CODEWITHSUNDEEP
ruby-on-railshas-many
Bruno
Bruno

Reputation: 6459

has_many binding on wrong parameter

I have show.html.erb:

<h3>Rooms (<%= @building.rooms.count %>)</h3>
<%= render @rooms %>

I'm getting this error: 

OCIError: ORA-00904: "ROOMS"."BUILDING_ID": invalid identifier: \
SELECT "ROOMS".* FROM "ROOMS" WHERE "ROOMS"."BUILDING_ID" = :a1`

Here are models:

class Building < ActiveRecord::Base
  has_many :rooms
end

class Room < ActiveRecord::Base
  belongs_to :building
end

Here's buildings_controller.rb:

class BuildingsController < ApplicationController

  def show
    @building = Building.find(params[:id])
    @rooms = @building.rooms.all
  end

The building model has attributes: 

ID, NAME, CREATED_AT, UPDATED_AT, CODE

The room model has attributes: 

ID, NAME, CREATED_AT, UPDATED_AT, BUILDING_CODE, NUMBER

Upvotes: 1

Views: 67

Answers (2)

xlembouras
xlembouras

Reputation: 8295

you should define an explicit foreign_key on Room

class Room < ActiveRecord::Base
  belongs_to :building, foreign_key: :code
end

that way you tell active record to use building.code for the lookup.

Of course you will also need the proper migration to define room.building_code

eg

def change
  add_column :rooms, :building_code, :integer # or :string
  add_index :rooms, :building_code
end

Upvotes: 1

Tamer Shlash
Tamer Shlash

Reputation: 9523

In your Room model, change the association to become like this:

class Room < ActiveRecord::Base
  belongs_to :building, primary_key: 'code'
end

This will tell rails that the association's primary key is code instead of the default id.

Upvotes: 0

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