近期碰到需要取日期最小的不同条件记录的问题,请各位xdjm赐教!! 表a:
序号 材料 数量 入库日期
1 A 8 2009-12-1
2 A 9 2009-12-5
3 B 12 2009-11-18
4 B 10 2009-11-19
5 C 5 2009-10-9
6 C 13 2009-11-8 想要的结果为: 序号 材料 数量 入库日期
1 A 8 2009-12-1
3 B 12 2009-11-18
5 C 5 2009-10-9 这语句该怎么写呢??
序号 材料 数量 入库日期
1 A 8 2009-12-1
2 A 9 2009-12-5
3 B 12 2009-11-18
4 B 10 2009-11-19
5 C 5 2009-10-9
6 C 13 2009-11-8 想要的结果为: 序号 材料 数量 入库日期
1 A 8 2009-12-1
3 B 12 2009-11-18
5 C 5 2009-10-9 这语句该怎么写呢??
from tb t
where not exists(select 1 from tb where 材料=t.材料 and 入库日期<t.入库日期)
from tb t
where not exists(select 1 from 材料=t.材料 and 日期<t.日期)
/******************************************************************************************************************************************************
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)
*/
*
from
tb t
where
入库日期=(select min(入库日期) from tb where 材料=t.材料)
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([序号] int,[材料] varchar(1),[数量] int,[入库日期] datetime)
insert [tb]
select 1,'A',8,'2009-12-1' union all
select 2,'A',9,'2009-12-5' union all
select 3,'B',12,'2009-11-18' union all
select 4,'B',10,'2009-11-19' union all
select 5,'C',5,'2009-10-9' union all
select 6,'C',13,'2009-11-8'
---查询---
select *
from tb t
where not exists(select 1 from tb where 材料=t.材料 and 入库日期<t.入库日期)
---结果---
序号 材料 数量 入库日期
----------- ---- ----------- ------------------------------------------------------
1 A 8 2009-12-01 00:00:00.000
3 B 12 2009-11-18 00:00:00.000
5 C 5 2009-10-09 00:00:00.000(所影响的行数为 3 行)
insert a
select 1,'A',8,'2009-12-1' union all
select 2,'A',9,'2009-12-5' union all
select 3,'B',12,'2009-11-18' union all
select 4,'B',10,'2009-11-19' union all
select 5,'C',5,'2009-10-9' union all
select 6,'C',13,'2009-11-8'
select t.* from a t where 入库日期 = (select min(入库日期) from a where 材料 = t.材料)select t.* from a t where not exists (select 1 from a where 材料 = t.材料 and 入库日期 < t.入库日期)drop table a/*
序号 材料 数量 入库日期
----------- ---- ----------- ------------------------------------------------------
1 A 8 2009-12-01 00:00:00.000
3 B 12 2009-11-18 00:00:00.000
5 C 5 2009-10-09 00:00:00.000(所影响的行数为 3 行)序号 材料 数量 入库日期
----------- ---- ----------- ------------------------------------------------------
1 A 8 2009-12-01 00:00:00.000
3 B 12 2009-11-18 00:00:00.000
5 C 5 2009-10-09 00:00:00.000(所影响的行数为 3 行)
*/
select *,min(入库日期) over(partition by 材料) as min_入库日期 from a) a
where 入库日期=min_入库日期
from a t
inner join a f on t.材料=f.材料
where t.入库日期 < f.入库日期
select 材料, min(入库日期) from product
group by 材料select 序号, 材料, 数量, 入库日期
from product, #temptable
where 材料 = #temptable.a and 入库日期 = #temptable.b
insert a
select 1,'A',8,'2009-12-1' union all
select 2,'A',9,'2009-12-5' union all
select 3,'B',12,'2009-11-18' union all
select 4,'B',10,'2009-11-19' union all
select 5,'C',5,'2009-10-9' union all
select 6,'C',13,'2009-11-8';with t as
(select *,row_number() over (partition by 材料 order by 入库日期 ) as xh from a)
select [序号] ,[材料],[数量] ,[入库日期] from t where xh=1drop table a