Why this works for one Model (SibTransac) and don't work for the other (DbCampaign)?!

camps_to_update_controller.rb

def update
    def db_campaign
      @db_campaign = DbCampaign.find_by_id(params[:id])
    end
    respond_to do |format|
      @db_campaign = DbCampaign.find_by_id(params[:id])
      if @db_campaign.update(db_campaign_params)
        format.html { redirect_to @db_campaign, notice: 'Campaign was successfully updated.' }
        format.json { render :show, status: :ok, location: @db_campaign }
        calculate_kpi
      else
        format.html { render :edit }
        format.json { render json: @db_campaign.errors, status: :unprocessable_entity }
      end
    end
  end
  # Calculate the KPIs for a single campaign beign edited
  def calculate_kpi
    @db_campaign = DbCampaign.find_by_id(params[:id])
    turnover = (@db_campaign.payout.to_f * @db_campaign.result.to_f)
    cost = (@db_campaign.sent.to_f * @db_campaign.cpm.to_f) / 1000
    @db_campaign.update_column(:turnover, turnover)
    @db_campaign.update_column(:cost, cost)

    margin = @db_campaign.turnover.to_f - @db_campaign.cost.to_f
    ecpm = (@db_campaign.turnover.to_f / @db_campaign.sent.to_f) * 1000
    orate = (@db_campaign.unique_views.to_f / @db_campaign.sent.to_f) * 100
    crate = (@db_campaign.clicker.to_f / @db_campaign.sent.to_f) * 100


    @db_campaign.update_column(:margin, margin)
    @db_campaign.update_column(:ecpm, ecpm)
    @db_campaign.update_column(:orate, orate)
    @db_campaign.update_column(:crate, crate)
  end

sib_transac_controller.rb

def update
    def single_day_transac
      @single_day_transac = SibTransac.find_by_id(params[:id])
    end
    respond_to do |format|
      if @sib_transac.update(sib_transac_params)
        format.html { redirect_to @sib_transac, notice: 'Sib transac was successfully updated.' }
        format.json { render :show, status: :ok, location: @sib_transac }
        calculate_kpi
      else
        format.html { render :edit }
        format.json { render json: @sib_transac.errors, status: :unprocessable_entity }
      end
    end
  end

  # Calculate the KPIs for a single day beign edited
  def calculate_kpi
    @single_day_transac = SibTransac.find_by_id(params[:id])
    turnover = (@single_day_transac.payout.to_f * @single_day_transac.result.to_f)
    cost = (@single_day_transac.requests.to_f * @single_day_transac.cpm.to_f) / 1000
    @single_day_transac.update_column(:turnover, turnover)
    @single_day_transac.update_column(:cost, cost)


    margin = (@single_day_transac.turnover.to_f - @single_day_transac.cost.to_f)
    ecpm = (@single_day_transac.turnover.to_f / @single_day_transac.requests.to_f) * 1000
    orate = (@single_day_transac.unique_opens.to_f / @single_day_transac.requests.to_f) * 100
    crate = (@single_day_transac.unique_clicks.to_f / @single_day_transac.requests.to_f) * 100


    @single_day_transac.update_column(:margin, margin)
    @single_day_transac.update_column(:ecpm, ecpm)
    @single_day_transac.update_column(:orate, orate)
    @single_day_transac.update_column(:crate, crate)
  end