# Relationship(_:deleteRule:minimumModelCount:maximumModelCount:originalName:inverse:hashModifier:) Specifies the options that SwiftData needs to manage the annotated property as a relationship between two models. ``` @attached(peer) macro Relationship(_ options: Schema.Relationship.Option..., deleteRule: Schema.Relationship.DeleteRule = .nullify, minimumModelCount: Int? = 0, maximumModelCount: Int? = 0, originalName: String? = nil, inverse: AnyKeyPath? = nil, hashModifier: String? = nil) ``` ## Parameters `options` A list of options to apply to the annotated property to customize its behavior. For possible values, see [`Schema.Relationship.Option`](/documentation/SwiftData/Schema/Relationship/Option). `deleteRule` The rule to apply when you delete the relationship’s owning persistent model. For possible values, see [`Schema.Relationship.DeleteRule`](/documentation/SwiftData/Schema/Relationship/DeleteRule-swift.enum). The default value is [`Schema.Relationship.DeleteRule.nullify`](/documentation/SwiftData/Schema/Relationship/DeleteRule-swift.enum/nullify). `minimumModelCount` The minimum number of models the relationship can reference. The default value is `0`. `maximumModelCount` The maximum number of models the relationship can reference. The default value is `0`. `originalName` The previous name of the attribute, if it’s different to the one in the current schema version. The default value is `nil`. `inverse` The key path of the relationship that represents the inverse of this relationship. The default value is `nil`. `hashModifier` A unique hash value that represents the most recent version of the annotated property. The default value is `nil`. ## Overview If one or more of a model’s properties represent relationships between their containing model and another model, annotate those properties with the `@Relationship` macro. This enables SwiftData to enforce those relationships at runtime — including what happens if you delete related data – as well as write any associated metadata to the persistent storage so the relationships exist across app launches. In the following example, a remote image may belong to a category, and a category can contain zero, one, or more images. ```swift @Model class RemoteImage { @Attribute(.unique) var sourceURL: URL @Relationship(inverse: \Category.images) var category: Category? var data: Data init(sourceURL: URL, data: Data = Data()) { self.sourceURL = sourceURL self.data = data } } @Model class Category { @Attribute(.unique) var name: String @Relationship var images = [RemoteImage]() init(name: String) { self.name = name } } ``` > Note: If you declare a relationship attribute as optional when defining your > persistent models, SwiftData only enforces `minimumModelCount` and > `maximumModelCount` when that attribute isn’t nil. For more information about defining relationships between models, see [Defining data relationships with enumerations and model classes](/documentation/SwiftData/Defining-data-relationships-with-enumerations-and-model-classes). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)