Question

I may be a bit rusty on my SQL syntax, so it’s nearly impossible for me to figure this out on my own. I have a typical MySQL installation with the following table, “history”.

userid        ip
----------- ----------
1            123.123.123.123  
1            123.123.123.123    
1            111.111.111.111    
2            213.213.213.213
2            214.214.214.214
2            215.215.215.215
3            163.123.121.123
4            111.222.121.212

Essentially, I am logging certain things under a certain user ID and what IP address they currently use (along with other things, but that’s not needed). However, my final task I want to achieve is to create a listing for every user with how many IPs have been used. The final result in this case would be.

userid       ipcount
-----------  ----------  
1            2  
2            3
3            1
4            1

I know this would be possible somehow, but I am quite the novice at SQL (I was able to get the count, but not to group it down by the userid). I could do this in PHP in a snatch, but that’s extra overload for the server (I have about 5K entries at the moment). SQL was made exactly to do this…

Thanks guys. 🙂

Answer 1

SELECT userid, COUNT(DISTINCT ip) AS ipcount
  FROM yourtable
 GROUP BY userid