Northwind.Data.NorthwindEntities.Sales_by_Year C# (CSharp) Method

        public virtual ObjectResult<Sales_by_Year_Result> Sales_by_Year(Nullable<System.DateTime> beginning_Date, Nullable<System.DateTime> ending_Date)
        {
            var beginning_DateParameter = beginning_Date.HasValue ?
                new ObjectParameter("Beginning_Date", beginning_Date) :
                new ObjectParameter("Beginning_Date", typeof(System.DateTime));
    
            var ending_DateParameter = ending_Date.HasValue ?
                new ObjectParameter("Ending_Date", ending_Date) :
                new ObjectParameter("Ending_Date", typeof(System.DateTime));
    
            return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction<Sales_by_Year_Result>("Sales_by_Year", beginning_DateParameter, ending_DateParameter);
        }
    

        // Task 05.
        // Write a method that finds all the sales by specified region
        // and period (start / end dates).
        public static IEnumerable<Sales_by_Year_Result> FindSalesByRegionAndPeriod(string shipRegion, DateTime startYear, DateTime endYear)
        {
            NorthwindEntities context = new NorthwindEntities();

            var salesByRegionAndYear =
                from salesByYear in context.Sales_by_Year(startYear, endYear)
                join order in context.Orders
                .Where(o => o.ShipRegion == shipRegion)
                on salesByYear.OrderID equals order.OrderID
                select salesByYear;

            return salesByRegionAndYear;
        }