Building SQL query on a one-to-many [closed]

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I have these tables:

threads:

+---------+--------------+
|thread_id|recent_post_id|
+---------+--------------+

posts:

+-------+---------+-------+
|post_id|thread_id|message|
+-------+---------+-------+

And I need to get something like:

+--------+--------------+----------------------------------------------------------+
|tread_id|recent_post_id|(array of posts WHERE posts.thread_id = threads.thread_id)|
+--------+--------------+----------------------------------------------------------+

Please, help me.

Answer 1

You can use GROUP_CONCAT() to list column content for a group.

select t.tread_id, t.recent_post_id, group_concat(message) as messages
from threads t
left join posts p on p.thread_id = t.thread_id
group by t.tread_id, t.recent_post_id