Realm

Realm이란? 

- Realm사에서 만든 Mobile Database

- 가벼운 객체 컨테이너

- RDBMS처럼 쿼리, 필터링, 관계형(상호 연결)이 가능하고 저장이 됨

- 라이브 오브젝트이며 반응형 객체임

- 기기와 애플리케이션 사이에서 매끄럽게 동기화 되며 스레드에서 안전하게 접근 가능

- String Key 보안체계 확립

- Android, iOS, Xamarin, React Native에서 이용가능

- 항상 오프라인 우선 방식으로 동작

간단한 예제(Swift)

import RealmSwift
 
// Define your models like regular Swift classes
class Dog: Object {
  dynamic var name = ""
  dynamic var age = 0
}
class Person: Object {
  dynamic var name = ""
  dynamic var picture: Data? = nil // optionals supported
  let dogs = List<Dog>()
}
 
// Use them like regular Swift objects
let myDog = Dog()
myDog.name = "Rex"
myDog.age = 1
print("name of dog: \(myDog.name)")
 
// Get the default Realm
let realm = try! Realm()
 
// Query Realm for all dogs less than 2 years old
let puppies = realm.objects(Dog.self).filter("age < 2")
puppies.count // => 0 because no dogs have been added to the Realm yet
 
// Persist your data easily
try! realm.write {
  realm.add(myDog)
}
 
// Queries are updated in realtime
puppies.count // => 1
 
// Query and update from any thread
DispatchQueue(label: "background").async {
  autoreleasepool {
    let realm = try! Realm()
    let theDog = realm.objects(Dog.self).filter("age == 1").first
    try! realm.write {
      theDog!.age = 3
    }
  }
}

출처

https://realm.io/docs/