在Swift 3和iOS中管理Sqlite数据库文件（从本地和/或bundle复制到app）

Question

我正在尝试将我的sqlite数据库文件上传到应用程序中。我一直在学习iOS文件系统，我不完全确定它是如何工作的并且迷路了。这是我想要实现的目标，但不确定如何：

1. 我想在这个位置有数据库my-xcode-project-path / data / foo.sqlite。现在我第一次运行模拟器，我想将这个数据库复制到模拟器的Document目录中。
2. 如果我已经安装了应用程序，我将跳过步骤1.并从bundle复制数据库。
3. 如果我试图运行模拟器，但没有可用的文件包，我想保留该数据库。

先感谢您！！！

我的代码看起来像这样：

func prepareDatabaseFile() -> String {
    let fileName: String = "foo.sqlite"

    let filemanager:FileManager = FileManager.default
    let directory = filemanager.urls(for: .documentDirectory, in: .userDomainMask).first!

    let newUrl = directory.appendingPathComponent(fileName)
    let bundleUrl = Bundle.main.resourceURL?.appendingPathComponent(fileName)

    // check bundle
    if filemanager.fileExists(atPath: (bundleUrl?.path)!) {
        print("bundle file exists!")
        return (bundleUrl?.path)! //probably I need to copy from bundle to new app and return new url
    // here check if file already exists on simulator, but not in bundle
    } else if filemanager.fileExists(atPath: (newUrl.path)) {
        print("prebuild file exists!")
        return newUrl.path //no copy is needed
    // finally, if nothing I need to copy local file
    } else {
        //todo copy local file from the path my-xcode-project-path/data/foo.sqlite
        print("todo")
    }

    return fileName
}

Answer 1

在@ Rob的帮助下，我开始遵循满足我要求的解决方案。以前有必要将sqlite文件添加到xcode项目中，并使用适当的目标。

func prepareDatabaseFile() -> String {
    let fileName: String = "foo.sqlite"

    let fileManager:FileManager = FileManager.default
    let directory = fileManager.urls(for: .documentDirectory, in: .userDomainMask).first!

    let documentUrl= directory.appendingPathComponent(fileName)
    let bundleUrl = Bundle.main.resourceURL?.appendingPathComponent(fileName)

    // here check if file already exists on simulator
    if fileManager.fileExists(atPath: (documentUrl.path)) {
        print("document file exists!")
        return documentUrl.path
    else if fileManager.fileExists(atPath: (bundleUrl?.path)!) {
        print("document file does not exist, copy from bundle!")
        fileManager.copyItem(at:bundleUrl, to:documentUrl)
    }

    return documentUrl.path
}

Answer 2

  self.copyfile(filename: "mydata.sqlite" )

        return true
    }

    func copyfile(filename : String)
    {
        let dbpath : String = getpath(filename: filename as String)

        let filemanager = FileManager.default

        if filemanager.fileExists(atPath: dbpath)
        {
            let documentsURl = Bundle.main.resourceURL

            let frompath = documentsURl?.appendingPathComponent(filename)

            print(frompath)

        }



    }

    func getpath(filename: String) -> String
    {

        let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]

        print(documentsURL)

        let fileURL = documentsURL.appendingPathComponent(filename as String)

        print(fileURL.path)
        return fileURL.path




    }