When selecting values from a view with sub selects the last column is returning a null even though it is not, it is possibly an API problem as the problem is duplicated in PHP compilation for 2.5RC3 and in Flamerobin. I've tested this on Windows 2.5 RC 3 & Linux and the problem replicates on both platforms. The reliability of views is compromised if the values returned are not trust worthy.

--drop table testvalues;

create table testvalues (id integer,
                         datum date,
                         sfield varchar (10),
                         num1 numeric (10,2),
                         num2 numeric (10,2),
                         primary key (id)
                        );
commit;
                         
insert into testvalues values (1, 'now', 'A', 10, 0);
insert into testvalues values (2, 'now', 'B', 0, 10);
insert into testvalues values (3, 'now', 'A', 20, 0);
insert into testvalues values (4, 'now', 'B', 0, 20);

create view test_values
as

select
    t.datum,
    iif ((select sum(num1-num2) from testvalues where sfield = 'A' and datum <= t.datum) is null, 0, (select sum(num1-num2) from testvalues where sfield = 'A' and datum <= t.datum)) A,
    iif ((select sum(num1-num2) from testvalues where sfield = 'A' and datum <= t.datum) is null, 0, (select sum(num1-num2) from testvalues where sfield = 'B' and datum <= t.datum)) B,
    iif ((select sum(num1-num2) from testvalues where sfield = 'A' and datum <= t.datum) is null, 0, (select sum(num1-num2) from testvalues where sfield = 'A' and datum <= t.datum)) A1,
    iif ((select sum(num1-num2) from testvalues where sfield = 'A' and datum <= t.datum) is null, 0, (select sum(num1-num2) from testvalues where sfield = 'B' and datum <= t.datum)) B1
from testvalues t
group by t.datum;

create view test_values2
as
select
    t.datum,
    0 as A,
    0 as B,
    0 as A1,
    10 as B1
from testvalues t
group by t.datum;

commit;

select t.* from test_values t;
select t.* from test_values2 t;