# Named collection forward fetching **URL:** \ **Category:** Rails\ **Created:** [March 4, 2008, 7:45pm UTC](https://www.ruby-forum.com/t/named-collection-forward-fetching/130955 "2008-03-04T19:45:53Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![grayson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/c77e96/32.png) [@grayson](https://www.ruby-forum.com/u/grayson)\ **Post date:** [March 4, 2008, 7:45pm UTC](https://www.ruby-forum.com/t/named-collection-forward-fetching/130955/1 "2008-03-04T19:45:53Z")
Hello, I’m getting an “NoMethodError” traversing a named collection. Let me explain I have a named collection called best\_friend in a class called user def self.best\_friend find :all, :conditions =\> “designation = ‘Best Friend’” end and if i do current\_user.best\_friend everything works great, I can pull up the user’s name as an example. My user model has a one-to-many relationship with interests. If I do current\_user.best\_friend.interests however it gives a no method error. Does this have anything to do with attr\_reader / attr\_writer? Thanks, GP ---
**Author:** ![grayson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/c77e96/32.png) [@grayson](https://www.ruby-forum.com/u/grayson)\ **Post date:** [March 4, 2008, 8:29pm UTC](https://www.ruby-forum.com/t/named-collection-forward-fetching/130955/2 "2008-03-04T20:29:46Z")
Grayson P. wrote: > def self.best\_friend > find :all, :conditions =\> “designation = ‘Best Friend’” > end > > and if i do current\_user.best\_friend everything works great, I can pull > up the user’s name as an example. My user model has a one-to-many > relationship with interests. If I do current\_user.best\_friend.interests > however it gives a no method error. The result of a “find :all” is an array, so your #best\_friend method returns an array which doesn’t respond (normally!) to #interests. If you change to “find :first” then this will work (except when there is no best friend, in which case #best\_friend would return nil and you’d get an error trying to call #interests on nil). ---
**Author:** ![grayson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/c77e96/32.png) [@grayson](https://www.ruby-forum.com/u/grayson)\ **Post date:** [March 5, 2008, 4:10am UTC](https://www.ruby-forum.com/t/named-collection-forward-fetching/130955/3 "2008-03-05T04:10:37Z")
On Tue, Mar 4, 2008 at 1:45 PM, Grayson P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > end > > and if i do current\_user.best\_friend everything works great, I can pull > up the user’s name as an example. My user model has a one-to-many > relationship with interests. If I do current\_user.best\_friend.interests > however it gives a no method error. you’ve defined a class level method. You’re calling it on an instance of your class. This shouldn’t even work. say you’ve got a typo and it’s actually defined as an instance method and you’re trying current\_user.best\_friend, you’re going to get an array of values returned. Of course the array has no ‘interests’ method, since that’s defined in your user model. I think what you may want is something like the following: def best\_friend User.find :first, :conditions =\> [‘designation = ?’, ‘Best Friend’] end but… looking back on your original method, it doesn’t really make sense to me. You’ve got: def self.best\_friend find :all, :conditions =\> “designation = ‘Best Friend’” end so you want to find all the users who are designated as a ‘Best Friend’. But a best friend to whom? Say you’ve got 10 users and each of them has ‘Best Friend’ set, so that means everyone is a best friend to everyone else, which is probably not what you want. I think what you want is either a self referential join, so each user can have an arbitrary number of best friends, or give each user a ‘best\_friend\_id’ and use a has\_one :best\_friend, :class =\> ‘User’ association if you only want each user to have a single best friend. Mike ---
**Author:** ![grayson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/c77e96/32.png) [@grayson](https://www.ruby-forum.com/u/grayson)\ **Post date:** [March 5, 2008, 1:01pm UTC](https://www.ruby-forum.com/t/named-collection-forward-fetching/130955/4 "2008-03-05T13:01:33Z")
On 4 Mar 2008, at 18:45, Grayson P. wrote: > end > > and if i do current\_user.best\_friend everything works great, I can > pull > up the user’s name as an example. My user model has a one-to-many > relationship with interests. If I do > current\_user.best\_friend.interests > however it gives a no method error. > Of course: your best\_friend method returns an array (bit odd that a > method return a collection is a singular). That array doesn’t have an > interests method, though its members do. > ALso from the code you’ve posted you’ve made best\_friend a class > method rather than an instance method. > Finally, why not use an association for this? Fred ---
**Author:** ![grayson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/c77e96/32.png) [@grayson](https://www.ruby-forum.com/u/grayson)\ **Post date:** [March 5, 2008, 1:45am UTC](https://www.ruby-forum.com/t/named-collection-forward-fetching/130955/5 "2008-03-05T01:45:54Z")
Mark B. wrote: > Grayson P. wrote: > > > def self.best\_friend > > find :all, :conditions =\> “designation = ‘Best Friend’” > > end > > > > and if i do current\_user.best\_friend everything works great, I can pull > > up the user’s name as an example. My user model has a one-to-many > > relationship with interests. If I do current\_user.best\_friend.interests > > however it gives a no method error. > > The result of a “find :all” is an array, so your #best\_friend method > returns an array which doesn’t respond (normally!) to #interests. If > you change to “find :first” then this will work (except when there is no > best friend, in which case #best\_friend would return nil and you’d get > an error trying to call #interests on nil). Mark, Thank you. That fixed it. It’s always the simple things that get you. GP