gistfile1.txt

  save_customers false
  save_events true

  total :unique_customers_count,     :sum
  total :events_count,               :sum
  total :events_sum,                 :sum
  total :events_bonus_sum,           :sum
  total :events_discount_sum,        :sum
  total :events_discount_percentage, :avg, type: "numeric(16,2)"
  total :avg_events_sum,             :avg, type: "numeric(16,2)"
  total :avg_payments_per_customer,  :avg, type: "numeric(16,2)"

  attribute :group_by_method, as: :string, values:
    %w{ hour day week month  customer_type event_customer customer_node
        customer_purchases avg_sum_customer_purchases node promo customer_purchase_order }

  source :outer do
    from :inner
    to ->(c) { c.outer_table_name }

    all_columns
    column :group_by_column, :group_by_column_field_value

    where :outer_conditions
  end

  source do
    from :outer
    column :group_by_column
    column :group_by_column_title,      :group_by_column_field_title
    column :unique_customers_count,     "COUNT(DISTINCT customer_id)"
    column :events_count,               "COUNT(event_id)"
    column :events_sum,                 "(SUM(event_sum))::numeric(16,2)"
    column :events_bonus_sum,           "(SUM(event_bonuses))::numeric(16,2)"
    column :events_discount_sum,        "(SUM(event_discount))::numeric(16,2)"
    column :events_discount_percentage, %{
      (
        100.0 * (
          SUM(event_discount) / SUM(event_sum)
        )
      )::numeric(16,2)
    }
    column :avg_events_sum,             "(AVG(event_sum) / 100.0)::numeric(16,2)"
    column :avg_payments_per_customer,  %{
      (COUNT(event_id)::float / COUNT(DISTINCT customer_id)::float)::numeric(16,2)
    }
    column :event_ids,                  "ARRAY_AGG(event_id)"
    column :position,                   "ROW_NUMBER() OVER (ORDER BY group_by_column)"

    group_by "group_by_column, group_by_column_title"
  end