public function fieldType($result_object,$index,$which_connection='')
    {
        if ($which_connection == '') {
            $which_connection = $this->default_db;
        }
        $fld = $result_object->FetchField($index);
        // mysqli puts a integer constant in the type property
        // ADOdb provides MetaType to convert to relative type
        $dbtype = $this->connectionType($which_connection);
        if (strtolower($dbtype) === 'mysqli') {
            $meta = $this->connections[$which_connection]->MetaType($fld->type);
            switch ($meta) {
                case 'C':
                case 'X':
                    $fld->type = 'varchar';
                    break;
                case 'B':
                case 'X':
                    $fld->type= 'blob';
                    break;
                case 'D':
                case 'T':
                    $fld->type= 'datetime';
                    break;
                case 'R':
                case 'I':
                    $fld->type= 'int';
                    break;
                case 'N':
                    $fld->type= 'numeric';
                    break;
            }
        }

        return $fld->type;
    }