How can I update related tables? - asp.net-mvc

Question

My project involves creating a new hotel room and 2 tables in my database will update. My tables are called RoomType and RoomFacility.
I can successfully update RoomType, but when I try to update RoomFacility and use RoomTypeID to make a new room facility, it fails. I always get 1 for my RoomFacilityID.
How can I update data for both tables, roomType and RoomFacility?
This is the code for my service to update my database
public void UpdateFacilityInRooms(List<int> FacilityIDs, int RoomTypeID)
{
List<HotelRoomFacility> hotelRoomFacilities =
_HotelRoomFacilityRopository.AsQueryable()
.Where(f => f.RoomTypeID == RoomTypeID).ToList();
foreach (int newRoomFacility in FacilityIDs)
{
if (hotelRoomFacilities.Where(h => h.RoomFacilityID == newRoomFacility).Count() == 0)
{
HotelRoomFacility facility = new HotelRoomFacility
{
RoomFacilityID = newRoomFacility,
RoomTypeID = RoomTypeID
};
_HotelRoomFacilityRopository.Add(facility);
}
}
_HotelRoomFacilityRopository.CommitChanges();
}
public RoomType NewRoom(int HotelID,int? RoomTypeID,
string RoomTypeName, string RoomTypeDescription)
{
RoomType room = new RoomType();
room.HotelID = HotelID;
room.RoomTypeID = RoomTypeID ?? 0;
room.RoomtypeName = RoomTypeName;
room.RoomTypeDescripton = RoomTypeDescription;
_RoomTypeRepository.Add(room);
_RoomTypeRepository.CommitChanges();
return room;
}

Answer 1

public RoomType UpdateRoom(int RoomTypeID, string RoomTypeName, string RoomTypeDescription, List<int> RoomFacilityIDs)
{
RoomType roomType = (from rt in _RoomTypeRepository.AsQueryable().Include(r => r.HotelRoomFacilities)
where rt.RoomTypeID == RoomTypeID
select rt).FirstOrDefault();
if (roomType == null)
return null;
roomType.RoomTypeName = RoomTypeName;
roomType.RoomTypeDescripton = RoomTypeDescription;
//Add New Room facilities
List<HotelRoomFacility> hotelRoomFacilities = _HotelRoomFacilityRopository.AsQueryable().Where(f => f.RoomTypeID == RoomTypeID).ToList();
foreach (int newRoomFacilityID in RoomFacilityIDs)
{
if (roomType.HotelRoomFacilities.Where(h => h.RoomFacilityID == newRoomFacilityID).Count() == 0)
{
roomType.HotelRoomFacilities.Add(new HotelRoomFacility
{
RoomFacilityID = newRoomFacilityID
});
}
}
foreach (HotelRoomFacility roomFacility in hotelRoomFacilities)
{
if (RoomFacilityIDs.Contains(roomFacility.RoomFacilityID) == false)
_HotelRoomFacilityRopository.Delete(roomFacility);
}
_RoomTypeRepository.Attach(roomType);
_RoomTypeRepository.CommitChanges();
return roomType;
}