Question

How can I count how many unique addresses have been on my site each day?
My table looks like this:

Row names: id, name, entity, ip_address, date

1,”Baldur”,”EntityA”,”85.221.18.251″,”2012-01-09 17:32:52″
2,”Baldur”,”EntityB”,”85.221.18.251″,”2012-01-09 17:32:57″
3,”Baldur”,”EntityB”,”85.221.18.252″,”2012-01-09 17:33:01″
4,”Baldur”,”EntityA”,”85.221.18.253″,”2012-01-10 17:33:12″
5,”Mango”,”EntityA”,”85.221.18.257″,”2012-01-10 17:32:52″
6,”Baldur”,”EntityB”,”85.221.18.251″,”2012-01-10 17:32:57″
7,”Mango”,”EntityB”,”85.221.18.253″,”2012-01-11 17:33:01″
8,”Mango”,”EntityA”,”85.221.18.251″,”2012-01-11 17:33:12″
9,”Mango”,”EntityA”,”85.221.18.253″,”2012-01-11 17:32:52″
10,”Baldur”,”EntityB”,”85.221.18.255″,”2012-01-11 17:32:57″
11,”Mango”,”EntityB”,”85.221.18.254″,”2012-01-11 17:33:01″
12,”Mango”,”EntityA”,”85.221.18.251″,”2012-01-12 17:33:12″

I’m thinking something along these lines:

SELECT date, COUNT(ip)
FROM mytable
GROUP BY date

This only gives me rows with count of one.

Answer 1

You are not grouping by a date (meaning one entry per day), but on the actual timestamp, which in your case comes down to a second. You have to apply the date function to extract the actual date from it.

On the other hand add the DISTINCT keyword to actually count different ips and ignore duplicate entries.

SELECT DATE( `date` ), COUNT( DISTINCT ip_address )
  FROM mytable
  GROUP BY DATE( `date` )