Strange Core Data Error During Migration

Question

I'm absolutely pulling my hair out with Core Data after yet another bizarre error that I can't seem to solve.

This will be the fourth version of the Data model, the previous migrations have worked (albeit with some headaches).

All I'm trying to do is add a property of String type to an 'Engines' entity. I create a new version of the model (version 4) based on the current version (v3). I select the newly created version 4 as the 'Current model' and add the string property to the Engines entity. I then create a new mapping model, using v3 as the source and v4 as the target. I delete the previous Engines NSManagedObject subclass, and create a new one using the new, modified Engines entity, checking to make sure that the new String property is in the header file. I clean build the app and run it, and boom! I get this error, about 18 times:

{NSDetailedErrors=( "Error Domain=NSCocoaErrorDomain Code=1570 \"The operation couldn\U2019t be completed. (Cocoa error 1570.)\" UserInfo=0x6015820 {NSValidationErrorObject= (entity: BodySet; id: 0x60ba670 ; data: ), NSValidationErrorKey=availableCar, NSLocalizedDescription=The operation couldn\U2019t be completed. (Cocoa error 1570.)}",

BodySet is another entity in the model, but I haven't touched it during this migration, so why is it causing all these errors?

I'm not sure if this is a help or not, but here's my Core Data code:

- (NSManagedObjectContext *) managedObjectContext {
    if (managedObjectContext != nil) {
        return managedObjectContext;
    }
    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil) {
        managedObjectContext = [[NSManagedObjectContext alloc] init];
        [managedObjectContext setPersistentStoreCoordinator: coordinator];
    }
    return managedObjectContext;
}

- (NSManagedObjectModel *)managedObjectModel {

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

    NSString *path = [[NSBundle mainBundle] pathForResource:@"CoreDataTest" ofType:@"momd"];
    NSURL *momURL = [NSURL fileURLWithPath:path];
    managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:momURL];

    return managedObjectModel;
}

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
    if (persistentStoreCoordinator != nil) {
        return persistentStoreCoordinator;
    }
    stringByAppendingPathComponent:@"<Project Name>.sqlite"]];

    //get the DB from the Documents directory: 
    NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory]
                                           stringByAppendingPathComponent: @"<Project Name>.sqlite"]];
    NSLog(@"Loading DB at path: %@", [storeUrl path]); 

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

    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(@"Something went wrong....%@", [error description]); 
    }

    return persistentStoreCoordinator;
}

Any help with this is very much appreciated.

Yuan Yuan · Accepted Answer · 2012-08-03T07:35:39

0

votes

i have fixed it ，maybe you can change "availableCar“ item to optional

Strange Core Data Error During Migration

1 Answers