Thanks for your help The last option worked for me
def increase_product_purchase product.update_attribute(:quantity, product.quantity + quantity) end it was pretty simple, but I couldn't figured out... Thanks again On Jul 20, 6:03 pm, Tom Meinlschmidt <to...@meinlschmidt.com> wrote: > God, > > def increase_product_purchase > product.increase_quantity(quantity) > end > > in product > def increase_quantity(quantity) > update_attribute(:quantity, number_of_purchases + quantity) > end > > or simply in purchase > > def increase_product_purchase > product.update_attribute(:quantity, product.quantity + quantity) > end > > ? > > On Jul 20, 2011, at 23:55 , Angelo Cordova wrote: > > > > > > > > > > > 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.comwww.maxwellrender.czwww.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 > > 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.
