Hi people I have a problem trying to update an attribute of one model using the value from another model, but those two models are not related.
My models are: class Order < ActiveRecord::Base has_many :order_details has_many :waybills end class OrderDetail < ActiveRecord::Base belongs_to :order, :foreign_key => "order_id" belongs_to :product, :foreign_key => "product_id" end class Waybill < ActiveRecord::Base has_many :purchases belongs_to :order, :foreign_key => 'order_id' end class Purchase < ActiveRecord::Base belongs_to :waybill, :foreign_key => 'waybill_id' has_many :detail_purchases end class DetailPurchase < ActiveRecord::Base belongs_to :purchase, :foreign_key => 'purchase_id' belongs_to :product, :foreign_key => 'product_id' end So, as you can see... a "DetailPurchase" belongs to an "Order", but in an indirect way. And an "OrderDetail" belongs to an "Order" directly. I need to update the attribute "quantity" of the product of "OrderDetail" using the attribute "quantity" of the product of "DetailPurchase". The idea is the "new" OrderDetail.quantity = "old" OrderDeatil.quantity - DetailPurchase.quantity (and obviously the product_id has to be the same) So, i don't know how to "write" the query using the "rails way" (could be "Model.find()", "Model.where()", "Model.update_attribute()") or just use a raw sql query (by the way, I don't know how to write or execute raw sql queries) What do you recommend? Thanks -- 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.
