List view with rawquery Could not execute method

I have a little issue that I don't know how to address. I have a Cursor that gets data from my data base it looks like this:

public Cursor getAllData(){
    int id;
    SQLiteDatabase DB = this.getWritableDatabase();
    String dateTime = Helper.getCurrentDate();
    String date = dateTime.substring(0, 10);
    String date_to_look = date.substring(0, 10);
    String sql = "SELECT h.product_id, h.qty, h.date_time, p.product " +
            " FROM product_history h " +
            " LEFT JOIN products p ON (p.rowid = h.product_id) ";
    Cursor res = DB.rawQuery(sql, null);
    return res;
}

Then on my activity I'm using the following method:

public void populateListView() {
      Cursor cursordata = myDb.getAllData();
      String productname = cursordata.getString(cursordata.getColumnIndex("product"));
       String [] products = {productname};    
       ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, products);
       ListView listviewman = (ListView)findViewById(R.id.listviewman);
       listviewman.setAdapter(adapter);

       }

Execute it with onclick:

public void shine(View v){
    Button shine = (Button)findViewById(R.id.shine);
    populateListView();
}

What am I doing wrong?