I have another problem finally I used
In Purchase model def after_create product.update_attribute(:quantity, product.quantity + quantity) end and it works fine, but now I'm trying to do something else with the update. I mean, sometimes you can input some wrong data, so you need to update values. So I was thinking in update the purchase.quantity and then automagically update the product.quantity, so I tried this def before_update product.update_attribute(:quantity, product.quantity - purchase.quantity) end def after_update product.update_attribute(:quantity, product.quantity + purchase.quantity) end but, that didn't work, in both cases purchase.quantity is the new value, and I need in the first case (before_update) the original value and in the second case (after_update) the new value for purchase.quantity On Jul 20, 6:21 pm, Angelo Cordova <acord...@gmail.com> wrote: > 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.