android - 如何用 Android Room 表示嵌套的@Relation？

Question

这是我在 kotlin 中的 POJO:

data class Pass(var uuid: String,
                var activationRestrictions:List<ActivationRestriction>)


data class ActivationRestriction(var uuid: String,
                                 var activationRestrictionExceptions:List<ActivationRestrictionException>)


data class ActivationRestrictionException(var uuid: String)

如何用 Room 表示这种嵌套关系？ Here是解决方案之一，但它不包含嵌套关系。我特别希望解决与 Room 的嵌套关系。

Answer 1

您可以对 POJO 类使用 @Relation 注释。

A convenience annotation which can be used in a Pojo to automatically fetch relation entities. When the Pojo is returned from a query, all of its relations are also fetched by Room.

Here是文档。

另外，这个答案有更多的细节:Android Persistence room: "Cannot figure out how to read this field from a cursor"