CODEWITHSUNDEEP
iosobjective-csortingcore-data
user3473089
user3473089

Reputation: 1

Sort data in array

I have an array coming from Core Data that I want to sort, using an orderNum field that I added to the database (Scene entity).

I make the following request to get data:

NSArray *scenes;

NSManagedObjectContext *context = [self managedObjectContext];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

NSEntityDescription *entity = [NSEntityDescription entityForName:@"Scenes" inManagedObjectContext:context];

[fetchRequest setEntity:entity];
NSError *error;

scenes = [context executeFetchRequest:fetchRequest error:&error];
return scenes;

How do I go about sorting the data returned in scenes by orderNum?

Upvotes: 0

Views: 79

Answers (2)

Gabriel.Massana
Gabriel.Massana

Reputation: 8225

The best approach is to retrieve the data from the Database sorted. Check @Wain answer for that.

However it is possible to sort the data into an NSArray of dictionaries, too:

NSSortDescriptor *sceneDescriptor = [[NSSortDescriptor alloc] initWithKey:@"orderNum" ascending:YES];
NSArray * sortDescriptors = [NSArray arrayWithObject: sceneDescriptor];
NSArray *sortedArray = [scene sortedArrayUsingDescriptors:sortDescriptors];

NSLog(@"sortedArray = %@", sortedArray);

Upvotes: 0

Wain
Wain

Reputation: 119031

Use an NSSortDescriptor with orderNum as the key and apply that sort descriptor to your fetchRequest.

NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"orderNum" ascending:YES];
[fetchRequest setSortDescriptors:@[ sort ]];

Upvotes: 1

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