CODEWITHSUNDEEP
ruby-on-railsrubypostgresqlruby-on-rails-4
patrickS
patrickS

Reputation: 3760

Rails 4 Migration: has_and_belongs_to_many table name

I currently try to switch a rails 3.2 app to rails 4.0. But I have one problem with a has_and_belongs_many model.

I have created a test app and I have the same problem there. This is what I have done:

Created two models: foo_clip and foo_url

class FooClip < ActiveRecord::Base
  has_and_belongs_to_many :foo_urls

  attr_accessible :id, :name
end


class FooUrl < ActiveRecord::Base
  has_and_belongs_to_many :foo_clips

  attr_accessible :url
end

After this I have updated the migration files:

class CreateFooClips < ActiveRecord::Migration
  def change
    create_table :foo_clips do |t|
      t.string :name
      t.timestamps
    end
  end
end

class CreateFooUrls < ActiveRecord::Migration
  def change
    create_table :foo_urls do |t|
      t.string :url
      t.timestamps
    end
  end
end

Now I have created the migration file for the has_and_belongs_to_many table

class CreateFooClipsFooUrls < ActiveRecord::Migration
  def change
    create_table :foo_clips_foo_urls do |t|
      t.belongs_to :foo_url
      t.belongs_to :foo_clip
    end
  end
end

As last step I created a seed file for testing:

foourl1 = FooUrl.create!(:url => 'http://www.google.com')
foourl2 = FooUrl.create!(:url => 'http://www.apple.com')

fooclip1 = FooClip.create!(:name => 'TestClip1')

fooclip1.foo_urls << foourl1
fooclip1.foo_urls << foourl2

fooclip1.save

Now I did:

rake db:drop
rake db:create
rake db:migrate
rake db:seed

And got this error:

PG::UndefinedTable: ERROR:  relation "foo_clips_urls" does not exist
LINE 5:         WHERE a.attrelid = '"foo_clips_urls"'::regcla...
                                          ^
:               SELECT a.attname, format_type(a.atttypid, a.atttypmod),
               pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
                FROM pg_attribute a LEFT JOIN pg_attrdef d
                  ON a.attrelid = d.adrelid AND a.attnum = d.adnum
               WHERE a.attrelid = '"foo_clips_urls"'::regclass
                 AND a.attnum > 0 AND NOT a.attisdropped
               ORDER BY a.attnum

If I take a look at the postgres database the table is called: foo_clips_foo_urls

Any ideas why this happens?

Upvotes: 28

Views: 18549

Answers (1)

patrickS
patrickS

Reputation: 3760

I fixed the problem by adding the join_table name to every model like:

has_and_belongs_to_many :foo_urls,  :join_table => :foo_clips_foo_urls

Upvotes: 54

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