Query to get list of customers with partial shipments

Question

I have a scenario where I need to find customers with open orders.  (Orders and Shipments have 1-to-many relationship ):
Orders = (order_id PK, cust_id FK, prod_id FK, order_quantity, order_date)
Shipments = (shipment_id, order_id FK, shipment_quantity, shipment_date)
Open orders have 2 scenarios:
1) orders without shipment records
2) partial shipments:
e.g. 1 order record with quantity 10.  
2 records in shipments table, 1 row with quantity 3, and the 2nd row with quantity 4; total shipped quantity is 7, which is less than order quantity of 10
How can I get this?

Answer 1

ZaafranAhmed wrote:
I have a scenario where I need to find customers with open orders.  (Orders and Shipments have 1-to-many relationship ):
Orders = (order_id PK, cust_id FK, prod_id FK, order_quantity, order_date)
Shipments = (shipment_id, order_id FK, shipment_quantity, shipment_date)
Open orders have 2 scenarios:
1) orders without shipment records
2) partial shipments:
e.g. 1 order record with quantity 10. 
2 records in shipments table, 1 row with quantity 3, and the 2nd row with quantity 4; total shipped quantity is 7, which is less than order quantity of 10
How can I get this?
SELECT order_id
FROM   orders
WHERE  order_quantity > (SELECT SUM(shipment_quantity)
                         FROM   shipments
                         WHERE  orders.order_id = shipments.order_id);