Takes patience and knowledge, but please help me with this function

Question

I know I am asking for a lot, but I've been sitting over this for hours and can't crack it.
I got these two tables
create table orders create table products
(order_no number, (item_no number (4)
item_no number(4), tem_name varchar2(50)
order qta number, price number,
order_date date supplier_id char(3));
delivered date)
I am trying to create a function that would give me owed amount for delayed delivery per order. Companies have 30 days to deliver the goods, otherwise they pay penalty 1% of order price for each day of delay.
I cooked up this and it's giving me results only in case there is one row per order in orders table. Like this:
ORDER_NO ITEM_NO ORDER_QTA ORDER_DATE RECEIVED
1002 2 90 29.01.10 01.05.10
but the moment there is more than one row in orders (like below) I execute the function and get the error message - ORA-01422: exact fetch returns more than requested number of rows
ORDER_NO ITEM_NO ORDER_QTA ORDER_DATE RECEIVED
1000 26 82 30.03.10 NULL
1000 14 35 30.03.10 NULL
I've written this and it contains a GROUP BY clause and sums the rows. I don't know why I am still getting the error message.PLS HELP!!
THANKS,
JANA
create or replace function debts (aorder_no in number)
return number is
amount number;
rec date;
begin
select received into rec from orders where order_no=aorder_no;
if rec is not null then
select (to_date(received,'DD-MM-YYYY')-to_date(order_date,'DD-MM-YYYY')-30)* sum((o.order_qta*p.price)*0.01)
into amount
from orders o, products p
where p.item_no = o.item_no
and o.order_no=aorder_no
group by (to_date(received,'DD-MM-YYYY')-to_date(order_date,'DD-MM-YYYY')-30);
return (amount);
end if;
if rec is null then
select (to_date(sysdate,'DD-MM-YYYY')-to_date(order_date,'DD-MM-YYYY')-30)* sum((o.order_qta*p.price)*0.01)
into amount
from orders o, products p
where p.item_no = o.item_no
and o.order_no=aorder_no
group by (to_date(sysdate,'DD-MM-YYYY')-to_date(order_date,'DD-MM-YYYY')-30);
return (amount);
end if;
end;
/

Answer 1

Sorry,
I' m new to this forum and to PL/SQL as well, so I am probably not posting these questions correctly . I am using 10g Ex edition. Here is some sample data.
when I created the function, it was complied ok.
I execute it on order_no 1001 and everything went fine, but if I execute it on order_no 1000, I get an error message. I think it has something to do with the SQL grouping in my statment, but I'm too unexperienced to figure it out on my own.
insert into orders values (     1000     ,     26     ,     25     ,'     30-Mar-10     ,     4-Apr-10     );
insert into orders values (     1000     ,     14     ,     31     ,'     30-Mar-10     ,     1-May-10     );
insert into orders values (     1001     ,     9     ,     39     ,'     28-Feb-10     ,     null     );
insert into orders values (     1002     ,     2     ,     95     ,'     29-Jan-10     ,     10-Dec-09     );
insert into orders values (     1003     ,     23     ,     2     ,'     6-Apr-10     ,     null     );
insert into orders values (     1004     ,     16     ,     70     ,'     8-Jun-04     ,     null     );
insert into orders values (     1005     ,     4     ,     76     ,'     6-May-10     ,     null     );
insert into orders values (     1005     ,     19     ,     86     ,'     6-May-10     ,     null     );
insert into orders values (     1006     ,     29     ,     86     ,'     8-Apr-10     ,     null     );
insert into orders values (     1006     ,     30     ,     55     ,'     8-Apr-10     ,     10-Mar-10     );
insert into orders values (     1007     ,     22     ,     54     ,'     6-Apr-10     ,     null     );
insert into orders values (     1008     ,     9     ,     54     ,'     23-Jan-10     ,     null     );
insert into orders values (     1009     ,     16     ,     22     ,'     5-Apr-10     ,     null     );
insert into orders values (     1010     ,     7     ,     53     ,'     2-Mar-10     ,     null     );
insert into products values (     1     ,'     product_name1'     ,     61000     ,'     EU1'     );
insert into products values (     2     ,'     product_name2'     ,     46000     ,'     EU1'     );
insert into products values (     3     ,'     product_name3'     ,     80000     ,'     EU2'     );
insert into products values (     4     ,'     product_name4'     ,     15000     ,'     EU3'     );
insert into products values (     5     ,'     product_name5'     ,     10000     ,'     EU2'     );
insert into products values (     6     ,'     product_name6'     ,     12000     ,'     EU1'     );
insert into products values (     7     ,'     product_name7'     ,     73000     ,'     EU3'     );
insert into products values (     8     ,'     product_name8'     ,     59000     ,'     EU2'     );
insert into products values (     9     ,'     product_name9'     ,     31000     ,'     EU3'     );
insert into products values (     10     ,'     product_name10'     ,     80000     ,'     EU1'     );
insert into products values (     11     ,'     product_name11'     ,     66000     ,'     EU2'     );
insert into products values (     12     ,'     product_name12'     ,     62000     ,'     US1'     );
insert into products values (     13     ,'     product_name13'     ,     75000     ,'     EU1'     );
insert into products values (     14     ,'     product_name14'     ,     32000     ,'     EU2'     );
insert into products values (     15     ,'     product_name15'     ,     44000     ,'     US1'     );
insert into products values (     16     ,'     product_name16'     ,     68000     ,'     EU1'     );
insert into products values (     17     ,'     product_name17'     ,     28000     ,'     US1'     );
insert into products values (     18     ,'     product_name18'     ,     10000     ,'     EU2'     );
insert into products values (     19     ,'     product_name19'     ,     69000     ,'     US2'     );
insert into products values (     20     ,'     product_name20'     ,     24000     ,'     US1'     );
insert into products values (     21     ,'     product_name1'     ,     40000     ,'     US3'     );
insert into products values (     22     ,'     product_name2'     ,     95000     ,'     US3'     );
insert into products values (     23     ,'     product_name3'     ,     31000     ,'     US1'     );
insert into products values (     24     ,'     product_name4'     ,     100000     ,'     US2'     );
insert into products values (     25     ,'     product_name5'     ,     64000     ,'     US2'     );
insert into products values (     26     ,'     product_name6'     ,     91000     ,'     US1'     );
insert into products values (     27     ,'     product_name7'     ,     65000     ,'     US3'     );
insert into products values (     28     ,'     product_name8'     ,     86000     ,'     US2'     );
insert into products values (     29     ,'     product_name9'     ,     62000     ,'     US3'     );
insert into products values (     30     ,'     product_name10'     ,     13000     ,'     US3'     );