How to fetch data from specific relationship entity in Swift? - ios

Question

I have two relationship entities in Core Data. In the first entity I add names of companies in attribute. Then I move to second UIViewController and I add other attributes of specific company in the second entity which is relationship with the first entity. Also I have two UITableViewControllers, the first UITableViewController shows names of every company in cell. When I selected the specific company I move to the second UITableViewController. I want the second UITableViewController shows data of the specific company which I selected. I tried several different methods but I could not to make how I want. How can I make it?
The second UITableViewController code
override func viewDidLoad() {
super.viewDidLoad()
self.definesPresentationContext = true
println(currentCompany)
fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest(), managedObjectContext: managedObjectContext, sectionNameKeyPath: "activityCompany", cacheName: nil)
fetchedResultsController.delegate = self
fetchedResultsController.performFetch(nil)
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest(), managedObjectContext: managedObjectContext, sectionNameKeyPath: nil, cacheName: nil)
self.tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - var and let
var currentCompany: String!
var managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext!
// MARK: - fetchResultsController
var fetchedResultsController: NSFetchedResultsController!
func fetchRequest() -> NSFetchRequest {
let fetchRequest = NSFetchRequest(entityName: "Information")
var sortDescriptor = NSSortDescriptor(key: "company", ascending: true)
fetchRequest.fetchBatchSize = 50
fetchRequest.sortDescriptors = [sortDescriptor]
fetchRequest.predicate = NSPredicate(format: "company contains [c] %#", currentCompany)
return fetchRequest
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return fetchedResultsController.sections?.count ?? 0
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return fetchedResultsController.sections?[section].numberOfObjects ?? 0
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! UITableViewCell
if var dataForCell = fetchedResultsController.objectAtIndexPath(indexPath) as? Information {
cell.textLabel?.text = dataForCell.activityCompany
cell.detailTextLabel?.text = dataForCell.foundedCompany
}
return cell
}
Entities
import Foundation
import CoreData
#objc(Company)
class Company: NSManagedObject {
#NSManaged var nameCompany: String
#NSManaged var information: NSSet
}
import Foundation
import CoreData
#objc(Information)
class Information: NSManagedObject {
#NSManaged var activityCompany: String
#NSManaged var foundedCompany: String
#NSManaged var company: Company
}
I save data into entites the following method.
// MARK: - #IBActions
#IBAction func saveData(sender: UIBarButtonItem) {
var companyEntity = NSEntityDescription.insertNewObjectForEntityForName("Company", inManagedObjectContext: managedObjectContext) as! NSManagedObject
var informationEntity = NSEntityDescription.insertNewObjectForEntityForName("Information", inManagedObjectContext: managedObjectContext) as! NSManagedObject
companyEntity.setValue(currentName, forKey: "nameCompany")
informationEntity.setValue(activityTextField.text, forKey: "activityCompany")
informationEntity.setValue(foundedTextField.text, forKey: "foundedCompany")
companyEntity.setValue(NSSet(object: informationEntity), forKey: "information")
var error: NSError?
managedObjectContext.save(&error)
var story = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
var naviController = story.instantiateViewControllerWithIdentifier("firstNavi") as! UINavigationController
presentViewController(naviController, animated: true, completion: nil)
}

Answer 1

I solved it.
func fetchRequest() -> NSFetchRequest {
let fetchRequest = NSFetchRequest(entityName: "Information")
var sortDescriptor = NSSortDescriptor(key: "activityCompany", ascending: true)
fetchRequest.fetchBatchSize = 50
fetchRequest.sortDescriptors = [sortDescriptor]
fetchRequest.predicate = NSPredicate(format: "company.nameCompany contains [c] %#", currentCompany)
return fetchRequest
}