在Android的备份/恢复的SQLite数据库 [英] Backup/restore sqlite db in android

问题描述

可能重复：
  <一href="http://stackoverflow.com/questions/5282936/android-backup-restore-how-to-backup-an-internal-database">Android备份/恢复？如何备份内部数据库

我开发一个应用程序，其中有SQL精​​简版数据库。我需要给用户备份数据库，然后再恢复它的能力。我该怎么办呢？样品code？

I am developing an app in which there is SQL lite db. I need to give the user the ability to back up the database and restore it again. How can I do that? Sample code?

和的情况下，我的用户保存的数据库，然后将应用程序升级到新的数据库版本code，将恢复工作？我怎么去的？

And in case my user saved the db, and then upgraded the app to a new DB version code, will restore work? How do I go about that?

请帮忙

推荐答案

在文件夹/data/data/'your.app.package'/databases/你有一个.db文件是数据库。您可以复制该文件，保存它，然后再次回到那里把它。

In the folder "/data/data/'your.app.package'/databases/" you have a .db file that is your database. You can copy that file, save it, and then place it back there again.

这是一个例子，如何备份数据库到外部存储：

One example on how to backup the database to the external storage:

    final String inFileName = "/data/data/<your.app.package>/databases/foo.db";
    File dbFile = new File(inFileName);
    FileInputStream fis = new FileInputStream(dbFile);

    String outFileName = Environment.getExternalStorageDirectory()+"/database_copy.db";

    // Open the empty db as the output stream
    OutputStream output = new FileOutputStream(outFileName);

    // Transfer bytes from the inputfile to the outputfile
    byte[] buffer = new byte[1024];
    int length;
    while ((length = fis.read(buffer))>0){
        output.write(buffer, 0, length);
    }

    // Close the streams
    output.flush();
    output.close();
    fis.close();

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