Question

My use case is simple:

Get all ads that have a category name of params[:category_name].

---

Here are my model associations:

class Ad < ActiveRecord::Base
  belongs_to :category

  attr_accessible :anonymous, :celular, :name, :precio, :category_id
end

class Category < ActiveRecord::Base
  has_many :ads

  attr_accessible :name
end

Here is my controller code:

def by_category
  @ads = Ad.where(:category => params[:category_name])
end

But it’s not working as intended and I get an exception:

SQLite3::SQLException: no such column: ads.category: SELECT “ads”.* FROM “ads” WHERE “ads”.”category” = ‘aeronautica’

How can I filter the ad objects by category name?

Answer 1

In your ads database you only have a column called category_id, so searching the ads database for a category name has no use.

 Category.find_by_name(params[:category_name]).ads

This would show all ads for a category with the category_name that is in the params.