Granada\Orm\Wrapper::assoc_to_keyval PHP Method

    public static function assoc_to_keyval($assoc = null, $key_field = null, $val_field = null)
    {
        if (empty($assoc) or empty($key_field) or empty($val_field)) {
            return null;
        }
        $output = array();
        foreach ($assoc as $row) {
            if (isset($row[$key_field]) and isset($row[$val_field])) {
                $output[$row[$key_field]] = $row[$val_field];
            }
        }
        return $output;
    }