similar to: Updating attributes in HABTM association

Hi, I''m currently having the situation where I have to implement a polymorphic has_and_belongs_to_many by introducing an in between model that handles all the "has_many :as" and "belongs_to :polymorphic" association implementations... and is not doing anything else. Thing I don''t like it here is, I am unnecessarily loading AR instances only to execute SQL

Hi, lets say I have a a table, "Linkings" that I am using for polymorphic associations. One of the associations is to the "person" table, and there are several other associations. "Person" has 2 types, "slacker" and "suckup". It is modelled as such: class Linking < ActiveRecord::Base belongs_to :person belongs_to :linkable, :polymorphic

Hello, is it possible to setup a model/table schema like this: Groupable --> Membership <-- Group ^ ^ | | User UserGroup I tried the following but failed: Groupable (table with ''type'' column) has_many :memberships, :as => :groupable has_many :groups, :through => :memberships

So having just learned how to do has_many :through as opposed to HABTM, and then, being concerned that I wouldn''t get it to work, I started thinking about these two approaches. It seems to me that the _only_ problem that the HM:T (has_many :through) approach solves that HABTM doesn''t is the issue of the potential collision of id columns between your join table and one of

Hi all I have the following models: class member has_and_belongs_to_many :disc_jockeys end class disc_jockey has_and_belongs_to_many :members end The relation table is called disc_jockeys_members and has the following fields: disc_jockeys_members(disc_jockey_id, member_id, status) So far, the field status can have values like valid, invalid, locked etc., but it is not regarded yet by

Taking time off from programming is always painful :-). I have the following Models: ==== class Tag < ActiveRecord::Base has_and_belongs_to_many :problems end class Problem < ActiveRecord::Base belongs_to :user has_and_belongs_to_many :tags end ==== And the following migrations: ==== create_table "problems" do |t| t.column "user_id", :integer

Hi, I''ve been googling and searching the forums for some time but can''t seem to find exactly what I''m looking for. Suppose User HABTM Products (for example a favorites list). I would like to construct a single query for finding Products ordered by the number of Users that have flagged them as favorites. Although I can construct the query using SQL a with a

All, I''m building model objects for existing tables that I cannot modify. In AWDWR, Dave says "Note that our join table has no id column...The second reason for not including an id column in the join table is that AR automatically includes all columns from the join tables when accessing rows using it. If the join table included a column called id, its id would overwrite the id

I''ve read the stuff about polymorphic associations here: http://wiki.rubyonrails.org/rails/pages/UnderstandingPolymorphicAssociations But I''m not sure what exactly they are and what their advantage is. Are they the same as HABTM, but they''re "two-way"? Joe -- Posted via http://www.ruby-forum.com/.

I''m new to RoR and trying to make a HABTM relationship work. I have no problems with displaying the fields (after I pumped the data into MySQL manually outside of RoR), but when I try to edit a record, it =does= save the changes in the primary record, but =not= the join table. When I look in the development log, I see the update to the main table, but nothing about the join

Hi, Why is it that polymorphic associations only work with the :has_many and :belongs_to relationships? Why can''t it be a :has_one? Matt

Hi, I have three Models: User, Group and File. User habtm groups and Group habtm Files How can I find all files that a particular user has access to? eg user.groups.files ? As user.groups returns an array, the above doesn''t work. Id like to find the files for all groups in that array, without adding any code to the User model. Thanks in advance PS I just posted this in the

If I have a class, Asset, which has and belongs to many associated Asset objects, how do I do this? has_and_belongs_to_many :associated_assets, :class => "Asset", :foreign_key => ?????, :association_foreign_key => ????? Right now, my table has a :first_asset_id and a :second_asset_id, but I don''t see how the objects themselves are supposed to distinguish one from the

Dear Railers, I am toying with a new project and have a schema design question. I have a tree-like node structure. Each of the nodes will be associated with a single object. This associated object can be of a variety of types. I represent the tree through a Node class which acts_as_tree. Now imagine three other classes--Animals, Fruits and Vegetables. Each node will have an association

Does the new has_many :through and belongs_to :through obsolete (well, replace and essentially deprecate) has_and_belongs_to_many? Joe -- Posted via http://www.ruby-forum.com/.

All, I''ve heard recently about has_many :through as a necessary alternative to HABTM (when the join table has it''s own id column, say, in a legacy schema). However, is the prevailing Rails wisdom now that one should use has_many :through in _all_ cases? If so, why? Thanks, Wes -- Posted via http://www.ruby-forum.com/.

So I''m one of those nasty people building a self-referential habtm-like Association using the funky new :through stuff. This is about users having friends, so here''s my user.rb: class User < ActiveRecord::Base has_many :friendships, :foreign_key => ''user_id'' has_many :friends, :through => :friendships, :source => :friend end And here''s

Quick question. Say I have a geographical database with counties and zip codes where counties have and belong to many zip codes. zip_codes (id, zip_code) counties (id, name) When I create the association table, the Rails way says to do the following: counties_zip_codes (county_id, zip_code_id). However, given that zip_codes.zip_code is itself a candidate key, I would much prefer to do the

>From the docs: "Note that any fields in the join table will override matching field names in the two joined tables. As a consequence, having an "id" field in the join table usually has the undesirable result of clobbering the "id" fields in either of the other two tables." I do have an ID field in the join table, and as a result it''s clobbering the ID

Hello, I''m stuck, I''ve got a model Product and would like to add a new model called Category. Furthermore, I want to set up a many2many relationship between the mentioned models. the problem is that I do not know how to set the primary key in the categories_products table. this is what I''ve got in my migration file: create_table :categories do |t| t.column :name,