Rails 3 build a select tag with has_many belongs_to association

Question

Based on following models

class Company < ActiveRecord::Base
  belongs_to :country
end

class Country < ActiveRecord::Base
  has_many :companies
end


        

Answer 1

collection_select should do the trick for you:

collection_select(:company, :country_id, Country.all, :id, :name, :prompt => 'Please select country')

The above code assumes that the countries table have a name column. If it doesn't, replace the fifth parameter with whatever the column of the country name is.

:prompt means that you're forcing the user to choose one country.

Find more information in the Rails API documentation.