CODEWITHSUNDEEP
iosobjective-csqlitecore-data
brettfazio
brettfazio

Reputation: 1156

Core Data error when fetching

I am new to Core Data and I have been trying to fetch the entities that I have created but I keep getting error messages thrown at me.

The error is as follows:

CoreData: error: -addPersistentStoreWithType:SQLite configuration:(null) URL:file:///var/mobile/Containers/Data/Application/4A0BBC17-674F-4A5D-80F7-72174D71B95F/Documents/Todogorithm.sqlite options:(null) ... returned error Error Domain=NSCocoaErrorDomain Code=134100 "The managed object model version used to open the persistent store is incompatible with the one that was used to create the persistent store." UserInfo={metadata={
    NSPersistenceFrameworkVersion = 641;
    NSStoreModelVersionHashes =     {
        Task = <3db44fe3 d21215ef eee9476a ae204647 b49829de 00b4784c 7715b5ff a252dcab>;
    };
    NSStoreModelVersionHashesVersion = 3;
    NSStoreModelVersionIdentifiers =     (
        ""
    );
    NSStoreType = SQLite;
    NSStoreUUID = "DFB8723E-7D5B-44A0-AFB9-E9E0F7E39E85";
    "_NSAutoVacuumLevel" = 2;
}, reason=The model used to open the store is incompatible with the one used to create the store} with userInfo dictionary {
    metadata =     {
        NSPersistenceFrameworkVersion = 641;
        NSStoreModelVersionHashes =         {
            Task = <3db44fe3 d21215ef eee9476a ae204647 b49829de 00b4784c 7715b5ff a252dcab>;
        };
        NSStoreModelVersionHashesVersion = 3;
        NSStoreModelVersionIdentifiers =         (
            ""
        );
        NSStoreType = SQLite;
        NSStoreUUID = "DFB8723E-7D5B-44A0-AFB9-E9E0F7E39E85";
        "_NSAutoVacuumLevel" = 2;
    };
    reason = "The model used to open the store is incompatible with the one used to create the store";
}

The error is thrown when the viewDidAppear on my view controller is called. Here is my viewDidAppear: [super viewDidAppear:animated];

AppDelegate *appDelegate = [[AppDelegate alloc] init];

NSManagedObjectContext *context = [appDelegate managedObjectContext];

NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"Task"];
_results = [context executeFetchRequest:request error:nil];

The code there calls the managedObjectContext in my appDelegate, and in that method the persistentStoreCoordinator method is called (this is where the error is actually thrown). The two methods from AppDelegate.m are below:

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
    // The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it.
    if (_persistentStoreCoordinator != nil) {
        return _persistentStoreCoordinator;
    }

    // Create the coordinator and store

    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Todogorithm.sqlite"];
    NSError *error = nil;
    NSString *failureReason = @"There was an error creating or loading the application's saved data.";
    if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
        // Report any error we got.
        NSMutableDictionary *dict = [NSMutableDictionary dictionary];
        dict[NSLocalizedDescriptionKey] = @"Failed to initialize the application's saved data";
        dict[NSLocalizedFailureReasonErrorKey] = failureReason;
        dict[NSUnderlyingErrorKey] = error;
        error = [NSError errorWithDomain:@"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
        // Replace this with code to handle the error appropriately.
        // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        abort();
    }

    return _persistentStoreCoordinator;
}


- (NSManagedObjectContext *)managedObjectContext {
    // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.)
    if (_managedObjectContext != nil) {
        return _managedObjectContext;
    }

    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (!coordinator) {
        return nil;
    }
    _managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
    [_managedObjectContext setPersistentStoreCoordinator:coordinator];

Any ideas as to why the error in persistentStoreCoordinator is being called?

Upvotes: 1

Views: 2965

Answers (3)

Ambrose Jesuraj
Ambrose Jesuraj

Reputation: 143

Clear your app data or delete the app from your device to solve this problem.

Upvotes: 0

Eugene Dudnyk
Eugene Dudnyk

Reputation: 6030

You probably changed your managed object model in Xcode, but you have still installed app on your device/simulator with older data model configuration.

That's why you getting this error. If your app is brand new and you don't have to bother with compatibility to already installed apps, you can just erase old app from the device/simulator and install new one.

If you need to keep compatibility of older data model configuration with newer one, you should use versioning of the model and make all your changes in the newer data model version.

Upvotes: 6

Shibin S
Shibin S

Reputation: 149

Remove the app from the Simulator/device , Perform a Clean and Re-Build your Project.

Whenever you perform changes to the Core Data definition, Delete the app installed on the Physical Device or Simulator, Clean the Project and Re-Build again.

Upvotes: 1

Related Questions