I am facing a bit of a challenge while working with the PROC SQL statement in SAS. I'm trying to perform some joins between multiple tables, but it seems like I'm missing something and not getting the expected results. PROC SQL; SELECT o.order_id, o.customer_id, SUM(od.quantity) AS total_quantity FROM orders AS o INNER JOIN order_details AS od ON o.order_id = od.order_id GROUP BY o.order_id; QUIT; I want to retrieve a list of ORDER ID, CUSTOMER ID, and the total quantity of products for each order. In other words, I want to sum up the quantity from the order details table for each order ID. ... View more