Show all product names and the total quantity ordered for each product name.
SELECT T2.product_name ,  sum(T1.product_quantity) FROM Order_items AS T1 JOIN Products AS T2 ON T1.product_id  =  T2.product_id GROUP BY T2.product_name
SELECT T2.product_name ,  sum(T1.product_quantity) FROM Order_items AS T1 JOIN Products AS T2 ON T1.product_id  =  T2.product_id GROUP BY T2.product_name
[{'product_name': 'Arts', 'sum(T1.product_quantity)': 5}, {'product_name': 'Beer Menus', 'sum(T1.product_quantity)': 2}, {'product_name': 'Chocolate', 'sum(T1.product_quantity)': 1}, {'product_name': 'Fans', 'sum(T1.product_quantity)': 9}, {'product_name': 'Hard Drive', 'sum(T1.product_quantity)': 10}, {'product_name': 'Harry Potter 2', 'sum(T1.product_quantity)': 8}, {'product_name': 'Harry Potter 3', 'sum(T1.product_quantity)': 15}, {'product_name': 'Harry Potter 4', 'sum(T1.product_quantity)': 3}, {'product_name': 'Learning English', 'sum(T1.product_quantity)': 5}, {'product_name': 'TV', 'sum(T1.product_quantity)': 7}]