HanSeokhyeon.log HanSeokhyeon.log

개요 개발하다보니 중복을 확인하고 제거할 일이 있어 기록 중복확인 SELECT COL_1, COL_2, COUNT(*) FROM TABLE GROUP BY COL_1, COL_2; --HAVING COUNT(*) > 1; 중복제거 조회 SELECT DISTINCT COL_1, COL_2 FROM TABLE; 중복제거 DELETE TABLE WHERE PK IN ( SELECT A.PK FROM TABLE A INNER JOIN ( SELECT MAX(PK) AS PK, COL_1, COL_2, COUNT(*) FROM TABLE GROUP BY COL_1, COL_2 HAVING COUNT(*) > 1 ) B ON A.COL_1 = B.COL_2 AND A.COL_1 = B.COL_2 AND A.PK !..