Question

我是.net开发者，并在空闲时间制作Android应用程序。我制作了一个有大约700首歌曲的音乐库应用程序。我在数据库中添加了歌曲。当我在实际应用程序时，我将从Asset文件夹中复制数据库，然后在SD卡中复制。现在我已经在Play商店中部署了应用程序，我想用更多歌曲更新数据库。我不想更新任何数据库结构，也不想删除任何东西。我想添加更多100首歌曲。所以我想在部署新版本时复制新数据库。

我google了很多，花了很多时间。每个人都说onUpgrade函数调用，我们去更新版本。我的问题是，Control永远不会出现这种方法。我已经把Log语句，我可以看到它永远不会执行。我已经多次更新了db并更新了版本，但是“onUpgrade”从未调用过。

这是我的代码......

public class DatabaseHelper extends SQLiteOpenHelper
{
private static String DB_PATH;  
private static String DB_NAME1 = "question.db"; // Asset Folder DB Name     
public static final String KEY_NAME = "Name";
protected static String DB_NEWPATH;
private Context myContext;
final static int DB_VERSION = 16;

private SQLiteDatabase myDataBase;

    public DatabaseHelper(Context context)      
    {                           
        super(context,DB_NAME1,null,DB_VERSION);            
        this.myContext = context;
        DB_PATH = "/data/data/"+context.getPackageName()+"/databases/";         
        Log.i("DatabaseHelper,Path", "********"+DB_PATH);
    }

    /*
     * Creates a empty database on the system a         
     * 
     */
    public void CreateDatabase() throws IOException
    {
        boolean dbExists = checkDatabase();
        Log.i("CreateDatabase",   "********CreateDatabase,dbExist="+dbExists);
        if(!dbExists)           
        {
            this.getReadableDatabase();
            try {
                copyDatabase();
            } catch (IOException e) {    
                throw new Error("Error copying database");   
            }
        }
    }


    public boolean checkDatabase()
    {
        Log.i("checkDatabase", "********checkDatabase");
        SQLiteDatabase checkDB = null; 
        try{ 
            Log.d("DB Path=", DB_NEWPATH);
            checkDB = SQLiteDatabase.openDatabase(DB_NEWPATH, null, SQLiteDatabase.OPEN_READONLY);  
        }catch(SQLiteException e){ } 

        if(checkDB != null){ checkDB.close(); } 

        return (checkDB != null) ? true : false;

    }       

    private void copyDatabase() throws IOException
    {
        //Open your local db as the input stream 
        Log.i("copyDatabase", "********copyDatabase");
        InputStream myInput = myContext.getAssets().open(DB_NAME1); // Path to the asset folder database

        // Path to the just created empty db
        Log.d("in CopyDB method DB Path=", DB_NEWPATH);
        String outFileName = DB_NEWPATH;

        FileOutputStream myOutput = new FileOutputStream(outFileName);
        byte[] buffer = new byte[1024];
        int length;
        while((length = myInput.read(buffer)) > 0)
        {
            myOutput.write(buffer,0,length);
        }
        Log.i("copyDatabase", "********copy Done");
        //Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

    /*
     * Open Database
     * 
     */
    public SQLiteDatabase openDB() throws SQLException
    {
        Log.i("openDB", "********openDB");
        myDataBase = SQLiteDatabase.openDatabase(DB_NEWPATH, null, SQLiteDatabase.OPEN_READWRITE);
        return myDataBase;
    }

    /*
     * Close Database 
     */
    public synchronized void close() {
    if(myDataBase != null)
    myDataBase.close();
    super.close();
    }

    @Override
    public void onCreate(SQLiteDatabase arg0) {         
        /* Database already created */
        Log.i("onCreate", "********onCreate");
    }

    @Override
    public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
        Log.i("OnUpgrade", "This method is not going to execute....What is the reason even I am updating version each time....");       
        /* No upgrade of Database */
    }

}

每次部署时，我都会复制新数据库。已安装应用程序的用户未获取我的更新cz此onUpgrade未执行。

任何帮助？

在Android sqlite数据库上没有调用onUpgrade（）

0 个答案: