The Pioneer Product in Every Category :Identify the First Product Sold and Its Earliest Sale Date by Category Intermediate

          with s as
  (select p.category,
          p.name,
          o.orderdate,
          o.orderid,
          p.productid
   from orderdetails od
   join orders o on od.orderid = o.orderid
   join products p on od.productid = p.productid)
select distinct category,
                FIRST_VALUE(name) over (partition by category
                                        order by orderdate,
                                                 orderid,
                                                 productid rows between unbounded PRECEDING and unbounded following) as productname,
                                       FIRST_VALUE(orderdate) over (partition by category
                                                                    order by orderdate,
                                                                             orderid,
                                                                             productid rows between unbounded PRECEDING and unbounded following) as firstsolddate
from s
order by category;