“SwiftData inheritance relationship”

I'm implementing SwiftData with inheritance in an app. I have an Entity class with a property name. This class is inherited by two other classes: Store and Person. The Entity model has a one-to-many relationship with a Transaction class. I can list all my Entity models in a List with a @Query annotation without a problem. However, then I try to access the name property of an Entity from a Transaction relationship, the app crashes with the following error: Thread 1: Fatal error: Never access a full future backing data - PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(0x96530ce28d41eb63 ))) with Optional(F07E7E23-F8F0-4CC0-B282-270B5EDDC7F3) From my attempts to fix the issue, I noticed that: The crash seems related to the relationships with classes that has inherit from another class, since it only happens there. When I create new data, I can usually acces

I can't find a way to make this relationship, Anyone to tell me what am i doing wrong please ? import SwiftUI import SwiftData @Model class Model1 { @Attribute(.unique) var id:String var date:Date @Relationship(.cascade) var model2:[Model2] init() { self.id = UUID().uuidString self.date = Date() self.model2 = [] } } @Model class Model2 { @Attribute(.unique) var id:String var date:Date @Relationship(inverse: Model1.model2) var model1:Model1 init( model1:Model1 ) { self.id = UUID().uuidString self.date = Date() self.model1 = model1 } } struct view1:View { @Environment(.modelContext) private var db var body: some View { Text(TapMe) .onTapGesture { let m1 = Model1() db.insert(m1) let m2 = Model2(model1: m1) db.insert(m2) } } } Error : Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Illegal attempt to establish a relationship 'm1' between objects in different contexts (source = (entity: Model2; id: 0x282896ca0 ; data: { date = 2023-07-1

I'm still getting started with SwiftData and having trouble understanding how to persist a model with a relationship in a container. I've tried to distill the example below to be pretty simple. Here are some example model definitions. I would like to be able to define a n Item. That Item can have SubItems related to it in a one-to-many fashion. Each SubItem is required to be attached to a parent Item. final class Item { var name: String var subitems: [Item]? init( name: String, subitems: [SubItem]? = nil ) { self.name = name } } @Model final class SubItem { var name: String init(name: String) { self.name = name } } In my app I am then defining a preview container with some pre-saved data already. Item( name: item1, subitems: [ SubItem(name: subItemA), SubItem(name: subItemB) ] ), Item( name: item2, subitems: [ SubItem(name: subItemC), SubItem(name: subItemD) ] ) ] @MainActor let PreviewContainer: ModelContainer = { do { let schema = Schema([ Item.self, SubItem.self, ]) let container = try Mo

In Xcode Version 15.0 beta (15A5160n) this predicate will not build: let thisPredicate = #Predicate { ($0.myStore != nil) } The definition of .myStore in the Ledgers class is: var myStore: Stores? an optional relationship. Is there anyway to test for nil optional relationships in SwiftData? The inverse relationship in Stores is: @Relationship(.deny, inverse: Ledgers.myStore) var myReceipts: [Ledgers]

SwiftData delete isn't working, when I attempt to delete a model, my app crashes and I get the following error: SwiftData/PersistentModel.swift:359: Fatal error: Cannot remove My_App.Model2 from relationship Relationship - name: model2, options: [], valueType: Model2, destination: Model2, inverseName: models3, inverseKeypath: Optional(Model2.models3) on My_App.Model3 because an appropriate default value is not configured. I get that it's saying I don't have a default value, but why do I need one? Isn't @Relationship .cascade automatically deleting the associated models? And onto of that, why is the error occurring within the do block, shouldn't it be caught by the catch, and printed? I have put together a sample project below. import SwiftUI import SwiftData @main struct MyApp: App { var body: some Scene { WindowGroup { ContentView() .modelContainer(for: Model3.self) } } } @Model class Model1 { var name: String @Relationship(deleteRule: .cascade,

Xcode 16.2 (16C5032a) FB16300857 Consider the following SwiftData model objects (only the relevant portions are shown) (note that all relationships are optional because eventually this app will use CloudKit): @Model final public class Team { public var animal: Animal? public var handlers: [Handler]? ... } @Model final public class Animal { public var callName: String public var familyName: String @Relationship(inverse: Team.animal) public var teams: [Team]? ... } @Model final public class Handler { public var givenName: String @Relationship(inverse: Team.handlers) public var teams: [Team]? } Now I want to display Team records in a list view, sorted by animal.familyName, animal.callName, and handlers.first.givenName. The following code crashes: struct TeamListView: View { @Query(sort: [SortDescriptor(Team.animal?.familyName), SortDescriptor(Team.animal?.callName), SortDescriptor(Team.handlers?.first?.givenName)]) var teams : [Team] var body: some View { List { ForEach(teams)

Given the code below the students array on the school is not being updated. Why? Since the relationship is explicit and non-optional I would expect this to work. import XCTest import SwiftData @Model class School { var name: String @Relationship(deleteRule: .cascade, inverse: Student.school) var students: [Student] init(name: String, students: [Student]) { self.name = name self.students = students } } @Model class Student { var name: String var school: School init(name: String, school: School) { self.name = name self.school = school } } final class Test: XCTestCase { func testScenario() throws { let modelContainer = try ModelContainer(for: School.self, Student.self ) let context = ModelContext(modelContainer) context.autosaveEnabled = false let school = School(name: school, students: []) context.insert(school) let student1 = Student(name: 1, school: school) let student2 = Student(name: 2, school: school) context.insert(student1) context.insert(student2) XCTAssertEqual(school.student

