oracle mysql sqlserver 数据库 用SQL语句，删除 去掉 重复 项只 保留一条 native耻物手办在哪买
2011-04-28 20:52
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
1、查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 mysql语句转oracle
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
2、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)
3、查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)
乱码转换器哪里下载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 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)
brake power是什么意思5、查表中多余的重复记录（多个字段），不包含rowid最小的记录
简单登录页面图片select * from vitae a 江苏移动网上营业厅
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) 
6.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%'
7.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'
8.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=-1
where peopleId in (select peopleId from vitae group by peopleId,seq having count(*) > 1) and seq in （select 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)

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