void PopulateBranch(CTreeCtrl& TreeCtrl, HTREEITEM hParent, int iParentId)
{
    _RecordsetPtr Recordset("ADODB.Recordset");
    CString sSql;
    HTREEITEM hChild;
    
    sSql.Format("SELECT имя FROM сотрудник WHERE ParentID = %d", iParentId);
    Recordset->Open(_bstr_t(sSql)...);

    while (!Recordset->ADOEOF) {
        hChild = TreeCtrl.InsertItem(_bstr_t(Recordset->Fields->Item[L"имя"]->Value, hParent);
        PopulateBranch(TreeCtrl, hChild, (int)Recordset->Fields->Item[L"имя"]->Value);
        Recordset->MoveNext();
    }

    Recordset->Close();
}