Oralce中SQL删除重复数据只保留一条(转)
时间：2021-07-01 10:21:17
帮助过：2人阅读
1、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)
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)
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)
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 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)
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
Oralce中SQL删除重复数据只保留一条(转)
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