Group using Sunspot/Solr? - ruby-on-rails

Question

I'm having some problem searching by group when using Sunspot.
Here is an example:
# == Schema Information
#
# Table name: movies
#
# id :integer(4) not null, primary key
# title :string(255)
class Movie < ActiveRecord::Base
has_and_belongs_to_many :actors
searchable do
text :title
integer :ages, multiple: true do
actors.map(&:age)
end
text :names, multiple: true do
actors.map(&:name)
end
end
end
# == Schema Information
#
# Table name: actors
#
# id :integer(4) not null, primary key
# name :string(255)
# age :integer(30)
class Actor < ActiveRecord::Base
has_and_belongs_to_many :movies
searchable do
integer :age
text :name
end
end
I want to find every movie that has an actor named John at age 30.
Movie.search do
with(:names).equal_to("John")
with(:ages).equal_to(30)
with(:title).equal_to("...")
# ...
end
The problem is here that it may find a movie that has two actors; one named John and one at age 30. Is there a way to somehow group this together so that the movie found have an actor named John at age 30?

Answer 1

The solution, just like Maurício Linhares wrote in his comment, is to go through the actors model and group by movies.
The problem is that Sunspot doesn't support Solr 3.3 or 4.0, which is the only Solr versions that support grouping.
Here is my solution using Sunspot 1.2.1 and Solr 3.3.
In my example movie_id is placed in the actors table, this isn't done in my real application.
# == Schema Information
#
# Table name: actors
#
# id :integer(4) not null, primary key
# name :string(255)
# created_at :datetime
# updated_at :datetime
# movie_id :integer(4)
#
class Actor < ActiveRecord::Base
searchable do
# We need to store the movie_id as an string
# So it can be sorted. We also need to pass the
# stored: true params
string :movie_id, stored: true do
movie_id.to_s
end
end
def search_using_solr
scoped = Sunspot.new_search(Actor)
scoped.build do
adjust_solr_params do |params|
params[:group] = true
params[:"group.field"] = "movie_id_s"
params[:"group.format"] = "simple"
end
end
# Sunspot 1.2.1 doesn't support grouping, so we need to do some hacking.
def scoped.hits
#hits ||= #solr_result["grouped"].values.first["doclist"]["docs"].map do |doc|
Sunspot::Search::Hit.new(doc, nil, self)
end
end
def scoped.total
#total ||= #solr_result["grouped"]["movie_id_s"]["matches"] || 0
end
# Here we'll only fetch the stored data from Solr it self,
# and then pass it manualy to ActiveRecord.
Movie.where({
id: scoped.execute.hits.map{ |h| h.stored(:movie_id) }
})
end
end
Cred to alindeman for his example gist.