无法使用EncryptedCoreData检索以前的数据

Question

After app is restarted data from core-data is not returned properly. And fetch request to get a particular record also fails. FetchRequestController do not grabs any record once app is re-started.

I am using encrypted-core-data to protect data in my project. I am able to parse and save data to managedObjectContext. My code looks like this

for (NSDictionary *data in categories) {
    //Use MagicRecord api to get a record
    CMCategories *Obj = [CMCategories MR_findFirstByAttribute:@"uniqueId" 
                    withValue:[data valueForKey:@"id"] 
                    inContext:managedObjectContext];
    if (!Obj) {
        Obj = [CMCategories MR_createEntityInContext:managedObjectContext];
    }
    Obj.name = [data valueForKey:@"CategoryName"];
    Obj.language = [data valueForKey:@"LanguageCode"];
    Obj.uniqueId = [data valueForKey:@"id"];

}
NSError *error = nil;
if (![_managedObjectContext save:&error]) {
    NSLog(@"Error saving context: %@\n%@", [error localizedDescription], [error userInfo]);
    abort();
}

The code works without error. My persistentStoreCoordinator and managedObjectContext code is same as this

When I print the obj before closing the app it prints

2016-01-24 23:59:11.806 Chare Dev[10556:158617] <CMCategories: 0x7feb00d24a90> (entity: CMCategories; id: 0x7feb02ef5890 <x-coredata://B947ACD3-E248-4D4F-B81E-236E100BB34D/CMCategories/p5> ; data: {
    channels =     (
    );
    language = en;
    name = Professional;
    order = 0;
    uniqueId = 15;
})

But after app restart, when we fetch all objects and print it prints like this

2016-01-24 23:59:11.795 Chare Dev[10556:158617] <CMCategories: 0x7feb02de4aa0> (entity: CMCategories; id: 0x7feb02de5c10 <x-coredata://B947ACD3-E248-4D4F-B81E-236E100BB34D/CMCategories/p2> ; data: {
    channels = "<relationship fault: 0x7feb02922450 'channels'>";
    language = nil;
    name = nil;
    order = nil;
    uniqueId = nil;
})

And if I try to get a property NSString *string = obj.uniqueId

2016-01-24 23:59:11.795 Chare Dev[10556:158617] CoreData: warning: An NSManagedObjectContext delegate overrode fault handling behavior to silently delete the object with ID '0x7feb02de5c10 ' and substitute nil/0 for all property values instead of throwing

If I use NSSQLiteStoreType instead of EncryptedStoreType everything works fine. Can you guide me what am I doing wrong?

Because due to above issue, database records are added multiple times and fetch request fails to fetch a managed object with uniqueId.

Answer 1

tl;dr

Don't use SQLite Keywords on your model (Properties, relationships, Entities, etc).

---

Usually with CoreData you are safe to use SQLite reserved keywords, but apparently is not the case when using EncryptedCoreData .

This #232 issue explains it as well.

In my project I had from as a property of one of my models, and this single property was the culprit.

I can see from that code:

2016-01-24 23:59:11.806 Chare Dev[10556:158617] <CMCategories: 0x7feb00d24a90> (entity: CMCategories; id: 0x7feb02ef5890 <x-coredata://B947ACD3-E248-4D4F-B81E-236E100BB34D/CMCategories/p5> ; data: {
    channels =     (
    );
    language = en;
    name = Professional;
    order = 0;
    uniqueId = 15;
})

You are using order , that is as well a keyword. Try to remove and check.

Note: Even after renaming that property from model I had to uninstall and install the app again, not much of a hassle for me since it is not published yet.