행 만들기

COPY_T 를 이용해서 없는 행을 만들곤 했는데
이렇게도 됨.

WITH TEST AS (
	SELECT 'A' service, '3' month FROM dual
	UNION ALL
	SELECT 'A', '4' FROM dual
	UNION ALL 
	SELECT 'A', '5' FROM dual
	UNION ALL 
	SELECT 'B', '5' FROM dual
)
SELECT distinct a.service, b.month
FROM TEST a, TEST b 
ORDER BY a.service