本教程操作环境:Windows10系统、Oracle 11g版、Dell G3电脑。
oracle怎么查询重复的数据
1、查找表中多余的重复记录,重复记录是根据单个字段(userCode)来判断
select
*
from
user
where
userCode
in
( select userCode from user group by userCode having count (userCode) > 1)
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2、删除表中多余的重复记录,重复记录是根据单个字段(userCode)来判断,只留有rowid最小的记录
delete from
user
where
userCode
in
( select userCode from user group by userCode having count (peopleId) > 1)
and rowid not in
( select min (rowid) from user group by userCode having count (userCode)>1)
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3、查找表中多余的重复记录(多个字段)
select
*
from
user a
where
(a.userCode,a.userName)
in
( select userCode,userName from user group by userCode,userName having count (*) > 1)
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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
user a
where
(a.userCode,a.userName)
in
( select userCode,userName from user group by userCode,userName having count (*) > 1)
and rowid not in
( select min (rowid) from user group by userCode,userName 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
user a
where
(a.userCode,a.userName)
in
( select userCode,userName from user group by userCode,userName having count (*) > 1)
and rowid not in
( select min (rowid) from user group by userCode,userName having count (*)>1)
|