Like so many others over the weekend I upgraded to the last RC builds of various Visual Studio 2012 related products.  While updating my Web Api sample project ChlodnyWebApi I ran into one error when upgrading to Entity Framework 5 RC (not bad if you ask me).

The name 'DatabaseGeneratedOption' does not exist in the current context

Looks like this was moved in this version.  Add the following using statement:

using System.ComponentModel.DataAnnotations.Schema;

The System.ComponentModel.DataAnnotations.Schema namespace provides support for attribute classes that are used to define metadata for ASP.NET MVC and ASP.NET data controls.