Using NSPredicate and NSSortDescriptor with NSSet in Core Data

Question

Similar question have been asked before on SO. I looked into each one of them but wasn't able to find a useful answer that applies to my case so here goes. My question has two parts. But first let me explain the basics.

I have a NSManagedObject subclass called Activity.

import Foundation
import CoreData

class Activity: NSManagedObject {

    @NSManaged var endTime: NSDate
    @NSManaged var id: NSNumber
    @NSManaged var startTime: NSDate
    @NSManaged var status: NSNumber
    @NSManaged var actions: NSSet
    @NSManaged var checkInAndOuts: NSSet

}

This class has two To-Many relationships (actions, checkInAndOuts) with two other classes. Below are those classes.

Action

import Foundation
import CoreData

class Action: NSManagedObject {

    @NSManaged var desc: String
    @NSManaged var id: NSNumber
    @NSManaged var status: NSNumber
    @NSManaged var name: String
    @NSManaged var activity: Activity

}

CheckInAndOut

import Foundation
import CoreData

class CheckInAndOut: NSManagedObject {

    @NSManaged var checkInDate: NSDate
    @NSManaged var checkInUserId: NSNumber
    @NSManaged var checkOutDate: NSDate
    @NSManaged var checkOutUserId: NSNumber
    @NSManaged var id: NSNumber
    @NSManaged var activity: Activity

}

One Activity can have multiple Actions and CheckInAndOuts. In a viewDidLoad method in a VC, I'm retrieving an array of Activities.

Now on to the issues I'm facing.

Using NSPredicate

In Action, there is a property called status. It can have only three values; 1, 2, -1. I want to filter out actions without the status -1. When I tried to run the following predicate on the actions property of the Activity class as described here, I got a EXC_BAD_ACCESS error.

let actionsPredicate = NSPredicate(format: "ANY actions.status != %@", -1)

How can I retrieve Activity objects which has actions with status of 1 and 2 only?

Using NSSortDescriptor

The other problem I'm facing is trying to sort the checkInAndOuts property. This property has a set of CheckInAndOut objects. I want these objects to be sorted in ascending order by its property checkInDate. When I ran the following line of code,

let CIAODescriptor = NSSortDescriptor(key: "checkInAndOuts.checkInDate", ascending: true)

The project crashed with the error to-many key not allowed here.

Can anyone experienced in core data please give me a helping hand? I'd really appreciate it.

Thank you.

@foolbear This is a very old question. I don't think I found a solution. If I did, I normally post the answer myself. Sorry. — Isuru

Rocker Rocker · Accepted Answer · 2014-09-28T21:12:40

Regarding NSPredicate status is NSNumber and in Predicate you are passing string which lead to bas Access use the below code.

let actionsPredicate = NSPredicate(format: "ANY actions.status != %@", [NSNumber numberWithInt:-1])

NSSortDescriptor issue use below code

let CIAODescriptor = NSSortDescriptor(key: "checkInDate", ascending: true)

Using NSPredicate and NSSortDescriptor with NSSet in Core Data

1 Answers