ORACLE SQL 超聚集运算GROUP BY ROLL UP CUBE
第十七章:增强group by(超聚集运算)
--计算部门编号和工作两列联合分组计算
select deptno,job,sum(sal)
from emp
group by deptno,job
order by deptno;
--rollup方式增强:
select deptno,job,sum(sal)
from emp
group by rollup(deptno,job)
order by deptno;
select deptno,job,sum(sal)
from emp
group by deptno,job
union
select deptno,null,sum(sal)
from emp
group by deptno
union
select null,null,sum(sal)
from emp
order by deptno;
--group by rollup(a,b,c) 会产生n+1种分组计算的结果
group by a
union
group by a,b
union
group by a,b,c
union
total
--cube方式增强:
select deptno,job,sum(sal)
from emp
group by cube(deptno,job)
order by deptno;
--group by cube(a,b,c),产生2的n次方种分组计算结果
group by a
union
group by b
union
group by c
union
group by a,b
union
group by b,c
union
group by a,c
union
group by a,b,c
union
total
--复合列的group by
select deptno,job,mgr,sum(sal) from emp
group by rollup(deptno,(job,mgr));
括号中的两列当作一列进行group by：
deptno --> A
(job,mgr) --> B
group by A,B
--grouping sets
select deptno,job,sum(sal) from emp
group by grouping sets
(deptno,job),(job);
返回的结果相当于：
group by deptno,job
union all
group by job
--grouping:区分小计和总计，grouping(deptno) , deptno 为空值的行 grouping 返回 1
select deptno,job,sum(sal),grouping(deptno) d,grouping(job) j
from emp
group by rollup(deptno,job)
order by deptno;
--借助grouping的标识打印“小计”和“总计“
select deptno,job,sum(sal),grouping(deptno)||grouping(job) f
from emp
group by rollup(deptno,job)
order by deptno;
select decode(grouping(deptno)||grouping(job),'01','小计','11','总计',deptno) deptno,job,sum(sal)
from emp
group by rollup(deptno,job);
--grouping_id : 返回所有grouping列组合位向量（二进制值）的十进制数:
col f for a4
select deptno,job,sum(sal),grouping(deptno)||grouping(job) f,grouping_id(deptno,job) b
from emp
group by rollup(deptno,job)
order by deptno;
DEPTNO JOB SUM(SAL) F B
------ --------- ---------- ---- ----------
10 CLERK 1300 00 0
10 MANAGER 2450 00 0
10 PRESIDENT 5000 00 0
10 8750 01 1
20 ANALYST 6000 00 0
20 CLERK 1900 00 0
20 MANAGER 2975 00 0
20 1087 01 1
30 CLERK 950 00 0
30 MANAGER 2850 00 0
30 SALESMAN 5600 00 0
30 9400 01 1
29025 11(二进制) 3 (十进制)
--打印如下结果集
DEPTNO JOB SUM(SAL)
------ --------- ----------
10 CLERK 1300
10 MANAGER 2450
10 PRESIDENT 5000
subtotal 8750
20 ANALYST 6000
20 CLERK 1900
20 MANAGER 2975
subtotal 10875
30 CLERK 950
30 MANAGER 2850
30 SALESMAN 5600
subtotal 9400
total 29025
select decode(grouping_id(deptno,job),1,'SUBTOTAL',3,'TOTAL',deptno) deptno,
job,
sum(sal)
FROM scott.emp a
GROUP BY ROLLUP(deptno,job);
select rownum,deptno,sum(sal),grouping(rownum) from emp group by rollup(deptno,rownum);
select deptno,rownum,grouping_id(deptno,rownum) flag,decode(grouping_id(deptno,rownum),3,'TOTAL',1,'SUBTOTAL',deptno) deptno,sum(sal)
from emp
group by rollup(deptno,rownum);
select deptno,job,grouping_id(deptno,job),
sum(sal)
FROM scott.emp a
GROUP BY ROLLUP(deptno,job);
select decode(grouping_id(deptno,job),3,'TOTAL',1,'SUBTOTAL',deptno) deptno,
job,
sum(sal)
FROM scott.emp a
GROUP BY ROLLUP(deptno,job);
select decode(grouping_id(deptno,job),3,'All departments''s sal '||'TOTAL',1,'department '||a.deptno||' '||'SUBTOTAL',deptno) deptno,
job,
sum(sal)
FROM scott.emp a
GROUP BY ROLLUP(deptno,job);
select decode(grouping_id(t2.deptno,rownum),3,'总计',1,'小计',t2.deptno) deptno,
decode(GROUPING(ROWNUM), 1, NULL, MAX(ENAME)) ENAME,
SUM(t1.sal)
FROM scott.emp t1, scott.dept t2
WHERE t1.deptno = t2.deptno
GROUP BY ROLLUP(t2.deptno,rownum);