I'm getting an error: Unknown Relationship Type - nil when using SwiftData and CloudKit. I've searched for this on Google, but seems like one has experienced it before. This is on iOS 18. I have a Transaction model: @Model final class Transaction { var timestamp: Date = Date() var note: String = var cost: Cost? = nil var receipt: Receipt? = nil //Relationships var merchant: Merchant? = nil var category: TransactionCategory? = nil var tags: [Tag]? = nil init(timestamp: Date) { self.timestamp = timestamp } } This has a relationship with TransactionCategory. @Model final class TransactionCategory { var id = UUID() var name: String = //Relationship var transactions: [Transaction]? = [] init() { } init(name: String) { self.name = name } } I've tried using @Relationship here in TransactionCategory, but it didn't make a difference. There is Picker that allows you to select a Category. In this case I created a random one, which was inserted into the context and

Is this Relationship correct? Does this cause a circular reference? This runs on 18 but crashes on 17 in the swift data internals. @Model final class Item { @Attribute(.unique) var id: UUID var date: Date @Relationship(deleteRule: .nullify, inverse: Summary.item) var summary: Summary? init(date: Date = Date.now) { self.id = UUID() self.date = Calendar.current.startOfDay(for: date) self.summary = Summary(self) } } @Model final class Summary { @Attribute(.unique) var id = UUID() @Relationship var item: Item? init(_ item: Item) { self.item = item } }

I have two one-to-many models and I'm getting an unexplained crash when trying to access the relationship properties of the models. The reason for the error is as follows: Thread 1: EXC_BREAKPOINT (code=1, subcode=0x1038f4448) Xcode shows that the error occurs in the model's .getValue(for: .rows) method. This is my SwiftData model and other code: @Model class Row { var section: Section? init(section: Section? = nil) { self.section = section } init() { self.section = nil } } @Model class Section { @Relationship(.cascade, inverse: Row.section) var rows: [Row] = [] init(rows: [Row]) { self.rows = rows } } class ViewController: UIViewController { var container: ModelContainer? override func viewDidLoad() { super.viewDidLoad() do { container = try ModelContainer(for: [Section.self, Row.self]) } catch { print(error) } let row = Row() let section = Section(rows: [row]) section.rows.append(row) var myRows = section.rows //Accessing relationship properties causes crash print(hello)

It seems that when you delete model objects with a relationship there seems to be a crash occurring if the collection your observing is tied to a ForEach. Below is an example of the models in SwiftData @Model class Category { @Attribute(.unique) var title: String var items: [Item]? init(title: String = ) { self.title = title } } The relationship is defined between the category and the item @Model final class Item { var title: String var timestamp: Date var isCritical: Bool var isCompleted: Bool @Relationship(.nullify, inverse: Category.items) var category: Category? init(title: String = , timestamp: Date = .now, isCritical: Bool = false, isCompleted: Bool = false) { self.title = title self.timestamp = timestamp self.isCritical = isCritical self.isCompleted = isCompleted } } So if I were to create a category individually so i can later tag it to an item i'm just following the standard proceedure of creating a category and inserting it into the context as you can see below Bu

The following complex migration consistently crashes the app with the following error: SwiftData/PersistentModel.swift:726: Fatal error: What kind of backing data is this? SwiftData._KKMDBackingData My app relies on a complex migration that involves these optional 1 to n relationships. Theoretically I could not assign the relationships in the willMigrate block but afterwards I am not able to tell which list and items belonged together. Steps to reproduce: Run project Change typealias CurrentSchema to ItemSchemaV2 instead of ItemSchemaV1. Run project again -> App crashes My setup: Xcode Version 16.2 (16C5032a) MacOS Sequoia 15.4 iPhone 12 with 18.3.2 (22D82) Am I doing something wrong or did I stumble upon a bug? I have a demo Xcode project ready but I could not upload it here so I put the code below. Thanks for your help typealias CurrentSchema = ItemSchemaV1 typealias ItemList = CurrentSchema.ItemList typealias Item = CurrentSchema.Item @main struct SwiftDataMigrationAp

I have two models a Person and a Possession the Person model has a one to many relationship to the Possession model. meaning each possession can only have one person but a person can have multiple possessions. I have set my model like the following Person: @Model class Person { @Attribute(.unique) let personID: String @Relationship(.cascade, inverse: Possession.person) var possetions: [Possession]? init(id: String, possessions: [Possession]) { self.personID = id self.possetions = possessions } } Possession: @Model class Possession { @Attribute(.unique) let id: String let name: String? var person: Person? init(id: String, name: String, person: Person) { self.id = id self.name = name self.person = person } } If i set a breakpoint i see that all the posessions are loaded into the memory this is something i do not want to happen. In Core Data we get a relationship fault however, i am not seeing the same behavior in SwiftData. here's how my view is implemented struct ContentView

Hi all, I’m trying to understand SwiftData’s runtime semantics around optional to-many relationships, especially in the context of CloudKit-backed models. I ran into behavior that surprised me, and I’d like to confirm whether this is intended design or a potential issue / undocumented behavior. Minimal example import SwiftUI import SwiftData @Model class Node { var children: [Node]? = nil var parent: Node? = nil init(children: [Node]? = nil, parent: Node? = nil) { self.children = children self.parent = parent print(self.children == nil) } } struct ContentView: View { var body: some View { Button(Create) { _ = Node(children: nil) } } } Observed behavior If @Model is not used, children == nil prints true as expected. If @Model is used, children == nil prints false. Inspecting the macro expansion, it appears SwiftData initializes relationship storage using backing data placeholders and normalizes to-many relationships into empty collections at runtime, even w