final public function queryArrayKey(string $query, string $keyField, string $keyPrefix = '')
    {
        $result = $this->queryResult($query);
        if (false === $result) {
            return false;
        }

        $return = [];
        while ($row = $result->fetchRow()) {
            if (! array_key_exists($keyField, $row)) {
                return false;
            }
            $return[$keyPrefix . $row[$keyField]] = $row;
        }
        return $return;
    }