Oracle 删除重复数据只留一条

 1 查询及删除重复记录的SQL语句

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 3 1、查找表中多余的重复记录，重复记录是根据单个字段（Id）来判断

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 5 select * from 表 where Id in (select Id from 表 group byId having count(Id) > 1)

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 7 2、删除表中多余的重复记录，重复记录是根据单个字段（Id）来判断，只留有rowid最小的记录

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 9 DELETE from 表 WHERE (id) IN ( SELECT id FROM 表 GROUP BY id HAVING COUNT(id) > 1) AND ROWID NOT IN (SELECT MIN(ROWID) FROM 表 GROUP BY id HAVING COUNT(*) > 1);

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11 3、查找表中多余的重复记录（多个字段）

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13 select * from 表 a where (a.Id,a.seq) in(select Id,seq from 表 group by Id,seq having count(*) > 1)

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15 4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录

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17 delete from 表 a where (a.Id,a.seq) in (select Id,seq from 表 group by Id,seq having count(*) > 1) and rowid not in (select min(rowid) from 表 group by Id,seq having count(*)>1)

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19 5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录

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21 select * from 表 a where (a.Id,a.seq) in (select Id,seq from 表 group by Id,seq having count(*) > 1) and rowid not in (select min(rowid) from 表 group by Id,seq having count(*)>1)