Setting a calculated field to 1

Hi, Please take a look and tweak accordingly.

Create table #test (Acode char(1), V1 int, V2 int, V3 int)
Insert into #test values('A',3,4,6),('B',0,null,0),('C',2,3,3), 
('D',NULL,NULL,NULL),  ('E',5,NULL,NULL)

Select Acode,
Case 
        When sum(ISNULL(v1, 0)+ISNULL(v2, 0)+ ISNULL(v3,0) ) > 0 Then sum(   ISNULL(v1, 0)+ISNULL(v2, 0)+ ISNULL(v3,0) ) 
        Else 1 
End  as TargetSum ,
case
        When  sum(coalesce(v1, 0)+coalesce(v2, 0)+ coalesce(v3,0) ) > 0 Then sum(    coalesce(v1, 0)+coalesce(v2, 0)+ coalesce(v3,0) )
        --sum(  ISNULL(v1, 0)+ISNULL(v2, 0)+ ISNULL(v3,0) ) > 0 Then sum(    ISNULL(v1, 0)+ISNULL(v2, 0)+ ISNULL(v3,0) )   
        Else 1 
End  as TargetMax 
from #test
Group by Acode

drop table #test