Question

I currently have the following:

users = User.all   
comments = users.collect(&:comments)

However, if there are thousands of comments, i’d like to only collect 10 from each user to limit the number of database queries that are made. Is there a way to do this?

Answer 1

users = User.all
comments = users.collect { |user| user.comments.limit(10) }

Or with another association in you model :

has_many :first_comments, :class_name => "Comment", :limit => 10

Then this will result in only two database queries:

users = User.includes(:first_comments)
comments = users.collect(&:first_comments)