[오라클] 가로를 세로로 묶기 (WM_CONCAT)

오라클 비공개 함수이다.

내부를 볼수없지만, 대용량 처리도 좋은 성능을 낸다.

-- 시급

WITH TEST AS (

                SELECT 1 AS IDX, 4000 AS WON FROM DUAL

    UNION ALL   SELECT 1 AS IDX, 1000 AS WON FROM DUAL

    UNION ALL   SELECT 3 AS IDX, 3000 AS WON FROM DUAL

    UNION ALL   SELECT 2 AS IDX, 4000 AS WON FROM DUAL

    UNION ALL   SELECT 5 AS IDX, 4000 AS WON FROM DUAL

    UNION ALL   SELECT 4 AS IDX, 6000 AS WON FROM DUAL

    UNION ALL   SELECT 4 AS IDX, 5000 AS WON FROM DUAL

)

SELECT  IDX, WM_CONCAT(WON)

FROM    TEST

GROUP BY IDX

;

기존에 RNK를 먹여서 하는 것보다 심플하다.

컬럼별로 쉼표로 구분되는데, 쉼표대신 다른걸로도 됬으면 하는데 ㅠㅠ