SwiftData Persistence Patterns

Critical Constraints

• ❌ DO NOT use Core Data syntax (NSManagedObject, NSFetchRequest, NSPredicate) → ✅ Use @Model, @Query, #Predicate
• ❌ DO NOT use @FetchRequest → ✅ Use @Query
• ❌ DO NOT use string-based predicates → ✅ Use #Predicate<ModelType> macro with Swift expressions
• ❌ DO NOT create NSPersistentContainer → ✅ Use ModelContainer and ModelContext
• ❌ DO NOT forget @Model on subclasses → ✅ Both base class AND subclasses need @Model
• ❌ DO NOT use @Model on structs → ✅ @Model is for classes only

Basic Model Definition

import SwiftData