Use core data in swift 2 without using tables - ios

Question

I'm learning to be an iOS app developer and I want to make an app which stores core data. I know how to do it using tables but is there a way I can store data without using tables? Like I'm trying to make an app which saves about a 100 different variables but m not using tables in it. Can someone please direct me to a full tutorial of how it's done? I came across one tutorial on Ray weindervich but it was done on swift 1.2 and it didn't work for me. Thanks

Answer 1

Core data depends on entities, now something that might help to share (probably you knew this already) is that Core data entity is not a table it represents a thing that can be identify and quantify for example a fruit regardless what your back end is; with that been said, now I have a question, when you say table do do you mean the entities or an actual database table? If you mean entity, with Core data you can say use SQLite as backend or xml file as back end but regardless how you store the data you will need to create at least one entity.
What was suggested in the comments still using entities. So my suggestion would be just create one entity using one of this options:
1. Entity
variable1 datatype
variable2 datatype
...
...
variable n datatype
or
2. Entity
key String
Value object
With option one you will have to know all the possible variables that your application will use and one good advantage is that you won't have to do down casting neither unwrapping.
With option two you don't need to know all the possible variables and also your data can grow without changing the app, the only downside is you will have to wrap and unwrap the data from each record.
These are my suggestions for you.
Hope this help
UPDATE :
So here are the steps that I think you need to follow to achieve your request (important: this a simple sample):
Make sure your project has enable since creation Core Data.
In the Model add the Entity as the picture shows:
Then add the attributes as the picture shows:
Add the add the subclass; this part is not mandatory but makes it easy to handle each entity and its properties.
Then you should have something similar to the following code for the entity:
import Foundation
import CoreData
class Generic: NSManagedObject {
#NSManaged var key: String?
#NSManaged var value: NSObject?
}
And your view controller should have something like this in order to read and save the data:
import UIKit
import CoreData
class ViewController: UIViewController {
#IBOutlet var txtVariable: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let delegate = UIApplication.sharedApplication().delegate as! AppDelegate
let context = delegate.managedObjectContext
let request = NSFetchRequest(entityName: "Generic")
let filter = NSPredicate(format: "key = %#", "xyz")
request.predicate = NSCompoundPredicate(andPredicateWithSubpredicates: [filter])
do {
let records = try context.executeFetchRequest(request) as! [Generic]
if (records.count>0)
{
txtVariable.text = (records[0].value as! String)
}
}
catch let error as NSError{
NSLog(error.localizedDescription)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func btnSave_Click(sender: AnyObject) {
let delegate = UIApplication.sharedApplication().delegate as! AppDelegate
let context = delegate.managedObjectContext
let record = NSEntityDescription.insertNewObjectForEntityForName("Generic", inManagedObjectContext: context) as? Generic
record?.key = "xyz"
record?.value = txtVariable.text
do {
try context.save()
}
catch let error as NSError{
NSLog(error.localizedDescription)
}
}}