Rails polymorphic has_many :through

问题:

I'm pulling some data from an external API and would like to cache the results locally. I have a class SearchTerm, which I would like to be associated with a few different ActiveRecord types through the table searchable_items. I'm pretty sure I have the tables set up correctly, but something in my associations must be wrong.

class Foo  :searchable, :through => :searchable_items end  class Bar  :searchable, :through => :searchable_items end  class SearchTerm  :searchable_items end  class SearchableItem  true end 

I would expect to be able to do something like SearchTerm.find_by_term('SearchTerm').searchables (and it would return an array of Foo and Bar objects) however, I get the error Could not find the association :searchable_items in model SearchTerm

Thanks in advance for any insight you can provide to me!

回答1:

You need to add has_many :searchable_items association to Foo, Bar and SearchTerm models because :through => :searchable_items option refers to that association.

http://guides.rubyonrails.org/association_basics.html#the-has_many-through-association

文章来源: Rails polymorphic has_many :through