Question: which person had order high amount of products | What attributes do you want to know about the customer who ordered the highest amount of products? | I want everything about it.
SQL: SELECT * FROM customers AS t1 JOIN customer_orders AS t2 ON t1.customer_id   =   t2.customer_id JOIN order_items AS t3 ON t2.order_id   =   t3.order_id  group by T2.customer_id order by sum ( T3.order_quantity )  desc limit 1