问题是这样的,在上千条的记录中,大部分按一定的规则生成唯一值,但是这其中会有几十条记录要进行修改。
修改的可能是这几十条数据的值进行交叉互换。这个问题用图表描述会比较清楚,原表可能是这样
-------------------------------------------------------
ID<唯一> Value<唯一>
-------------------------------------------------------
1 A
2 B
3 C
4 D
5 E
6 F修改后可能是这样
-------------------------------------------------------
ID<唯一> Value<唯一>
-------------------------------------------------------
1 F
2 A
3 B
4 C
5 D
6 E我试了一次批量修改,就是把这些记录一性筛选出来,修改好后一次性批量更新,没有成功。希望大家给一个好办法,谢谢啦
修改的可能是这几十条数据的值进行交叉互换。这个问题用图表描述会比较清楚,原表可能是这样
-------------------------------------------------------
ID<唯一> Value<唯一>
-------------------------------------------------------
1 A
2 B
3 C
4 D
5 E
6 F修改后可能是这样
-------------------------------------------------------
ID<唯一> Value<唯一>
-------------------------------------------------------
1 F
2 A
3 B
4 C
5 D
6 E我试了一次批量修改,就是把这些记录一性筛选出来,修改好后一次性批量更新,没有成功。希望大家给一个好办法,谢谢啦
解决方案 »
- 时间
- 超时问题?请邹捷等大虾帮忙!
- 求一个:取得表结构详细信息的SQL
- 这样的insert语句怎么写?
- 帮忙解释一下一个较复杂的SQL语句,谢谢!
- 触发器的问题?
- 新人来看看
- 怎么使用 .sql 文件啊~(我很笨,可是我很努力)
- 如何做到 Connection =nothing 时, 该连接创建的##临时表 不消失?求救!
- Sql Server 的日志显示“SQL Server 已为 8 个并发查询而优化。2 个查询超过了此限制,因而性能可能会受到不良影响。”这个时候数据库的
- 我的SQL Sserver 2005 安装不了 我原来安装过SQL Server 2008,没装成功
- 请教:我想根据一个标准数据库复制200个数据库,要求在visual studio中完成 该如何做
-- -----------t_mac 小编-------------------
--------------------希望有天成为大虾----
-- =========================================IF OBJECT_ID('tb') IS NOT NULL
DROP TABLE tb
GO
CREATE TABLE tb( id int, value varchar(10))
go
insert tb SELECT
1 , 'A' UNION ALL SELECT
2 , 'B' UNION ALL SELECT
3 , 'C' UNION ALL SELECT
4 , 'D' UNION ALL SELECT
5 , 'E' UNION ALL SELECT
6 , 'F'
go
declare @i int
set @i=(select MAX(id) from tb )
update tb
set value=case when value='A' then (select value from tb where id=@i) else
(select value from tb where t.id=id+1) end
from tb t
go
select * from tb
/*
id value
----------- ----------
1 F
2 A
3 B
4 C
5 D
6 E*/
-- =========================================
-- -----------t_mac 小编-------------------
--------------------希望有天成为大虾----
-- =========================================IF OBJECT_ID('tb') IS NOT NULL
DROP TABLE tb
GO
CREATE TABLE tb( id int, value varchar(10))
go
insert tb SELECT
1 , 'A' UNION ALL SELECT
2 , 'B' UNION ALL SELECT
3 , 'C' UNION ALL SELECT
4 , 'D' UNION ALL SELECT
5 , 'E' UNION ALL SELECT
6 , 'F'
go
declare @i int,@s varchar(10),@i2 int
set @i=(select MAX(id) from tb )
set @i2=(select MIN(id) from tb )
set @s=(select value from tb where id=@i2 )
update tb
set value=case when value=@s then (select value from tb where id=@i) else
(select value from tb where t.id=id+1) end
from tb t
go
select * from tb
/*
id value
----------- ----------
1 F
2 A
3 B
4 C
5 D
6 E*/
ID最大的VALUE换到ID最小的VALUE的位置 下面依次往后退一个
交换没有规则,是人为改的,
我现在是这么做的,
比如他要把
A改B,先记下 原A新B,然后显示B,提示修改
B改C,先记下 原B新C,……
最后设置完成,提交,这里才后台保存也就是没有规则,是人为设置这些值。
--处理表重复记录(查询和删除)
/******************************************************************************************************************************************************
1、Num、Name相同的重复值记录,没有大小关系只保留一条
2、Name相同,ID有大小关系时,保留大或小其中一个记录
整理人:中国风(Roy)日期:2008.06.06
******************************************************************************************************************************************************/--1、用于查询重复处理记录(如果列没有大小关系时2000用生成自增列和临时表处理,SQL2005用row_number函数处理)--> --> (Roy)生成測試數據
if not object_id('Tempdb..#T') is null
drop table #T
Go
Create table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))
Insert #T
select 1,N'A',N'A1' union all
select 2,N'A',N'A2' union all
select 3,N'A',N'A3' union all
select 4,N'B',N'B1' union all
select 5,N'B',N'B2'
Go
--I、Name相同ID最小的记录(推荐用1,2,3),方法3在SQl05时,效率高于1、2
方法1:
Select * from #T a where not exists(select 1 from #T where Name=a.Name and ID<a.ID)方法2:
select a.* from #T a join (select min(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID方法3:
select * from #T a where ID=(select min(ID) from #T where Name=a.Name)方法4:
select a.* from #T a join #T b on a.Name=b.Name and a.ID>=b.ID group by a.ID,a.Name,a.Memo having count(1)=1 方法5:
select * from #T a group by ID,Name,Memo having ID=(select min(ID)from #T where Name=a.Name)方法6:
select * from #T a where (select count(1) from #T where Name=a.Name and ID<a.ID)=0方法7:
select * from #T a where ID=(select top 1 ID from #T where Name=a.name order by ID)方法8:
select * from #T a where ID!>all(select ID from #T where Name=a.Name)方法9(注:ID为唯一时可用):
select * from #T a where ID in(select min(ID) from #T group by Name)--SQL2005:方法10:
