with t1 as ( select o.product_id, year(o.order_date) as year_date, round(sum(o.quantity*p.unit_price),2) as total_sales, p.unit_price, sum(o.quantity) as total_quantity, round(sum(o.quantity*p.unit_price)/12,2) as avg_monthly_sales from orders o left join products p on o.product_id=p.product_id left...
