| WITH ROLLUP | 按分组列从右向左逐级小计，输出层级汇总行 |
|---|---|
| WITH CUBE | 输出所有列组合的小计 |
| WITH TOTALS | 额外输出一行不分组的总计（键列为 0 或空） |
示例
示例
SELECT
region,
product,
sum(amount) AS total
FROM sales
GROUP BY region, product
WITH ROLLUP
ORDER BY region, product;ROLLUP/CUBE 返回的行含默认值键（如空字符串或 0），前端展示时要与真实分组值区分。