Да они должны, только привести к беспорядку иначе.
Coming back to this question, to delete all the data from my CoreData storage I decided to simple delete the sqlite database file. So I just implemented the NSPersistentStoreCoordinator
like this:
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator != nil) {
return persistentStoreCoordinator;
}
NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"myAppName.sqlite"]];
NSError *error = nil;
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) {
NSLog(@"Error opening the database. Deleting the file and trying again.");
//delete the sqlite file and try again
[[NSFileManager defaultManager] removeItemAtPath:storeUrl.path error:nil];
if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
//if the app did not quit, show the alert to inform the users that the data have been deleted
UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"Error encountered while reading the database. Please allow all the data to download again." message:@"" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil] autorelease];
[alert show];
}
return persistentStoreCoordinator;
}