Undefined method 'add_reference'

Question

I'm trying to add a user reference to my post tables with following code:

class AddUserIdToPosts < ActiveRecord::Migration
  def change
    add_reference :posts, :user, index: true
  end
end

but I've received an error message:

undefined method 'add_reference'

Anyone knows how to solve this?

I'm using Rails 3.2.13

this might help? http://stackoverflow.com/questions/4954969/rails-3-migrations-adding-reference-column — dax, Aug 29 '13 at 11:44

Luís Ramalho · Accepted Answer · 2013-11-14T13:51:37.980

16

In Rails 3 you must do it like so

class AddUserIdToPosts < ActiveRecord::Migration
  def change
    add_column :posts, :user_id, :integer
    add_index :posts, :user_id
  end
end

Only in Rails 4 you can do it the way you posted.

edited Nov 14 '13 at 13:51

answered Aug 29 '13 at 11:44

Luís Ramalho

Thank you Luis, I didn't know that this method was valid only in Rails 4 – Guilherme Carlos Aug 29 '13 at 18:05

score 3 · Answer 2 · answered Aug 29 '13 at 11:52

add_reference is specific to rails 4.0.0, so you should try this instead :

class AddUserIdToPosts < ActiveRecord::Migration
  def change
    add_column :posts, :user_id, :integer
    add_index :posts, :user_id
  end
end

this is a great post about this subject

Rajarshi Das · Answer 3 · 2013-08-29T12:47:56.400

3

Your migration should be

rails generate migration AddUserRefToPosts user:references

edited Aug 29 '13 at 12:47

answered Aug 29 '13 at 12:04

Rajarshi Das

this is virtually copy of my answer. :) – Marek Lipka Aug 29 '13 at 12:37
@MarekLipka sorry I have not seen your post let me delete it – Rajarshi Das Aug 29 '13 at 12:44

score 2 · Answer 4 · answered Aug 29 '13 at 11:44

2

How about this:

def change
  change_table :posts do |p|
    p.references :user, index: true
  end
end

answered Aug 29 '13 at 11:44

Marek Lipka

score 1 · Answer 5 · answered Aug 29 '13 at 11:44

1

This method apperead in Rails 4.0

I think you may create some monkey patch with this functionality for Rails 3.2

answered Aug 29 '13 at 11:44

crackedmind

5 Answers5