数据库oracle中求部门薪水最高的人的名字

我用select ename,sal from emp join (select deptno, max(sal) max_sal from emp group by deptno) t on (emp.sal = t.max_sal and emp.deptno = t.deptno);显示出来了
但是select ename,sal,deptno from emp join ..///加了deptno(select deptno, max(sal) max_sal from emp group by deptno) t on (emp.sal = t.max_sal and emp.deptno = t.deptno);这样就出现deptno是未详细定义列了怎么回事啊

select max(ename)keep(dense_rank last order by sal) ename,max(sal) sal,deptnofrom emp group by deptno;后面的问题描述不清，能把具体的语句和错误信息都贴出来吗

select ename from emp where sal=(select max(sal) from emp); select ename from (select * from emp order by sal desc) where rownum<=1;

不知道是不是版本的事，我用的是oracle10g，语句如下：select deptno,job,sal from emp where sal in (select max(sal) from emp group by deptno)