Question

I cannot figure out why this is not working. Basically, I am running a subquery to count all rows of p.songid WHERE trackDeleted=0. The subquery works fine when I execute it by itself, but when I implement I get “subquery returned more than 1 row”.

SELECT u.username, u.id, u.score, s.genre, s.songid, s.songTitle, s.timeSubmitted, s.userid, s.insWanted, s.bounty,
(SELECT COUNT(p.songid)
 FROM  songs s
 LEFT JOIN users u
 ON u.id = s.userid
 LEFT JOIN posttracks p
 ON s.songid = p.songid
WHERE p.trackDeleted=0
 GROUP BY s.timeSubmitted ASC
 LIMIT 25)
AS trackCount
 FROM  songs s
 LEFT JOIN users u
 ON u.id = s.userid
 LEFT JOIN posttracks p
 ON s.songid = p.songid
WHERE paid=1 AND s.timeSubmitted >= ( CURDATE() - INTERVAL 60 DAY )
 GROUP BY s.timeSubmitted ASC
 LIMIT 25

Answer 1

Obviously, a sub-query can’t return more than one row, as this makes no sense. You only expect one value to be returned – COUNT(p.songid) – yet you GROUP BY s.timeSubmitted, which will make it return multiple rows, and multiple counts of p.songid.