sql中删除重复数据
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发布时间：2022-04-26 00:02
共1个回答
热心网友
时间：2022-04-08 00:53
Server删除重复行是我们最常见的操作之一，下面就为您介绍六种适合不同情况的SQL
Server删除重复行的方法，供您参考。
1.如果有ID字段，就是具有唯一性的字段
delect
table
where
id
not
in
(
select
max(id)
from
table
group
by
col1,col2,col3...
)
group
by
子句后跟的字段就是你用来判断重复的条件，如只有col1，那么只要col1字段内容相同即表示记录相同。
2.
如果是判断所有字段也可以这样
select
*
into
#aa
from
table
group
by
id1,id2,....
delete
table
insert
into
table
select
*
from
#aa
3.
没有ID的情况
select
identity(int,1,1)
as
id,*
into
#temp
from
tabel
delect
#
where
id
not
in
(
select
max(id)
from
#
group
by
col1,col2,col3...)
delect
table
inset
into
table(...)
select
.....
from
#temp
4.
col1+','+col2+','...col5
联合主键
select
*
from
table
where
col1+','+col2+','...col5
in
(
select
max(col1+','+col2+','...col5)
from
table
where
having
count(*)>1
group
by
col1,col2,col3,col4
)
group
by
子句后跟的字段就是你用来判断重复的条件，如只有col1，那么只要col1字段内容相同即表示记录相同。
5.
select
identity(int,1,1)
as
id,*
into
#temp
from
tabel
select
*
from
#temp
where
id
in
(
select
max(id)
from
#emp
where
having
count(*)>1
group
by
col1,col2,col3...)
6.
select
distinct
*
into
#temp
from
tablename
delete
tablename
go
insert
tablename
select
*
from
#temp
Sqlclub
go
drop
table
#temp
以上就是SQL
Server删除重复行的方法介绍。
