swift - CoreData从预填的SQLite [英] swift - CoreData from prepopulated SQLite

问题描述

我已经使用CoreData填充了一个数据库，现在我想在我的应用程序中使用它作为默认数据库。
我已经阅读过，但我只在Objective-C中找到教程，Xcode6在AppDelegate中创建的Core Data方法对我来说很奇怪...

I've populated a database with CoreData and now I want to use it as the default database in my app in swift. I've read about it but I only found tutorials in Objective-C and the methods of Core Data that Xcode6 creates in the AppDelegate are kindly strange for me...

这是代码：

    // MARK: - Core Data stack

lazy var applicationDocumentsDirectory: NSURL = {
    // The directory the application uses to store the Core Data store file. This code uses a directory named "RLopez.BORRAME" in the application's documents Application Support directory.
    let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
    return urls[urls.count-1] as NSURL
    }()

lazy var managedObjectModel: NSManagedObjectModel = {
    // The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
    let modelURL = NSBundle.mainBundle().URLForResource("iManager", withExtension: "momd")
    return NSManagedObjectModel(contentsOfURL: modelURL)
    }()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
    // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
    // Create the coordinator and store
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("iManager.sqlite")
    println(url)
    var error: NSError? = nil
    var failureReason = "There was an error creating or loading the application's saved data."
    if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil {
        coordinator = nil
        // Report any error we got.
        let dict = NSMutableDictionary()
        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 coordinator
    }()

lazy var managedObjectContext: NSManagedObjectContext? = {
    // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
    let coordinator = self.persistentStoreCoordinator
    if coordinator == nil {
        return nil
    }
    var managedObjectContext = NSManagedObjectContext()
    managedObjectContext.persistentStoreCoordinator = coordinator
    return managedObjectContext
    }()

// MARK: - Core Data Saving support

func saveContext () {
    if let moc = self.managedObjectContext {
        var error: NSError? = nil
        if moc.hasChanges && !moc.save(&error) {
            // Replace this implementation 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()
        }
    }
}

我想要的是使用我在应用程序包中的sqlite文件，而不是创建一个空数据库。
如何实现？

What I want is to use a sqlite file I have in my app bundle instead of creating an empty database. How can I achieve that?

提前感谢！

推荐答案

您将sqlite文件从应用程序包复制到持久存储所在的位置。

You copy sqlite file from app bundle to the place where persistent store is.

这是我的代码：

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("db.sqlite")

   //this part
    if (!NSFileManager.defaultManager().fileExistsAtPath(url.path!)) {
        let defaultStorePath = NSBundle.mainBundle().pathForResource("db", ofType:"sqlite")

        NSFileManager.defaultManager().copyItemAtPath(defaultStorePath!, toPath:url.path!, error: nil)
    }

    if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: nil) == nil {
        coordinator = nil
    }
    return coordinator
    }()

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