUMBER(8,1)
);

INSERT INTO employee VALUES (100,50000,0)
INSERT INTO employee VALUES (101,70000,0)

DECLARE
eno int := 101;
msal NUMBER(9);
asal NUMBER(9);
ytax NUMBER(8,1);

BEGIN
SELECT sal INTO msal FROM employee WHERE empno = eno;
asal := msal * 12;
IF asal <= 700000 THEN
    ytax := 0;
ELSIF asal <= 1500000 THEN
    ytax := 0.1 * (asal - 700000);
ELSIF asal <= 2000000 THEN
    ytax := 0.2 * (asal - 700000);
ELSE
    ytax := 0.3 * (asal - 700000);
END IF;
UPDATE employee SET tax = ytax WHERE empno = eno;
END;
/
SELECT * FROM employee;

CREATE OR REPLACE PROCEDURE factorial (n int) AS
fact int:=1;
BEGIN
FOR i IN 1..n LOOP
fact:= fact * i;
END LOOP;
DBMS_OUTPUT.put_line('Factorial of ' || n || ' is ' || fact);
END;
/

exec factorial(6);