I can't get data from Cursor Object

Question

I've following table structure in my SQLite Database. enter image description here

In my SqliteOpenHelper class, I wrote following method.

public Form getAllForms(){
   SQLiteDatabase db = this.getReadableDatabase();
   Cursor cursor = db.rawQuery("select * from "+FORM_TABLE, null);
   int count = cursor.getCount();
   String formID = cursor.getString(0);
   Form form = new Form();
   form.setId(formID);
   cursor.close();
   db.close();
   return form;
}

I'm sure there's some data in it because I already watched count in debugging mode and I saw the quantity of row that actually existing in database. But CursorIndexOutOfBoundException shows up at cursor.getString(0). plus cursor.getInt(0) and cursor.getString(1) didn't work also. What's the problem might be?

score 3 · Accepted Answer · answered Jun 12 '14 at 06:15

3

You need to move the cursor to a valid row.

Valid rows are indexed from 0 to count-1. At first the cursor will point to row index -1 i.e. the one just before the first row.

The canonical way of looping through all rows is

if (cursor.moveToFirst()) {
    do {
         // now access cursor columns
    } while (cursor.moveToNext());
}

answered Jun 12 '14 at 06:15

laalto

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`while (cursor.moveToNext()) { ... }` would be even simpler. – CL. Jun 12 '14 at 07:09
@CL. It assumes the cursor is at -1, which is a valid assumption here but not everywhere. – laalto Jun 12 '14 at 07:12
Yap.., I just forget to moveToFirst. Thank you so much laalto. – Zin Win Htet Jun 12 '14 at 07:34

Giru Bhai · Answer 2 · 2014-06-12T07:14:26.993

1

You need to call moveToFirst() to get to the first row before asking for values:

  if ((cursor!= null) && (cursor.getCount() > 0)) {
                cursor.moveToFirst();
                while (cursor.isAfterLast() == false) {
}

So Simply use your code as

public Form getAllForms(){
   Form form = new Form();
   SQLiteDatabase db = this.getReadableDatabase();
   Cursor cursor = db.rawQuery("select * from "+FORM_TABLE, null);
    if ((cursor != null) && (cursor.getCount() > 0)) {
              cursor.moveToFirst();
          while (cursor.isAfterLast() == false) {
              String formID = cursor.getString(0);
              form.setId(formID);
         cursor.moveToNext();
        } 
     cursor.close();
    }
   db.close();
   return form;
}

edited Jun 12 '14 at 07:14

answered Jun 12 '14 at 06:17

Giru Bhai

14,370
5
46
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The `null` check is not needed. The `while` loop will never end. – CL. Jun 12 '14 at 07:06
@CL. it checks whether the cursor is after the last result and if false it will exists from loop – Giru Bhai Jun 12 '14 at 07:09
But the cursor is never moved after the last row. – CL. Jun 12 '14 at 07:11
@CL yes then it will return false and exists from loop. – Giru Bhai Jun 12 '14 at 07:11
Yap.. I need to put moveToFirst(). Thank you so much all...! – Zin Win Htet Jun 12 '14 at 07:40

score 1 · Answer 3 · answered Jun 12 '14 at 06:25

Try this

       try {
        cursor.moveToFirst();

        for (int i = 0; i < cursor.getCount(); i++) {

            Form form = new Form();
                              form.setId(formID);

            cursor.moveToNext();
        }
                   } finally {
        // database.close();
        cursor.close();
        dbHelper.close();
    }

I can't get data from Cursor Object

3 Answers3