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  • Oracle 删除重复数据只留一条

    查询及删除重复记录的SQL语句
     
    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
    select * fromwhere Id in (select Id fromgroup byId having count(Id) > 1)
    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
    DELETE fromWHERE (id) IN ( SELECT id FROMGROUP BY id HAVING COUNT(id) > 1) AND 
    ROWID NOT IN (SELECT MIN(ROWID) FROMGROUP BY id HAVING COUNT(*) > 1);
    3、查找表中多余的重复记录(多个字段)
    select * from 表 a where (a.Id,a.seq) in(select Id,seq fromgroup by Id,seq having count(*) > 1)
    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
    delete from 表 a where (a.Id,a.seq) in (select Id,seq fromgroup by Id,seq having count(*) > 1) and 
    rowid not in (select min(rowid) fromgroup by Id,seq having count(*)>1)
    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
    select * from 表 a where (a.Id,a.seq) in (select Id,seq fromgroup by Id,seq having count(*) > 1) and 
    rowid not in (select min(rowid) fromgroup by Id,seq having count(*)>1)
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  • 原文地址:https://www.cnblogs.com/Jace06/p/8862054.html
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