代碼如下:

--建立數據表createtable TestData 
( 
ID int identity(1,1) primary key, 
Data int, 
ColA varchar(20), 
ColB varchar(20) 
) 
go 

--插入測試數據 
declare @counts int 
declare @i int 
set @counts = 10000 
set @i = 1 

while @i<=@counts 
begin 
insert TestData (Data,ColA,ColB) values(cast(rand()*10000 as int),cast(rand() as varchar(20)),cast(rand() as varchar(20))) 
set @i=@i+1 
end 

--獲取數據(重復數據只取一條) 
select * from TestData 
where 
id in 
( 
--根據Data分類獲取數據最小ID列表 
select min(id) from TestData 
group by Data 
)