The Merchant’s Remaining Riches: Measure Remaining Order Value Over Time with SQL Analytic Techniques

          with OrderValues as
  (select o.OrderDate::date as OrderDate,
          SUM(od.Quantity * od.UnitPrice * c.ExchangeRateToBase) as OrderValueBase
   from Orders o
   join OrderDetails od on o.OrderID = od.OrderID
   join Currency c on od.CurrencyID = c.CurrencyID
   where o.OrderDate between '2245-10-01' and '2245-10-31'
     and o.Status = 'Completed'
   group by o.OrderID,
            o.OrderDate)
select OrderDate,
       OrderValueBase,
       SUM(OrderValueBase) over (
                                 order by OrderDate rows between current row and unbounded following) as RemainingValueBase
from OrderValues
order by OrderDate;