Database: customers_and_addresses
Question: Display amount of products ordered before 2015-03-17 00:00:00.
SQL: 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_date  <  "2015-03-17 00:00:00."