How to find all database rows with a time AFTER a specific time

Question

I have a "last_action" column in my users table that updates a unix timestamp every time a user takes an action. I want to select all users in my users table who have made an action on the site after a specific time (probably 15 minutes, the goal here is to make a ghetto users online list).

I want to do something like the following...

time = Time.now.to_i - 900 # save the timestamp 15 minutes ago in a variable 
User.where(:all, :where => :last_action > time)

What's the best way to do this? Is there a way of doing it without using any raw SQL?

Answer 1

Maybe this will work?

User.where("users.last_action > ?", 15.minutes.ago)

Answer 2

Try this:

time = Time.now.to_i - 900
User.where("last_action > #{time}")

There might be a nicer/safer syntax to put variable arguments in to the where clause, but since you are working with integers (timestamps) this should work and be safe.