Teradata中ROLLUP和GROUPING的使用
例如：
SELECT department_number ,SUM(salary_amount) FROM employee WHERE department_number < 402 GROUP BY ROLLUP (department_number) ORDER BY 1;
结果如下：
department_number Sum(salary_amount)
----------------------------- ------------------------------
? 591925.00
100 100000.00
201 73450.00
301 116400.00
302 56500.00
401 245575.00
产生了一个department_number 为null的汇总记录。
2，为了区分那个是汇总那个是空值，我们可以根据下面的例子来做。
SELECT
CASE GROUPING (department_number) WHEN 1 THEN 'Total' ELSE department_number END AS Deptno
,SUM(salary_amount)
FROM employee
GROUP BY ROLLUP (department_number)
ORDER BY 1;
结果如下：
Deptno Sum(salary_amount)
----------- ------------------------------
? 60000.00
100 100000.00
201 73450.00
301 116400.00
302 56500.00
401 245575.00
402 77000.00
403 233000.00
501 200125.00
Total 1162050.00
综合运用
SELECT CASE GROUPING (department_number) WHEN 1 THEN 'Total Depts' ELSE (COALESCE (department_number,'Null Dept') ) END AS Deptno ,CASE GROUPING (job_code) WHEN 1 THEN 'All Job Codes' ELSE (COALESCE (job_code,'Null Job Code') ) END AS job_code ,SUM(salary_amount) FROM employee GROUP BY ROLLUP (department_number,job_code) ORDER BY 1,2;
结果如下
Deptno job_code Sum(salary_amount) ---------------- ------------------- ----------------------------- 403 431100 31200.00 403 432101 201800.00 403 All Job Codes 233000.00 501 511100 66000.00 501 512101 134125.00 501 All Job Codes 200125.00 Null Dept All Job Codes 60000.00 Null Dept Null Job Code 60000.00 Total Depts All Job Codes 1162050.00
生成逐层汇总的效果，很想CUBE吧，哈哈。