Question

Can anyone tell me why I’m getting Invalid use of group function and how to stop it?

SELECT Name, Message
FROM flux_chat_messages
WHERE id >= ( MAX( id ) -5 )
ORDER BY id ASC

Answer 1

You cannot use MAX() in a WHERE. So wrap it in a subquery like:

SELECT Name, Message
FROM flux_chat_messages
WHERE id >= (SELECT MAX( id ) - 5 FROM flux_chat_messages)
ORDER BY id ASC

Also probably you could have

SELECT Name, Message
FROM flux_chat_messages
ORDER BY id DESC
LIMIT 5

and reverse the results in your program (or use another subquery for that)