Shantanu's Blog

Corporate Consultant

October 23, 2005

 

Detecting IP range

I have a mysql table called "visitors" which lists all the hits to my website.

somedate user_name user_ip
2005-09-07 Blah-blah 202.21.23.21
2005-09-08 wah-wah 202.21.23.22
2005-09-09 Blah-blah 202.221.213.221
2005-09-09 nah-nah 202.21.23.21

In the table there is a column called "user_ip" which lists ip addresses in the usual format eg 202.21.23.21

I want to prevent a user from creating multiple identities so I need to find addresses which are coming from the same computer. If the user has a dynamic rather than static address then the last two figures will change, but the first two figures, eg 202.21 in the above example, should stay the same.

What query can I use to find out how many ip addresses in the list have the same first two figures?


I can use the wildcard %, say

SELECT * FROM visitors
WHERE user_ip LIKE '202.21.%'

somedate user_name user_ip
2005-09-07 Blah-blah 202.21.23.21
2005-09-08 wah-wah 202.21.23.22
2005-09-09 nah-nah 202.21.23.21


But I want to do this where I don't know what the first two figures are.

select substring_index(user_ip, '.', 2) pf, count(*)
from visitors group by pf

pf count(*)
202.21 3
202.221 1

I can just change the 2 to 3, or 4 if I want the whole (exact) ip.

select substring_index(user_ip, '.', 4) pf, count(*)
from visitors group by pf

pf count(*)
202.21.23.21 2
202.21.23.22 1
202.221.213.221 1

Once I have the user_ip, for e.g. I have found there are 2 instances of 202.21.23.21, how do I query the table to bring up user_id and user_name for that ip?

select i, substring_index(somefile, '.', i) pf, count(*), group_concat(distinct someblah)
from
(select (1) as i union select (2) union select (3) union select (4)) as n
join youneek
group by i, pf
order by i desc;


i pf count(*) group_concat(distinct user_name)
4 202.21.23.21 2 Blah-blah,nah-nah
4 202.21.23.22 1 wah-wah
4 202.221.213.221 1 Blah-blah
3 202.21.23 3 wah-wah,Blah-blah,nah-nah
3 202.221.213 1 Blah-blah
2 202.21 3 wah-wah,Blah-blah,nah-nah
2 202.221 1 Blah-blah
1 202 4 Blah-blah,nah-nah,wah-wah


Now adding the line after group by
having i > 2 and count(*) > 1
will pin point the person who is accessing the site using two (or three) different user names from the same IP or the IP range

select i, substring_index(user_ip, '.', i) pf, count(*), group_concat(distinct user_name)
from
(select (1) as i union select (2) union select (3) union select (4)) as n
join visitors
group by i, pf
having i > 2 and count(*) > 1
order by i desc

i pf count(*) group_concat(distinct user_name)
4 202.21.23.21 2 Blah-blah,nah-nah
3 202.21.23 3 nah-nah,wah-wah,Blah-blah

Comments: Post a Comment

<< Home

Archives

June 2001   July 2001   January 2003   May 2003   September 2003   October 2003   December 2003   January 2004   February 2004   March 2004   April 2004   May 2004   June 2004   July 2004   August 2004   September 2004   October 2004   November 2004   December 2004   January 2005   February 2005   March 2005   April 2005   May 2005   June 2005   July 2005   August 2005   September 2005   October 2005   November 2005   December 2005   January 2006   February 2006   March 2006   April 2006   May 2006   June 2006   July 2006   August 2006   September 2006   October 2006   November 2006   December 2006   January 2007   February 2007   March 2007   April 2007   June 2007   July 2007   August 2007   September 2007   October 2007   November 2007   December 2007   January 2008   February 2008   March 2008   April 2008   July 2008   August 2008   September 2008   October 2008   November 2008   December 2008   January 2009   February 2009   March 2009   April 2009   May 2009   June 2009   July 2009   August 2009   September 2009   October 2009   November 2009   December 2009   January 2010   February 2010   March 2010   April 2010   May 2010   June 2010   July 2010   August 2010   September 2010   October 2010   November 2010   December 2010   January 2011   February 2011   March 2011   April 2011   May 2011   June 2011   July 2011   August 2011   September 2011   October 2011   November 2011   December 2011   January 2012   February 2012   March 2012   April 2012   May 2012   June 2012   July 2012   August 2012   October 2012   November 2012   December 2012   January 2013   February 2013   March 2013   April 2013   May 2013   June 2013   July 2013   September 2013   October 2013   January 2014   March 2014   April 2014   May 2014   July 2014   August 2014   September 2014   October 2014   November 2014   December 2014   January 2015   February 2015   March 2015   April 2015   May 2015   June 2015   July 2015   August 2015   September 2015   January 2016   February 2016   March 2016   April 2016   May 2016   June 2016   July 2016   August 2016   September 2016   October 2016   November 2016   December 2016   January 2017   February 2017   April 2017   May 2017   June 2017   July 2017   August 2017   September 2017   October 2017  

This page is powered by Blogger. Isn't yours?