/* 1 */
select s.sno, sname, city, phone
from supplier s, ps, part p
where s.sno=ps.sno and ps.pno=p.pno and p.pname='º¼Æ®'
order by s.sno;

/* 2 */
select sname, phone
from supplier s, ps
where s.sno=ps.sno and  
 ps.pno in (select p.pno
  from part p, gp
  where gp.pno=p.pno and (p.color='°ËÁ¤' or p.color='»¡°­') and gp.gno='g1');

/* 3 */
select sname, city, phone, ps.price
from supplier s, ps
where s.sno=ps.sno and ps.pno in (select p.pno
    from part p, gp
    where p.pno=gp.pno and usage>=30 and wgt > 20);

/* 4 */
select pname, avg(price) as Æò±Õ´Ü°¡
from part, ps
where part.pno=ps.pno
group by part.pname
having avg(price) >=15;

/* 5 */
select gname, price, gc.date, gc.qty
from goods g, gc
where gc.gno=g.gno and g.price = (select max(price)
     from goods);