Core Data Automatic Lightweight Migration failing after moving sqlite file

1
votes

in my app I've used Core Data Automatic Lightweight Migration fine for multiple versions. About a year ago I implemented iOS File Sharing so I moved the sqlite database to the /Library folder rather than the /Documents directory to keep it hidden. I haven't added another Core Data version since that time.

Now when I try to add another Entity and increase the model version I get the following error (truncated to show just the tail end): 

"_NSAutoVacuumLevel" = 2;
}, reason=Can't find model for source store}
Terminating app due to uncaught exception     
'NSInternalInconsistencyException', reason: 
'This NSPersistentStoreCoordinator has no persistent stores.  
It cannot perform a save operation.'

I've verified that the .sqlite file exists on disk as expected. I've been troubleshooting for a few days and it seems if I move the sqlite file back to the /Documents directory the migration works OK.

Below is the code for the persistent store coordinator:

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator != nil) {
    return persistentStoreCoordinator;
}

NSURL *storeUrl = [NSURL fileURLWithPath: [[self libraryDocumentsDirectory] stringByAppendingPathComponent: @"myappdb.sqlite"]];

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

//Pass options in for lightweight migration....    
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                         [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
                         [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];

if(![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
                                             configuration:nil URL:storeUrl options:options error:&error]) {
    /*Error for store creation should be handled in here*/
    NSLog(@"ERROR IN MIGRATION........%@", error);        
}

return persistentStoreCoordinator;
}

- (NSString *)libraryDocumentsDirectory {
return [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) lastObject];
}

Has anyone encountered this situation before?

Thanks in advance for your help.

2
ioscore-datacore-data-migration
My guess is that your code is looking for the old directory instead of the new one. Some details would be appreciated. In other words, your code is looking for the Document dir. Maybe that's the problem. Try to modify the path. – Lorenzo B
Show the code for the creation of your core data stack so that we can diagnose the problem. – Marcus S. Zarra

2 Answers

0
votes

"Now when I try to ad another model entity and increase the version number..."

You need to create a new model version before you create a new entity or make changes to existing entities. Make sure your changes were not made in the old model version by mistake.

0
votes

After creating version and marking it as a current version you have to add an extra value in options which is used to add PersistentStore and then you go( I am not sure about other iOS version but yeah it will definitely work on iOS 7).

-(NSManagedObjectModel *)managedObjectModel
{
    if (managedObjectModel != nil)
    {
        return managedObjectModel;
    }
    managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
    return managedObjectModel;
}

-(NSPersistentStoreCoordinator *)persistentStoreCoordinator
 {

   if (persistentStoreCoordinator != nil)
   {
       return persistentStoreCoordinator;
   }

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"ABC.sqlite"];

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

//Creating Lightweight migration.
    NSDictionary *options =
    @{
      NSMigratePersistentStoresAutomaticallyOption:@YES
      ,NSInferMappingModelAutomaticallyOption:@YES
      ,NSSQLitePragmasOption: @{@"journal_mode": @"DELETE"}
     };


   if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error])
    {
       NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
       abort();
    }
return persistentStoreCoordinator;
}