public function displayHtmlTable($aColList = [])
    {
        $r = '';
        if (count($aColList) > 0) {
            $r .= '<table border="1">';
            $r .= '<thead>';
            $r .= '<tr>';
            foreach ($aColList[0] as $k => $v) {
                $r .= '<td>' . $k . '</td>';
            }
            $r .= '</tr>';
            $r .= '</thead>';
            $r .= '<tbody>';
            foreach ($aColList as $record) {
                $r .= '<tr>';
                foreach ($record as $data) {
                    $r .= '<td>' . $data . '</td>';
                }
                $r .= '</tr>';
            }
            $r .= '</tbody>';
            $r .= '<table>';
        } else {
            $r .= '<div class="no-results">No results found for query.</div>';
        }

        return $r;
    }