How to display query result in a Hash in view Ruby On rails

Question

My controller has the following query :

# reports_between_two_dates is already defined
@data_count_by_city = reports_between_two_dates
                        .joins('JOIN "places" ON "places"."id"="reported_regs"."reported_place_id" JOIN "cities" ON "places"."city_id" = "cities"."id" ')
                        .where('"reported_regs"."reported_place_id" IN (SELECT "places"."id" FROM "places") AND "places"."city_id" IN (SELECT "cities"."id" FROM "cities")')
                        .group('"display_name"')
                        .select('COUNT(*) AS count, "display_name" AS cities')
                        .order('count DESC')
                        .limit(3)

I also have this in the controller :

respond_to do |format|
  format.js { 
    render json: { 
    html: render_to_string(
      partial: 'data_stats', 
      locals: { 
        data_count_by_city: @data_count_by_city
    }) } }
  format.html
end

The query's result in psql is as follows :

 count |    cities     
-------+---------------
   409 | NYC
   244 | SF
   156 | LA

My end goal is to display the above result as a hash, having as keys the cities, and the count as values..

In the view I've tried doing :

<td><%= Hash[@data_count_by_city.map{ |r| [r.cities,r.count] }] %></td>

But all I get is an empty hash.. What am I missing?

Answer 1

It appears the relation was returning no results (empty relation: #<ActiveRecord::Relation []> ). OP find out he was running the query on Production and the code on a different environment.

Other than that, the code seems to work as expected, as long as @data_count_by_city stores an array-like structure with both cities and count . On that note, I think

.group('display_name').count shouldn't need the .select('COUNT(*) AS count, "display_name" AS cities')