Revenue के आधार पर users का bucketing

WITH user_revenues AS (
  SELECT
    -- Select the user IDs and the revenues they generate
    ___,
    ___ AS revenue
  FROM meals AS m
  JOIN orders AS o ON m.meal_id = o.meal_id
  GROUP BY user_id)

SELECT
  -- Fill in the bucketing conditions
  CASE
    WHEN ___ THEN 'Low-revenue users'
    WHEN ___ THEN 'Mid-revenue users'
    ELSE 'High-revenue users'
  END AS revenue_group,
  ___ AS users
FROM user_revenues
GROUP BY revenue_group;