core-data Questions

29

Solved

I'm using Core Data to locally persist results from a Web Services call. The web service returns the full object model for, let's say, "Cars" - could be about 2000 of them (and I can't make the Web...
Immitigable asked 5/9, 2009 at 15:29

1

I run into performance issues with the diffable data source when having a larger data set, around 22,000 items. I am surprised that applying the snapshot takes so much time when animation is ON. Se...

4

Solved

Suppose I have a list of books stored in Core Data. I want to search for a book by it's primary key ID. I know the sqlite file created by Core Data has an ID column in each table, but this doesn't ...
Explant asked 18/1, 2011 at 3:19

10

Solved

I read much about Core Data.. but what is an efficient way to make a count over an Entity-Type (like SQL can do with SELECT count(1) ...). Now I just solved this task with selecting all with NSFetc...
Tonsillectomy asked 15/7, 2009 at 21:47

5

Solved

I know that I can use @distinctUnionOfObjects to find something like the following in SQL: SELECT a_value FROM my_table GROUP BY a_value; What I'm looking for is all of the data returned in an a...
Brut asked 1/2, 2011 at 17:12

6

Solved

I am trying to observe individual NSManagedObject changes on NSManagedObjectContextWillSaveNotification: - (void)managedObjectContextWillSave:(NSNotification *)notification { for (NSManagedObject...
Gadabout asked 10/10, 2014 at 7:13

3

I have a Core Data model with an entity generated into class Task. I am trying to get the Combine publisher objectWillChange from the NSManagedObject to send (automatically, without manual work), b...
Gaige asked 23/9, 2019 at 18:47

5

Below is one of the requirements to use Core Data with Cloudkit in Apple's doc: All relationships must be optional. Due to operation size limitations, relationship changes may not be saved atomica...
Radioscopy asked 26/2, 2021 at 5:4

13

Solved

I am duplicating an existing Objective-C TV Show app to a new Swift version using Xcode 6.1 and am having some issues with CoreData. I have created a model of 4 entities, created their NSManagedOb...
Lymphocytosis asked 28/10, 2014 at 16:51

10

Solved

Unfortunately the new Core Data semantics make me crazy. My previous question had a clean code that didn't work because of incorrect auto generation of header files. Now I continue my work with del...
Mhd asked 24/6, 2016 at 15:54

4

I'm deleting all objects from my Model, except certain objects which the user has interacted with. After deleting I fetch those saved objects and update their information, from a JSON, and when I s...
Cromwell asked 26/1, 2015 at 15:10

5

Solved

I'm having some trouble getting my Core Data entities to play nice and order when using an UITableView. I've been through a number of tutorials and other questions here on StackOverflow, but there...
Hildahildagard asked 30/10, 2009 at 5:54

3

Solved

How do you set the default value of a UUID attribute in the core data xcdatamodel. if I set the attribute as non-optional it requires a default value. in code I'd set it using UUID() to assign a va...
Sugarplum asked 4/8, 2020 at 7:55

3

Solved

Ok I have a basic iPad app that asks for 5 search/filter criteria from the user. Based on this data, I need to go to my core data db, and pull out any managed objects that fit that criteria. It see...
Doubledealing asked 14/11, 2011 at 23:7

1

Solved

I thought there used to be a relationship graphs for Xcode at the right corner(As indicated by the orange rect). But it's missing for Xcode 14. Does anyone knows where it goes? Or how could I get i...
Hydrogenous asked 1/7, 2022 at 3:47

4

I have a SwiftUI project with Core Data. The data model is a simple one-to-many and two primary views which each have a textfield at the top and a button to add a new item to the list view below. T...
Blaineblainey asked 30/3, 2020 at 20:13

6

Solved

I have two versions of my model Model001.xcdatamodel and Model002.xcdatamodel. These two are in the Model.xcdatamodeld bundle. I also have a Model001to002.xcmappingmodel which is not part of the Mo...
Hagiocracy asked 8/10, 2012 at 13:16

3

Solved

Im facing issues with displaying my Core Data inside of SwiftUI because of relationships being Sets. What is the best way to go about displaying a many relationship set inside of a SwiftUI ForEach ...
Kirksey asked 6/11, 2019 at 23:6

2

Solved

I have two Entities that have a relationship like so... I want to create a fetched property on the conversation to return the most recent message that belongs to it. I don't want to have to main...
Tricycle asked 12/6, 2014 at 10:52

4

Solved

The problem that I am having is that when I update a core data Asset object from a sheet view, the change is not reflected in the UI of the AssetListView. (Note that Inserting a new object from the...
Renal asked 8/7, 2020 at 21:51

2

Solved

I'm attempting to use an IN clause with an NSPredicate. I'm getting the following error: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSTaggedPointerStr...
Changeling asked 7/3, 2017 at 15:48

3

I'm trying to follow the MVVM pattern in swiftUI and I’m running into a problem with core data and fetch request. All of the videos I've seen and articles I have read on it, have a @FetchRequest in...
Canula asked 1/10, 2019 at 20:19

3

I am using CloudKit to store publicly available data and the new NSPersistentCloudKitContainer as part of my Core Data stack to store/sync private data. When a user opens my app, they are in 1 of ...

3

Solved

I've been trying to use a custom migration policy in an application I'm putting together. So far migrations have worked from v1 -> v2 when using a mapping model. However, whenever I add a custom po...
Tippet asked 10/7, 2015 at 18:20

1

Solved

Currently, we are using local CoreData with CloudKit feature, by using NSPersistentCloudKitContainer. Why we enable persistent history tracking feature? Due to the problem described at https://mcma...
Doyenne asked 9/6, 2022 at 8:28

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