Simple method to retrieve the keys of an entity in EF. The thing here is to convert the dumb DbContext into a much more powerful ObjectContext.

GetKeys.cs

public IEnumerable<string> GetPrimaryKeyNames<T>() {
  ObjectSet<T> objCtx = (ctx as IObjectContextAdapter).ObjectContext.CreateObjectSet<T>();
  return objCtx.EntitySet.ElementType.KeyMembers.Select(k => k.Name);
}