【功能】连续求和分析函数
【参数】具体参示例
【说明】Oracle分析函数
NC示例：
select bdcode,sum(1) over(order by bdcode) aa from bd_bdinfo
【示例】
SQL> select deptno,ename,sal from emp order by deptno;
DEPTNO ENAME SAL
---------- ---------- ----------
10 CLARK 2450
KING 5000
MILLER 1300
20 SMITH 800
ADAMS 1100
FORD 3000
SCOTT 3000
JONES 2975
30 ALLEN 1600
BLAKE 2850
MARTIN 1250
JAMES 950
TURNER 1500
WARD 1250
使用 sum(sal) over (order by ename)... 查询员工的薪水“连续”求和,
注意over (order by ename)如果没有order by 子句，求和就不是“连续”的，
放在一起，体会一下不同之处：
SQL> select deptno,ename,sal,
sum(sal) over (order by ename) 连续求和,
sum(sal) over () 总和, -- 此处sum(sal) over () 等同于sum(sal)
100*round(sal/sum(sal) over (),4) "份额(%)"
from emp
/
DEPTNO ENAME SAL 连续求和 总和 份额(%)
---------- ---------- ---------- ---------- ---------- ----------
20 ADAMS 1100 1100 29025 3.79
30 ALLEN 1600 2700 29025 5.51
30 BLAKE 2850 5550 29025 9.82
10 CLARK 2450 8000 29025 8.44
20 FORD 3000 11000 29025 10.34
30 JAMES 950 11950 29025 3.27
20 JONES 2975 14925 29025 10.25
10 KING 5000 19925 29025 17.23
30 MARTIN 1250 21175 29025 4.31
10 MILLER 1300 22475 29025 4.48
20 SCOTT 3000 25475 29025 10.34
20 SMITH 800 26275 29025 2.76
30 TURNER 1500 27775 29025 5.17
30 WARD 1250 29025 29025 4.31
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)。
SQL> select deptno,ename,sal,
sum(sal) over (partition by deptno order by ename) 部门连续求和,--各部门的薪水"连续"求和
sum(sal) over (partition by deptno) 部门总和, -- 部门统计的总和，同一部门总和不变
100*round(sal/sum(sal) over (partition by deptno),4) "部门份额(%)",
sum(sal) over (order by deptno,ename) 连续求和, --所有部门的薪水"连续"求和
sum(sal) over () 总和, -- 此处sum(sal) over () 等同于sum(sal)，所有员工的薪水总和
100*round(sal/sum(sal) over (),4) "总份额(%)"
from emp
/
DEPTNO ENAME SAL 部门连续求和 部门总和 部门份额(%) 连续求和 总和 总份额(%)
------ ------ ----- ------------ ---------- ----------- ---------- ------ ----------
10 CLARK 2450 2450 8750 28 2450 29025 8.44
KING 5000 7450 8750 57.14 7450 29025 17.23
MILLER 1300 8750 8750 14.86 8750 29025 4.48
20 ADAMS 1100 1100 10875 10.11 9850 29025 3.79
FORD 3000 4100 10875 27.59 12850 29025 10.34
JONES 2975 7075 10875 27.36 15825 29025 10.25
SCOTT 3000 10075 10875 27.59 18825 29025 10.34
SMITH 800 10875 10875 7.36 19625 29025 2.76
30 ALLEN 1600 1600 9400 17.02 21225 29025 5.51
BLAKE 2850 4450 9400 30.32 24075 29025 9.82
JAMES 950 5400 9400 10.11 25025 29025 3.27
MARTIN 1250 6650 9400 13.3 26275 29025 4.31
TURNER 1500 8150 9400 15.96 27775 29025 5.17
WARD 1250 9400 9400 13.3 29025 29025 4.31
SQL> select deptno,ename,sal,sum(sal) over (partition by deptno order by sal) dept_sum,
sum(sal) over (order by deptno,sal) sum
from emp;
DEPTNO ENAME SAL DEPT_SUM SUM
---------- ---------- ---------- ---------- ----------
10 MILLER 1300 1300 1300
CLARK 2450 3750 3750
KING 5000 8750 8750
20 SMITH 800 800 9550
ADAMS 1100 1900 10650
JONES 2975 4875 13625
SCOTT 3000 10875 19625
FORD 3000 10875 19625
30 JAMES 950 950 20575
WARD 1250 3450 23075
MARTIN 1250 3450 23075
TURNER 1500 4950 24575
ALLEN 1600 6550 26175
BLAKE 2850 9400 29025
SQL> select deptno,ename,sal,
sum(sal) over (partition by deptno order by deptno desc,sal desc) dept_sum,
sum(sal) over (order by deptno desc,sal desc) sum
from emp;
DEPTNO ENAME SAL DEPT_SUM SUM
---------- ---------- ---------- ---------- ----------
30 BLAKE 2850 2850 2850
ALLEN 1600 4450 4450
TURNER 1500 5950 5950
WARD 1250 8450 8450
MARTIN 1250 8450 8450
JAMES 950 9400 9400
20 SCOTT 3000 6000 15400
FORD 3000 6000 15400
JONES 2975 8975 18375
ADAMS 1100 10075 19475
SMITH 800 10875 20275
10 KING 5000 5000 25275
CLARK 2450 7450 27725
MILLER 1300 8750 29025
里已经有排序的语句了，如果再在句尾添加排序子句，一致倒罢了，不一致，结果就令人费劲了。如：
SQL> select deptno,ename,sal,sum(sal) over (partition by deptno order by sal) dept_sum,
sum(sal) over (order by deptno,sal) sum
from emp
order by deptno desc;
DEPTNO ENAME SAL DEPT_SUM SUM
---------- ---------- ---------- ---------- ----------
30 JAMES 950 950 20575
WARD 1250 3450 23075
MARTIN 1250 3450 23075
TURNER 1500 4950 24575
ALLEN 1600 6550 26175
BLAKE 2850 9400 29025
20 SMITH 800 800 9550
ADAMS 1100 1900 10650
JONES 2975 4875 13625
SCOTT 3000 10875 19625
FORD 3000 10875 19625
10 MILLER 1300 1300 1300
CLARK 2450 3750 3750
KING 5000 8750 8750