[postgreSQL] FULL OUTER JOIN

--5)FULL OUTER 조인
--INNER + LEFT OUTER + RIGHT OUTER 조인 집합을 모두 출력하는 조인방식
--두 테이블간 출력가능한 모든 데이터를 포함한 집합을 출력
SELECT A.ID AS ID_A, A.FRUIT AS FRUIT_A,
	   B.ID AS ID_B, B.FRUIT AS FRUIT_B
FROM BASKET_A A 
FULL OUTER JOIN BASKET_B B 
	ON A.FRUIT = B.FRUIT;

--ONLY OUTER 조인
SELECT A.ID AS ID_A, A.FRUIT AS FRUIT_A,
	   B.ID AS ID_B, B.FRUIT AS FRUIT_B
FROM BASKET_A A 
FULL OUTER JOIN BASKET_B B 
	ON A.FRUIT = B.FRUIT
WHERE A.ID IS null	--A.ID가 널(RIGHT OUTER) 혹은 B.ID가 널(LEFT OUTER)인 값을 추출 
   OR B.ID IS NULL;	--즉, 전체에서 교집합만 뺀것