Question

Here’s my SQL (MySQL) command:

SELECT pp.pluginid
FROM plugins pp
WHERE 
    (pp.limit=-1)
    OR
    (pp.limit>(select count(a.pluginid) from ads a where a.pluginid = pp.pluginid))
ORDER BY count(a.pluginid)

The last line (order by) doesn’t work, and I understand why (because I don’t output this value from a subquery). But I don’t know how, and don’t know what command to look for.

Fixed!!!
Here’s what I did:

SELECT pp.pluginid, (select count(a.pluginid) from ads a where a.pluginid = pp.pluginid) as bb
FROM plugins pp
WHERE 
    (pp.limit=-1)
    OR
    (pp.limit>(select count(a.pluginid) from ads a where a.pluginid = pp.pluginid))
ORDER BY bb

Thanks!

Answer 1

Try using a join and a group by, like this:

SELECT pp.pluginid,pp.limit
FROM plugins pp
LEFT OUTER JOIN ads a ON a.pluginid = pp.pluginid
GROUP BY pp.pluginid
HAVING pp.limit=-1 OR pp.limit > COUNT(1)
ORDER BY COUNT(1)

Note that you need to use HAVING in place of WHERE because the condition uses an aggregation.

Here is a link to a demo on sqlfiddle.