删除核心数据中的对象

Question

I'm trying to delete all objects in a core data entity.
I've tried with following code, but keep getting this error:

 'An NSManagedObjectContext cannot delete objects in other contexts.'

Here is the code:

- (NSManagedObjectContext *)managedObjectContext {
    NSManagedObjectContext *context = nil;
    id delegate = [[UIApplication sharedApplication] delegate];
    if ([delegate performSelector:@selector(managedObjectContext)]) {
        context = [delegate managedObjectContext];
    }
    return context;
}


- (void) deleteObjects {

    NSManagedObjectContext *managedObjectContext = [self managedObjectContext];
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:@"Fixture"];

    NSError *error;
    NSArray *array = [managedObjectContext executeFetchRequest:fetchRequest error:&error];
    if (array == nil) {
        NSLog(@"Error");
    } else {
        NSManagedObject *funFixture = [[managedObjectContext executeFetchRequest:fetchRequest error:nil] mutableCopy];
        [managedObjectContext deleteObject:funFixture];
    }


}

Answer 1

Your issue is here:

NSManagedObject *funFixture = [[managedObjectContext executeFetchRequest:fetchRequest error:nil] mutableCopy];

You've already executed the fetchRequest, and you have the objects in array . You need to delete those objects, not re-run the execute. Something like this:

for (NSManagedObject* object in array) {
    [managedObjectContext deleteObject:object];
}