关于rollup的简单用法和层次查询

select t.deptno,t.job,sum(sal) from emp t group by rollup(t.deptno,t.job); 等价于 web select t.deptno,t.job,sum(sal) from emp t group by t.deptno,t.job + select t.deptno,sum(sal) from emp t group by t.de

>>阅读原文<<