Core Data is really super awesome and comes in a handy on almost my all of projects. I am posting quick code for deleting all your rows from entity. This code might do the job when you are in need of clearing all data.
- (void) clearAllRecords{ NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Chat" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSError *error; NSArray *items = [managedObjectContext executeFetchRequest:fetchRequest error:&error]; fetchRequest = nil; for (NSManagedObject *managedObject in items) { [managedObjectContext deleteObject:managedObject]; } if (![managedObjectContext save:&error]) { } }