将数据库添加到我的片段但没有显示

Question

我正在使用简单的记事本应用。我在我的片段中添加了一个数据库，但是当我运行应用程序时它没有出现。

这是我的片段代码。一切似乎工作正常但应用程序上没有任何内容。我在onActivityCreated。

中调用了数据库

public class TomorrowFragment extends Fragment   {
  NDb myNDb;
public TomorrowFragment() {
    // Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_tomorrow, container, false);
}
/**
 * how i called my DataBase
 */
@Override
public void onActivityCreated( Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    myNDb = new NDb(getActivity());

   }
}

这是数据库代码：

public NDb(Context context) {
    super(context, dbname, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub
    db.execSQL("create table mynotes"
            + "(_id integer primary key, name text,remark text,dates     text)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)      

   {
    // TODO Auto-generated method stub
    db.execSQL("DROP TABLE IF EXISTS " + mynotes);
    onCreate(db);
}

public Cursor fetchAll() {

    db = this.getReadableDatabase();
    Cursor mCursor = db.query(mynotes, new String[] { "_id", "name",
            "dates", "remark" }, null, null, null, null, null);
    if (mCursor != null) {
        mCursor.moveToFirst();
    }

    return mCursor;
}

public boolean insertNotes(String name, String dates, String remark) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put("name", name);
    contentValues.put("dates", dates);
    contentValues.put("remark", remark);
    db.insert(mynotes, null, contentValues);
    return true;
}

public Cursor getData(int id) {
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor z = db.rawQuery("select * from " + mynotes + " where _id=" + id
            + "", null);
    return z;
}

public int numberOfRows() {
    SQLiteDatabase db = this.getReadableDatabase();
    int numRows = (int) DatabaseUtils.queryNumEntries(db, mynotes);
    return numRows;
}

public boolean updateNotes(Integer id, String name, String dates,
                           String remark) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put("name", name);
    contentValues.put("dates", dates);
    contentValues.put("remark", remark);
    db.update(mynotes, contentValues, "_id = ? ",
            new String[] { Integer.toString(id) });
    return true;
}

public Integer deleteNotes(Integer id) {
    SQLiteDatabase db = this.getWritableDatabase();
    return db.delete(mynotes, "_id = ? ",
            new String[] { Integer.toString(id) });
}
public ArrayList getAll() {
    ArrayList array_list = new ArrayList();
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor res = db.rawQuery("select * from " + mynotes, null);
    res.moveToFirst();
    while (res.isAfterLast() == false) {
        array_list.add(res.getString(res.getColumnIndex("_id")));
        array_list.add(res.getString(res.getColumnIndex(remark)));
        array_list.add(res.getString(res.getColumnIndex(dates)));
        array_list.add(res.getString(res.getColumnIndex(name)));
        res.moveToNext();
    }
    return array_list;
}
}

这是logcat输出：