declare @t table ([ID] [int] IDENTITY(1,1) not null, strName varchar(20),intSL int)
insert @t  
select '小明' , 10 union all
select '小明' , 20 union all
select '小明' , 20 union all
select '小红' , 20 union all
select '小红' , 20 union all
select '小红' , 30  

;with t1 as (
    select min([ID]) as ID,strName,sum(intSL) as intSL
    from @t a 
    group by strName
),t2 as 
(
    select strName,sum(intSL) as intSL2 from (
        select row_number() over (partition by strName order by id ) as Row,strName,intSL 
        from @t 
    ) tmp where Row<=2
    group by strName
)
,t3 as 
(
    select strName,sum(intSL) as intSL3 from (
        select row_number() over (partition by strName order by id ) as Row,strName,intSL 
        from @t where intSL > 10
    ) tmp where Row<=2
    group by strName
)


select row_number() over (order by a.id) as ID,a.strName,a.intSL,b.intSL2,c.intSL3
from t1  a 
inner join t2 b on a.strName = b.strName 
inner join t3 c on a.strName = c.strName

/*

(6 行受影响)
ID                   strName              intSL       intSL2      intSL3
-------------------- -------------------- ----------- ----------- -----------
1                    小明                   50          30          40
2                    小红                   70          40          40

(2 行受影响)

*/

------解决方案--------------------

SQL code
if object_id('[tb]') is not null drop table [tb]
go
create table [tb] ([ID] [int] IDENTITY(1,1) not null, strName varchar(20),intSL int)
insert [tb]  
select '小明' , 10 union all
select '小明' , 20 union all
select '小明' , 20 union all
select '小红' , 20 union all
select '小红' , 20 union all
select '小红' , 30 union all
select '小东' , 10 
go


select
   strname,
   sum(intSL) as intSL1,
   sum(case when px<=2 then intSL else 0 end) as intSL2,
   sum(case when px>2 then intSL else 0 end) as intSL3
from
   (select px=row_number()over(partition by strname order by getdate()),* from tb)t
group by
    strname
    
 /*
 strname              intSL1      intSL2      intSL3
-------------------- ----------- ----------- -----------
小东                   10          10          0
小红                   70          40          30
小明                   50          30          20

(3 行受影响)
*/