I have a really annoying problem, which I just can't seem to get fixed. I have a view when I send a message that gets saved to the Core Data, when thats done it asked the database for a random me...

I have around 10000 objects of entity 'Message'. When I add a new 'Message' i want to first see whether it exists - and if it does just update it's data, but if it doesn't to create it. Right now...

I have two classes: Profile and Config. A Profile contains an NSSet of Config objects. Both Profile and Config are NSManagedObject subclasses. @interface Profile : NSManagedObject @property (nona...

NSManagedObject provides access to its NSManagedObjectContext, but does it retain it? According to "Passing Around a NSManagedObjectContext on iOS" by Marcus Zarra, "The NSManagedObject retains a ...

Recently I came to know that "You really shouldn't be calling down to the AppDelegate to get the managed object context". Apple also has put this recommendation into their documentation here. It go...

My understanding from the documentation and from this answer is that if the data exists, NSManagedObjectContext's existingObjectWithID:error: and objectWithID: methods should return the same object...

What would cause an error to come back null, this is what I have + (BOOL)saveContext:(NSManagedObjectContext *)context { NSError *error = nil; if (![context save:&error]) { DLog(@"ERROR...

UPDATE : I suppose the issue is that the parent context is not updated when the child context is saved. Still, need help. I have tried many examples of Multi-context (Parent-Child) Core Data. ...

I'm using a remote database with Core Data and when I execute the following fetch requests, depending on the internet connection, it can take some time. I'd like to monitor these two requests and, ...

I am working with coreData, I have one to many relationship between folders and files. I am using only one MOC through out my application.I am just passing it to different viewControllers , perf...

I'm trying to create a temporary managed object context, and after a few screens of the user putting in information, I merge that context with the main context (to ensure that there are no "incompl...

I have an NSOperationQueue that imports objects into Core Data that I get from a web api. Each operation has a private child managedObjectContext of my app's main managedObjectContext. Each operati...

I've looked for this solution for a while, and I've always given up and found a work around, but does anyone know how do find the NSManagedObjectContext from an instance of an NSManagedObject? I a...

In my application, I have the ability to clear all data from the database. Once this operation completes, a bundled JSON is then parsed and then saved to the database (in order to return the databa...

the docs state: ...This method always returns an object. The data in the persistent store represented by objectID is assumed to exist—if it does not, the returned object throws an exception ...

I am having issues with a CoreData-based iOS app when it tries to build the initial DB from data sent from the server. Basically, the server sends down 1MB chunks of objects (about 3,000 per chunk)...

I'm having some thoughts on how to use some core data's NSManagedObject subclasses to handle persistent data and non persistent data. Let's say you have a recipe app displaying a list of your own...

Currently, I am developing an app to book cars. All booking related data are stored in an entity 'Bookings'. As some attributes of 'Bookings' or relationships between 'Bookings' and other enties ar...

[EDIT: simplified version of the question] mainMOC is the primary managed object context editorMOC is a managed object context created in editorViewController with an undo manager so the user can...

I am using RestKit 0.20 to parse JSON data and save to database. THere is a mapped entity SchoolClass, which is handled by RestKit and saves fine. I have another entity called MyClass, which stores...

In my app I have UITableViewController that shows event list. This controller uses ManagedObjectContext Say ParentContext. Now if any Event is selected, then a detailed View Controller is shown whe...

I keep getting crashes from a save: command on a managedObjectContext. It doesn't even fulfill the NSLog statement so I don't see the unresolved error statement, so I can't figure out what the prob...

I'm working on my diploma project, which includes an iOS client with a Core Data database and a Ruby on Rails server. I'm using RestKit for the communication between them. Currently I'm having a bi...

I expect (hope even) that this will be a stupid question, but after wrestling for many hours with this problem I need some insight. My iOS 5.1 app uses nested MOCs, having a PrivateQueueConcurrenc...

How to update child managed object context so it has the same data with parent? As far as I know, when saving, child only goes one step, namely to parents. Yet when fetching fetch always go really...