What is NSFetchRequest?
A description of search criteria used to retrieve data from a persistent store.
What is NSSortDescriptor?
An immutable description of how to order a collection of objects according to a property common to all the objects.
What is used to sort Core data results?
The sorting is done through a special data type called NSSortDescriptor , which is a trivial wrapper around the name of what you want to sort (in our case “date”), then a boolean setting whether the sort should be ascending (oldest first for dates) or descending (newest first).
How do I use NSBatchDeleteRequest?
Setting up an NSBatchDeleteRequest is fairly simple. It requires either passing in an NSFetchRequest instance or a collection of managed object identifiers. After that, you simply execute the batch delete request on your managed object context.
How do I get data from Core Data?
Fetch from Core Data
- Prepare the request of type NSFetchRequest for the entity.
- Fetch the result from context in the form of array of [NSManagedObject]
- Iterate through an array to get value for the specific key.
How do I sort a list in Swift?
Strings in Swift conform to the Comparable protocol, so the names are sorted in ascending order according to the less-than operator ( < ). To sort the elements of your collection in descending order, pass the greater-than operator ( > ) to the sort(by:) method.
How do you sort an array in ascending order in Objective C?
iOS – Objective-C – Sorting an Array
- NSArray* data = @[@”Grapes”, @”Apples”, @”Oranges];
- NSSortDescriptor *sd = [[NSSortDescriptor alloc] initWithKey:nil ascending:YES];
- Apples, Oranges, Grapes.
- NSSortDescriptor *sd = [[NSSortDescriptor alloc] initWithKey:@”lastName” ascending:YES];
How do I delete everything from my Core Data?
Delete Everything (Delete All Objects, Reset Core Data) One approach to delete everything and reset Core Data is to destroy the persistent store. Deleting and re-creating the persistent store will delete all objects in Core Data.
What is NSManagedObjectContext?
An object space to manipulate and track changes to managed objects. iOS 3.0+