ALTER TABLE `fa_fastim_message`
    MODIFY COLUMN `type`  enum('kbs_list','friend_apply','group_invitation','group_notice','group_apply','system','link','file','video','audio','image','default','position') CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT 'default' COMMENT '消息类型:default=普通,image=图片,audio=音频,video=视频,file=文件,link=链接,system=系统,group_apply=申请入群,group_notice=群通知,group_invitation=邀请入群,friend_apply=好友申请,kbs_list=知识库消息,position=位置消息' AFTER `id`;

