MySQL计算具有不同IP地址的用户代理

Question

I built an app that records user events. Each event contains the user's IP address and their useragent (and other data like a timestamp and other stuff that is not relevant here).

I would like to use a single query to get (in one row) the total number of events, the number of distinct IP addresses, and the number of iPad users (number of distinct IP/useragent combinations where ugeragent contains "iPad").

Sample table: EVENTS

id    ip         useragent
=================================
1    "x1"    "blabla iPad blabla"
2    "x2"    "blabla"
3    "x3"    "blabla iPad blabla"
4    "x3"    "blabla iPad blabla"
5    "x3"    "blabla iPad blabla"

Result expected

event_count    ip_count    ipad_users
=======================================
    5             3            2

---

My attempts

The following query returns 4 iPad users because it does not check IP+useragent.

SELECT
    COUNT(*) as event_count,
    COUNT(DISTINCT ip) as ip_count,
    COUNT(IF( useragent LIKE '%iPad%', 1, NULL )) as ipad_users
FROM events

This one only returns 1 iPad user because I'm doing it wrong.

SELECT
    COUNT(*) as event_count,
    COUNT(DISTINCT ip) as ip_count,
    COUNT(DISTINCT ip AND IF( useragent LIKE '%iPad%', 1, NULL )) as ipad_users
FROM events

How can I do this? The closest related question I could find on SO was this one , but I cannot figure it out.

SQL Fiddle

This set of data should return 3 iPad users.

Answer 1

I think you just want a condition count(distinct) :

SELECT
    COUNT(*) as event_count,
    COUNT(DISTINCT ip) as ip_count,
    COUNT(DISTINCT (case when useragent LIKE '%iPad%' then ip end)) as ipad_users
FROM events;

That is, count the distinct number of ip s when the user agent is an iPad.