rollup与cube分析函数学习总结

cube: 有2的n次方种组合:

select empno,ename,job,

sum(sal),

grouping(empno) gempno,

grouping(ename) gename,

grouping(job) gjob

from scott.emp group by cube(empno,ename,job)

order by gempno,gename,gjob;

等效于：以上SQL总共有8种组合

empno,ename,job

empno,ename,null

empno,null,job

empno,null,null

null,ename,job

null,ename,null

null,null,job

null,null,null

select empno,ename,job,0 gempno,0 gename,0 gjob, sum(sal) from scott.emp group by empno,ename,job

union all

select empno,ename,null,0 gempno,0 gename,1 gjob ,sum(sal) from scott.emp group by empno,ename

union all

select empno,null,job,0 gempno,1 gename,0 gjob ,sum(sal) from scott.emp group by empno,job

union all

select empno,null,null,0 gempno,1 gename,1 gjob,sum(sal) from scott.emp group by empno

union all

select null,ename,job,1 gempno,0 gename,0 gjob,sum(sal) from scott.emp group by ename,job

union all

select null,ename,null,1 gempno,0 gename,1 gjob,sum(sal) from scott.emp group by ename

union all

select null,null,job,1 gempno,1 gename,0 gjob,sum(sal) from scott.emp group by job

union all

select null,null,null,1 gempno,1 gename,1 gjob,sum(sal) from scott.emp

order by gempno,gename,gjob;

rollup:有2*n种组合，从左到右的方法

select empno,ename,job,

sum(sal),

grouping(empno) gempno,

grouping(ename) gename,

grouping(job) gjob

from scott.emp group by rollup(empno,ename,job)

order by gempno,gename,gjob;

等效于：以上SQL总共有4种组合

empno,ename,job

empno,ename,null

empno,null,null

null,null,null

select empno,ename,job,0 gempno,0 gename,0 gjob, sum(sal) from scott.emp group by empno,ename,job

union all

select empno,ename,null,0 gempno,0 gename,1 gjob ,sum(sal) from scott.emp group by empno,ename

union all

select empno,null,null,0 gempno,1 gename,1 gjob,sum(sal) from scott.emp group by empno

union all

select null,null,null,1 gempno,1 gename,1 gjob,sum(sal) from scott.emp

order by gempno,gename,gjob;