analytics

class ReportsController < ApplicationController
  def monthly_sales
    year = params.fetch(:year, Date.current.year).to_i
    rows = Order.monthly_sales(year: year)
    @report = MonthlySalesReport.new(rows, year: year)

-- ROLLUP for hierarchical subtotals
SELECT
  COALESCE(category, 'ALL CATEGORIES') AS category,
  COALESCE(subcategory, 'ALL SUBCATEGORIES') AS subcategory,
  SUM(revenue) AS total_revenue,
  COUNT(*) AS order_count