From: Luis Lavena Date: 2010-04-24T02:00:08+09:00 Subject: Re: What is the difference build and new? On Apr 23, 4:34 am, Manoj Kumar wrote: > What is the difference between > > parent.children << child.new > > and > > parent.children.build(params[:child]) http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html Under has_many examples, build is used to automatically fill up the relationship data. The documentation is your friend, spend some time reading it. Now that I've google that for you, another useful link: http://rubyonrails.org/community Post your Ruby on Rails related questions there in the Rails mailing lists, not here as there are better chances you don't get any answer at all since this list is mainly Ruby. -- Luis Lavena