kotlin android Realm DB创建外键(链接对象)

open class Person : RealmObject() {
    var name: String = ""
    var age: Int = 0
    var addresses: RealmList<Address> = RealmList()
}

open class Address : RealmObject() {
    var street: String = ""
    var city: String = ""
}

open class Person : RealmObject() {
    var name: String = ""
    var age: Int = 0
    var addresses: RealmList<Address> = RealmList()

    @LinkingObjects("person")
    val linkedAddresses: RealmResults<Address>? = null
}

open class Address : RealmObject() {
    var street: String = ""
    var city: String = ""
    var person: Person? = null
}

// 创建一个Person对象
val person = Person()
person.name = "John"
person.age = 25

// 创建一个Address对象
val address = Address()
address.street = "123 Main St"
address.city = "New York"

// 将Address对象添加到Person对象的外键字段中
person.addresses.add(address)

// 保存数据到Realm数据库
val realm = Realm.getDefaultInstance()
realm.beginTransaction()
realm.copyToRealmOrUpdate(person)
realm.commitTransaction()

// 查询Person对象及其关联的Address对象
val query = realm.where(Person::class.java)
val results = query.findAll()
for (person in results) {
    println("Name: ${person.name}")
    for (address in person.linkedAddresses) {
        println("Address: ${address.street}, ${address.city}")
    }
}

// 关闭Realm数据库连接
realm.close()