undefined method `event_id' when using a belongs_to/has_many association

Question

I'm creating a site that has events. Each event acts as a gallery and has_many images. Each image belongs_to and event.

I followed the RailsCast #253 CarrierWave gem. When I try to add a new image, it says

undefined method `event_id' for # Image:0x7302438

<%= form_for @image, :html => {:multipart => true} do |f| %>

<%= f.error_messages %>

<%= f.hidden_field :event_id %>

<%= f.label :title %><br />

<%= f.text_field :title %>

Here is my image.rb

class Image < ActiveRecord::Base

attr_accessible :event_id, :title, :image

validates :title, :image, :presence => :true, :uniqueness => :true

belongs_to :event

mount_uploader :image, ImageUploader

end

and the event.rb

class Event < ActiveRecord::Base

attr_accessible :title, :date, :about

validates :title, :about, :date, :presence => :true

validates :title, :uniqueness => :true

has_many :images

extend FriendlyId

friendly_id :title, use: [:slugged, :history]

end

Answer 1

Running this in a migration worked. Column wasn't added.

def up
   change_table :images do |t|
      t.references :event
   end
end