Question

I have the following model classes…

class Image < ActiveRecord::Base
  attr_accessible :description, :title
  has_many :imageTags
  has_many :tags, :through => :imageTags
end

class Tag < ActiveRecord::Base
  attr_accessible :name
  has_many :imageTags
  has_many :images, :through => :imageTags
end

class ImageTag < ActiveRecord::Base
  attr_accessible :position
  belongs_to :image
  belongs_to :tag
end

And when I use find for getting the Tag with the id 1

t = Tag.find(1);
@images = t.images;

But when I do the same with where, I get a NoMethodError, with the description undefined method 'images':

t = Tag.where(:name => "foo");
@images = t.images;

I also tried adding .includes(:images) before the .where statement, but that doesn’t work too. So, how can I get all Images that belong to a Tag?

Answer 1

.where returns an ActiveRecord::Relation instance, not a single object. Tack on a .first to grab (presumably) the only record returned:

t = Tag.where(name: "foo").first
@images = t.images