SQL query to compare yearly sales

Question

How do I compare sales in 2005 versus sales in 2004?
sales calendar year go from October 1 through Sep 30 (sales 2004 is from Oct 1, 2003 thro Sep 2004)
Have an orders table as:
(dist_id number,
prod_type varchar2(1),
prod_line varchar2(1),
quantity number,
sales_date date)
I could have easily done the following SQL if sales calendar year was from Jan 1 thro Dec 30, but this will not work since sales calendar year is from Oct 1 thro Sep 30.--
"select dist_id, prod_type, prod_line, sum(decode(to_char(sales_date,'yyyy'),'2004',quantity,0)) Sales2004, sum(decode(to_char(sales_date,'yyyy'),'2005',tot,0)) Sales2005
from orders
group by dist_id, prod_type, prod_line"
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Answer 1

select dist_id, prod_type, prod_line,
       sum (case when sales_date between to_date ('oct-01-2003', 'mon-dd-yyyy')
                                 and     to_date ('sep-30-2004', 'mon-dd-yyyy')
                 then quantity
                 else 0
            end) Sales2004,
       sum (case when sales_date between to_date ('oct-01-2004', 'mon-dd-yyyy')
                                 and     to_date ('sep-30-2005', 'mon-dd-yyyy')
                 then quantity
                 else 0
            end) Sales2005
from   orders
group   by dist_id, prod_type, prod_line;