similar to: Prevent duplicate HABTM associations

This may have been asked/answered before - if so, i apologise... I have the following table layout in a habtm relationship: ------------ ----------------------- -------------- | products | ----| categories_products |-----| categories | ------------ ----------------------- -------------- What would be the best way to pull out all the products for a given category? At the

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,

I have two tables ("products" and "categories") that have a has_and_belongs_to_many relationship, and I need to be able to arbitrarily sort products in the scope of a category using something like acts_as_list. Problem is, since each product can belong to multiple categories, it doesn''t work to use acts_as_list and have the "position" field be in the

I have a problem with ruby on rails validation total_book_toy.rhtml ================ <%= text_field ''book1'', ''title1'' %> <%= text_field ''book2'', ''title2'' %> I want to validate these text_field so user can''t insert same title. However, I was stuck how to do it. Or maybe you have another way how to do it.

In a one-to-many relationship (domain has_many :categories and category belongs_to :domain) In the category model I use: validates_uniqueness_of :name, :case_sensitive => false but upon creation of a category this validation is performed on ALL domains, can I restrict it only to the categories of the current domain, the to which teh category being saved belongs_to ? if yes ? how ? thanks

As per http://rails.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html Possible callbacks are: before_add, after_add, before_remove and after_remove. Should any of the before_add callbacks throw an exception, the object does not get added to the collection. Same with the before_remove callbacks; if an exception is thrown the object doesn‘t get removed. However, when the add

The AWDwR book has the following: add_index :categories_products, [:product_id, :category_id] add_index :categories_products, :category_id The first, composite index actually serves two purposes: it creates an index which can be searched on both foreign key columns, and with most databases it also creates an index that enables fast lookup by the product id. The second index then completes

I am having problems with a validation, the full model code is below. The validate routine is attempting to see if another record with the same artist_name, title, & catalogue_no exists in the products table. If so, it should throw an error. This is the validation code: def validate if Product.find(:all, :conditions => ["artist_name = ?, title = ?, catalogue_no = ?",

hey all. I''m trying to set up a many-to-many relationship with products and categories. I''ve got the product model (product.rb) set up: class Product < ActiveRecord::Base has_and_belongs_to_many :categories end and a similar one for category.rb And I''ve got the tables set up -- products, categories, categories_products But when I load, I get: undefined method

Hello, I have the usual Categories and Products table scenario, mediated by a Categories_Products join table. When I create a new Product and into a given Category, I notice that my join table is not being populated. Shouldn''t the join Categories_Products table be populated? Thanks, gk -- Posted via http://www.ruby-forum.com/.

I have a loans table and a payments table. Each loan has_many payments. So far no problem. Now, the payments table has a payment_number field, and each payment has a payment_number unique within that loan. For example, Loan A can have payment_numbers 0, 1, and 2 and Loan B can have payment_numbers 0, 1, 2, and 3 (but only one of each payment_number). I can enforce this with a unique index in

problem: validation error is not functionning in callback callback for many-to-many association: # keyword.rb :before_add => :reject_self_related def reject_self_related(related_keyword) if (related_keyword == self) # this does not work: errors.add(:name, "Relating a keyword to itself is forbidden!") raise "Relating a keyword to itself is

Hi all, I''ve got a rails and database question. Accounts have jobs, and job numbers should be assigned per account. Account 89 should have jobs 1-whatever, which are not the same as account 67, which has jobs 1-whatever. In the past, I have accomplished this quite easily with: create table job ( accountid int(10) unsigned not null default 0, jobid int(10) unsigned not null

Hi, New to RoR and I just wanted to check the correct process flow for this... I presently have a controller action: def destroy_category_association category = CatalogueCategory.find(params[:id]) product = Product.find(params[:product_id]) product.catalogue_categories.delete(category) end I display a list of categories assigned to a product, some of which I may wish to delete

I have 2 tables: products and categories. They are both linked by a habtm association. I have a fixture to import all the data in each table but I dont know how to import the data in the categories_products table since that table has no model, so I cant use that code: f = Fixtures.new(Category.connection, # a database connection "categories", # table name

Hello, Is there a way to implement a callback for somehting like before_add and after_ad on a statement like this with a has_many relation? x.children << Item.create(:title=>"test") I want that x has a callback that is called when the item is added. I found something in

it''s a blog... class Entry < ActiveRecord::Base has_and_belongs_to_many :categories end similarly: class Category < ActiveRecord::Base has_and_belongs_to_many :entries end I wish to make sure that the owner doesn''t add the same category to a given entry more than once... I''m thinking that validates_uniqueness_of should be usable here. But can''t

Hi, I have a scenario where a doctor can have one or more specialties. For each doctor, one and only one of her specialties can be designated as primary. So I have tables called doctors, specialties, and doctors_specialties, the last of which has a boolean is_primary column. The doctor model class specifies that: has_and_belongs_to_many :specialties I want to enforce, at the lowest possible

I have a database with a field called ''category''. ''category'' contains the categories separated by a "," i.e. 1, 2, 5 I know with something like: @products = Product.find(:all, :condition => "category = ''1''") I could get some results if any of the ''category'' fields only contained "1" but

hi all, i''m new to this group and currently using Rails 3.0.3 and meta_where 0.9.10. i''m considering how to make a full-text searching feature to my project, and my models, for example, should be defined like below: class Group < ActiveRecord::Base has_and_belongs_to_many :users # :title (string) end class Comment < ActiveRecord::Base has_and_belongs_to_many :users