How to create CoreData database swift4 - ios

Question

Plese share some sample code snippet for database save details and fetch saved details in swift 4

Answer 1

This is my answer
Step 1 : Create Coredata Stack Class see below
var coreDataStack: CoreDataStack = CoreDataStack() // add this line on appDelegate
class Stack
{
lazy var managedObjectModel: NSManagedObjectModel = {
let modelUrl = Bundle.main.url(forResource: "Model", withExtension: "momd")!
return NSManagedObjectModel(contentsOf: modelUrl)!
}()
lazy var peristentStoreCoordinator: NSPersistentStoreCoordinator = {
let coordinator: NSPersistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let applicationDocumentsDirectory: URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last!
let persistentStoreUrl: URL = applicationDocumentsDirectory.appendingPathComponent("Model.sqlite")
do {
try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: persistentStoreUrl, options: nil)
}
catch {
fatalError("Persistent store error! \(error)")
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext = {
let managedObjectContext: NSManagedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = self.peristentStoreCoordinator
return managedObjectContext
}()
func saveContext() {
if self.managedObjectContext.hasChanges {
do {
try self.managedObjectContext.save()
}
catch {
fatalError("There was an error saving the managed object context \(error)")
}
}
}
}
Step 2 : Create entity
Step 3 : Create ManagedObjectModelSubclass -- Editor -> ManagedObjectModelSubclass
Step 4 : import core data on class and add below code
var person = [Person]() //[Person] here denote subclassclass name
var appDelegate = UIApplication.shared.delegate as! AppDelegate
let personEntity: NSEntityDescription? = NSEntityDescription.entity(forEntityName: "EntityName", in: self.appDelegate.coreDataStack.managedObjectContext)
if personEntity != nil {
let person1: Person = Person(entity: personEntity!, insertInto: self.appDelegate.coreDataStack.managedObjectContext)
person1.name = "name"
person1.country = "US"
person1.age = "26"
person1.place = "NewYork"
}
Step 5 : For fetch data use below code
var persons: [Person] = [] // subclass name
var appDelegate: AppDelegate = UIApplication.shared.delegate as! AppDelegate
var listdata = [ModelClass]() // create a modelclass object
func fetchDemoData() {
let fetchRequest: NSFetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "EntityName")
do {
if let results = try self.appDelegate.coreDataStack.managedObjectContext.fetch(fetchRequest) as? [NSManagedObject] {
let personList: [Person]? = results as? [Person]
if personList != nil {
self.persons = personList!
for eachData in persons {
let name = eachData.name as String!
let username = eachData.age as String!
let email = eachData.country as String!
let address = eachData.place as! [String : Any]
self.listdata.append(ModelClass(name: name!, username: username!,email : email!,address : address))
}
//self.tableview.reloadData()
}
}
}
catch {
fatalError("There was an error fetching the items")
}
}

Answer 2

let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "Users", in: context)
let newUser = NSManagedObject(entity: entity!, insertInto: context)
newUser.setValue("Shashikant", forKey: "username")
newUser.setValue("1234", forKey: "password")
newUser.setValue(1, forKey: "age")
do {
try context.save()
} catch {
print("Failed saving")
}
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Users")
//request.predicate = NSPredicate(format: "age = %#", "12")
request.returnsObjectsAsFaults = false
do {
let result = try context.fetch(request)
for data in result as! [NSManagedObject] {
print(data.value(forKey: "id") as! String)
print(data.value(forKey: "username") as! String)
}
} catch {
print("Failed")
}

Answer 3

import UIKit
import CoreData
class ViewController: UIViewController {
#IBOutlet weak var txtName: UITextField!
#IBOutlet weak var txtId: UITextField!
#IBOutlet weak var txtMark: UITextField!
#IBOutlet weak var labelStatus: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func buutonSave(_ sender: Any) {
let appDelegateObject:AppDelegate = UIApplication.shared.delegate as! AppDelegate
let managedObject:NSManagedObjectContext = appDelegateObject.persistentContainer.viewContext
let entityDescription =
NSEntityDescription.entity(forEntityName: "Student",
in: managedObject)
var student = NSManagedObject(entity: entityDescription!, insertInto: managedObject)
[student .setValue(self.txtName.text, forKey: "name")]
[student .setValue(self.txtId.text, forKey: "id")]
[student .setValue(self.txtMark.text, forKey: "mark")]
labelStatus.text = "Contact Saved"
}
#IBAction func buttonFind(_ sender: Any) {
let appDelegateObject:AppDelegate = UIApplication.shared.delegate as! AppDelegate
let managedObject:NSManagedObjectContext = appDelegateObject.persistentContainer.viewContext
let entityDescription =
NSEntityDescription.entity(forEntityName: "Student",
in: managedObject)
let request = NSFetchRequest<NSFetchRequestResult>()
request.entity = entityDescription
let pred = NSPredicate(format: "(name = %#)", txtName.text!)
request.predicate = pred
do {
var results =
try managedObject.fetch(request)
if results.count > 0 {
let match = results[0] as! NSManagedObject
txtName.text = match.value(forKey: "name") as? String
txtId.text = match.value(forKey: "id") as? String
txtMark.text = match.value(forKey: "mark") as? String
labelStatus.text = "Matches found: \(results.count)"
} else {
labelStatus.text = "No Match"
}
} catch let error as NSError {
labelStatus.text = error.localizedFailureReason
}
}
}

Answer 4

//CoreDataRose
ad = (UIApplication.shared.delegate as! AppDelegate) moc = ad.persistentContainer.viewContext
actorEntity = NSEntityDescription.entity(forEntityName: "Actors", in: moc)
func fetch() {
let fetchReq = NSFetchRequest<NSFetchRequestResult>(entityName: "Actors")
do{
let actorsArr = try moc.fetch(fetchReq)
for i in 0..<actorsArr.count
{
let mo:NSObject = actorsArr[i] as! NSManagedObject
print(mo.value(forKey: "empFName")!)
DispatchQueue.main.async {
actorsArray.append(actors(firstName: (mo.value(forKey: "empFName") as? String), lastName: (mo.value(forKey: "empLName") as? String ), age: (mo.value(forKey: "empAge") as? Int)))
}
}
}catch{
print("Error Message")
}
}
#IBAction func submitBtn(_ sender: Any) {
// var secondView = storyboard?.instantiateViewController(withIdentifier: "DisplayView") as! DisplayView
// secondView.firstView = self
// present(secondView, animated: true)
actorsArray.append(actors(firstName: "\(firstNameTF.text!)", lastName: "\(lastNameTF.text!)", age: ageTF.text! as? Int))
var mo2 = NSManagedObject(entity: actorEntity, insertInto: moc)
mo2.setValue(firstNameTF.text, forKey: "empFName")
mo2.setValue(lastNameTF.text, forKey: "empLName")
mo2.setValue(Int(ageTF.text!), forKey: "empAge")
do{
try moc.save()
}catch{
print("Error")
}
}
#IBAction func chooseImageButton(_ sender: Any) {
let image = UIImagePickerController()
image.delegate = self
image.sourceType = UIImagePickerController.SourceType.photoLibrary
image.allowsEditing = false
self.present(image, animated: true)
{
}
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage
{
importImage.image = image
}
else{
print("error message")
}
self.dismiss(animated: true, completion: nil)
}