select
section_name, topic.topic_id, topic_name, landing_url, topic_content.url
from topic
left join
topic_content on topic_content.topic_id = topic.id
left join section on topic.section_guid = section.section_guid
left join forum on section.forum_guid = forum.forum_guid
where topic.id in (
select id from topic where topic.section_guid in (
select section_guid from section
where forum_guid in ('423h54bb3bf3b42')));