[Perc Total - Over time - Part 2] How to compute a percentage of total in BigQuery using SQL #SQL #BigQuery

over_time_percentage.sql

WITH
  revenue_product AS (
  SELECT
    product_category,
    DATE(DATE_TRUNC(order_date,MONTH)) AS order_month,
    ROUND(SUM(product_revenue),0) AS revenue_per_category
  FROM
    `datastic.variables.base_table`
  GROUP BY
    1,
    2)
  -- Main Query
SELECT
  *
FROM (
  SELECT
    *,
    SAFE_DIVIDE(revenue_per_category,
      SUM(revenue_per_category) OVER(PARTITION BY order_month)) AS ratio
  FROM
    revenue_product) a 
WHERE
  product_category IN ('Apparel',
    'Office',
    'Drinkware',
    'Other')