的与功能很相似,也是在数据统计分析领域的一把好手。
关于ROLLUP的查询统计功能请参考文章《【ROLLUP】Oracle分组函数之ROLLUP魅力》(http://space.itpub.net/519536/viewspace-610995)。 1.先看一下ROLLUP的数据统计效果 1)创建测试表group_test SECOOLER@ora11g> create group_test (group_id int, job varchar2(10), name varchar2(10), salary int); Table created. 2)初始化数据 insert into group_test values (10,'Coding', 'Bruce',1000); insert into group_test values (10,'Programmer','Clair',1000); insert into group_test values (10,'Architect', 'Gideon',1000); insert into group_test values (10,'Director', 'Hill',1000); insert into group_test values (20,'Coding', 'Jason',2000); insert into group_test values (20,'Programmer','Joey',2000); insert into group_test values (20,'Architect', 'Martin',2000); insert into group_test values (20,'Director', 'Michael',2000); insert into group_test values (30,'Coding', 'Rebecca',3000); insert into group_test values (30,'Programmer','Rex',3000); insert into group_test values (30,'Architect', 'Richard',3000); insert into group_test values (30,'Director', 'Sabrina',3000); insert into group_test values (40,'Coding', 'Samuel',4000); insert into group_test values (40,'Programmer','Susy',4000); insert into group_test values (40,'Architect', 'Tina',4000); insert into group_test values (40,'Director', 'Wendy',4000); commit; 3)初始化之后的数据情况如下: SECOOLER@ora11g> set pages 100 SECOOLER@ora11g> select * from group_test; GROUP_ID JOB NAME SALARY ---------- ---------- ---------- ---------- 10 Coding Bruce 1000 10 Programmer Clair 1000 10 Architect Gideon 1000 10 Director Hill 1000 20 Coding Jason 2000 20 Programmer Joey 2000 20 Architect Martin 2000 20 Director Michael 2000 30 Coding Rebecca 3000 30 Programmer Rex 3000 30 Architect Richard 3000 30 Director Sabrina 3000 40 Coding Samuel 4000 40 Programmer Susy 4000 40 Architect Tina 4000 40 Director Wendy 4000 16 rows selected. 4)ROLLUP的数据统计效果 sec@ora10g> select group_id,job,grouping(GROUP_ID),grouping(JOB),sum(salary) from group_test by rollup(group_id, job); GROUP_ID JOB GROUPING(GROUP_ID) GROUPING(JOB) SUM(SALARY) ---------- ---------- ------------------ ------------- ----------- 10 Coding 0 0 1000 10 Director 0 0 1000 10 Architect 0 0 1000 10 Programmer 0 0 1000 10 0 1 4000 20 Coding 0 0 2000 20 Director 0 0 2000 20 Architect 0 0 2000 20 Programmer 0 0 2000 20 0 1 8000 30 Coding 0 0 3000 30 Director 0 0 3000 30 Architect 0 0 3000 30 Programmer 0 0 3000 30 0 1 12000 40 Coding 0 0 4000 40 Director 0 0 4000 40 Architect 0 0 4000 40 Programmer 0 0 4000 40 0 1 16000 1 1 40000 21 rows selected. 2.进一步体验CUBE的魅力 sec@ora10g> select group_id,job,grouping(GROUP_ID),grouping(JOB),sum(salary) from group_test group by cube(group_id, job) order by 1; GROUP_ID JOB GROUPING(GROUP_ID) GROUPING(JOB) SUM(SALARY) ---------- ---------- ------------------ ------------- ----------- 10 Architect 0 0 1000 10 Coding 0 0 1000 10 Director 0 0 1000 10 Programmer 0 0 1000 10 0 1 4000 20 Architect 0 0 2000 20 Coding 0 0 2000 20 Director 0 0 2000 20 Programmer 0 0 2000 20 0 1 8000 30 Architect 0 0 3000 30 Coding 0 0 3000 30 Director 0 0 3000 30 Programmer 0 0 3000 30 0 1 12000 40 Architect 0 0 4000 40 Coding 0 0 4000 40 Director 0 0 4000 40 Programmer 0 0 4000 40 0 1 16000 Architect 1 0 10000 Coding 1 0 10000 Director 1 0 10000 Programmer 1 0 10000 1 1 40000 25 rows selected. 解释如上结果中GROUPING函数返回值“0”和“1”的含义。 如果显示“1”表示CUBE函数对应的列(例如JOB字段)是由于CUBE函数所产生的空值对应的信息,即对此列进行汇总计算后的结果。 如果显示“0”表示此行对应的这列参未与ROLLUP函数分组汇总活动。 如果还是没有理解清楚,请参见Oracle官方文档中的描述内容:“Using a single column as its argument,GROUPINGreturns 1 when it encounters aNULLvalue created by aROLLUPorCUBEoperation. That is, if theNULLindicates the row is a subtotal,GROUPINGreturns a 1. Any other type of value, including a storedNULL, returns a 0.” 3.仔细观察一下,CUBE与ROLLUP之间的细微差别 rollup(a,b) 统计列包含:(a,b)、(a)、() rollup(a,b,c) 统计列包含:(a,b,c)、(a,b)、(a)、() ……以此类推ing…… cube(a,b) 统计列包含:(a,b)、(a)、(b)、() cube(a,b,c) 统计列包含:(a,b,c)、(a,b)、(a,c)、(b,c)、(a)、(b)、(c)、() ……以此类推ing…… So,上面例子中CUBE的结果比ROLLUP多了下面关于第一列GROUP_ID的统计信息: Architect 1 0 10000 Coding 1 0 10000 Director 1 0 10000 4.小结 CUBE在ROLLUP的基础上进一步从各种维度上给出细化的统计汇总结果。 CUBE与GROUP BY的关系可以参考Oracle官方文档中的例子,链接如下:,链接如下:《CUBE Extension to GROUP BY》http://docs.oracle.com/cd/E11882_01/server.112/e25554/aggreg.htm#DWHSG8614Good luck.
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