2과목) 다음 중 OUTER JOIN에 대한 설명으로 가장 적절한 것은?

SELECT * FROM A LEFT OUTER JOIN B ON A.ID = B.ID; SELECT * FROM A RIGHT OUTER JOIN B ON A.ID = B.ID; SELECT * FROM A FULL OUTER JOIN B ON A.ID = B.ID; SELECT * FROM A LEFT OUTER JOIN B WHERE A.ID = B.ID;