จำนวนการสั่งซื้อผลิตภัณฑ์ภาพถ่ายทั้งหมดคือเท่าใด?ไม่จำเป็นต้องใช้ตารางทั้งหมด
What are the total order quantities of photo products?It is not neccessary to use all the tables.
 stores:  store_id [ text]  address_id [ number]  marketing_region_code [ text]  store_name [ text]  store_phone [ text]  store_email_address [ text]  other_details [ text] 
SELECT SUM(T1.order_quantity) FROM order_items AS T1 JOIN products AS T2 ON T1.product_id = T2.product_id WHERE T2.product_name = "photo"