无法在iOS中读取dtabase.sqlite文件（无此类表Z_METADATA）

Question

In new version I start using Core Data. But when I try to migrate from an old database to the new one, I'm getting an error:

let dbName = "db.sqlite:"

guard let modelURL = Bundle.main.url(forResource: "Ex", withExtension: "momd"), 
      let model = NSManagedObjectModel(contentsOf: modelURL) else {
    fatalError("model not found")
}

let psc = NSPersistentStoreCoordinator(managedObjectModel: model)
let databaseUrl = URL.defaultUrl.appendingPathComponent(dbName)

do {
    try psc.addPersistentStore(ofType: NSSQLiteStoreType, 
                    configurationName: nil, 
                                   at: databaseUrl, 
                              options: [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true])
} catch {
    fatalError("database migration error")
}

context = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
context.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy
context.persistentStoreCoordinator = psc

Error message:

 Error Domain=NSCocoaErrorDomain Code=256 "The file couldn't be opened." UserInfo={NSUnderlyingException=I/O error for database at /var/mobile/Containers/Data/Application/dsdasda-6Basdsd9C-4AE9-sad-sd/Documents/db.sqlite. SQLite error code:1, 'no such table: Z_METADATA', NSSQLiteErrorDomain=1} error: The file couldn't be opened. 

How i can resolve that?

Answer 1

The trailing colon in the dbName looks extraneous. ("db.sqlite**:**")