java - SQlite WHERE 语句不起作用？

Question

我正在制作一个应用程序，用于存储书名、添加日期和需要归还图书的日期。下面，我展示了 where 语句，该语句获取所有在今天和两天之间归还的书籍，并以 ListView 的形式返回。但是，它不起作用，我不确定哪里出错了:

    public Cursor fetchAllDue() {

    //get todays date
    Calendar cal=Calendar.getInstance();
    int currentDay=cal.get(Calendar.DAY_OF_MONTH);

    //Add days on to todays date
    cal.set(Calendar.DAY_OF_MONTH, currentDay+2);
    cal.getTime(); //Result

    //format back to string
    String formattedDate = new SimpleDateFormat("dd-MM-yyyy HH:mm").format(cal.getTime());


  //get todays date
    Calendar cal1=Calendar.getInstance();
    int currentDay1=cal1.get(Calendar.DAY_OF_MONTH);

    //Atodays date
    cal1.set(Calendar.DAY_OF_MONTH, currentDay1);
    cal1.getTime(); //Result

    //format back to string
    String formattedDate1 = new SimpleDateFormat("dd-MM-yyyy HH:mm").format(cal1.getTime());


    //body = date added, needs to be changed
    return mDb.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,
            KEY_BODY, KEY_EXTRA, KEY_DUE }, KEY_DUE + " BETWEEN 'formattedDate1' and 'formattedDate2'", null, null, null, null);
}

这是为“截止日期”输入日期的代码:

                //convert string to int.
            int myNum = Integer.parseInt(editbox3.getText().toString());

            //get todays date
            Calendar cal=Calendar.getInstance();
            int currentDay=cal.get(Calendar.DAY_OF_MONTH);

            //Add days on to todays date
            cal.set(Calendar.DAY_OF_MONTH, currentDay+myNum);
            cal.getTime(); //Result

            //formate back to string
            String formattedDate = new SimpleDateFormat("dd-MM-yyyy HH:mm").format(cal.getTime());


            bundle.putString(NotesDbAdapter.KEY_DUE,formattedDate
                    .toString());

日期都是字符串。谁能帮忙？

Answer 1

您的查询有误。您使用 formattedDate1 和 formattedDate2 但您的代码正在设置 formattedDate 和 formattedDate1，更不用说这些非常重要的事实不会进入您的查询，因为您没有通过它。它应该是这样的:

String where = KEY_DUE + " BETWEEN ? AND ?";
String[] args = { String.valueOf(formattedDate1), String.valueOf(formattedDate2) };
return mDb.query(DATABASE_TABLE, where, args, null, null, null, null);