mySQL Sum Production_Needed Group BY Part_ID - mysql

Question

Want to generate a result of Open orders where Production is needed. At issue is each part may have more than one open order. With the GROUP BY my code gives me only one order but does give me the total Production_Needed (which is also a negative in value for orders with enough inventory).
Does my SUM(...) as Production_Needed need to be in the WHERE ?
Thanks,
SELECT part.part_ID AS Part_Part_ID,
part.Inventory, part.part_number,
ord.part_id AS Order_Part_ID,
ord.order_type, ord.quantity_ordered, ord.quantity_shipped,
SUM(ord.quantity_ordered - ord.quantity_shipped - part.Inventory) AS Production_Needed
FROM production_orders ord
JOIN production_part part ON ord.part_ID = part.part_ID
WHERE ord.is_Active = True AND ord.order_type = 0
GROUP BY Order_Part_ID
ORDER BY part.part_number ASC
Data Production_Part part
Part_ID
Part_Inventory
Part_Number
1
12500
97-528
2
0
FC2569
3
1000
39367
Data Production_Orders Ord
Order_Part_ID
Order_Type
Quantity_Ordered
Quantity_Shipped
1
0
8000
0
2
0
1000
500
2
0
1000
0
3
1
10
0
Desired Result - Only Parts that need production
Part_ID
Quantity_Ordered
Quantity_Shipped
2
1000
500
2
1000
0

Answer 1

Untested: need a sampled data set and structure for testing:
This creates an inline view and totals the inventory order amounts then stubtracts it from the inventory to determine if there is a production needed to fulfil open orders. I'd have to use some additional analytical functions if we needed to do this on an order by order basis however; or join these results back into the orders...
--Show parts which lack inventory to fullfill outstanding open orders.
SELECT
P.Part_ID as Part_Part_ID
, P.Inventory
, P.Part_Number
, O.Part_ID as Order_Part_ID
, UnDel_Units-coalesce(P.Inventory,0) as Production_Needed --use coalesce incase no part record exists for some reason.
FROM Production_Part P
RIGHT JOIN ( --use right join just incase part record doesn't exist for some reason
SELECT part_ID, SUM(quantity_ordered-quantity_shipped) as UnDel_Units
FROM PRODUCTION_ORDERS
WHERE IS_ACTIVE=TRUE
and ORDER_TYPE=0
GROUP BY PART_ID) O --derived table "O" for orders showing sum ottal by part of units undelivered
on O.Part_ID=P.Part_ID
WHERE UnDel_Units > coalesce(P.Inventory,0)
-- If inventory is > undelivered units for the part, ignore as additional production isn't needed