Listing 4: Script That Creates Version 2 of the Stored Procedure
ALTER PROC dbo.usp_GetOrders
  @OrderID    AS INT      = NULL,
  @CustomerID AS NCHAR(5) = NULL,
  @EmployeeID AS INT      = NULL,
  @OrderDate  AS DATETIME = NULL
WITH RECOMPILE
AS

SELECT OrderID, CustomerID, EmployeeID, OrderDate, filler
FROM dbo.Orders
WHERE OrderID    = COALESCE(@OrderID,    OrderID)
  AND CustomerID = COALESCE(@CustomerID, CustomerID)
  AND EmployeeID = COALESCE(@EmployeeID, EmployeeID)
  AND OrderDate  = COALESCE(@OrderDate,  OrderDate);
GO