Ah, got it. Then how would one display that on a custom show view? I tried <% this.rating %> and <% book.rating %> but that doesn't seem to do the trick... Sorry for the newb question!
Thanks, Jake On Apr 29, 3:14 pm, Bryan Larsen <[email protected]> wrote: > It should be fairly easy. For instance, you can add this to your book model: > > def rating > reviews.average('rating') > end > > assuming that the column on the review model is called rating. > > Bryan > > > > > > > > On Sun, Apr 29, 2012 at 2:43 PM, Jake K <[email protected]> wrote: > > Hi Brain, > > > Thanks for the hint! Is it possible to calculate the average of a star > > rating field, for example, from all of the reviews (children) of a > > book (parent)? Or would this only work if I were trying to calculate > > an average of some field within a single model? If it's possible to > > calculate this for a parent based on all its children, would I want to > > put the calculation in the child model or the parent model? > > > Thanks, > > Jake > > > On Apr 29, 9:22 am, Bryan Larsen <[email protected]> wrote: > >> Here's a starting hint: > > >>http://ar.rubyonrails.org/classes/ActiveRecord/Calculations/ClassMeth... > > >> If you need more help than a hint, don't be afraid to ask. > > >> Bryan > > >> On Sat, Apr 28, 2012 at 6:07 PM, Jake K <[email protected]> wrote: > >> > Hi all, > > >> > I'm making a review application, and am working with two kinds of > >> > items - "books" and "reviews", where books have many reviews and > >> > reviews are children of books. Each review has a few integer fields > >> > where reviewers can rate some quality of the book. How would I go > >> > about calculating an average value for some question from all the > >> > reviews, and display it on the book's view page? Essentially I'm > >> > trying to show the average star rating for a book based on all the > >> > star values in its children reviews. > > >> > Thanks for any advice! > >> > -Jake > > >> > -- > >> > You received this message because you are subscribed to the Google > >> > Groups "Hobo Users" 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 > >> > athttp://groups.google.com/group/hobousers?hl=en. > > > -- > > You received this message because you are subscribed to the Google Groups > > "Hobo Users" 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 > > athttp://groups.google.com/group/hobousers?hl=en. -- You received this message because you are subscribed to the Google Groups "Hobo Users" 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/hobousers?hl=en.
