Android cursor columns

Is is safe to assume that Android cursor only has the columns I requested and returns them in the same order as they are in the select statement, i. e. will the following code always work?

Cursor cursor = db.query("NAMES",
    new String[] {"FIRSTNAME", "LASTNAME", "MOBILE"},
    "ID = " + requestedId, null, null, null, null, null);

if (cursor.moveToFirst()) {
    firstname = cursor.getString(0);
    lastname = cursor.getString(1);
    mobile = cursor.getString(2);
}

or should I stick to getting column indices explicitly like below because Android SQLite may add some auxiliary data in the cursor returned by query() or change the order of the columns?

firstname = cursor.getString(cursor.getColumnIndex("FIRSTNAME"));
lastname = cursor.getString(cursor.getColumnIndex("LASTNAME"));
mobile = cursor.getString(cursor.getColumnIndex("MOBILE"));