drop table student2;
create table student2
as select studno,name,id,grade, replace(jumin,substr(jumin,6,13),'-*******') "jumin",birthday,tel,height,weight,
(select d.dname from department d where g.deptno1=d.deptno) "dename1",
(select d.dname from department d where g.deptno2=d.deptno) "dename2",
(select p.name from professor p where p.profno=g.profno) "profname" from student g;
select * from student2;