SQL JOIN

1. INNER JOIN -> 교집합
2. OUTER JOIN -> 합집합
3. LEFT/RIGHT JOIN -> 부분집합

INNER JOIN

SELECT *
FROM -A- A INNER JOIN -B- B
ON A.VALUE = B.VALUE

FULL OUTER JOIN

SELECT *
FROM -A- A FULL OUTER JOIN -B- B
ON A.VALUE = B.VALUE

TABLE A와 TABLE B 교집합 제외하고 출력

SELECT *
FROM -A- A FULL OUTER JOIN -B- B
ON A.VALUE = B.VALUE
WHERE A.VALUE IS NULL OR B.VALUE IS NULL

LEFT JOIN

SELECT *
FROM -A- A LEFT JOIN -B- B
ON A.VALUE = B.VALUE

LIGHT JOIN

SELECT *
FROM -A- A RIGHT JOIN -B- B
ON A.VALUE = B.VALUE

A테이블만 출력 (B테이블과 교집합 되는 것 제외)

SELECT *
FROM -A- A LEFT JOIN -B- B
ON A.VALUE = B.VALUE
WHERE B.VALUE IS NULL

B테이블만 출력 (A테이블과 교집합 되는 것 제외)

SELECT *
FROM -A- A RIGHT JOIN -B- B
ON A.VALUE = B.VALUE
WHERE A.VALUE IS NULL