Question

When visitor votes, I store information answer_id, ip, etc.

My website visitors vote in multiple polls.

I want to know visitors who vote for example ( answer_id (767) ) on what else they vote for. Based on ip. lets say answer_id=767

Table: poll_stat

`id` int(11) NOT NULL auto_increment,
`question_id` int(11) NOT NULL,
`answer_id` int(11) NOT NULL,
`ip` varchar(255) NOT NULL,
`date` date NOT NULL,
`country` text NOT NULL,
`time` int(11) NOT NULL,
`age` int(11) NOT NULL,

Answer 1

I think this will work for you.

select ip, question_id
from poll_stat
where ip in (select ip from poll_stat where answer_id = 767 group by ip)
and answer_id <> 767

edit

Hmm…you might check that there is an INDEX created on the ip column. If that isn’t it, perhaps it doesn’t like the IN clause. I will rewrite as a join:

select ip, question_id
from poll_stat ps1
inner join (select ip from poll_stat where answer_id = 767 group by ip) ps2
on ps1.ip = ps2.ip
where answer_id <> 767