--> 测试数据：[test]
if object_id('[test]') is not null drop table [test]
create table [test](
[ID] int,
[Company] varchar(3),
[Name] varchar(1),
[Mobile] int
)
insert [test]
select 0,'IBM','R',123456 union all
select 1,'KDO','P',987654 union all
select 2,'JCN','S',234567 union all
select 3,'KDO','K',345678 union all
select 4,'IBM','L',654321 union all
select 5,'HAL','W',765432

select * from test a
where [ID]=(select MIN([ID]) from test b where a.Company=b.Company)
order by ID

/*
ID    Company    Name    Mobile
0    IBM    R    123456
1    KDO    P    987654
2    JCN    S    234567
5    HAL    W    765432
*/

------解决方案--------------------

SQL code

--> 测试数据：[test]
if object_id('[test]') is not null drop table [test]
create table [test](
[ID] int,
[Company] varchar(3),
[Name] varchar(1),
[Mobile] int
)
insert [test]
select 0,'IBM','R',123456 union all
select 1,'KDO','P',987654 union all
select 2,'JCN','S',234567 union all
select 3,'KDO','K',345678 union all
select 4,'IBM','L',654321 union all
select 5,'HAL','W',765432

--2005以上版本
with t
as(
select 
px=ROW_NUMBER()over(partition by Company order by id),
* from test
)
select ID,Company,Name,Mobile from t
where px=1
order by id

/*
ID    Company    Name    Mobile
0    IBM    R    123456
1    KDO    P    987654
2    JCN    S    234567
5    HAL    W    765432
*/