求一sql的算法

[liangyubin2005]

有以下員工表：

ID Name age department image inputDate
1 Jim 20 13 301 2006-01-01
2 Tom 22 13 302 2006-05-01
3 Ben 22 13 303 2006-03-01
4 Sam 20 14 304 2006-04-01
5 Jion 21 14 305 2006-05-01
6 Carry 20 15 306 2006-06-01
7 Apple 21 15 307 2006-01-11
8 Cenny 23 15 308 2007-01-01
9 Lucy 20 15 309 2006-02-01
10 Sruory 23 15 400 2007-01-01

我想在每個部門中找出一位員工，邏輯是：在本部門中age最大的，如age相同的選inputDate較小的，如inputDate也相同就選擇ID較小的。

我的方法如下：


declare @tbPerson table
(ID int ,
Name varchar(20),
age int,
departmentID int,
ImageID int,
InputDate datetime,
UpdateDate datetime
)

insert into @tbPerson
select 1,'Jim',20,13,301,'2006-01-01'
union all
select 2,'Tom',22,13,302,'2006-05-01'
union all
select 3,'Ben',22,13,303,'2006-03-01'
union all
select 4,'Sam',20,14,304,'2006-04-01'
union all
select 5,'Jion',21,14,305,'2006-05-01'
union all
select 6,'Carry',20,15,306,'2006-06-01'
union all
select 7,'Apple',21,15,307,'2006-01-11'
union all
select 8,'Cenny',23,15,308,'2007-01-01'
union all
select 9,'Lucy',20,15,309,'2006-02-01'
union all
select 10,'Sruory',23,15,400,'2007-01-01'

select departmentID,max(age) as MaxAge
into #tbMaxAge
from @tbPerson
group by departmentID

select a.departmentID,
a.MaxAge,
min(b.InputDate) as MinDate
into #tbMaxAge_InputDate
from #tbMaxAge as a
inner join @tbPerson as b
on a.departmentID=b.departmentID
and a.MaxAge=b.age
group by a.departmentID,
a.MaxAge

select * from @tbPerson where ID in(
select min(ID)
from #tbMaxAge_InputDate as a
inner join @tbPerson as b
on a.departmentID=b.departmentID
and a.MaxAge=b.age
and a.MinDate=b.InputDate
group by a.departmentID,
a.MaxAge,
a.MinDate
)

drop table #tbMaxAge
drop table #tbMaxAge_InputDate

但我覺得這種方法比較煩，請教有無更好的方法呢？

[bugchen888]

declare @tbPerson table
(ID int ,
Name varchar(20),
age int,
departmentID int,
ImageID int,
InputDate datetime
)

insert into @tbPerson
select 1,'Jim',20,13,301,'2006-01-01'
union all
select 2,'Tom',22,13,302,'2006-05-01'
union all
select 3,'Ben',22,13,303,'2006-03-01'
union all
select 4,'Sam',20,14,304,'2006-04-01'
union all
select 5,'Jion',21,14,305,'2006-05-01'
union all
select 6,'Carry',20,15,306,'2006-06-01'
union all
select 7,'Apple',21,15,307,'2006-01-11'
union all
select 8,'Cenny',23,15,308,'2007-01-01'
union all
select 9,'Lucy',20,15,309,'2006-02-01'
union all
select 10,'Sruory',23,15,400,'2007-01-01'

SELECT * FROM @tbPerson

SELECT * FROM @tbPerson t1
WHERE NOT EXISTS
(SELECT 1
FROM @tbPersON t2
WHERE t2.departmentID=t1.departmentID
AND
((t2.age>t1.age) OR (t2.age=t1.age AND t2.InputDate<t1.InputDate)
OR (t2.age=t1.age AND t2.InputDate=t1.InputDate AND t2.id<t1.id)) )


(10 row(s) affected)

ID Name age departmentID ImageID InputDate
----------- -------------------- ----------- ------------ ----------- ------------------------------------------------------
1 Jim 20 13 301 2006-01-01 00:00:00.000
2 Tom 22 13 302 2006-05-01 00:00:00.000
3 Ben 22 13 303 2006-03-01 00:00:00.000
4 Sam 20 14 304 2006-04-01 00:00:00.000
5 Jion 21 14 305 2006-05-01 00:00:00.000
6 Carry 20 15 306 2006-06-01 00:00:00.000
7 Apple 21 15 307 2006-01-11 00:00:00.000
8 Cenny 23 15 308 2007-01-01 00:00:00.000
9 Lucy 20 15 309 2006-02-01 00:00:00.000
10 Sruory 23 15 400 2007-01-01 00:00:00.000

(10 row(s) affected)

ID Name age departmentID ImageID InputDate
----------- -------------------- ----------- ------------ ----------- ------------------------------------------------------
3 Ben 22 13 303 2006-03-01 00:00:00.000
5 Jion 21 14 305 2006-05-01 00:00:00.000
8 Cenny 23 15 308 2007-01-01 00:00:00.000

(3 row(s) affected)

[caixia615]

LS的强人,呵呵