Write a query to display the buyer number, material id, material name, purchase date, current purchase total, total of all purchases by that buyer, and the percentage of the total of all purchases by that buyer that is represented by the current purchase. The current purchase is the purchase quantity multiplied by the purchase price for that purchase. The total of all purchases is the sum of adding up all purchases (quantity multiplied by price) made by that buyer. The percentage of the total of all purchases by that buyer that is represented by the current purchase is calculated at the current purchase divided by the total of all purchases by that buyer multiplied by 100. Sort the result by the total of all purchases for each buyer in descending order, then by the buyer number in ascending order, then by the current purchase in descending order. For example, the first row of output shows that buyer 480 purchased material 289, which is Scrap Iron, on April 22, 2019. The total cost of that purchase was $472,350. All purchases in the history of buyer 480 is $1,689,466. The current p