SQL删除重复数据的操作方式
原创
SQL删除重复数据的操作方式
原创
用户7639835
修改于 2021-08-27 09:50:48
修改于 2021-08-27 09:50:48
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代码可运行
用SQL语句,删除掉重复项只保留一条，适合新手学习参考使用
在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢
查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断
select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)扩展：
删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录
delete from people
where peopleName in (select peopleName from people group by peopleName having count(peopleName) > 1)
and peopleId not in (select min(peopleId) from people group by peopleName having count(peopleName)>1)查找表中多余的重复记录（多个字段）
select * from vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)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 vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)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 vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)消除一个字段的左边的第一位：
update tableName set [Title]=Right([Title],(len([Title])-1)) where Title like '村%'消除一个字段的右边的第一位：
update tableName set [Title]=left([Title],(len([Title])-1)) where Title like '%村'假删除表中多余的重复记录（多个字段），不包含rowid最小的记录
update vitae set ispass=-1where peopleId in (select peopleId from vitae group by peopleId原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。
如有侵权，请联系 cloudcommunity@tencent.com 删除。
原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。
如有侵权，请联系 cloudcommunity@tencent.com 删除。
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