Percent Rank: Species Spending Edition :Compare Customer Spending Across Species by Relative Ranking and Percentage Share Intermediate

          with customertotals as
  (select c.species,
          o.customerid,
          sum(o.totalamount) as totalspending
   from orders o
   join customers c on o.customerid = c.customerid
   group by c.species,
            o.customerid)
select species,
       customerid,
       totalspending,
       percent_rank() over (partition by species
                            order by totalspending desc) as percentrank
from customertotals;