Oracle 删除重复数据只留一条
查询及删除重复记录的SQL语句
1、查找表中多余的重复记录,重复记录是根据单个字段(Id)来判断
select
*
from
表
where
Id
in
(
select
Id
from
表
group
byId
having
count
(Id) > 1)
2、删除表中多余的重复记录,重复记录是根据单个字段(Id)来判断,只留有rowid最小的记录
DELETE
from
表
WHERE
(id)
IN
(
SELECT
id
FROM
表
GROUP
BY
id
HAVING
COUNT
(id) > 1)
AND
ROWID
NOT
IN
(
SELECT
MIN
(ROWID)
FROM
表
GROUP
BY
id
HAVING
COUNT
(*) > 1);
3、查找表中多余的重复记录(多个字段)
select
*
from
表 a
where
(a.Id,a.seq)
in
(
select
Id,seq
from
表
group
by
Id,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
表 a
where
(a.Id,a.seq)
in
(
select
Id,seq
from
表
group
by
Id,seq
having
count
(*) > 1)
and
rowid
not
in
(
select
min
(rowid)
from
表
group
by
Id,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
表 a
where
(a.Id,a.seq)
in
(
select
Id,seq
from
表
group
by
Id,seq
having
count
(*) > 1)
and
rowid
not
in
(
select
min
(rowid)
from
表
group
by
Id,seq
having
count
(*)>1)
转自https://blog.csdn.net/albertliangyg/article/details/100150761
原文:https://www.cnblogs.com/chenwei1124/p/14425685.html