similar to: Has_one and Class Table Inheritance

I am having a problem with using SIngle Table Inheritance with a has_one relationship, and I am at a loss of what could be causing it. Below is the related code and the error message. class User < ActiveRecord::Base has_one :wishlist end class List < ActiveRecord::Base belongs_to :user end class Wishlist < List has_and_belongs_to_many :items, :class_name =>

I''ve been searching the web, wikis, and more, and I haven''t turned up examples of how to have multiple entities in a single-table inheritance related to anything. I have an addresses table, but multiple entities can have Addresses: both Person (which has 2 addresses) and Retailer. I''ve been told that I need to use single-table inheritance, and this was my attempt:

I''m trying to build a system for generically storing an object graph, on top of AR itself. The idea is to define one base class, and use AR''s automatic single table inheritance to have it create the right class. Here''s what I have so far: table generic_objects: id int(11) not null auto_increment primary key type varchar(255) table generic_fields: id

Hi Everyone, I hope I get some feedback on my question. Here it goes. I have a situation here, I have a company table and then using Single Table inheritance it is of 3 types: class Company < ActiveRecord::Base end class Vendor < Company end class Customer < Company end class Agent < Company end Now I have a active record Association class QuoteSheet < ActiveRecord::Base

Please tell me if this train of thinking makes sense, I need help on solving this association model problem: I am doing an app that creates and manages stereoscopic images, one stereoscopic image is formed by two photos, say photo1 and photo2 The user uploads photo1 and then photo2 and gets a preview if he likes the preview he/she authorizes it and gets a final stereoscopic image All this

Hi, How do I relate a table to another when one of the models uses single table inheritance? Will this even work? This is the specific problem I am having: There''s an "Address" model with "ShippingAddress" and "BillingAddress" as subclasses. It looks like this: class Address < ActiveRecord::Base End class ShippingAddress < Address has_one :order

I am using RoR ActiveRecord polymorphic inheritance and was wondering if it''s possible to access the base class'' association methods in the invocation of either to_xml or to_json without having to depict the base class data in the serialized string. Here are my classes: # base class class Asset < ActiveRecord::Base belongs_to :resource, :polymorphic => true

Hi, I am very confused about an aspect of has_one and has_many relations, with regard to using the build method, and saving the belongs_to side. It''s a somewhat long post. so please bear with me :) First let''s consider the has_one scenario. Let''s say I have a student who must own exactly one car: class Student has_one(:car) end class Car belongs_to(:student)

Hi, I''m trying to write a blog application where each post has a single header image associated. My models: ---------- class Post < ActiveRecord::Base belongs_to :blog has_many :images has_one :header end class Header < ActiveRecord::Base file_column :image_path end class Image < ActiveRecord::Base belongs_to :post file_column :image_path end The controller targets I

While I''m happy to continue talking about the vagaries of Rails deployments, I also need to actually build apps. :) I may have discovered a bit of a problem with :include as it applies to has_one associations. First, let me say that I''m a big fan of :include for reducing the number of SQL calls. There are times when I wish it could go more than 1 step away from the parent

Hi. My model data is the following: - Place - User - Checkin Instead of having a Checkin that belongs to both User and Place, I chose to add another model, Program, that allows to list all the places a user can checkin into, and also hide the checkins he''s no longer involved in (= the user sign out of a specific program). That give me crazy relationships: Program has_many Checkin

With a has_one/belongs_to relationship, what''s the best way to guarantee that the belongs_to object gets created and is accessible alongside the has_one object? I *think* the after_create callback is a good choice, but I discovered an oddity while trying it. F''rinstance, if every horse has a carriage: ============ ActiveRecord::Schema.define do create_table(:horses) {|t|

Hello all, I have a syntax question. How does one refer to a field brought in via a has_one/belongs_to relationship in a form helper? Basically, I have two models: class Resource < ActiveRecord::Base has_one :other_thing end class OtherThing < ActiveRecord::Base belongs_to :resource end It has the normal id-resource_id foreign key relationship. OtherThing has two fields, plus the

I''ve got an order model that stores order data. One piece of data is a credit card type, which is a digit 1,2 or 3. I have a cardType model that has an id, shortName and LongName for the credit card merchant (visa, mastercard, amex). I want to be able to say: order.cardType.shortName, but can''t seem to get has_one working. It works with has_many and a finder_sql statement on

Heya everyone! I am quite new to Rails and I am reading AWDwR. I am at Task E "Check Out!". I understand it quite well, but I have a problem with the last playground exercise: Add a Table which contains the payment types. All goes well, but I am not sure whether I should use has_many or has_one(as in the Playground wiki at http://wiki.pragprog.com/cgi-bin/wiki.cgi/PT-E-3). I use the

There really doesn''t seem to be a *declarative* way to define a default value for belongs_to and has_one associations class Person < ActiveRecord::Base belongs_to :address end p = Person.new p.address.city = ''Atlantis'' # Bummer! Of course, there''s an easy way to avoid this class Person < ActiveRecord::Base belongs_to :address

Hi there, I''m currently building a membership application and I want to be able to select, not just all the memberships, but the most current membership from the database on a per user basis. I have linked the tables as shown:- class Membership < ActiveRecord::Base belongs_to :payment belongs_to :person end class Person < ActiveRecord::Base has_many :memberships

I''m having a difficult time wrapping my head around a set of models and their associations and seeing how they map into Rails. I''ll try to lay out my problem using the has_many and belongs_to structures. I have a RuleSpace, a Rule, and a Subject. A RuleSpace has_many Rules A RulesSpace has_many Subjects through Rules A Rule belongs_to (many) RuleSpaces A Rule has_many

Hi to everyone, I have the following models: class Attachment < ActiveRecord::Base has_attachment :content_type => [:image, ''application/pdf''], :max_size => 3.megabytes, :path_prefix => ''../private/attachments'', :storage => :file_system, :processor => :rmagick,

Let me preface by saying i''m a total noob at ruby/rails. :-) For some reason, I am just not grasping the concept of has_one & belongs_to... I''m working on a project that includes user authentication, and 3 different types of user profiles. User profiles are either "fan", "band", or "venue" objects, and user logins are "user"