How do I bucket orders as bulk vs single at a quantity threshold of 2 in SQL?

SELECT
  CASE WHEN quantity >= 2 THEN 'bulk' ELSE 'single' END AS order_size,
  COUNT(*) AS orders,
  SUM(quantity * unit_price) AS revenue
FROM data
GROUP BY order_size;

Moving the threshold in `CASE WHEN quantity >= 2` changes where the split between "bulk" and "single" falls, without changing the shape of the query — the bucketed label still becomes a group-able column exactly like a real one.

A table named data with columns: order_id (integer), customer (text), country (text), category (text), quantity (integer), unit_price (real), order_date (text, YYYY-MM-DD).