Realm Mobile Database Tutorial - How to Build Better Apps, Faster

    Over 1 billion users rely on Realm

Trusted by Fortune 500 mainstays, innovative startups, and #1‑ranked app store successes, Realm is built into apps used by hundreds of millions of people every day.

• Realm Sync Engine

  • Automatic two-way data synchronization and conflict resolution.

• Realm Object Store

  • Persist and manage data as objects mirrored on mobile devices.

• Dashboard

  • Monitor and manage your entire system at a glance.

• Realm Event Framework

  • Trigger server-side events in response to data changes.

• Realm Authentication System

  • Identify users with prebuilt mechanism or use your own.

• Realm Access Control

  • Grant users the permissions they need for reading and writing data.

• Realm Mobile Database

  • Embedded object database for mobile apps. Realm Mobile Platform extensions allow synchronization of live objects with Realm Object Server.

  • Sync available for Realm Java, Realm Objective‑C & Realm Swift. Coming soon for Realm React Native & Realm Xamarin.

• Realtime collaboration
  • Create realtime collaboration experiences, similar to Google Docs.
• Two-way data sync
  • Realtime data synchronization with automatic conflict resolution.
• Data push
  • Update client databases effortlessly with automated data push.
• Messaging
  • Share text, images, maps, or custom data. No server work needed.
• API bridge
  • Easily connect your mobile apps to existing system and APIs.
• Presence
  • Know when users are online and track state.

1. Install CocoaPods 1.1.0 or later.
2. Run pod repo update to make CocoaPods aware of the latest available Realm versions.
3. In your Podfile, add use_frameworks! and pod 'RealmSwift' to your main and test targets.
4. From the command line, run pod install.
5. Use the .xcworkspace file generated by CocoaPods to work on your project!

platform :ios, ‘9.0’
use_frameworks!

target 'MyApp' do
  pod 'RealmSwift'
end

import RealmSwift

class Person: Object {
    
    @objc dynamic var id = 0
    @objc dynamic var name = ""
    @objc dynamic var email = ""
    
    /**
     Override Object.primaryKey() to set the model’s primary key. Declaring a primary key allows objects to be looked up and updated efficiently and enforces uniqueness for each value.
     */
    override static func primaryKey() -> String? {
        return "id"
    }
    
    convenience init(id: Int, name: String, email: String) {
        self.init()
        
        self.id = id
        self.name = name
        self.email = email
    }
}

import RealmSwift

class RealmManager {
    
    let realm = try! Realm()
    
    /**
     Delete local database
     */
    func deleteDatabase() {
        try! realm.write({
            realm.deleteAll()
        })
    }
    
    /**
     Save array of objects to database
     */
    func saveObjects(objs: [Object]) {
        try! realm.write({
            // If update = true, objects that are already in the Realm will be 
            // updated instead of added a new.
            realm.add(objs, update: true)
        })
    }
    
    /**
     Returs an array as Results<Object>?
     */
    func getObjects(type: Object.Type) -> Results<Object>? {
        return realm.objects(type)
    }
}

class TestClass {
    
    let realm = RealmManager()
    
    var persons = [Person]()
    
    func testAll() {
        addTestPersons()
        
        // save persons array to database
        realm.saveObjects(objs: persons)
        
        // get persons array from database
        getObjects()
    }
    
    func addTestPersons() {
        for index in 0...9 {
            let newPerson = Person(id: index, name: "Name\(index)", email: "p\(index)@gmail.com")
            persons.append(newPerson)
        }
    }
    
    func getObjects() {
        if let objects = realm.getObjects(type: Person.self) {
            for element in objects {
                if let person = element as? Person {
                    // Do whatever you like with 'person' object
                    print("\(person.name), \(person.id), \(person.email)")
                }
            }
        }
    }
}

Name0, 0, p0@gmail.com
Name1, 1, p1@gmail.com
Name2, 2, p2@gmail.com
Name3, 3, p3@gmail.com
Name4, 4, p4@gmail.com
Name5, 5, p5@gmail.com
Name6, 6, p6@gmail.com
Name7, 7, p7@gmail.com
Name8, 8, p8@gmail.com
Name9, 9, p9@gmail.com