Top Selling Product Each Month

For each month return the product with the largest total quantity sold (month as 'YYYY-MM', product, total quantity). Order by month.

Table schema

Sales(sale_date DATE, product VARCHAR(20), qty INT)

Sample data

sale_date | product | qty
2026-01-05 | Pen | 5
2026-01-10 | Book | 7
2026-02-03 | Pen | 3
2026-02-20 | Bag | 6