Android - load values from sqlite database to an arraylist

Question

I am new to android . I have an application working with SQLite DB. I need to push values from database to an arraylist of type object. The code i used is given here.

Answer 1

try this:

private ArrayList<objectname> objectList  = getResults();

private ArrayList<objectname> getResults() {

    MyDb db = new MyDb(this); //my database helper file
    db.open(); 

    ArrayList<objectname> resultList = new ArrayList<objectname>();


    Cursor c = db.getAllValues(); //function to retrieve all values from a table- written in MyDb.java file
    while (c.moveToNext())
    {
        String date = c.getString(c.getColumnIndex("date"));

        try
        {
            ob = new objectname();
            ob.setDate(date);// setDate function is written in Class file
            resultList.add(ob);
        }
        catch (Exception e) {
            Log.e(MY_DEBUG_TAG, "Error " + e.toString());
        }

    }

    c.close();

    db.close();
    return resultList;
}

Answer 2

Probably your query is drawing a blank and moveToFirst is returning false.

What about logging the value of c.getCount() before your if statement?

Answer 3

I had a similar issue with retrieving values from the db using cursors and displaying on screen.. The below solution works for me..

            Cursor cur = db.getAllValues();
            int index = c.getColumnIndex("date");
    cur.moveToFirst();

    while (cur.isAfterLast() == false) {
        System.out.println(cur.getString(index)); // For debug purposes
        String date = cur.getString(index);
        try {
            ob = new objectname();
            ob.setDate(date);
            resultList.add(ob);
        } catch (Exception e) {
            Log.e(MY_DEBUG_TAG, "Error " + e.toString());
        }
        cur.moveToNext();
    }
    cur.close();