MSTest with Moq to Mock EF5 Linq query

Question

I have following class and method which i want to mock using MSTest with Moq

public AuditRepository: IAuditRepository
{
    private readonly SQLDBContext _context;
    public AuditRepository(SQLDBContext context)
    {
      _context = context;
    }

   public AddAuditData(Audit auditData)
   {
     
       var isAuditEnabled = from s in context.settings
                          where s.Name = "AuditEnabled" select s.value;

       if(isAuditEnabled )
       {
         context.AddObject(typeof(AuditData).Name,auditData);
         context.SaveChanges();
       }
   }
}

The SQLDBContext is like

public partial class SQLDBContext :ObjectContext
{
   //..EF5 stuff
}