sum的分析函数疑惑

SELECT sum(sal) over(partition by t.deptno order by sal),--部门累加薪水 sum(sal) over(partition by t.deptno)--部门总薪水 FROM emp t 刚才在写sql遇到个需求，是根据部门的求和，一开始我写成了sum(sal) over(partition by t.deptno order by sal) ...