MsSql教程网-sqlserver中重复数据值只取一条的sql语句

复制代码 代码如下:

–建立数据表createtable TestData

(

ID int identity(1,1) primary key,

Data int,

ColA varchar(20),

ColB varchar(20)

)

go

–插入测试数据

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

–获取数据(重复数据只取一条)

select * from TestData

where

id in

(

–根据Data分类获取数据最小ID列表

select min(id) from TestData

group by Data

)