The term you're looking for is LineItem, and it is typical to include things like Peter suggests above -- snapshot information of any Product info that would be necessary for printing invoices -- as well as tax calculations, fulfillment status, return status, etc. In this case, you would probably want the following relationships:
Product has many LineItems / LineItem belongs to Product Order has many LineItems / LineItem belongs to Order Order has many Products through LineItems Product has many Orders through LineItems HTH... On Tue, Jul 26, 2011 at 10:01 PM, Peter Bell <[email protected]> wrote: > On Jul 26, 2011, at 3:58 PM, KlausG wrote: > > > I whonder why a product should have many orders? It belongs to > > orders.. > > Not being paying much attention to this thread, but whenever I see comments > like this I'm cautious. Bear in mind that if products are mutable (can vary > over time), typically you want to replicate some of their data as of a point > in time so that a order has-many order_items which contain product > information as at that point in time. > > Otherwise if you're not careful, updating the price on your products > completely changes the value of all of your historic orders containing that > product. > > Apologies if it's not relevant to the thread, but if it is, it's something > that should be considered in the design. > > Best Wishes, > Peter > > > > >>> class Customer < ActiveRecord::Base > >>> has_many :orders > >>> end > >>> class Order < ActiveRecord::Base > >>> belongs_to :customer > >>> has_many :products > >>> end > >>> class Product < ActiveRecord::Base > >>> belongs_to :orders > >>> end > > > > -- > > 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. > > > > -- > 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. > > -- 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.
