Q:

Rails link from one model to another based on db field? 

I have a company model and a person model with the following relationships:
class Company < ActiveRecord::Base
  has_many :kases
  has_many :people
  def to_s; companyname; end
end

class Person < ActiveRecord::Base
  has_many :kases # foreign key in join table
  belongs_to :company
end

In the create action for the person, I have a select box with a list of the companies, which assigns a company_id to that person's record:
<%= f.select :company_id, Company.all.collect {|m| [m.companyname, m.id]} %>

In the show view for the person I can list the company name as follows:
<%=h @person.company.companyname %>

What I am trying to work out, is how do I make that a link to the company record? 
I have tried:
<%= link_to @person.company.companyname %>

but that just outputs the company name inside a href tag but links to the current page. 
Thanks,
Danny

A:

You need pass in second argument the path where you want go
<%= link_to @person.company.companyname, @person.company %>

or with the full version :
<%= link_to @person.company.companyname, company_url(@person.company) %>

