MySQL Stored Procedure Column Name Join Syntax - mysql

Question

I'm getting all kinds of errors with this stored procedure, from undefined column names to ambiguous field names.
What I'm trying to do is select each subscriber ID where action, share, test, viral, and total are at the highest value. The subscriberID can will be different for each highest value, so you might be returning up to 5 subscriberIDs. Maybe my logic is off here, but below is my code(Please note this is just for the 'action' column):
SELECT `set1.subscriber_id`, `set1.action`, `set1.share`, `set1.test`, `set1.viral`, ( `set1.action` + `set1.share` + `set1.test` + `set1.viral` ) AS "total", `abuse_flag`
FROM `subscribers_points` set1
JOIN
(
SELECT `subscriber_id`, MAX(`action`) AS actionMax
FROM `subscribers_points`
WHERE `year` = _year
AND `month` = _month
GROUP BY `subscriber_id`
) groupedAction
ON set1.subscriber_id=groupedAction.subscriber_id
WHERE `year` = _year
AND `month` = _month;
^ This resulted in 'Unknown column 'set1.subscriber_id' in 'field list'
This looks correct to me. I don't know what's causing the error.

Answer 1

try this ... without most of the backticks ... you only need the backticks to escape reserved words, etc.
SELECT set1.subscriber_id, set1.action, set1.share, set1.test, set1.viral,
( set1.action + set1.share + set1.test + set1.viral ) AS "total", abuse_flag
FROM subscribers_points set1
JOIN (
SELECT subscriber_id, MAX(`action`) AS actionMax
FROM subscribers_points
WHERE year = _year
AND month = _month
GROUP BY subscriber_id
) as groupedAction
ON set1.subscriber_id=groupedAction.subscriber_id
WHERE year = _year
AND month = _month;

Answer 2

Use 'as' before groupedAction.
SELECT `set1.subscriber_id`, `set1.action`, `set1.share`, `set1.test`, `set1.viral`, ( `set1.action` + `set1.share` + `set1.test` + `set1.viral` ) AS "total", `abuse_flag`
FROM `subscribers_points` set1
JOIN
(
SELECT `subscriber_id`, MAX(`action`) AS actionMax
FROM `subscribers_points`
WHERE `year` = _year
AND `month` = _month
GROUP BY `subscriber_id`
) as groupedAction
ON set1.subscriber_id=groupedAction.subscriber_id
WHERE `year` = _year
AND `month` = _month;