SwiftData Q&A

I have several Swift Data types with a property of type enum. Whenever I've tried to write a predicate returning data objects only of a certain enum case, the compiler throws an error from the macro at build time. (which I don't have handy, sorry...). Is this supported? And if so, how would you write the predicate? @Model public final class AlbumList { // ... public var listType: AlbumListType // ... } public enum AlbumListType: String, CaseIterable, Codable { case listener case dj }

Hi, does SwiftData supports aggregate functions through NSExpression for operations like SUM, AVG, MIN, and MAX?

Hello, world! First and foremost, thank you for all the enhancements made to SwiftData and kudos to the team! In Thomas’ video demonstrating “What’s new in SwiftData”, I notice the keyPath (trip.destination) used to create sections in the list is a String. I can’t help but wonder if a keyPath of another data type could be used (like trip.startDate), were one to want to create sections based on whether a trip is past or upcoming for example? Thank you in advance for your much appreciated input! Zoé

I’m using Swift Charts in my app to display data in a visual way. For that (as well as some sum calculations) I’d like to create a fetch request that searches for all the data in a given time range plus one older and newer entry. Building a predicate that searches for a time range is easy, but how can I tell the fetch request that I would also like to have the first entry that comes before that time range and the first that comes after? I don’t know when these entries appear, so I can’t extend the time range. Example Let’s say I have the following data (timestamp – value): Feb 1, 2024 – 20 Oct 1, 2024 – 30 Jan 1, 2025 – 40 Sep 1, 2025 – 50 May 1, 2026 – 60 Oct 1, 2026 – 70 Now I want to search for the range Jan to Dec 2025. How can I retrieve the two entries that are in the range (No. 3 & 4) as well as the first entry before (No. 2) and the first after that (No. 5)? Without knowing the timestamp of No. 2 and 5. I’d appreciate some best practices or tips how to handle this special case. 🙏

I'm migrating an existing Core Data app to SwiftData and encountering a persistent schema hash mismatch that prevents the store from loading. The Core Data store has been in production for years with version 4 of the model. I have two models, lets call the Crew and Astronaut Create is a parent in the to-many relationship to Astronaut, the child. When I try the migration, the Crew model‘s hash matches, but the Astronaut model’s mismatches. I also tried changing relationship parameters; deleteRule, maximumModelCount, inverse, originalName, and hashModifier. hashModifier changes the hash, but to a third value, so it does not appear to be a way to match the existing Core Data hash. So, is there a supported way for SwiftData to generate an optional to-one relationship that is Core Data hash-compatible with optional=YES minCount=1 maxCount=1? Or is a migration/rehash/copy step required before SwiftData can adopt this V4 store in place?

Greetings, Thank you for SwiftData + new features. I am looking forward to the SwiftData Group Lab on Friday. How does the performance of SwiftData + CloudKit private database compare to CoreData + NSPersistenceCloudKitContainer? Also, will SwiftData + CloudKit support the CK public database, in the future? Thank you!

This is relating to the question I have for the App Intents framework (see my question). I know that SwiftData started to support compound predicates with macOS 14.4/iOS 17.4 or later. But from what I understand they are not dynamic and are validated at compile time. Is there a way to update/construct predicates while the app is running? For example to create a search tab that allows searching and filtering for my items in the app.