To-One Relationship


I want to save a attributes of an entity that has one-to-one relationship. For example, above is a screen shot of a part of my model. “Teshis” entity has relationship to TME entity (there can be many teshis but only one TME for each). In my code I can save Teshis entity like this:

teshisler is a relationship from hasta entity.

let teshisEntity = NSEntityDescription.entityForName("Teshis", inManagedObjectContext: managedContext)
      let yeniTeshis = Teshis(entity: teshisEntity!, insertIntoManagedObjectContext: managedContext)
      yeniTeshis.tarih = NSDate()
      yeniTeshis.notlar = notlar_TF.text
      yeniTeshis.onTani = onTani_TF.text
      yeniTeshis.tedaviPlani = tedaviPlani_TF.text
      let teshisler = hasta.teshisler!.mutableCopy() as! NSMutableOrderedSet
      hasta.teshisler = teshisler.copy() as? NSOrderedSet
      do {
      } catch let error as NSError {
        print("Could not save:\(error)")

my question is how can I save “r_Kliking” attribute of TME to my context and how can I retrieve it back?