public IActionResult GenerateMembers(int noMembers = 5) { var existingEmails = _context.Member.Select(m => m.Email).ToList(); for (int i = 0; i < noMembers; i++) { var member = _parkedVehicleGenerator.GenerateMember(); //If email does noe exist if (existingEmails.IndexOf(member.Email) == -1) { existingEmails.Add(member.Email); _context.Add(member); } } _context.SaveChanges(); return(RedirectToAction(nameof(Index))); }