select ID,Name,Memo from (select *,min(ID)over(partition by Name) as MinID from #T a)T where ID=MinID方法11:select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID) as MinID from #T a)T where MinID=1生成结果:
/*
ID Name Memo
----------- ---- ----
1 A A1
4 B B1(2 行受影响)
*/
--II、Name相同ID最大的记录,与min相反:
方法1:
Select * from #T a where not exists(select 1 from #T where Name=a.Name and ID>a.ID)方法2:
select a.* from #T a join (select max(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID order by ID方法3:
select * from #T a where ID=(select max(ID) from #T where Name=a.Name) order by ID方法4:
select a.* from #T a join #T b on a.Name=b.Name and a.ID<=b.ID group by a.ID,a.Name,a.Memo having count(1)=1 方法5:
select * from #T a group by ID,Name,Memo having ID=(select max(ID)from #T where Name=a.Name)方法6:
select * from #T a where (select count(1) from #T where Name=a.Name and ID>a.ID)=0方法7:
select * from #T a where ID=(select top 1 ID from #T where Name=a.name order by ID desc)方法8:
select * from #T a where ID!<all(select ID from #T where Name=a.Name)方法9(注:ID为唯一时可用):
select * from #T a where ID in(select max(ID) from #T group by Name)--SQL2005:方法10:
select ID,Name,Memo from (select *,max(ID)over(partition by Name) as MinID from #T a)T where ID=MinID方法11:
select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID desc) as MinID from #T a)T where MinID=1生成结果2:
/*
ID Name Memo
----------- ---- ----
3 A A3
5 B B2(2 行受影响)
*/--2、删除重复记录有大小关系时,保留大或小其中一个记录
--> --> (Roy)生成測試數據if not object_id('Tempdb..#T') is null
drop table #T
Go
Create table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))
Insert #T
select 1,N'A',N'A1' union all
select 2,N'A',N'A2' union all
select 3,N'A',N'A3' union all
select 4,N'B',N'B1' union all
select 5,N'B',N'B2'
Go--I、Name相同ID最小的记录(推荐用1,2,3),保留最小一条
方法1:
delete a from #T a where exists(select 1 from #T where Name=a.Name and ID<a.ID)方法2:
delete a from #T a left join (select min(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID where b.Id is null方法3:
delete a from #T a where ID not in (select min(ID) from #T where Name=a.Name)方法4(注:ID为唯一时可用):
delete a from #T a where ID not in(select min(ID)from #T group by Name)方法5:
delete a from #T a where (select count(1) from #T where Name=a.Name and ID<a.ID)>0方法6:
delete a from #T a where ID<>(select top 1 ID from #T where Name=a.name order by ID)方法7:
delete a from #T a where ID>any(select ID from #T where Name=a.Name)select * from #T生成结果:
/*
ID Name Memo
----------- ---- ----
1 A A1
4 B B1(2 行受影响)
*/
--II、Name相同ID保留最大的一条记录:方法1:
delete a from #T a where exists(select 1 from #T where Name=a.Name and ID>a.ID)方法2:
delete a from #T a left join (select max(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID where b.Id is null方法3:
delete a from #T a where ID not in (select max(ID) from #T where Name=a.Name)方法4(注:ID为唯一时可用):
delete a from #T a where ID not in(select max(ID)from #T group by Name)方法5:
delete a from #T a where (select count(1) from #T where Name=a.Name and ID>a.ID)>0方法6:
delete a from #T a where ID<>(select top 1 ID from #T where Name=a.name order by ID desc)方法7:
delete a from #T a where ID<any(select ID from #T where Name=a.Name)
select * from #T
/*
ID Name Memo
----------- ---- ----
3 A A3
5 B B2(2 行受影响)
*/--3、删除重复记录没有大小关系时,处理重复值
--> --> (Roy)生成測試數據
if not object_id('Tempdb..#T') is null
drop table #T
Go
Create table #T([Num] int,[Name] nvarchar(1))
Insert #T
select 1,N'A' union all
select 1,N'A' union all
select 1,N'A' union all
select 2,N'B' union all
select 2,N'B'
Go方法1:
if object_id('Tempdb..#') is not null
drop table #
Select distinct * into # from #T--排除重复记录结果集生成临时表#truncate table #T--清空表insert #T select * from # --把临时表#插入到表#T中--查看结果
select * from #T/*
Num Name
----------- ----
1 A
2 B(2 行受影响)
*/--重新执行测试数据后用方法2
方法2:alter table #T add ID int identity--新增标识列
go
delete a from #T a where exists(select 1 from #T where Num=a.Num and Name=a.Name and ID>a.ID)--只保留一条记录
go
alter table #T drop column ID--删除标识列--查看结果
select * from #T/*
Num Name
----------- ----
1 A
2 B(2 行受影响)*/--重新执行测试数据后用方法3
方法3:
declare Roy_Cursor cursor local for
select count(1)-1,Num,Name from #T group by Num,Name having count(1)>1
declare @con int,@Num int,@Name nvarchar(1)
open Roy_Cursor
fetch next from Roy_Cursor into @con,@Num,@Name
while @@Fetch_status=0
begin
set rowcount @con;
delete #T where Num=@Num and Name=@Name
set rowcount 0;
fetch next from Roy_Cursor into @con,@Num,@Name
end
close Roy_Cursor
deallocate Roy_Cursor--查看结果
select * from #T
/*
Num Name
----------- ----
1 A
2 B(2 行受影响)
*/