有张表字段很简单:
编号 卡号 时间 ID
26798 0006842542 2008-06-23 14:07:00 2
26798 0006842542 2008-06-23 14:31:00 2
26798 0006842542 2008-06-23 14:30:00 2
10948 0006826692 2008-06-23 14:06:00 2
10948 0006826692 2008-06-23 14:12:00 2
10948 0006826692 2008-06-23 14:36:00 2
...
编号和卡号,ID都是固定的,一天可能回出现同卡号N个时间,如何实现每个卡号每天只保留最早和最晚的那两条记录?
用于公司考勤。
编号 卡号 时间 ID
26798 0006842542 2008-06-23 14:07:00 2
26798 0006842542 2008-06-23 14:31:00 2
26798 0006842542 2008-06-23 14:30:00 2
10948 0006826692 2008-06-23 14:06:00 2
10948 0006826692 2008-06-23 14:12:00 2
10948 0006826692 2008-06-23 14:36:00 2
...
编号和卡号,ID都是固定的,一天可能回出现同卡号N个时间,如何实现每个卡号每天只保留最早和最晚的那两条记录?
用于公司考勤。
/******************************************************************************************************************************************************
Name相同ID最小或最大的记录整理人:中国风(Roy)日期:2008.06.06
******************************************************************************************************************************************************/--> --> (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
--1、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:
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
生成结果:
/*
ID Name Memo
----------- ---- ----
1 A A1
4 B B1(2 行受影响)
*/
--2、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:
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生成结果2:
/*
ID Name Memo
----------- ---- ----
3 A A3
5 B B2(2 行受影响)
*/
where not exists( select 1 from ta where a.num = num and datecol > a.datecol)select * from ta a
where not exists( select 1 from ta where a.num = num and datecol < a.datecol)
declare @tb table (编号 varchar(10),卡号 varchar(10),时间 datetime,Id int)
insert into @tb
select '26798','0006842542','2008-06-23 14:07:00',2 union all
select '26798','0006842542','2008-06-23 14:31:00',2 union all
select '26798','0006842542','2008-06-23 14:30:00',2 union all
select '10948','0006826692','2008-06-23 14:06:00',2 union all
select '10948','0006826692','2008-06-23 14:12:00',2 union all
select '10948','0006826692','2008-06-23 14:36:00',2select * from @tb a where 时间 in (select max(时间) from @tb where 卡号=a.卡号) or 时间 in (select min(时间) from @tb where 卡号=a.卡号)
insert into @tb
select '26798','0006842542','2008-06-23 14:07:00',2 union all
select '26798','0006842542','2008-06-23 14:31:00',2 union all
select '26798','0006842542','2008-06-23 14:30:00',2 union all
select '10948','0006826692','2008-06-23 14:06:00',2 union all
select '10948','0006826692','2008-06-23 14:12:00',2 union all
select '10948','0006826692','2008-06-23 14:36:00',2select *
from @tb t
where not exists(select 1 from @tb where 卡号=t.卡号 and 时间<t.时间)
union
select *
from @tb t
where not exists(select 1 from @tb where 卡号=t.卡号 and 时间>t.时间)
order by 编号
/*
所影响的行数为 6 行)编号 卡号 时间 ID
---------- ---------- ------------------------------------------------------ -----------
10948 0006826692 2008-06-23 14:06:00.000 2
10948 0006826692 2008-06-23 14:36:00.000 2
26798 0006842542 2008-06-23 14:07:00.000 2
26798 0006842542 2008-06-23 14:31:00.000 2(所影响的行数为 4 行)*/