The First Order Ever Placed :Find Each Customer’s Earliest Order Date and Amount in the Galactic Trading Post Intermediate

          with first_order as
  (select customerid,
          orderid,
          orderdate,
          totalamount,
          first_value(orderdate) over (partition by customerid
                                       order by orderdate asc) as firstorderdate
   from orders)
select customerid,
       orderid,
       totalamount,
       firstorderdate
from first_order
where orderdate=firstorderdate;