plz answer to this query

Write a query to display customer name & rating for all pairs of customers having the same rating, each pair should come once only. There should be three columns displayed as Customer1, Customer2, rating. Eg – Ram, Sita, 500. Ram and Sita are pair of customers who have the same rating as 500.Sort the result by rating in descending order and then by customer 1 in descending order and then by customer 2 in descending order.