java - 如何在 Realm 数据库中创建或实现自关系？

Question

我有一个名为 User 的表。用户有 friend 。

public class User extends RealmObject {
    @PrimaryKey
    private long id;
    private String name;
    private int age;
    private String email; 
}

我正在使用 User 类将 User 及其 friend 添加到 Realm 。我的问题是，如何将用户链接到其 friend ？

Answer 1

我刚刚浏览了 Realm 文档并在那里找到了我的问题答案。

It is possible to declare recursive relationships which can be useful when >modelling certain types of data.

public class Person extends RealmObject {
    private String name;
    private RealmList<Person> friends;
    // Other fields…
}

Use recursive relationships with care as Realm does not currently have cycle detection and you can easily end in infinite loops.

Setting the value to null for a RealmList field will clear the list. That is, the list will be empty (length zero), but no objects have been deleted. The getter for a RealmList will never return null. The returned object is always a list but the length might be zero.