Querying through polymorphic associations

Question

Just playing around RoR, trying to find a way through some modelling. Please, mind the code below:

 class Picture < ActiveRecord::Base
      belongs_to :imageable, :polymorphic => true
 end

 class Employee < ActiveRecord::Base
      has_many :pictures, :as => :imageable
 end

 class Product < ActiveRecord::Base
      has_many :pictures, :as => :imageable
 end

Is there a way to get a Product by its specific Picture? I'm trying this, but its not working:

picure = Picture.last
product = Product.where(picture: picure)

Its failing with:

SQLite3::SQLException: no such column: products.picture: SELECT "products".*
FROM "products" WHERE "products"."picture" IS NULL LIMIT 1```

Answer 1

如果你有一个实例Picture @picture ，您可以使用belongs_to得到它相关的Product （假设它的Picture实际上是属于实例Product ，而不是Employee ）

product = @picture.imageable