多个单列查询汇总

eg. 按入职日期、部门、职务 分别汇总工资和

select to_char(b.hiredate) as 上班日期,a.dname as 部门,b.job as 职务,sum(b.sal) sum_sal from dept a,emp b
where a.deptno=b.deptno group by grouping sets(
to_char(b.hiredate),a.dname,b.job )

综合查询：

select to_char(b.hiredate) as 上班日期,emp b
where a.deptno=b.deptno group by grouping sets( rollup( to_char(b.hiredate)),cube(a.dname,b.job ))