Most Popular Products in the Galaxy :Rank Galactic Products by Total Quantity Sold and Popularity Intermediate

          with producttotals as
  (select p.productid,
          p.name as productname,
          sum(od.quantity) as totalquantity
   from orderdetails od
   join products p on od.productid = p.productid
   group by p.productid,
            p.name)
select productid,
       productname,
       totalquantity,
       rank() over (
                    order by totalquantity desc) as rank
from producttotals;