1. LAG LAG(컬럼명) OVER(ORDER BY 정렬기준) - 이전 컬럼 가져오기 - 없으면 NULL 예시) SELECT NAME , LAG(NAME) OVER(ORDER BY NAME) FROM STUDENT ORDER BY NAME 2. LEAD LEAD(컬럼명) OVER(ORDER BY 정렬기준) - 다음 컬럼 가져오기 - 없으면 NULL 예시) SELECT NAME , LEAD(NAME) OVER(ORDER BY NAME) FROM STUDENT ORDER BY NAME
