现有表:用电器 状态 时间
-------------------------------------
灯光1 开 2010-11-04 10:41:00
灯光1 关 2010-11-04 10:42:00
灯光1 关 2010-11-04 10:43:00
灯光1 关 2010-11-04 10:44:00
灯光1 开 2010-11-04 10:45:00
灯光1 开 2010-11-04 10:46:00
灯光1 开 2010-11-04 10:47:00
灯光1 关 2010-11-04 10:48:00
灯光1 关 2010-11-04 10:49:00
灯光1 开 2010-11-04 10:50:00现在要把重复状态去掉,取的是最后状态的时间,查询出如下结果:用电器 状态 时间
-------------------------------------
灯光1 开 2010-11-04 10:41:00
灯光1 关 2010-11-04 10:44:00
灯光1 开 2010-11-04 10:47:00
灯光1 关 2010-11-04 10:49:00
灯光1 开 2010-11-04 10:50:00求此SQL语句
-------------------------------------
灯光1 开 2010-11-04 10:41:00
灯光1 关 2010-11-04 10:42:00
灯光1 关 2010-11-04 10:43:00
灯光1 关 2010-11-04 10:44:00
灯光1 开 2010-11-04 10:45:00
灯光1 开 2010-11-04 10:46:00
灯光1 开 2010-11-04 10:47:00
灯光1 关 2010-11-04 10:48:00
灯光1 关 2010-11-04 10:49:00
灯光1 开 2010-11-04 10:50:00现在要把重复状态去掉,取的是最后状态的时间,查询出如下结果:用电器 状态 时间
-------------------------------------
灯光1 开 2010-11-04 10:41:00
灯光1 关 2010-11-04 10:44:00
灯光1 开 2010-11-04 10:47:00
灯光1 关 2010-11-04 10:49:00
灯光1 开 2010-11-04 10:50:00求此SQL语句
[Author]: OrchidCat[OC]_轻骑兵(向高手学习...)
[Time]: 2010-11-08 13:49:24
[Place]: From Beijing
[Version]:
Microsoft SQL Server 2005 - 9.00.3042.00 (Intel X86)
Feb 9 2007 22:47:07
Copyright (c) 1988-2005 Microsoft Corporation
Enterprise Edition on Windows NT 5.2 (Build 3790: Service Pack 2)*/
--> 测试数据:[TB]
if object_id('[TB]') is not null drop table [TB]
create table [TB]([用电器] varchar(5),[状态] varchar(2),[时间] datetime)
insert [TB]
select '灯光1','开','2010-11-04 10:41:00' union all
select '灯光1','关','2010-11-04 10:42:00' union all
select '灯光1','关','2010-11-04 10:43:00' union all
select '灯光1','关','2010-11-04 10:44:00' union all
select '灯光1','开','2010-11-04 10:45:00' union all
select '灯光1','开','2010-11-04 10:46:00' union all
select '灯光1','开','2010-11-04 10:47:00' union all
select '灯光1','关','2010-11-04 10:48:00' union all
select '灯光1','关','2010-11-04 10:49:00' union all
select '灯光1','开','2010-11-04 10:50:00'select * from [TB]SELECT A.*
FROM TB A
INNER JOIN TB B ON A.[用电器] = B.[用电器]
AND DATEADD(mi, 1, A.时间) = B.时间
AND A.[状态] <> B.[状态]/*
用电器 状态 时间
灯光1 开 2010-11-04 10:41:00.000
灯光1 关 2010-11-04 10:44:00.000
灯光1 开 2010-11-04 10:47:00.000
灯光1 关 2010-11-04 10:49:00.000*/
DECLARE @table Table(title varchar(10),Status VARCHAR(4),cpDate datetime)
insert into @table
select '灯光1','开','2010-11-04 10:41:00' union all
select '灯光1','关','2010-11-04 10:42:00' union all
select '灯光1','关','2010-11-04 10:43:00' union all
select '灯光1','关','2010-11-04 10:44:00' union all
select '灯光1','开','2010-11-04 10:45:00' union all
select '灯光1','开','2010-11-04 10:46:00' union all
select '灯光1','开','2010-11-04 10:47:00' union all
select '灯光1','关','2010-11-04 10:48:00' union all
select '灯光1','关','2010-11-04 10:49:00' union all
select '灯光1','开','2010-11-04 10:50:00' select identity(int,1,1) ID,* into #talbe
from @table
select t.*
,case when exists(select 1 from #talbe t2 where (t2.ID-1)=t.ID AND t.Status=t2.Status)
THEN 'No'
ELSE 'Yes'
END 'Value'
INTO #resultTable
from #talbe t order by t.cpDateselect title,Status,cpDate from #resultTable where Value='Yes'drop table #talbe,#resultTable/*
title Status cpDate
---------- ------ -----------------------
灯光1 开 2010-11-04 10:41:00.000
灯光1 关 2010-11-04 10:44:00.000
灯光1 开 2010-11-04 10:47:00.000
灯光1 关 2010-11-04 10:49:00.000
灯光1 开 2010-11-04 10:50:00.000(5 行受影响)
*/
from tb
select t.*
,case when exists(select 1 from #talbe t2 where (t2.ID-1)=t.ID AND t.Status=t2.Status)
THEN 'OFF'
ELSE 'OPEN'
END 'Value'
INTO #resultTable
from #talbe t order by t.cpDateselect title,Status,cpDate from #resultTable where Value='OPEN'
/******************************************************************************************************************************************************
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)
*/