Versioning OData controllers

It is good practice to plan for future versions of your OData models that might have different schemas and behavior.

To maintain backward compatibility, you can use OData URL prefixes to specify a version number:

1. In the Northwind.OData.Service project, in Program.cs, in the services configuration section, after adding the two OData models for catalog and orders, add a third OData model that has a version number and uses the same GetEdmModelForCatalog method, as shown highlighted in the following code:

   .AddRouteComponents(routePrefix: "catalog", 
     model: GetEdmModelForCatalog())
   .AddRouteComponents(routePrefix: "ordersystem", 
     model: GetEdmModelForOrderSystem())
   .AddRouteComponents(routePrefix: "catalog/v{version}", 
     model: GetEdmModelForCatalog())
   

2. In ProductsController.cs, modify the Get methods to add a string parameter named version that defaults to "1", and use it to change...