Problems with "not in" statement

Question

I have a query that should return less than 20 lines, but instead I get about 51. I'm not sure what's wrong here. I've tried a bunch of different things.
select i.w_id, i.p_id,
count(decode(o.ord_id, ' ', i.p_id, 0)) ORDERS_ISSUED,
sum(decode(o.order_status, 'P', i.quantity, 0)) QUANTITY_ORDERED
from
inventories i,
orders o,
products p
where p.p_id not in
(select i.p_id from inventories i)
group by i.w_id, i.p_id;
What I'm trying to achieve is:
Which warehouses have pending orders for products, which are not in stock at the warehouse at the moment? Provide warehouse number, id of the product that is not in stock, number of orders issued for this product and total quantity ordered.
The tables I'm using are:
Inventories
Name
P_ID
W_ID
QUANTITY
Orders
Name
ORD_ID
SUPPLIER_ID
ISSUING_EMP_ID
ORDER_DATE
ORDER_STATUS
Products
Name
P_ID
NAME
MODEL
And I think I might have to use this one:
Employees
Name
EMP_ID
SALARY
WAR_ID
Edited by: user4555857 on 30-Nov-2009 13:48

Answer 1

select i.w_id, i.p_id,
count(decode(o.ord_id, ' ', i.p_id, 0)) ORDERS_ISSUED,
sum(decode(o.order_status, 'P', i.quantity, 0)) QUANTITY_ORDERED
from
inventories i,
you should not select from this table aboveorders o,
products p
where p.p_id not in
(select i.p_id from inventories i)
can you tell me the way you expect to map orders & products together?group by i.w_id, i.p_id;