轻量级迁移麻烦iOS

Question

i am having a bit of a hassle, i created a new version of my context & made it the default one, after that i changed my code according to the apple docs and it looks like that now:

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{

    if (persistentStoreCoordinator != nil)
    {
        return persistentStoreCoordinator;
    }
    NSError *error = nil;
    persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"database.sqlite"];
    NSPersistentStoreCoordinator *psc = persistentStoreCoordinator;
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
                             [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];


    BOOL success = [psc addPersistentStoreWithType:NSSQLiteStoreType
                                     configuration:nil URL:storeURL
                                           options:options error:&error];
    if (!success) {
        NSLog(@"Unresolved Error");
        abort();
    }

    return persistentStoreCoordinator;
}

but i get an error even though it is 1:1 the same code, in the line BOOL sucess i get an incompatible pointer to integer conversion 'BOOL' with 'NSPersistentstore'

somehow the mapping has worked though and i get the new model in lets say 4 out of 5 times it works, the 5th it throws an error in that line.

any ideas how to fix it?

UPDATE i changed the code a bit and it now looks like that

NSPersistentStore *store = [psc addPersistentStoreWithType:NSSQLiteStoreType
                                     configuration:nil URL:storeURL
                                           options:options error:&error];
if (!store) {
        NSLog(@"Unresolved Error");
        abort();
}

Answer 1

The warning and the error are two separate things.

The warning is that you are treating a pointer as if it were a number. addPersistentStoreWithType:configuration:URL:options:error does not return a BOOL (which is essentially a number), it returns the NSPersistentStore object you are creating. Instead of a boolean success variable, you should be assigning the result to an NSPersistentStore * variable.

In the case of failure, it returns nil and populates the error object. You can obtain more information about the error from this object, such as logging its localizedDescription .