similar to: database design Q

I have to tables: "articles" and "groups". Between I have article_groups as a jointable. Now I want to select every article who is a member of group with id ''1'' and id ''2''. Whats best way to get that? Extract from schemas: CREATE TABLE articles ( id int auto_increment, ingress text NOT NULL, story_text longtext, constraint fk_items_users

In a social netowrk data model, users belongs other users, and can have many friends as users, so it is a many to many relatioship. the class definition could be class User < ApplicationController has_mang_ang_belongs_to users But how it looks like in the mysql database tables in a "joined" users table. The question really is: what is the table looks like when a model has

Hi, I have good this cool challenge from my boss on developing a very simple cms-like system to publish articles within. The caveat is that he wants to have multi-lingual content. At first I thought RoR would be perfect for the assignment but right now I''m not so sure. My first attempt involved creating a table for each model/languagde like this: articles_en articles_dk articles_de

Ok, to keep things short. Im wondering if I need a secondary relationship table to handle my many-to-one relationships. Here is an example of what I''ve written down. For instance say I want to find all of the people in a given location. class Location < AR:Base has_many :people end class Person < AR:Base belongs_to :location end My SQL tables look like: CREATE TABLE

Hi everyone, I''ve tried posting the same question to the list last Friday but somehow did not see it being posted.. I''ve just started with Rails and Ruby. I just started to play one of those RPG and to get my feet wet I''m writing an app to keep track of item fusions. So the scoop is that item can be fused with another items to create a higher level item. The higher

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

I''m experimenting with Rails on the Recipes example first before I dive into applying it to my intended application. I''m exploring which will be more work: to rename all the primary id''s in the legacy database, or to work around the fact that the primary id''s are not called ''id'' within RoR instead. I''ve been successful in using a

Imagine I want to track people, and the clubs that they belong to. table people with columns person_id, person_name table clubs with columns club_id, club_name And I have the association table: table clubs_people with columns person_id, club_id Now I know how to do this habtm between the two, in order to associate people with clubs that they belong to. However my application also needs a

Hi all, I''m working with a legacy sqlserver db and I''m trying to override the insert sql in as defined in the HABTM method below(becasue the join has three primary keys), but I''m getting the error: ''undefined local variable or method `record'' for Project:Class'' has_and_belongs_to_many :people, :class => ''Person'',

Hello! I have 2 table: users and buddies User: id, name, ... Buddy: id, user_id, user_buddy_id, ... So if you have 2 users 1,jack and 2,fred and fred is a buddy of jack, there is a Buddy object: id=1, user_id=1, user_buddy_id=2 I can declare only one belongs_to in Buddy and one has_many in User. And there is conflict if I had the second one (the first one is discarded) class User has_many

Heyo! I am setting up a self-referencial habtm relationship with the users of my app. I am using Chad Fowler''s "Rails Recipes" to get me started, and everything works great with the join table "people_friends". I add friends by doing somebody.friends << somebodyelse. However, with my app, there is an approval process so my join table has columns person_id,

Hi, I''m having a little trouble figuring out how to make a self- referential HABTM bi-directional. I have a Employee class. Each employee can have a couple of bosses, who are also employees. The employee class has the following HABTM: has_and_belongs_to_many :bosses, :class_name => "Employee", :join_table => "bosses_courses", :association_foreign_key =>

I just took my HABTM and turned it into a :through since my join table has another "non-joiny" attribute. I went from this: has_many_and_belongs_to :jobs, :join_table => ''tablename'', :foreign_key => ''x'', :association_foreign_key => ''y'' to this: has_many :jobs, :through =>

Hi, I''m trying to figure the most efficient way to model the following. I can think of at least two ways to relate the tables but from a client/server perspective! I''m wondering how to best (and elegantly)relate them from an AR perspective. A project has many people, A person can work on many projects at any time, A project has many roles, A role is performed by a person, A

I am trying to create a messaging system for my users but I''m having a hard time designing my db. This is what i have in mind, but I am not sure if its the best approach. user has_one inbox user has_one outbox inbox has_many messages outbox has_many messages inbox table user_id outbox table user_id messages table box_id (refers to either inbox or outbox - how?) from_id to_id

Hey everyone, I''m working on allow users to follow other users in my app so they can receive updates to what all their friends are doing (like Facebook/ Twitter). I''m wondering on how the relationship would be for the model. Sounds like a HABTM type of association, but how would I go about doing it for only one model? Thanks, Tony

Hi all I have a model Member that has a habtm relationship to buddies (also members). Now I wanted to sort them using sort, but this ends in an error "undefined method <=>"! Where''s the problem here? Sorry, I''m still beginning to learn Ruby. ;-) Thanks Josh -- Posted via http://www.ruby-forum.com/.

Greetings railsers - I''m trying to add to a collection through HABTM, but the sql insert is trying to insert a PK rather than letting mysql produce the auto_increment''ed PK. ## @medication_dose holds a validated, saved model @medication_dose.medication_frequencies << MedicationFrequency.find (:all) The above bails with, Mysql::Error: #23000Duplicate

Here''s a simplistic model class. class Person < ActiveRecord::Base has_and_belongs_to_many :relatives, :class_name => ''Person'', :join_table => ''relatives'', :foreign_key => ''from_id'', :association_foreign_key => ''to_id'' has_and_belongs_to_many :brothers, :class_name =>

Dear all, I'm discovering the somehow confusing (for me) world of linear mixed models after having been advised it could be the best option to analyze my dataset. After several days of reading, I'm not sure that what I ended up with makes some sense and I'd greatly appreciate any help and explanations. The dataset has been obtained as follows. In 15 different locations, I counted