oracle数据库。查询部门平均工资,平且显示工资等级,按部门分组,sql语句...答:(select a.deptno, b.dname, round(avg(a.sal), 2) avgsal from emp a, dept b where a.deptno = b.deptno group by a.deptno, b.dname) t1, salgrade t2 group by t1.deptno, t1.dname, t1.avgsal order by t1.deptno;查询结果 ...