ALTER TABLE `im_conference` CHANGE `rid` `rid` CHAR(40) NOT NULL DEFAULT ''; ALTER TABLE `im_conferenceaction` CHANGE `rid` `rid` CHAR(40) NOT NULL DEFAULT ''; ALTER TABLE `im_conferenceaction` CHANGE `type` `type` enum('create','invite','join','leave','close','publish') NOT NULL DEFAULT 'create'; ALTER TABLE `im_conferenceaction` ADD `data` text NOT NULL DEFAULT '' AFTER `type`;