Rails includes with scope

ruby-on-rails activerecord scope rails-activerecord
MonsieurNinja picture MonsieurNinja · Oct 2, 2014 · Viewed 33.1k times · Source

I have a model called Author. An author has many Articles. Articles have a scope called .published that does: where(published: true).

I want to load the author, with the published articles. I tried:

Author.includes(:articles.published).find(params[:author_id])

But that throws an error: undefined method 'published'. Any idea?

Answer

NikCasper picture NikCasper · Oct 19, 2015

I think the best solution would be:

Author.includes(:articles).where(:articles=>{published: true}).find(params[:author_id])

Or you can create scope:

class Author < ActiveRecord::Base 
    scope :with_published_articles, -> { includes(:articles).where(articles: { published: true}) }
end

and then:

Author.with_published_articles.find(params[:author_id].to_s)

Related questions

default_scope in rails 3

I know named_scope has been changed to scope in rails 3. How do I perform default_scope in rails 3, I've had a good google but found nothing for defaults scopes.

Read More
How to drop columns using Rails migration

What's the syntax for dropping a database table column through a Rails migration?

Read More
Rails: select unique values from a column

I already have a working solution, but I would really like to know why this doesn't work: ratings = Model.select(:rating).uniq ratings.each { |r| puts r.rating } It selects, but don't print unique values, it prints all values, including …

Read More