Re: Most Occurring Value
От | Colin Wetherbee |
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Тема | Re: Most Occurring Value |
Дата | |
Msg-id | 47FAC57F.8020904@denterprises.org обсуждение исходный текст |
Ответ на | Most Occurring Value (Mike Ginsburg <mginsburg@collaborativefusion.com>) |
Список | pgsql-general |
Mike Ginsburg wrote: > 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) = ??? > > Any and all help is appreciated. Thank you. I'd say... SELECT user_id, count(event_id) AS event_count FROM log GROUP BY user_id ORDER BY event_count DESC LIMIT 1; Or something to that effect. Colin
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