Question

I have the following query to MySQL database:

SELECT inboxes.*
   , count(inboxes.conv) AS times
   , max(created_at) AS created_at
FROM `inboxes`
WHERE to_user = 2
   OR account_id = 2
GROUP BY conv
ORDER BY id DESC

This query works on my localhost, but if I deploy it to Heroku, I’ll get this error:

PGError: ERROR:  column "inboxes.id" must appear in the GROUP BY clause or
                 be used in an aggregate function

Answer 1

You need to specify all fields in GROUP BY, which you wanna select, ie:

SELECT inboxes.id, count(inboxes.conv) AS times, max(created_at) as created_at FROMinboxesWHERE (to_user = 2 OR account_id = 2) GROUP BY inboxes.id, conv ORDER BY inboxes.id DESC