Tunds Tunds - 1 year ago 83
Swift Question

Inserting data with one to one relationship - realm

So i'm trying to set up and pre populate a database for later use when the actual application ships.

The issue i'm having is i'm not able to insert into the field which is creating the relationship the field is just empty. Screenshot below:

Screenshot should type field is empty
These are my data models

The data model holding the info the type is the key to the other object

class sourceRecentData: Object {

// Name
dynamic var sourceName: String = ""

// Description
dynamic var sourceDesc: String = ""

// TypeID
dynamic var type : sourceType?

// Key
dynamic var sourceKey: String = ""

// Enabled
dynamic var sourceEnabled: Bool = true

// Unlocked
dynamic var sourceUnlocked: Bool = false

The id in this object links to the object above

class sourceType: Object {

// NewsType
dynamic var typeOfNews: String = ""


The method i'm using to perform the insert for now it's just dummy data

func createTopDB() {

let recentData = sourceRecentData()

let realm = try! Realm()

recentData.sourceName = "dfdfd"
recentData.sourceDesc = "fdfd"
recentData.sourceKey = "fdfdf"
recentData.sourceEnabled = true
recentData.sourceUnlocked = false
recentData.type?.typeOfNews = "fdfdfd"

try! realm.write({ () -> Void in



You need to initialize your property first with a related object, before you can write values on it. I'd recommend to that in a separate variable like shown below, so you can avoid writing on an optional value (recentData.type?.typeOfNews = …):

let type = SourceType()
type.typeOfNews = "fdfdfd"
recentData.type = type

You can query for the object like that:

let realm = try! Realm()
let objects = realm.objects(SourceRecentData).filter("type.id = 1")

PS: I'd recommend to name your classes beginning with an uppercase letter as this is a general best-practice in the Swift programming community and make it easier to differentiate between classes and variables. I applied that in the following example code to make it easier to read, because SO's syntax highlighting relies on that convention as well.