I think you not should do that. If you store price in products table, why you are store same thing in another table?
среда, 7 октября 2015 г., 8:57:00 UTC+3 пользователь peter williams написал: > > Hi people, > > > i'm new to rails and have difficulties in actively using the model > relationships. > I'm building an onlinestore with rails 4.2.4 following the book agile > development with rails 4. > The asignment is to create a migration that copies the product price to > the line item. > > Class Product < ActiveRecord::Base > > has_many :line_items > > Class LineItem < ActiveRecord::Base (is a jointable between product and > cart) > > belongs_to :product > > My question is how do i instruct rails to copy an attribute from one model > to the other (in this case product.price to line_item.price) > > I understand that the belongs_to and has_many methods bring in new > methods when called. > e.g > @line_item = @product.line_items > I somehow can't make pratical use of this knowledge!! What really confuses > me is these are instance_variable > of the models but when it comes to use the author has been using the > tablenames > eg :line_items, :products etc how i'm i supposed to copy the > attribute_price from product using instance_variables? > > My migration for the new added price column to LineItem model > > class AddPriceToLineItem < ActiveRecord::Migration > def up > add_column :line_items, :price, :decimal, precision: 8, scale: 2 > end > end > > If the question is not clear just let me whats confusing. > > Thanks for help > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/72425246-6fea-489d-a758-7aead6a74d1d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
