如何从Sqlite获取最后一条记录? [英] How to get Last record from Sqlite?

问题描述

我有一张桌子 question_table 和一个 ImageButton(返回).单击返回后，我需要从数据库中获取最后插入的记录.

I have a one table question_table and one ImageButton (Back). I need to get the last inserted record from the database after clicking on the Back.

我的行包含以下列:question、optionA、optionB、optionC、optionD，我需要在我的 Activity 上使用的数据.我在数据库中创建了一种方法，但它不起作用.

My row contains the following columns: question, optionA, optionB, optionC, optionD, and I need the data for use on my Activity. I create one method in database but it's not working.

这里是代码供参考:

MySQLiteHelper.java 摘录:

public List<ObjectiveWiseQuestion> getLastInsertQuestion()
{
    // long index = 0;
    List<ObjectiveWiseQuestion>LocwiseProfileList=new ArrayList<ObjectiveWiseQuestion>();
    db = getReadableDatabase();
    Cursor cursor = db.query(
            "sqlite_sequence",
            new String[]{"seq"},
            "name = ?",
            new String[]{TABLE_QUESTION},
            null,
            null,
            null,
            null );

    if (cursor.moveToFirst())
    {
        do {
            ObjectiveWiseQuestion owq= new ObjectiveWiseQuestion();

            owq.setQuestion(cursor.getString(2));
            owq.setOptionA(cursor.getString(3));
            owq.setOptionB(cursor.getString(4));
            owq.setOptionC(cursor.getString(5));
            owq.setOptionD(cursor.getString(6));
            owq.setCorrectOption(cursor.getString(7));
            LocwiseProfileList.add(owq);
        } while(cursor.moveToNext());

        db.close();
    }

    return LocwiseProfileList;
}

OnClickListner 来自 AddQuestionActivity.java

imgBack.setOnClickListener( new View.OnClickListener() 
{                       
    @Override
    public void onClick(View v) 
    {
        msg();
        emptyFormField();

        try {
            final List<ObjectiveWiseQuestion> LocWiseProfile =  db.getLastInsertQuestion();       

            for (final ObjectiveWiseQuestion cn : LocWiseProfile)
            {   
                db=new MySQLiteHelper(getBaseContext());
                db.getWritableDatabase();
                txtQuestion.setText(cn.getQuestion());
                txtOptionA.setText(cn.getOptionA());
                txtOptionB.setText(cn.getOptionB());
                txtOptionC.setText(cn.getOptionC());
                txtOptionD.setText(cn.getOptionD());
                txtCorrectOption.setText(cn.getCorrectOption());
                db.close();
            }
        } catch(Exception e) {
            e.printStackTrace();
        }           
    }
});

请给我一些提示.

推荐答案

试试这个:

SELECT * 
    FROM    TABLE
    WHERE   ID = (SELECT MAX(ID)  FROM TABLE);

或

您也可以使用以下解决方案:

you can also used following solution:

SELECT * FROM tablename ORDER BY column DESC LIMIT 1;

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