CREATE TABLE IF NOT EXISTS `message_for_users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `date_from` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `date_to` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `text` mediumtext NOT NULL,
  `gr` varchar(255) NOT NULL,
  `title` varchar(255) NOT NULL,
  `users` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
);

UPDATE `message_for_users` SET gr='';
ALTER TABLE `message_for_users` CHANGE COLUMN `gr` TO `role_ids`;