Trying to use ID in MySQL SubSubQuery - mysql

Question

So I'll show you what I'm trying to do and explain my problem, there may be an answer different to the approach I'm trying to take.
The query I'm trying to perform is as follows:
SELECT *
FROM report_keywords rk
WHERE rk.report_id = 231
AND (
SELECT SUM(t.conv) FROM (
SELECT conv FROM report_keywords t2 WHERE t2.campaign_id = rk.campaign_id ORDER BY conv DESC LIMIT 10
) t
) >= 30
GROUP BY rk.campaign_id
The error I get is
Unknown column 'rk.campaign_id' in 'where clause'
Obviously this is saying that the table alias rk is not making it to the subsubquery. What I'm trying to do is get all of the campaigns where the sum of the top 10 conversions is greater than or equal to 30.
The relevant table structure is:
id INT,
report_id INT,
campaign_id INT,
conv INT
Any help would be greatly appreciated.
Update
Thanks to Kickstart I was able to do what I wanted. Here's my final query:
SELECT campaign_id, SUM(conv) as sum_conv
FROM (
SELECT campaign_id, conv, #Sequence := if(campaign_id = #campaign_id, #Sequence + 1, 1) AS aSequence, #campaign_id := campaign_id
FROM report_keywords
CROSS JOIN (SELECT #Sequence := 0, #campaign_id := 0) Sub1
WHERE report_id = 231
ORDER BY campaign_id, conv DESC
) t
WHERE aSequence <= 10
GROUP BY campaign_id
HAVING sum_conv >= 30

Answer 1

Possibly use a user variable to add a sequence number to get the latest 10 records for each one, then use SUM to get the count of those.
Something like this:-
SELECT rk.*
FROM report_keywords rk
INNER JOIN
(
SELECT campaign_id, SUM(conv) AS SumConv
FROM
(
SELECT campaign_id, conv, #Sequence := if(campaign_id = #campaign_id, #Sequence + 1, 1) AS aSequence, #campaign_id := campaign_id
FROM report_keywords
CROSS JOIN (SELECT #Sequence := 0, #campaign_id := "") Sub1
ORDER BY campaign_id, conv
) Sub2
WHERE aSequence <= 10
GROUP BY campaign_id
) Sub3
ON rk.campaign_id = Sub3.campaign_id AND Sub3.SumConv >= 30
WHERE rk.report_id = 231