如果條目存在，如何使sql數據庫更新，如果不存在，則插入新記錄

Question

我的代碼中有問題，這是一個井字游戲，每次用戶贏得游戲時，它會將高分（點）保存到sql數據庫中。 如果用戶名不存在，它將在列表視圖中創建一個新的用戶名。 我似乎找不到這些點沒有增加的原因。 有什么幫助嗎？

這是我嘗試更新數據庫並在用戶名已經存在的情況下將點增加一的活動。 否則，請創建新的。

private boolean player1Turn = true;
private int roundCount;
private TextView currentPlayer;
private Button[][] buttons = new Button[3][3];
private int player1Points;
private int player2Points;
private DbHighscoresHelper dbHelper;
private ArrayAdapter<String> mAdapter;
private ListView mScoreListView;
private SQLiteDatabase scoreDB;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_board);
    createTable();

    dbHelper  = new DbHighscoresHelper(this);
    mScoreListView = findViewById(R.id.highscore_list);
}

private void createTable() {

    //create the table
    for(int i = 0; i < 3; i++) {
        for(int j = 0; j < 3; j++) {
            String btn_id = "button_" + i + j;

            int resID = getResources().getIdentifier(btn_id, "id", getPackageName());
            buttons[i][j] = findViewById(resID);
            buttons[i][j].setOnClickListener(this);
        }
    }
}

@Override
public void onClick(View v) {

    TextView whoseTurn = (TextView) findViewById(R.id.whose_turn);

    if (checkForWin() == true) {
        Toast.makeText(this, "Game over", Toast.LENGTH_SHORT).show();
        return;
    }

    //checks if the clicked button is empty(empty string), if not, the button is full
    if(!((Button) v).getText().equals("")) {
        return;
    }
    //lets check if its player1turn, puts the mark in the button
    if(player1Turn) {
        ((Button) v).setText("X");
    } else {
        ((Button) v).setText("O");
    }

    if(player1Turn) {
        whoseTurn.setText("Player 1's turn");
    } else {
        whoseTurn.setText("Player 2's turn");
    }

    //one round is over until all the rounds are used(9)
    roundCount++;

    if(checkForWin()) {
        if(player1Turn) {
            winnerPlayer1();
        } else {
            winnerPlayer2();
        }
    } else if(roundCount == 9) {
        draw();
    } else {
        player1Turn = !player1Turn;
    }

}

private boolean checkForWin() {
    String[][] checkBoard = new String[3][3];

    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            //check if the checkboard stuff is in the same place than in the buttons board
            checkBoard[i][j] = buttons[i][j].getText().toString();
        }
    }

    //lets go through all the rows
    for (int i = 0; i < 3; i++) {
        //columns, check field to the one next to it and all three of them
        if(checkBoard[i][0].equals(checkBoard[i][1])
                && checkBoard[i][0].equals(checkBoard[i][2])
                && ! checkBoard[i][0].equals("")) {
            return true; //theres a winner
        }
    }

    //lets go through columns
    for (int i = 0; i < 3; i++) {
        //columns, check field to the one next to it and all three of them
        if(checkBoard[0][i].equals(checkBoard[1][i])
                && checkBoard[0][i].equals(checkBoard[2][i])
                && ! checkBoard[0][i].equals("")) {
            return true; //theres a winner
        }
    }

    //lets check diagonals
    if(checkBoard[0][0].equals(checkBoard[1][1])
            && checkBoard[0][0].equals(checkBoard[2][2])
            && ! checkBoard[0][0].equals("")) {
        return true; //theres a winner
    }
    //lets check diagonals
    if(checkBoard[0][2].equals(checkBoard[1][1])
            && checkBoard[0][2].equals(checkBoard[2][0])
            && ! checkBoard[0][2].equals("")) {
        return true; //theres a winner
    }

    return false; //we dont have a winner
}



public void winnerPlayer1() {
     Toast.makeText(getApplicationContext(), "Player 1 won", Toast.LENGTH_SHORT).show();
     player1Points++;
     enterName(player1Points);
}

public void winnerPlayer2() {
    Toast.makeText(getApplicationContext(), "Player 2 won", Toast.LENGTH_SHORT).show();
    player2Points++;
    enterName(player2Points);
}

private void draw() {
    Toast.makeText(getApplicationContext(), "Draw", Toast.LENGTH_SHORT).show();
}


public boolean enterName(final int points) {
    if(checkForWin()) {
        final EditText editText = new EditText(this);
        android.support.v7.app.AlertDialog alert = new android.support.v7.app.AlertDialog.Builder(this)
                .setTitle("You won!")
                .setMessage("Enter your name")
                .setView(editText)
                .setPositiveButton("Apply", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        String getText = editText.getText().toString();
                        new backGroundStuff(points, getText).execute();
                    }
                })
                .setNegativeButton("Cancel", null)
                .create();
                alert.show();

    }
    return false;
}


public static boolean doesDatabaseExists(Context c, String scoreDb) throws IOException {
    File dbFile = c.getDatabasePath(scoreDb);
    FileOutputStream file = new FileOutputStream(dbFile);
    file.close();
    return dbFile.exists();
}

public boolean nameExists(String tableName, String dbField, String fieldValue) {
    SQLiteDatabase scoreDb = dbHelper.getWritableDatabase();
    String Query = "SELECT " + highscores.highscoreEntry._ID + " FROM " + tableName + " WHERE " + fieldValue + " = " + fieldValue;

    Cursor cursor = scoreDb.rawQuery(Query, null);
        if (cursor.getCount() <= 0) {
            cursor.close();
            return false;
        }
        cursor.close();
        return true;
}


public static class backGroundStuff extends AsyncTask<String, Void, Boolean> {
    int points;
    String getText;

    backGroundStuff(int points, String getText) {
        this.points = points;
        this.getText = getText;
    }

    @Override
    protected void onPreExecute() {

    }

    @Override
    protected Boolean doInBackground(String...params) {
        SQLiteDatabase scoreDB = dbHelper.getWritableDatabase(); 
        ContentValues values = new ContentValues();
        values.put(highscores.highscoreEntry.COL_HIGHSCORE_TITLE, this.getText);
        values.put(highscores.highscoreEntry.COL_HIGHSCORE_SCORE, this.points);

        Cursor c = scoreDB.rawQuery("SELECT * FROM highscores WHERE title LIKE '" + this.getText + "'", null);

        if (c.getCount() == 0) {
            c.close();
            scoreDB.insert(highscores.highscoreEntry.TABLE, null, values);
        } else {
            c.moveToNext();
            scoreDB.update(highscores.highscoreEntry.TABLE, values, highscores.highscoreEntry.COL_HIGHSCORE_SCORE + "  ?" , new String[] {Integer.toString(this.points)});
        }


        scoreDB.close();
        return true;
    }

    @Override
    protected void onPostExecute(Boolean result) {
        super.onPostExecute(result);

    }

}

Answer 1

在查找您使用的現有行時

Cursor c = scoreDB.rawQuery("SELECT * FROM highscores WHERE title LIKE '" + this.getText + "'", null);

您不應該使用百分比修飾符使它匹配“包含”而不是“等於”，如下所示：

Cursor c = scoreDB.rawQuery("SELECT * FROM highscores WHERE title LIKE '%" + this.getText + "%'", null);

如果沒有通配符百分號，則實際上是在直接匹配。 另外，我不確定區分大小寫的匹配是否也是一個問題。

Cursor c = scoreDB.rawQuery("SELECT * FROM highscores WHERE LOWER(title) LIKE '%" + this.getText.toLowerCase() + "%'", null);