[MYSQL] SUM(컬럼명) OVER(정렬)

• SUM(합할 컬럼명) OVER()
  • 합하려고 하는 컬럼의 모든 값을 합함
  • NULL값인 데이터 제외하고 누적 계산
• SUM(합할 컬럼명) OVER(누적 계산할 순서)
  • OVER는 SUM의 기준이 되는 값
  • NULL인 데이터 제외 누적 계산
  • 중복인 데이터는 제거하고 누적계산한다

  SELECT 
  		RE.COL1
  	,	SUM(RE.WON) OVER (ORDER BY RE.COL1)
  FROM (
  		SELECT 1 AS COL1, 100 AS WON UNION ALL
      SELECT 1 AS COL1, 100 AS WON UNION ALL
      SELECT 2 AS COL1, 200 AS WON UNION ALL
      SELECT 2 AS COL1, 200 AS WON UNION ALL
      SELECT 3 AS COL1, 300 AS WON UNION ALL
      SELECT 3 AS COL1, NULL AS WON UNION ALL
      SELECT 4 AS COL1, 400 AS WON 
  ) RE
  GROUP BY RE.COL1
  ;
  

• SUM(합할 컬럼명) OVER (PARTITION BY 그룹핑할 컬럼명 ORDER BY 누적 정렬할 기준)
  • PARTITION BY[MYSQL] SUM(컬럼명) OVER(정렬)