AX query with group, sum statment

hi,

 I would like get from DB:

itemId, ItemName, sum(availPhysical)

I wrote below query but I can't get data from inventTable.Record is empty? Why?

    Query                                  query;
    QueryRun                           queryRun;
    QueryBuildDataSource    qbdsIT, qbdsIM, qbdsIS;
    InventTable                         inventTable;
    InventSum                          inventSum;
    ;

    query = new Query();

    qbdsIT = query.addDataSource(tablenum(inventTable));
    qbdsIT.addRange(fieldnum(InventTable, ItemGroupId)).value("01");

    qbdsIS = qbdsIT.addDataSource(tablenum(InventSum));
    qbdsIS.addSelectionField(fieldNum(InventSum, AvailPhysical), SelectionField::Sum);
    qbdsIS.addGroupByField(fieldnum(InventSum, ItemId));
    qbdsIS.relations(true);
    qbdsIS.joinMode(JoinMode::InnerJoin);

   queryRun = new QueryRun(query);

    while (queryRun.next())
    {
        inventSum = queryRun.get(tablenum(InventSum));
        inventTable = queryRun.get(tablenum(InventTable));

        info(strfmt("Indeks %1, ilosc %2", inventTable.ItemId, inventSum.AvailPhysical));
    }