Group By multiple column for sql count statement , in rails environment - sql

Question

I have two Relations (class)
class RecommendedForType < ActiveRecord::Base
attr_accessible :description, :name
has_many :recommended_for_type_restaurants
end
And
class RecommendedForTypeRestaurant < ActiveRecord::Base
attr_accessible :recommended_for_type_id, :restaurant_id, :user_id
belongs_to :restaurant
belongs_to :user
belongs_to :recommended_for_type
def self.get_count(rest_id)
r = RecommendedForTypeRestaurant.where(restaurant_id: rest_id)
#result = r.includes(:recommended_for_type)
.select("recommended_for_type_id, recommended_for_types.name")
.group ("recommended_tor_type_id, recommended_for_types.name")
.count
end
end
if I call
RecommendedForTypeRestaurant.get_count(1) # get stat of restaurant_id: 1
I get
{"dinner"=>1, "fast food"=>1, "lunch"=>3, "romantic dinner"=>1}
My goal is to get both id and name of RecommendTypeFor in the return result as well. currently i can only make it return either id or name. Something like this
{{"id" => 1, "name" => "dinner", "count" => 1}, {"id" =>2, "name" => "lunch", "count" => 3} }
For sure i can do another round of sql once i get id or name to create that hash but i think that not the efficient way. Appreciate any help or suggestion :)

Answer 1

You need to group separately, try the following group.
.group ("recommended_tor_type_id", "recommended_for_types.name").count

Answer 2

I believe that if you remove the .count at the end and change the select to:
.select("count(*), recommended_for_type_id, recommended_for_types.name")
You will get an array of models that will have the attributes you need and the count.
You should be able to test it out in the console by do something like this:
r = RecommendedForTypeRestaurant.where(restaurant_id: rest_id)
#result = r.includes(:recommended_for_type)
.select("recommended_for_type_id, recommended_for_types.name, count(*)")
.group ("recommended_tor_type_id, recommended_for_types.name")
#result.each do |r|
puts r.recommended_for_type_id
puts r.name
puts r.count
end
Hope it helps!