Oralce中SQL删除重复数据只保留一条(转)

用SQL语句,删除掉重复项只保留一条
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) > ) 

、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) > )
and   peopleId not in (select min(peopleId) from people group by peopleName     having count(peopleName)>) 

、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(*) > ) 

、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(*) > )
and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>) 

、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(*) > )
and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>)   

.消除一个字段的左边的第一位：

update tableName set [Title]=Right([Title],(len([Title])-)) 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])-)) 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=-
where peopleId in (select peopleId from vitae group by peopleId