sorting tables

Hi everybody I am doing a select in my oracle DB where i get some records. These records are grouped by product id, cost, etc, and amount sold every month. Then, i show all regs in a table, but as the ORDER BY is done also with the month / year, because i want to show how much every month is sold, it creates a new line even also the product is the same. Then i have my table with x times the same product, in every month column zero values except the amount for that month. Is there a way to show one product per row with every amount on every month column? Thx in advance