similar to: has_and_belongs_to_many and collections management

I''m having a problem with a has_and_belongs_to_many (habtm) association between two models with extra attributes. I''m writing a comic book database, and each issue has many creators on it. Thing is, some creators perform multiple duties. They may write one issue, draw another, etc. However, if I add a creator twice to an issue and try to delete it, it removes both creators:

I was able to create a has_and_belongs_to_many relationship for my app, but now I''m not too sure how to write queries for it. Basically, I have a table ''courses'' that has_and_belongs_to_many ''categories'' and vice versa So I''m trying to figure out how I would find only the courses that belong to a category that I specify. Let''s

Say I have a post model that has_and_belongs_to_many :categories, and a category model that has_and_belongs_to_many :posts. So I have a categories_posts table to do the join. That''s all find and dandy. However I want to be able to find all the posts that belong to a specific category. I tried Post.find_by_category(:id) but that doesn''t work. Does anyone have any insight?

Hi folks, I''m wondering if it''s possible to use foreign key constraints on the join tables of a has_and_belongs_to_many relation. Specifically, I get this error when I try and delete a model I''m using, named saved_search, which is many-to-many with neighborhoods. Any ideas? Thanks for any help. :-) -Eric Code: @saved_search.destroy Error: Mupdate or delete on

I''m having a problem with belongs_to and has_and_belongs_to_many. Here''s a brief summary of the models involved: class Member < ActiveRecord::Base set_primary_key ''member_id'' has_and_belongs_to_many :projects, :join_table => ''projects__members'' has_many :projects, :foreign_key => ''created_by'' end class

I am working with mapping ActiveRecord onto a legacy database. All is going well (using set_table_name, set_primary_key, etc), but I can''t get my many<=>many relationships to work. My contrived example of the situation: Student has_and_belongs_to_many Teachers. This is mapped via table student2teacher where the foreign keys are studentId and teacherId. The primary key in Student

I''m trying to create a search where I can find pages by their tag name. Here''s a sample of my code (not working). @tags = Page.find(:all, :conditions => ["#{:tag.name} LIKE ?",''%'' + @params[''searchtags''] + ''%'' ]) My enviroment: I''ve got a table called tags, and a table called pages, both with a

Hallo -- can anyone offer me any pointers as to I should handle many-to-many relationships in Rails tests? Cheers, doug. -- Posted via http://www.ruby-forum.com/.

hey, i have users who are in groups, and i have a search form, where i can search on group, user lastname, and user firstname. All this is also with pagination. these are my models class User < ActiveRecord::Base has_and_belongs_to_many :groups end class Group < ActiveRecord::Base has_and_belongs_to_many :users end in my controller i do this THIS works (but in need pagination) @users2

hey, i my database i have users and groups, each user can get in different groups my db structure: table groups: id, name, basegroup, firm_id table users: id, firstname, lastname, email table groups_users: group_id, users_id my relation is a many to many: class Group < ActiveRecord::Base has_and_belongs_to_many :users end class User < ActiveRecord::Base has_and_belongs_to_many

Does has_and_belongs_to_many know to delete an object when the last reference to it is removed? In my case I have Receiver <<->> Message (with a join table of course), but have noticed that when the last receiver removes a message from the association the message still exists. Before adding code to manage this situation I want to check to see if I am missing something? --

I''ve got a situation where I''m trying to model the following relationship: a ''page'' has multiple lineitems a ''lineitem'' can be either a ''page'' or a ''entity'' The ''lineitem'' looks like it should be polymorphic but the ''page'' and ''lineitem''

I''am newbie in RoR, so my question might look stupid, but I stuck in one thing. I''ve created 3 tables: users{ id, user } books { id, book } books_users{ book_id, user_id} Model class Book< ActiveRecord::Base has_and_belongs_to_many:users I can''t figure out how to insert data to the books_users table. For example users post info about new book and information

Hi, I have a user model and a privilege model. They have the has_and_belongs_to_many relationship. Here are the model defs: class User < ActiveRecord::Base belongs_to :status has_and_belongs_to_many :privileges end class Privilege < ActiveRecord::Base has_and_belongs_to_many :users end Now I have a migration script to create the join table and populate a few users with some

I am attempting to use find_or_create on a foreign table with a has_and_belongs_to_many relationship with my current table. I am doing the following: term = school.terms.find_or_create_by_code("FALL06") the queries in the log show the expected SELECT statement to query if there is a join table record between the school and term with code "FALL06": SELECT * FROM term INNER

My web server has a list of users, and each of them has a collection of books. I want to save some certain number of books for each user, including the book''s name, author, and display the information for the user. Which method should I use to store the subject information into each user subject? Do I have to create arrays to store it? Thanks for help! -- Posted via

Hi there, I''ve got a table construction like this: presentation contactstate Hilton new Mc Donalds emailed etc. called visited etc. Now i''ve created an join table presentationcontactstate with extra fields like comment and date time. so i know for example when i called a specific presentation. Now

I know that for has_many, and has_one. I can do :dependent => true and the associated object will be destroyed when the main object is destroyed. However, there does not seem to be a dependent like option for has_and_belongs_to_many. Is there one I do not know of? Is there a simple solution to this? Thanks, Brian -- www.kenlet.com

I am trying to create a model that allows only unique assets to be added to a category. However, they could be added again to a different category. Finally, an asset can be shared across many categories. So my question is how do you check the uniqueness across a join table? This does not compile.... has_and_belongs_to_many :categories, :foreign_key => ''asset_id''

When a user creates a post I also want to save all the tags associated with it. I do that in the post_controller like this presently: def save @post = Post.new(@params[:post]) @tags = Tag.new(@params[:tags]) @post.user_id = session[:id] if @post.save @tags.title.split('','').each do |tag| present_tag = Tag.find_by_title(tag.strip) present_tag =