db2 쿼리

db2일때 coallesce value nvl 차이

SELECT COALESCE(NULL, NULL, 'A', 'B') FROM SYSIBM.SYSDUMMY1
-- 결과: 'A'

SELECT VALUE(NULL, 'A') FROM SYSIBM.SYSDUMMY1
-- 결과: 'A'

SELECT NVL(NULL, 'A') FROM SYSIBM.SYSDUMMY1
-- 결과: 'A'