Data in DB in Ruby on Rails

Question

我的朋友问这个问题，我不确定为什么它在我的StackOverflow配置文件中。

Answer 1

Rails supports a technique called counter cache, where you can store the number of messages, comments or anything you want, without executing redundant commands.

There is a railscast that describes it very nicely :

http://railscasts.com/episodes/23-counter-cache-column

If you, however, need to stick to a cron based task, it would be very easy to store the count yourself in a statistics model like :

Statistic.new
Statistic.total_users = User.count 
Statistic.total_comments = Comment.count 
Statistic.save