HABTM not working - unknown bind - ruby-on-rails-4

Question

I created three models:
class Role < ActiveRecord::Base
has_many :users
has_and_belongs_to_many :permissions
accepts_nested_attributes_for :users, :permissions
end
class Permission < ActiveRecord::Base
has_and_belongs_to_many :roles
accepts_nested_attributes_for :roles
end
and a migration as following:
class Changetable < ActiveRecord::Migration
def change
create_table :permissions_roles, id: false do |t|
t.belongs_to :permissions
t.belongs_to :roles
end
end
end
And that leeds to following schema.rb which looks exactly the same in my sql database:
create_table "permissions", force: true do |t|
t.string "subject_class"
t.string "subject_id"
t.string "action"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "permissions_roles", id: false, force: true do |t|
t.integer "permissions_id"
t.integer "roles_id"
end
create_table "roles", force: true do |t|
t.string "name"
t.datetime "created_at"
t.datetime "updated_at"
end
Now when I call Roles.first.permissions I got following error message:
irb(main):001:0> Role.first.permissions
←[1m←[36mSQL (1.0ms)←[0m ←[1mUSE [rails_confreport_develop]←[0m
←[1m←[35mRole Load (2.0ms)←[0m EXEC sp_executesql N'SELECT TOP (1) [roles].* FROM [roles] ORDER BY [roles].[id] ASC'
RuntimeError: Unknown bind columns. We can account for this.
Same happens if I call Permission.first.roles! What am I missing?
Best regards!

Answer 1

The mistake was the spelling of the foreign keys in my joined-table.
Changed this:
create_table "permissions_roles", id: false, force: true do |t|
t.integer "permissions_id"
t.integer "roles_id"
end
to this:
create_table "permissions_roles", id: false, force: true do |t|
t.integer "permission_id"
t.integer "role_id"
end
And it works.