--> 测试数据：[point]
if object_id('[point]') is not null drop table [point]
create table [point]([POINT] int,[TYPE] int)
insert [point]
select 3,1 union all
select 4,2 union all
select 2,1 union all
select 4,1 union all
select 1,2 union all
select 3,1

select case when [type]=2 then -[POINT] else [POINT] end as [POINT],
[TYPE] from [point]

/*
POINT    TYPE
3    1
-4    2
2    1
4    1
-1    2
3    1
*/
--求和：
select [TYPE],sum(case when [type]=2 then -[POINT] else [POINT] end) as [POINT]
 from [point] group by [TYPE]
 
 /*
 TYPE    POINT
1    12
2    -5
 */

------解决方案--------------------
SQL code

--求和：
select sum(case when [type]=2 then -[POINT] else [POINT] end) as [POINT]
 from [point] 
 /*
POINT
7
*/