no, that's not what I'm looking for product.quantity is the current amount of products purchase.quantity is the amount of products I buy
so the new product.quantity should be the "old" product.quantity + purchase.quantity eg current product.quantity = 5 purchase.quantity = 20 new product.quantity = 25 On Jul 20, 5:32 pm, Tom Meinlschmidt <to...@meinlschmidt.com> wrote: > do you have some relation here? > > eg > > product > has_many :purchases > > puchase (has column product_id) > belongs_to :product > > and in purchase.rb > after_create :increase_product_purchase > > def increase_product_purchase > product.increase_purchase > end > > and in product.rb > > def increase_purchase > update_attribute(:number_of_purchases, number_of_purchases + 1) > end > > On Jul 20, 2011, at 23:08 , Angelo Cordova wrote: > > > > > > > > > > > Hi people > > > I have a doubt. > > > I have 2 tables (models) "Product" and "Purchase". I want to use the > > callback after_create to update the attribute Product.quantity every > > time a Purchase is created, so I think this should be work, but I > > don't know the right syntax > > > In purchase model > > > def after_create > > Product.update(product.quantity = product.quantity + > > purchase.quantity) > > end > > > can somebody help me with this?? > > 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 rubyonrails-talk@googlegroups.com. > > To unsubscribe from this group, send email to > > rubyonrails-talk+unsubscr...@googlegroups.com. > > For more options, visit this group > > athttp://groups.google.com/group/rubyonrails-talk?hl=en. > > -- > =============================================================================== > Tomas Meinlschmidt, MS {MCT, MCP+I, MCSE, AER}, NetApp Filer/NetCache > > www.meinlschmidt.com www.maxwellrender.cz www.lightgems.cz > =============================================================================== -- 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 rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
