/*1.1*/
select e.ename,e.hiredate 
from emp e
where e.hiredate=(select min(hiredate) from emp) or  e.hiredate=(select max(hiredate) from emp);
/*1.2*/
select grade,count(*)
from emp e,salgrade s
where sal<=s.hisal and sal>=s.losal
group by grade;
/*1.3*/
select d.dname,sum(e.sal)
from emp e,dept d
where d.deptno=e.deptno
group by d.dname;
/*1.4*/
select e.deptno,e.ename,e.sal
from emp e
order by e.deptno,e.sal desc;
/*1.5*/
select e1.ename,e2.ename manger 
from emp e1,(select empno,ename from emp) e2 
where e1.mgr=e2.empno
/*1.6*/
select e.deptno,sum(e.sal+nvl(e.comm,0)),avg(e.sal+nvl(e.comm,0)),max(e.sal+nvl(e.comm,0)),min(e.sal+nvl(e.comm,0))
from emp e
group by e.deptno;