What is the total number of products?
select sum ( t2.order_quantity ) from customer_orders as t1 join order_items as t2 on t1.order_id = t2.order_id
What is the total number of products that are in orders with status "Delivered"?
select sum ( t2.order_quantity ) from customer_orders as t1 join order_items as t2 on t1.order_id = t2.order_id where t1.order_status = "Delivered"
What is the total number of products that are in orders with status "Cancelled"?
select sum ( t2.order_quantity ) from customer_orders as t1 join order_items as t2 on t1.order_id = t2.order_id where t1.order_status = "Cancelled"