android studio数据库表按名称调用字段不是索引

public class DatabaseHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "mydatabase.db";
    private static final int DATABASE_VERSION = 1;

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String createTableQuery = "CREATE TABLE mytable (" +
                "id INTEGER PRIMARY KEY AUTOINCREMENT," +
                "name TEXT NOT NULL," +
                "age INTEGER NOT NULL" +
                ");";
        db.execSQL(createTableQuery);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS mytable;");
        onCreate(db);
    }
}

public void insertData(String name, int age) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put("name", name);
    values.put("age", age);
    db.insert("mytable", null, values);
    db.close();
}

public List<String> getData() {
    List<String> dataList = new ArrayList<>();
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.query("mytable", new String[]{"name", "age"}, null, null, null, null, null);

    if (cursor.moveToFirst()) {
        do {
            String name = cursor.getString(cursor.getColumnIndex("name"));
            int age = cursor.getInt(cursor.getColumnIndex("age"));
            dataList.add("Name: " + name + ", Age: " + age);
        } while (cursor.moveToNext());
    }

    cursor.close();
    db.close();
    return dataList;
}