[lev]

Вот пример:

...

    if (!newItem)
        newItem = tree.getItem(tree.getSelection());

    oldIdx  = oldItem.idx();
    newIdx  = newItem.idx();

    selectedData = newItem.data();
    qbds = formDataSource.query().dataSourceTable(tableNum(MyTable));

    if (selectedData)
    {
        qbds.addRange(fieldNum(MyTable, MyField)).value(QueryValue(selectedData));
    }

    formDataSource.executeQuery();

    formDataSource.refresh();
    formDataSource.active();