Question

I have the following MySQL query:

SELECT SUM(IF(num_content>3,3,num_content)) 
FROM
(
SELECT DATE(FROM_UNIXTIME(content_timestamp)) as dt, COUNT(id) as num_content
FROM content     
WHERE author = 'newbtophp'
GROUP BY DATE(FROM_UNIXTIME(content_timestamp))
)a

Which returns the a count of content (from a specific content author) but with the following restriction => it will only consider a maximum of 3 rows of data per day (using the content_timestamp).

It is working fine, however now I’m wanting to return all ids (do a query then a while loop with mysql_fetch_assoc) which fall under that restriction, I’ve tried the following query:

SELECT id 
FROM
(
SELECT DATE(FROM_UNIXTIME(content_timestamp)) as dt, COUNT(id) as num_content, id      FROM content     
WHERE author = 'newbtophp'
GROUP BY DATE(FROM_UNIXTIME(content_timestamp))
)a

But no luck (as its not returning the ids with the restriction).

The main issue for me is I’m not sure how to integrate the restriction whilst returning the ids.

I appreciate all responses.

Answer 1

There certainly must exist a more efficient solution (JOIN), but the following is readable:

SELECT id, content_timestamp
FROM content c
WHERE author = 'newbtophp'
AND (SELECT COUNT(*)
     FROM content
     WHERE DATE(FROM_UNIXTIME(content_timestamp)) = DATE(FROM_UNIXTIME(c.content_timestamp))
     AND content_timestamp < c.content_timestamp
    ) < 3
ORDER BY content_timestamp