>>948
おそらくこんな感じだろう。

SELECT ename, (sal + nvl (comm., 0) ) * 12
FROM emp;

SELECT e.ename 社員, m.ename 上司
FROM emp e, emp m
WHERE e.mgr = m.empno;

SELECT cname, ename, lname
FROM emp, cust, loc
WHERE emp.empno = cust.salesno
AND cust.locno = loc.locno;