Mike Ginsburg <mginsburg@xxxxxxxxxxxxxxxxxxxxxxx> writes:
> There is probably a really simple solution for this problem, but for
> the life of me I can't see to think of it. I have three tables
>
> --contains u/p for all users in the site
> TABLE users (user_id INT primary key, username VARCHAR(50), password TEXT)
> --list of all possible events (login, logout, timeout)
> TABLE events (event_id INT primary key, event VARCHAR(255))
> --logs the activity of all users logging in/out, etc
> TABLE log (log_id INT primary key, user_id INT REFERENCES users,
> event_id INT REFERENCES event);
>
> How would I query to find out which user has the most activity?
> SELECT user_id, COUNT(event_id)
> FROM log
> GROUP BY (user_id)
> HAVNG COUNT(event_id) = ???
SELECT user_id, max(count(event_id))
FROM log
GROUP BY user_id;
or
SELECT user_id, count(event_id)
FROM log
GROUP BY user_id
ORDER BY count(event_id) DESC
LIMIT 1;
Regards.
P.S. It'd be better if you can send such questions to pgsql-sql mailing
list.
