CREATE TABLE customers (customer_name VARCHAR, customer_phone VARCHAR, customer_id VARCHAR)
CREATE TABLE order_items (order_id VARCHAR, order_quantity INT)
CREATE TABLE customer_orders (customer_id VARCHAR, order_id VARCHAR)

What are the name and phone of the customer with the most ordered product quantity?
SELECT T1.customer_name, T1.customer_phone FROM customers AS T1 JOIN customer_orders AS T2 ON T1.customer_id = T2.customer_id JOIN order_items AS T3 ON T3.order_id = T2.order_id GROUP BY T1.customer_id ORDER BY SUM(T3.order_quantity) DESC LIMIT 1
SELECT "T1"."customer_name", "T1"."customer_phone" 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 "T1"."customer_id" ORDER BY SUM("T3"."order_quantity") DESC NULLS LAST LIMIT 1