CODEWITHSUNDEEP
iosobjective-csqlitecore-data
soltzu
soltzu

Reputation: 139

Can't open sqlite DB from iOS app

I'm relatively new to iOS development and it is my first time trying to use the CoreData.framework.

I created a very simple DB with "sqlitebrowser" and copied it into my project in XCode. I can see the file is included in the app bundle. I tried to access the DB in the AppDelegate class, following method:

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

    //For now using the `SQLite` store generate manually. Make sure to open the
    //store in read only mode since we cannot modify files in the bundle.

    NSURL *storeURL = [[NSBundle mainBundle] URLForResource:@"MatchWatcher" withExtension:@"sqlite"];
    //Should be like below
    NSDictionary *storeOptions = @{NSReadOnlyPersistentStoreOption:@YES, NSSQLitePragmasOption: @{@"journal_mode":@"DELETE"} };
//    NSDictionary *storeOptions = @{NSSQLitePragmasOption: @{@"journal_mode" : @"DELETE"} };
    NSError *error = nil;
    _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if(![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
                                              configuration:nil
                                                        URL:storeURL
                                                    options:storeOptions
                                                      error:&error]) {
        NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
    }

    return _persistentStoreCoordinator;
}

As you can see, I try to use the storeOptions variable that includes the ReadOnly opening of the DB, but this gives me the following exception:

2015-07-06 14:15:18.372 MatchWatcher[27495:3849154] CoreData: error: -addPersistentStoreWithType:SQLite configuration:(null) URL:file:///Users/john/Library/Developer/CoreSimulator/Devices/F8C9B7DC-3C1D-495C-8FB6-80A9EA5976BB/data/Containers/Bundle/Application/CA64DE15-428B-4356-BB2B-066258E5FBAE/MatchWatcher.app/MatchWatcher.sqlite options:{ NSReadOnlyPersistentStoreOption = 1; NSSQLitePragmasOption = { "journal_mode" = DELETE; }; } ... returned error Error Domain=NSCocoaErrorDomain Code=257 "The operation couldn’t be completed. (Cocoa error 257.)" UserInfo=0x7fa38a73cbb0 {NSUnderlyingException=Cannot create a new database file with the read only option at path: /Users/john/Library/Developer/CoreSimulator/Devices/F8C9B7DC-3C1D-495C-8FB6-80A9EA5976BB/data/Containers/Bundle/Application/CA64DE15-428B-4356-BB2B-066258E5FBAE/MatchWatcher.app/MatchWatcher.sqlite} with userInfo dictionary { NSUnderlyingException = "Cannot create a new database file with the read only option at path: /Users/john/Library/Developer/CoreSimulator/Devices/F8C9B7DC-3C1D-495C-8FB6-80A9EA5976BB/data/Containers/Bundle/Application/CA64DE15-428B-4356-BB2B-066258E5FBAE/MatchWatcher.app/MatchWatcher.sqlite"; } 2015-07-06 14:15:18.373 StockWatcher[27495:3849154] Unresolved error Error Domain=NSCocoaErrorDomain Code=257 "The operation couldn’t be completed. (Cocoa error 257.)" UserInfo=0x7fa38a73cbb0 {NSUnderlyingException=Cannot create a new database file with the read only option at path: /Users/john/Library/Developer/CoreSimulator/Devices/F8C9B7DC-3C1D-495C-8FB6-80A9EA5976BB/data/Containers/Bundle/Application/CA64DE15-428B-4356-BB2B-066258E5FBAE/MatchWatcher.app/MatchWatcher.sqlite}, { NSUnderlyingException = "Cannot create a new database file with the read only option at path: /Users/john/Library/Developer/CoreSimulator/Devices/F8C9B7DC-3C1D-495C-8FB6-80A9EA5976BB/data/Containers/Bundle/Application/CA64DE15-428B-4356-BB2B-066258E5FBAE/MatchWatcher.app/MatchWatcher.sqlite"; }

Any ideas of what I'm doing wrong? Some help would be appreciated! Thanks.

Upvotes: 1

Views: 1195

Answers (1)

Marcus S. Zarra
Marcus S. Zarra

Reputation: 46718

The SQLite file that Core Data uses is structured in a closed way. It is not meant to be used against a SQLite file that you have developed outside of Core Data.

Core Data is designed to be the model of your application. Treating it as a relational database tool will cause you issues. Use it as the model of your application and then let it persist to disk. Not the other way around.

Upvotes: 1

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