Grid does not work

public void init()
{
    super();
     // headerSelection = MultiSelectionHelper::construct();


    queryDs = PurchTable_ds.query().dataSourceNo(1);
    queryDs2 = PurchLine_ds.query().dataSourceNo(1);



}

void zakupy() // SalesLine datasource
{

   InventTable InventMark;
   PurchLine items;
   queryDs.clearRanges();


     if (InventTable_ds.mark())

        {
        InventMark = InventTable_ds.getFirst(1,false);


            while select * from items
            where items.ItemId == InventMark.ItemId
            {

            queryDs.addRange(fieldnum(PurchTable,PurchId)).value(queryValue(items.PurchId));

            info(items.PurchId);

            }
        }




}

I have two grids. one with datasource InventTable, secont with dataSource PurchTable. Why it does't show me in second grid expected values.