Sequel dataset extension. For a reporting page query params can be given. These are used for the selects, joins, filters etc. I tried an approach where methods (like: apply_joins, apply_filters, etc.) passed the dataset around but this is cumbersome. Thinking you can also extend dataset it would prevent passing the dataset around. But now im hav…

test.rb

module Stats
  def select_metrics(metrics)
    metrics.inject(self) do |ds, metric|
      ds.select_metric(metric)
    end
  end

  def select_metric(metric)
    case metric
      when 'total'
        select_append{ count(subject_picks__id).as(total) }
      when 'odd_avg'
        select_append{ round(avg(subject_picks__odd), ROUND_TO_DECIMALS).as(odd_avg) }
      # ...
    end
  end
end

DB[:my_table].extend(Stats).
  select(:user_id).
  select_metrics(['total', 'odd_avg']).
  group(:user_id).
  all