ORACLE分析函数

sum(sal) over (partition by deptno order by ename) 按部门“连续”求总和 sum(sal) over (partition by deptno) 按部门求总和 sum(sal) over (order by deptno,ename) 不按部门“连续”求总和 sum(sal) over () 不按部门,求所有员工总和,效果等同于sum(sal)