Oracle 数据去重_oracle去重查询

在Oracle数据库中删除重复数据

一，查询及删除重复记录的SQL语句

Person01表：

1. 查询表中多余的重复数据，根据ID字段来判断是否重复

SELECT * FROM PERSON01 WHERE ID IN (SELECT ID FROM PERSON01 GROUP BY ID HAVING COUNT(ID) > 1)
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2. 根据ID字段来判断是否重复删除表中多余的重复记录、重复记录根据ID字段来判断，多条重复记录只保留 ROWID 最小的那条

DELETE FROM PERSON01 WHERE (ID) IN (SELECT ID FROM PERSON01 GROUP BY ID HAVING COUNT(ID) > 1) AND ROWID NOT IN (SELECT MIN(ROWID) FROM PERSON01 GROUP BY ID HAVING COUNT(*) > 1);
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3. 查询表中多余的重复数据，根据多个字段来判断是否重复

SELECT * FROM PERSON01 A WHERE (A.ID, A.PERSON01) IN(SELECT ID, PERSON01 FROM PERSON01 GROUP BY ID, PERSON01 HAVING COUNT(*) > 1)
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4. 删除表中多余的重复记录，根据多个字段来判断是否重复