Thanks. I am sure it is something I am missing. I am trying to learn about SQL and Rails. Here is the script I am using. I am really just trying to create a script that explores all of the database relationships and how to implement them in Rails.
The code: http://rafb.net/p/iUgqjX46.html The output and SQL: http://rafb.net/p/tpvlVc44.html On Mar 17, 2:48 am, "\"Wolas!\"" <[email protected]> wrote: > I replicated 2 scenareos and neither of them do what you have > described: > > has and belongs to many scenario > > == models > > class Product > has_and_belongs_to_many :categories > end > > class Category > has_and_belongs_to_many :products > end > > == db > > create_table "categories", :force => true do |t| > t.string "name" > end > > create_table "categories_products", :id => false, :force => true do | > t| > t.integer "product_id" > t.integer "category_id" > end > > create_table "products", :force => true do |t| > t.string "name" > t.integer "price" > end > > == test > > >> p = Product.new :name => "cool bike", :price => 123 > > => #<Product id: nil, name: "cool bike", price: 123>>> p.categories << c > > => [#<Category id: 1, name: "bikes">]>> p.save > => true > >> p.categories > > => [#<Category id: 1, name: "bikes">] > > Same thing with has_many :through. which leads me to believe you > havent set your relationships right. Could you show us the mdoel and > table code plz? > > On Mar 17, 5:11 am, ball <[email protected]> wrote: > > > It didn't exist before hand. ActiveRecord is triggering two inserts. I > > have included a full example and the SQL > > > catBike = Category.new(:name => "Bikes") > > catBike.save > > > p = Product.new(:name => "Cannondale Bike", :price => 1000) > > p.save > > p.categories << catBike # This works great. > > > p = Product.new(:name => "Trek Bike", :price => 900) > > p.categories << catBike # this causes two entriens to be created > > p.save > > > Category Create (1.0ms) INSERT INTO `categories` (`name`) VALUES > > ('Bikes') > > Product Create (0.0ms) INSERT INTO `products` (`name`, `price`) > > VALUES('Cannondale Bike', 1000) > > SQL (0.0ms) COMMIT > > SQL (0.0ms) BEGIN > > categories_products Columns (10.0ms) SHOW FIELDS FROM > > `categories_products` > > SQL (1.0ms) INSERT INTO `categories_products` (`product_id`, > > `category_id`) VALUES (1, 1) > > SQL (0.0ms) COMMIT > > SQL (0.0ms) BEGIN > > SQL (0.0ms) COMMIT > > SQL (0.0ms) BEGIN > > Product Create (1.0ms) INSERT INTO `products` (`name`, `price`) > > VALUES('Trek Bike', 900) > > categories_products Columns (7.0ms) SHOW FIELDS FROM > > `categories_products` > > SQL (1.0ms) INSERT INTO `categories_products` (`product_id`, > > `category_id`) VALUES (2, 1) > > categories_products Columns (7.0ms) SHOW FIELDS FROM > > `categories_products` > > SQL (0.0ms) INSERT INTO `categories_products` (`product_id`, > > `category_id`) VALUES (2, 1) > > SQL (0.0ms) COMMIT > > > On Mar 16, 4:50 pm, Phlip <[email protected]> wrote: > > > > > p.categories now has TWO catBike > > > > Because << does not ask questions. It just adds a catBike. If you already > > > had > > > one, now you have two. > > > > You might need some combination of these: > > > > a :unique => true on the habtm (spelling?) > > > a unique key (index) on the database --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
