CoreData delete multiple objects

Question

I know how to delete a single object in CoreData I'm just wondering if theres a simpler way of deleting multiple objects?

For single delete you can use

[moc deleteObject:someManagedObject];

but there is no equivalent for multiple objects.

At the moment I'm thinking of doing...

NSArray *arrayOfManagedObjectsToDelete = //...

for (SomeManagedObjectClass *managedObject in arrayOfManagedObjectsToDelete) {
    [moc deleteObject:managedObject];
}

but I wasn't sure if there was another way of doing this?

ideally a method like...

- (void)deleteObjects:(NSSet*)objects

on NSManagedObjectContext or some similar method.

Answer 1

iOS 9

Swift

let fetchRequest = NSFetchRequest(entityName: "EntityName") let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)

do {
    try myPersistentStoreCoordinator.executeRequest(deleteRequest, withContext: myContext) } catch let error as NSError {
    // TODO: handle the error 
}

Objective-C

NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"EntityName"];
NSBatchDeleteRequest *deleteRq = [[NSBatchDeleteRequest alloc] initWithFetchRequest:request];

NSError *deleteError = nil;
[myPersistentStoreCoordinator executeRequest:deleteRq withContext:myContext error:&deleteError];

iOS 8 and older

NSFetchRequest *fr = [[NSFetchRequest alloc] init];
[fr setEntity:[NSEntityDescription entityForName:@"EntityName" inManagedObjectContext:myContext]];
[fr setIncludesPropertyValues:NO]; //only fetch the managedObjectID

NSError *error = nil;
NSArray *objects = [myContext executeFetchRequest:fr error:&error];

//error handling goes here
for (NSManagedObject *object in objects) {
  [myContext deleteObject:object];
}
NSError *saveError = nil;
[myContext save:&saveError];
//more error handling here

Answer 2

iOS10 & Swift 3

    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "EntityName")
    let deleteRequest = NSBatchDeleteRequest( fetchRequest: fetchRequest)

    do{
        try mContext.execute(deleteRequest)
    }catch let error as NSError {//handle error here }

This deletes all the objects of EntityName but you can apply additional filtering with NSPredicate

Answer 3

As I know, there isn't a method for that... You should do like you're already doing. There is a method called deletedObjects but it just returns the set of objects that will be removed from their persistent store during the next save operation, as described in class reference.