GROUP BY와 GROUP BY~ROLLUP의 비교

SELECT  TO_CHAR(T1.ORD_DT,'YYYYMM') ORD_YM 
		,T1.CUS_ID
		,SUM(T1.ORD_AMT) ORD_AMT
FROM    T_ORD T1
WHERE   T1.CUS_ID IN ('CUS_0001','CUS_0002')
AND     T1.ORD_DT >= TO_DATE('20170301','YYYYMMDD') 
AND     T1.ORD_DT < TO_DATE('20170501','YYYYMMDD')
GROUP BY TO_CHAR(T1.ORD_DT,'YYYYMM') ,T1.CUS_ID
ORDER BY TO_CHAR(T1.ORD_DT,'YYYYMM') ,T1.CUS_ID;

| ORD_YM | CUS_ID   | ORD_AMT |
| ------ | -------- | ------- |
| 201703 | CUS_0001 | 2800    |
| 201703 | CUS_0002 | 4300    |
| 201704 | CUS_0001 | 5000    |
| 201704 | CUS_0002 | 1900    |

SELECT TO_CHAR(T1.ORD_DT,'YYYYMM') ORD_YM 
		,T1.CUS_ID
		,SUM(T1.ORD_AMT) ORD_AMT
FROM    T_ORD T1
WHERE   T1.CUS_ID IN ('CUS_0001','CUS_0002')
AND     T1.ORD_DT >= TO_DATE('20170301','YYYYMMDD') 
AND     T1.ORD_DT < TO_DATE('20170501','YYYYMMDD')
GROUP BY ROLLUP(TO_CHAR(T1.ORD_DT,'YYYYMM') ,T1.CUS_ID)
ORDER BY TO_CHAR(T1.ORD_DT,'YYYYMM') ,T1.CUS_ID;

| ORD_YM | CUS_ID   | ORD_AMT |
| ------ | -------- | ------- |
| 201703 | CUS_0001 | 2800    |
| 201703 | CUS_0002 | 4300    |
| 201703 |          | 7100    |
| 201704 | CUS_0001 | 5000    |
| 201704 | CUS_0002 | 1900    |
| 201704 |          | 6900    |
|        |          | 14000   |

-- 주문상태, 주문년월, 고객ID 순서로 ROLLUP
SELECT  T1.ORD_ST ,TO_CHAR(T1.ORD_DT,'YYYYMM') ORD_YM ,T1.CUS_ID
		,SUM(T1.ORD_AMT) ORD_AMT
FROM    T_ORD T1
WHERE   T1.CUS_ID IN ('CUS_0001','CUS_0002')
AND     T1.ORD_DT >= TO_DATE('20170301','YYYYMMDD') 
AND     T1.ORD_DT < TO_DATE('20170501','YYYYMMDD')
GROUP BY ROLLUP(T1.ORD_ST ,TO_CHAR(T1.ORD_DT,'YYYYMM') ,T1.CUS_ID)
ORDER BY T1.ORD_ST ,TO_CHAR(T1.ORD_DT,'YYYYMM') ,T1.CUS_ID;

| ORD_ST | ORD_YM | CUS_ID   | ORD_AMT |
| ------ | ------ | -------- | ------- |
| COMP   | 201703 | CUS_0001 | 2800    |
| COMP   | 201703 | CUS_0002 | 4300    |
| COMP   | 201703 |          | 7100    |
| COMP   | 201704 | CUS_0001 | 4100    |
| COMP   | 201704 | CUS_0002 | 1900    |
| COMP   | 201704 |          | 6000    |
| COMP   |        |          | 13100   |
| WAIT   | 201704 | CUS_0001 | 900     |
| WAIT   | 201704 |          | 900     |
| WAIT   |        |          | 900     |
|        |        |          | 14000   |