Adding a new relationship to an existing model in Realm - ios

Question

I'm developing an iOS application using Realm and have a object MedicationObject which contains the information about the Medication being used. This then has a many to one relationship class MedicationRecording which stores the information when the time the medication was taken.
import Foundation
import RealmSwift
class MedicationObject : Object {
//This model requires a Primary Key
#objc dynamic var id = 0
override static func primaryKey() -> String? {
return "id"
}
#objc dynamic var medicationName : String = ""
//stores the refrences to medication recoridngs
var messurements = List<MedicationRecording>()
public func addNewMesurment() {
print(self)
let medicationRecording = MedicationRecording()
medicationRecording.medicationTaken = self
medicationRecording.timeTaken = Date()// this saves the time to now
medicationRecording.medicationTaken = self
RealmAccess().updateMedicationObject(medicationObject: self, medicationRecord: medicationRecording) //this should work
}
}
here is my MedicationRecording:
import Foundation
import RealmSwift
class MedicationRecording : Object {
#objc dynamic var medicationTaken : MedicationObject? = MedicationObject()
#objc dynamic var timeTaken : Date = Date()
#objc dynamic var id = 0
override static func primaryKey() -> String? {
return "id"
}
}
and this is the method I'm calling to save the data to
func updateMedicationObject(medicationObject : MedicationObject, medicationRecord : MedicationRecording) {
let realm = try! getRealmAccess()
let mediObject = MedicationObject()
mediObject.medicationName = medicationObject.medicationName
do {
try! realm.write {
realm.add(medicationRecord, update: true)
medicationObject.messurements.append(medicationRecord)
}
}
}
At the moment when I'm saving the data it is then losing all the information in MedicationObject and only saving the last data.
Any help with be greatly appreciated
Thank you