当我使用mysql进行子查询时，我在where子句中得到未知列“tv.last\u time”，我该怎么办？在执行子查询时，我想使用外部条件来过滤不符合要求的记录

SELECT
    info_topic.*, b.newMessage
FROM
    info_topic
LEFT JOIN `info_topic_visit` AS tv ON tv.topic_id = info_topic.id
AND tv.user_id = 225
LEFT JOIN (
    SELECT
        p.topic_id,
        count(*) AS newMessage
    FROM
        info_post p
    WHERE
        p.create_time > tv.last_time
    GROUP BY
        p.topic_id
) AS b ON b.topic_id = info_topic.id
ORDER BY b.newMessage DESC

数据库架构：

CREATE TABLE `info_topic` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT '' COMMENT 'topic name',
  `summary` varchar(500) COLLATE utf8mb4_unicode_ci DEFAULT '' COMMENT 'summary`',
  `create_time` datetime DEFAULT NULL COMMENT '',
  `sort` int(11) DEFAULT '0' COMMENT '',
  PRIMARY KEY (`id`),
);

CREATE TABLE `info_topic_visit` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `topic_id` int(11) DEFAULT '0' COMMENT '',
  `user_id` int(11) DEFAULT '0' COMMENT '',
  `last_time` datetime DEFAULT NULL COMMENT '',
  PRIMARY KEY (`id`)
);