Question

I have below query running on my users and chats table to join and I’m trying to group by on my chats table for user_id OR receiver_id not just user_id like you can see below in SQL query inside INNER JOIN.

SELECT c.*, users.username, users.firstname, users.lastname 
FROM chats c 
INNER JOIN( SELECT MAX(created) AS Date, user_id, receiver_id, chat, type, id 
FROM chats 
WHERE receiver_id = 286 OR user_id = 286 
GROUP BY user_id ) cc ON cc.Date = c.created AND cc.user_id = c.user_id 
LEFT JOIN users ON users.id = c.user_id 
WHERE c.receiver_id = 286 OR c.user_id = 286

I tried GROUP BY user_id OR receiver_id but I can’t seem to get information for id 286 for either receiver_id or user_id.

Is there a way we can achieve it and group by so that we can look into both columns and come up with results from both?

Do I need to do two queries and join them together instead?

Answer 1

If you are looking for most recent chat record, why don’t you just sort the results by created and get the first row like this:

SELECT c.*, users.username, users.firstname, users.lastname 
FROM chats c, users u
WHERE (c.receiver_id = 286 OR c.user_id = 286) AND
      u.id = c.user_id 
ORDER BY created DESC
LIMIT 1