在SQL中，如何根据用户拥有的项目数量对用户进行细分？(红移)

SELECT user_id, COUNT(project_id) AS project_count
FROM projects
GROUP BY user_id

SELECT project_count_range, COUNT(user_id) AS user_count
FROM (
    SELECT user_id, COUNT(project_id) AS project_count,
        CASE
            WHEN COUNT(project_id) <= 5 THEN '1-5'
            WHEN COUNT(project_id) <= 10 THEN '6-10'
            ELSE '11+'
        END AS project_count_range
    FROM projects
    GROUP BY user_id
) AS subquery
GROUP BY project_count_range