Question

is it possible to populate a listview based on a row Id from a custom cursor adapter. I keep getting an error “illegalArguementException column: _id does not exist”. but the database has it and is already being used correctly. I don’t know what to do, because I would need to populate different listviews from the same database and i don’t want to have to create multiple database which will still have the same column names. Any ideas will be greatly appreciated. thanks

HERE is the database code is being cold:

public Cursor retrieveItemRow(long Id){
        open();
String[] Columns = new String[] {TITLE,DATE, TIME};
Cursor row = db.query(true,DATABASE_TABLE, Columns, KEY_ID +"=" +Id, null, null, null, null,null);
    if(row != null){
    row.moveToNext();
    return row;
    }
    return row;
      }

Here is a method i am trying to call it in:

 public void fillRowData(long Id) {

Cursor cursor = adapter.retrieveRow(id);
startManagingCursor(cursor);
String[] from = new String[]{DBAdapter.TITLE, DBAdapter.DATE, DBAdapter.TIME};
int[] to = new int[]{R.id.Name, R.id.Date, R.id.Time};

customCursor items = new customCursor(this, R.layout.viewlist, cursor, from, to);
setListAdapter(items);          

}

Answer 1

Make sure you include _id in the SELECT statement represented by the Cursor you pass into your adapter. For example, if I were using the SimpleCursorAdapter(Context context, int layout, Cursor c, String[] from, int[] to), my Cursor c would originate with something like “SELECT _id, name FROM users;”.

From the Notepad Tutorial:

private void fillData() {
     // Get all of the notes from the database and create the item list
     Cursor c = mDbHelper.fetchAllNotes();
     startManagingCursor(c);

     String[] from = new String[] { NotesDbAdapter.KEY_TITLE };
     int[] to = new int[] { R.id.text1 };

     // Now create an array adapter and set it to display using our row
     SimpleCursorAdapter notes =
          new SimpleCursorAdapter(this, R.layout.notes_row, c, from, to);
     setListAdapter(notes);
}

The tutorial defines a method in the database helper class that returns all of the Note objects. Essentially they’re using SQLiteDatabase‘s query method that returns a Cursor object. The query’s select string is where you should include the _id column.

So in your case, you need to add KEY_ID to your Columns String array variable, because those are the columns that are included in your select statement (db.query()). This is also hinted at in the CursorAdapter documentation:

The Cursor must include a column named
“_id” or this class will not work.