1:列出所有员工的姓名,部门名称,和工资 select a1.ename,a1.sal,a2.dname from emp a1,dept a2 where a1.deptno = a2.deptno; 2:列出所有部门的详细信息和部门人数 select a2.deptno,a2.dname,a2.loc,count(a1.empno) from emp a1,dept a2 where a1.deptno(+) = a2.deptno group by a2.deptno,a2.dname,a