CREATE TABLE `t_messages` (
  `id` bigint(20) NOT NULL COMMENT '主键ID',
  `version` int(11) DEFAULT '0' COMMENT '乐观锁版本',
  `create_user` bigint(20) DEFAULT NULL COMMENT '创建者',
  `create_time` datetime DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `update_user` bigint(20) DEFAULT NULL COMMENT '更新者',
  `update_time` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
  `remark` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '备注',
  `sender_id` bigint(20) NOT NULL COMMENT '发送者ID（系统消息为0）',
  `receiver_id` bigint(20) NOT NULL COMMENT '接收者ID',
  `content` text COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '消息内容',
  `content_format` varchar(20) COLLATE utf8mb4_unicode_ci DEFAULT 'PLAIN' COMMENT '内容格式',
  `type` varchar(50) COLLATE utf8mb4_unicode_ci NOT NULL COMMENT '消息类型',
  `notify_popup` tinyint(4) DEFAULT '0' COMMENT '是否弹窗',
  `notify_subscribe` tinyint(4) DEFAULT '0' COMMENT '是否订阅推送',
  `status` tinyint(4) DEFAULT '0' COMMENT '状态（0未读1已读2已删除）',
  `read_time` datetime DEFAULT NULL COMMENT '阅读时间',
  `is_deleted` tinyint(4) DEFAULT '0' COMMENT '软删除标志',
  PRIMARY KEY (`id`),
  KEY `idx_sender_id` (`sender_id`),
  KEY `idx_receiver_id` (`receiver_id`),
  KEY `idx_status` (`status`),
  KEY `idx_type` (`type`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='站内消息表';