Limit the maximum number of results in ActiveRecord + Kaminari

Question

When using Rails and Kaminari, is it possible to limit the maximum number of results to be returned for a given query?

@things = Thing.page(params[:page]).per(10)

Assuming we have 500k+ Thing records in the database, how can I ensure that Kaminari's paginate method will never return more than 10,000 rows to paginate?

Answer 1

Kaminari有一个max_per_page选项可能会有所帮助，但可以通过此处也提供的limit scope方法来工作。

Answer 2

So, I figured out a way to do that using an initializer for Kaminari in config/initializers/kaminari_config.rb :

Kaminari.configure do |config|
  config.default_per_page = 10
  config.max_per_page = 100
  config.max_pages = 100
end

In the above case, 100 * 100 = 10,000 maximum total results

More info here

Answer 3

So you're interested in just the top 10k rows? This should do it, but I would consider adding some sorting criteria in there (before the call to limit ) so that your chosen 10000 rows make sense.

Thing.limit(10000).page(params[:page]).per(10)

Answer 4

max_per_page actually sets settings globally. To have individual resource based settings, Kaminari supports Array type objects as well. So, something like below works perfect:

limited_newsfeeds = Newsfeed.order(:created_at).limit(20)

@newfeeds = Kaminari.paginate_array(limited_newsfeed).page(params[:page]).per(3)

You may easily use this @newsfeed object same like normal collection in kaminari views, like

<%= paginate @newsfeeds, remote: true %>

TIP : Using limit() method directly before/after page() doesn't serve the purpose. It either overwrites kaminari's limit (when used after page() method), or gets replaced-by kaminari's limit (when used before page() method)

Source: https://github.com/kaminari/kaminari#paginating-a-generic-array-object