List out 3 best seller products during year 2003 with their total quantity sold during 2003.
Best selling products refer to products with MAX(quantityOrdered); 2003 refers to year(orderDate) = 2003;
SELECT t3.productName, SUM(t2.quantityOrdered) FROM orders AS t1 INNER JOIN orderdetails AS t2 ON t1.orderNumber = t2.orderNumber INNER JOIN products AS t3 ON t2.productCode = t3.productCode WHERE STRFTIME('%Y', t1.orderDate) = '2003' GROUP BY t3.productName ORDER BY SUM(t2.quantityOrdered) DESC LIMIT 3