Android 连接到现有SQLite数据库

我正在尝试做与本教程相同的事情： 但是我面临一些困难。 这是我的班级：

public class TechAgrumeSQLiteHelper extends SQLiteOpenHelper {    



      //The Android's default system path of your application database.
    private static String DB_PATH = "/data/data/test.test.test/databases/";

    private static String DB_NAME = "Player_Club";

    private SQLiteDatabase myDataBase; 

    private final Context myContext;
    private static final String TABLE_PLAYERS = "Player";
    private static final int DATABASE_VERSION = 3;
    // Contacts Table Columns names
    private static final String KEY_CODE = "_id";
    private static final String KEY_NOM = "nom_Player";
    private static final String KEY_SURNOM = "surnom_Player";
    private static final String KEY_AGE = "age_Player";

    /**
     * Constructor
     * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
     * @param context
     */
    public TechAgrumeSQLiteHelper(Context context) {

        super(context, DB_NAME, null, 1);
        this.myContext = context;
        Log.d("I'm here: ","I'm here!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
        boolean dbExist = checkDataBase();
        if(dbExist){
            //do nothing - database already exist
            Log.d("Copy BD","database already exists!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
        }else{

            //By calling this method and empty database will be created into the default system path
               //of your application so we are gonna be able to overwrite that database with our database.
            this.getReadableDatabase();

            try {

                copyDataBase();
                        Log.d("Copy BD","Datbase copied!!!!!!!!!!!!!!!!!!!!!!!!!!!");

            } catch (IOException e) {

                throw new Error("Error copying database");

            }
        }
    }   

  /**
     * Creates a empty database on the system and rewrites it with your own database.
     * */
    public void createDataBase() throws IOException{



    }

    /**
     * Check if the database already exist to avoid re-copying the file each time you open the application.
     * @return true if it exists, false if it doesn't
     */
    private boolean checkDataBase(){

        SQLiteDatabase checkDB = null;

        try{
            String myPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

        }catch(SQLiteException e){

            //database does't exist yet.

        }

        if(checkDB != null){

            checkDB.close();

        }

        return checkDB != null ? true : false;
    }

    /**
     * Copies your database from your local assets-folder to the just created empty database in the
     * system folder, from where it can be accessed and handled.
     * This is done by transfering bytestream.
     * */
    private void copyDataBase() throws IOException{

        //Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);

        // Path to the just created empty db
        String outFileName = DB_PATH + DB_NAME;

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

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

        //Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();

    }

    public void openDataBase() throws SQLException{

        //Open the database
        String myPath = DB_PATH + DB_NAME;
        myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

    }

    @Override
    public synchronized void close() {

            if(myDataBase != null)
                myDataBase.close();

            super.close();

    }

    @Override
    public void onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

        // Add your public helper methods to access and get content from the database.
       // You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
       // to you to create adapters for your views.



        void addPlayer(Player player) {
            SQLiteDatabase db = this.getWritableDatabase();
            ContentValues values = new ContentValues();
            values.put(KEY_NOM, player.getNom_Player()); // Contact Name
            values.put(KEY_SURNOM, player.getSurnom_Player()); // Contact Phone
            values.put(KEY_AGE, player.getAge_Player()); // Contact Phone

            // Inserting Row
            db.insert(TABLE_PLAYERS, null, values);
            db.close(); // Closing database connection
        }

        public List<Player> getAllPlayers() {
            List<Player> playerList = new ArrayList<Player>();
            // Select All Query
            String selectQuery = "SELECT  * FROM " + TABLE_PLAYERS;

            SQLiteDatabase db = this.getWritableDatabase();
            Cursor cursor = db.rawQuery(selectQuery, null);

            // looping through all rows and adding to list
            if (cursor.moveToFirst()) {
                do {
                    Player player = new Player();
                    player.setCode_Player(Integer.parseInt(cursor.getString(0)));
                    player.setNom_Player(cursor.getString(1));
                    player.setSurnom_Player(cursor.getString(2));
                    player.setAge_Player(Integer.parseInt(cursor.getString(3)));
                    // Adding contact to list
                    playerList.add(player);
                } while (cursor.moveToNext());
            }

            // return contact list
            return playerList;
        }

}

我去看看Player_Club.db是否真的存在：

    adb shell
    shell@android:/ $ run-as test.test.test
    run-as test.test.test
    <a href="mailto:shell@android:/data/data/test.test.test">shell@android:/data/data/test.test.test</a> $ cd /data/data/test.test.test/databases
    .test.test/databases                                                          <
    <a href="mailto:shell@android:/data/data/test.test.test">shell@android:/data/data/test.test.test</a>/databases $ ls
    ls
   Player_Club.db
   webview.db
   webview.db-shm
   webview.db-wal

adb外壳
shell@android：/$run as test.test.test
作为test.test.test运行
$cd/data/data/test.test.test/databases
.test.test/databases<
/数据库$ls
ls
Player_Club.db
webview.db
webview.db-shm
webview.db-wal

---

从这些行中我可以看出数据库确实存在，所以我不知道它为什么要在webview.db上查找Player表？

我建议切换到SQLiteAssetHelper:from log cat error db=/data/data/test.test.test/databases/webview.db意味着你的数据库名是webview.db，但你已经提到Player_Club.db是你的数据库名。所以请在ddms中检查你的数据库名，并签入yoyr assest文件夹也

D/I'm here:   ( 6548): I'm here!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
D/KeyguardViewMediator(  216): setHidden false
D/Copy BD( 6548): database already exists!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
D/Insert: ( 6548): Inserting ................................................
I/SqliteDatabaseCpp( 6548): sqlite returned: error code = 1, msg = no such table: Player, db=/data/data/test.test.test/databases/webview.db
E/SQLiteDatabase( 6548): Error during inserting
E/SQLiteDatabase( 6548): android.database.sqlite.SQLiteException: no such table: Player: , while compiling: INSERT INTO Player(surnom_Player,nom_Player,age_Player) VALUES (?,?,?)

    adb shell
    shell@android:/ $ run-as test.test.test
    run-as test.test.test
    <a href="mailto:shell@android:/data/data/test.test.test">shell@android:/data/data/test.test.test</a> $ cd /data/data/test.test.test/databases
    .test.test/databases                                                          <
    <a href="mailto:shell@android:/data/data/test.test.test">shell@android:/data/data/test.test.test</a>/databases $ ls
    ls
   Player_Club.db
   webview.db
   webview.db-shm
   webview.db-wal