行转列求和：不加 in 条件，sum的数据会不会准确?

create table zy
(
F01 varchar(4),
F02 int
)

insert into zy
select 'A',10
union all
select 'B',10
union all
select 'C',10
union all
select 'D',10
union all
select 'E',10

select
sum(case F01 when 'A' then F02 end) A,
sum(case F01 when 'B' then F02 end) B
from zy