Issue with datatable

reports_datatable.rb

class CampaignOfferIspReportDatatable < AjaxDatatablesRails::Base
  def sortable_columns
    # Declare strings in this format: ModelName.column_name
    @sortable_columns ||= [
      'Offer.name',
      'Campaign.name',
      'Carrier.name',
      'visits',
      'clicks',
      'conversions',
      'revenue',
      'cost',
      'profit',
      'roi',
    ]
  end

  def searchable_columns
    # Declare strings in this format: ModelName.column_name
    @searchable_columns ||= [
      'Offer.name',
      'Campaign.name',
      'Carrier.name',
    ]
  end

  private

  def data
    records.decorate.map do |record|
      [
        record.o_name,
        record.c_name,
        record.isp_name,
        record.visits,
        record.clicks,
        record.conversions,
        record.format_revenue,
        record.format_cost,
        record.format_profit,
        record.format_roi,
        record.format_cpv,
        record.format_epv,
        record.detail_link
      ]
    end
  end

  def get_raw_records
    daterange = Calculation.get_start_and_end_time(options[:daterange])
    CampaignOfferIspReport.joins(campaign_offer: [:offer, :campaign]).joins(:carrier)
    .where('offers.active = ?', true)
    .where("start_time >= '#{daterange[:start_time]}'")
    .where("end_time <= '#{daterange[:end_time]}'")
    .having('sum(`campaign_offer_isp_reports`.`visits`) > ?',options[:min_visits].to_i)
    .group(:campaign_offer_id, :carrier_id)
    .select("carriers.name as isp_name","campaigns.name as c_name", "offers.name as o_name", :campaign_offer_id, :carrier_id, "sum(`campaign_offer_isp_reports`.`clicks`) as clicks","sum(`campaign_offer_isp_reports`.`cost`) as cost","sum(`campaign_offer_isp_reports`.`revenue`) as revenue", "sum(`campaign_offer_isp_reports`.`profit`) as profit", "sum(`campaign_offer_isp_reports`.`conversions`) as conversions", "sum(`campaign_offer_isp_reports`.`visits`) as visits" ,"MIN(`campaign_offer_isp_reports`.`start_time`) as start_time", "MAX(`campaign_offer_isp_reports`.`end_time`) as end_time")
    .select("(((sum(`campaign_offer_isp_reports`.`revenue`) - sum(`campaign_offer_isp_reports`.`cost`)) / sum(`campaign_offer_isp_reports`.`cost`) ) * 100) as roi")
    .select("(sum(`campaign_offer_isp_reports`.`cost`) / sum(`campaign_offer_isp_reports`.`visits`)) as cpv")
    .select("(sum(`campaign_offer_isp_reports`.`cost`) / sum(`campaign_offer_isp_reports`.`clicks`)) as cpc")
    .select("(sum(`campaign_offer_isp_reports`.`revenue`) / sum(`campaign_offer_isp_reports`.`visits`)) as epv")
  end
end