With what you've described, I can't see what would cause your problem. I tried it.

(Since you didn't provide any schema or sample data I invented some.)

-- T-SQL
create table milestones (
    [id] int not null,
    project_ID char(1) null,
    title char(1),
    details char(1) null,
    date_expected smalldatetime null,
    date_completed smalldatetime null
)
go
insert into milestones values (1,'a','a','a','2004-01-01', '2004-01-01
+')
insert into milestones values (1,'b','a','a','2004-01-02', '2002-01-01
+')
insert into milestones values (1,'c','a','a','2004-02-10', null)
insert into milestones values (1,'d','a','a', null, null)
insert into milestones values (1,'e','a','a','2004-11-11', null)
go    
select * from milestones
go
-- Milestones now contains -
id          project_ID title details date_expected          date_compl
+eted     
----------- ---------- ----- ------- ---------------------- ----------
+---------
1           a          a     a       2004-01-01 00:00:00    2004-01-01
+ 00:00:00
1           b          a     a       2004-01-02 00:00:00    2002-01-01
+ 00:00:00
1           c          a     a       2004-02-10 00:00:00    NULL
1           d          a     a       NULL                   NULL
1           e          a     a       2004-11-11 00:00:00    NULL

(5 row(s) affected)

# Perl code
use strict;
use warnings;
use DBI;

my $dbh = DBI->connect("dbi:ODBC:driver=SQL Server;database=pubs;serve
+r=(local)", 'sa', 'mypassword') or die "can't connect";

my $q = qq{
    
select
    ID,
    project_ID,
    title,
    details,
    DATEPART(dd, date_expected),
    DATEPART(mm, date_expected),
    DATEPART(yyyy, date_expected),
    DATEPART(dd, date_completed),
    DATEPART(mm, date_completed),
    DATEPART(yyyy,date_completed),
    is_complete = case 
        when date_completed is null then 0
        else 1
    end
from
    MILESTONES
where
    ID = 1
    
};
my $sth= $dbh->prepare($q);

$sth->execute;

while (my @row = $sth->fetchrow_array) {
    $_ ||= 'NULL' for @row;    
    print "@row\n";
}

$sth->finish;

$dbh->disconnect;

__END__
d:\tmp>Test.pl
1 a a a 1 1 2004 1 1 2004 1
1 b a a 2 1 2004 1 1 2002 1
1 c a a 10 2 2004 NULL NULL NULL NULL
1 d a a NULL NULL NULL NULL NULL NULL NULL
1 e a a 11 11 2004 NULL NULL NULL NULL
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