Data duplicate while migrate PersistentStoreCoordinator from local to iCloud

Question

I am doing iCloud sync with core data works fine. Now i want to add on/off switch(migrate store). If i migrate store to iCloud to local works fine but if migrate back to iCloud datas getting duplicate. Even i tried to remove ubiquity container before migrate not helping. I could not deduplicate because "StoreDidImportUbiquitousContent" method not called after duplicate data.

Code below :

        // Migrate to local 

    -(NSURL *)localStoreURL
    {
        NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"LocalExpns.sqlite"];
        return storeURL;

    }

  - (void)moveStoreToLocal
{      
         NSError *error = nil;
            NSPersistentStoreCoordinator * persistentStoreCoordinator = self.persistentStoreCoordinator;

            NSPersistentStore * persistentStore = [[persistentStoreCoordinator persistentStores] firstObject];

            if([[NSFileManager defaultManager]fileExistsAtPath:[self localStoreURL].path])
            {
                NSLog(@"File exists");
                [[NSFileManager defaultManager] removeItemAtPath:[self localStoreURL].path error:& error];
                NSLog(@"Removing error = %@", error);

            }

            NSMutableDictionary *localStoreOptions = [[self localStoreOptions] mutableCopy];
            [localStoreOptions setObject:[NSNumber numberWithBool:YES] forKey:NSPersistentStoreRemoveUbiquitousMetadataOption];

           id result = [persistentStoreCoordinator migratePersistentStore:persistentStore toURL:[self localStoreURL] options:localStoreOptions withType:NSSQLiteStoreType error:&error];

}

Above code working fine.

// Migrate to iCloud back

// fileURL is local file url

-(NSURL *)storeURL
{
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Expns.sqlite"];
    return storeURL;
}


    - (void)moveStoreFileToICloud:(NSURL*)fileURL 
    {
     NSPersistentStoreCoordinator * persistentStoreCoordinator = self.persistentStoreCoordinator;

            id sourceStore = [[persistentStoreCoordinator persistentStores] firstObject];

            if (!sourceStore) {

                NSLog(@" failed to add old store");

            } else {
                NSLog(@" Successfully added store to migrate");

                bool moveSuccess = NO;
                NSError *error;


                NSLog(@" About to migrate the store...");
                // Now migrate the store using the iCloud options
                id migrationSuccess = [self.persistentStoreCoordinator migratePersistentStore:sourceStore toURL:[self storeURL] options:[self icloudStoreOptions] withType:NSSQLiteStoreType error:&error];

                if (migrationSuccess) {
                    moveSuccess = YES;
                    NSLog(@"store successfully migrated");

                    // Now delete the local file
                    if (shouldDelete) {
                        NSLog(@" deleting local store");
                        [self deleteLocalStore];
                    } else {
                        NSLog(@" not deleting local store");
                    }
                }
                else {
                    NSLog(@"Failed to migrate store: %@, %@", error, error.userInfo);
                }

            }
    }

Now data get duplicate what ever in before migrate. I tried to remove ubiquity container also not helping.

You are effectively adding the data to the cloud twice, which is why you get duplicates. The advised way to handle this is to de-duplicate your data after a sync. A Google search will give you some code to do that. Here's one: http://www.atomicbird.com/blog/icloud-complications-part-2 — Drew McCormack, Jul 17 '15 at 19:04
Hi @DrewMcCormack thanks for reply. i have tried that also, it tells deduplicate within storedidimport:. It works fine when i have two device. If i have only one device storedidimport: method is not called and datas got duplicated. — Madhubalan K, Jul 18 '15 at 13:44
Hmm, are you sure? I would have thought NSPersistentStoreDidImportUbiquitousContentChangesNotification would be posted whenever a background change was made to the store for sync. I would think that if you dedupe there, it should always work. — Drew McCormack, Jul 22 '15 at 10:24
@DrewMcCormack while change store from local to iCloud (while using single device) NSPersistentStoreDidImportUbiquitousContentChangesNotification is not called(this will call after entry changed by iCloud sdk right?) . Now i have writ de-duplication while fetch data. I knew it is not a good way but it works. Do you have any better idea? — Madhubalan K, Jul 22 '15 at 10:32

score 0 · Accepted Answer · answered Aug 07 '15 at 05:34

0

I have solved this problem by de-duplicate my db manually like this

answered Aug 07 '15 at 05:34

Madhubalan K

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Data duplicate while migrate PersistentStoreCoordinator from local to iCloud

1 Answers1