a. Write an anonymous block that contains a PL/SQL function. Given an order number orderNo, the function will calculate the total number of the parts in the order. Then the anonymous block should use the function to find the total number of parts for the order with orderNo=1020. Verify if the result is correct.
b. Write a stored function. Similarly, the function has an input parameter orderNo and calculates the total number of the parts in the order.