text: SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
  SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
  SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';
  
  ALTER TABLE `subscribes` 
  ADD COLUMN `subscriber_users_id` INT(11) NOT NULL AFTER `notify`,
  ADD INDEX `fk_subscribes_users2_idx` (`subscriber_users_id` ASC);
  
  ALTER TABLE `subscribes` 
  ADD CONSTRAINT `fk_subscribes_users2`
    FOREIGN KEY (`subscriber_users_id`)
    REFERENCES `users` (`id`)
    ON DELETE CASCADE
    ON UPDATE CASCADE;
  
  ALTER TABLE `videos_statistics` 
  ADD INDEX `when_statisci` (`when` ASC);
  
  ALTER TABLE `videos_statistics` 
  ADD COLUMN `session_id` VARCHAR(45) NOT NULL AFTER `videos_id`,
  ADD INDEX `session_id_statistics` (`session_id` ASC);
  
  UPDATE configurations SET  version = '6.7', modified = now() WHERE id = 1;
  
  SET SQL_MODE=@OLD_SQL_MODE;
  SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
  SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;
  