核心数据-迁移问题？

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
    {
    if (persistentStoreCoordinator)
        return persistentStoreCoordinator;

    NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @\"MyStore.sqlite\"]];

    NSError *error = nil;
   persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];

    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, nil];

   if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType 
                                        configuration:nil
                                        URL:storeUrl
                                        options:options
                                        error:&error])
        {
        // Handle error
        NSLog(@\"Error adding persistent store...%@\", error);
        // Handle the error. 
        NSLog(@\"Failed to save to data store: %@\", [error localizedDescription]);
        NSArray* detailedErrors = [[error userInfo] objectForKey:NSDetailedErrorsKey];
        if(detailedErrors != nil && [detailedErrors count] > 0)
            {
            for(NSError* detailedError in detailedErrors)
                {
                NSLog(@\"  DetailedError: %@\", [detailedError userInfo]);
                }
            }
        else
            {
            NSLog(@\"  %@\", [error userInfo]);
            }

        }
    else
        {
        DLog(@\"Persistent store added without incident, apparently.\");
        }

    return persistentStoreCoordinator;
    }

NSArray *theBundles = [NSArray arrayWithObject:[NSBundle mainBundle]];
    mappingModel = [NSMappingModel mappingModelFromBundles:theBundles
                                            forSourceModel:source 
                                          destinationModel:target];