在SQL中，聚合函数可以帮助我们对数据进行汇总和计算。以下是一些灵活使用聚合函数的方法：
SELECT column1, SUM(column2)
FROM table_name
GROUP BY column1;
SELECT column1, SUM(column2)
FROM table_name
GROUP BY column1
HAVING SUM(column2) > 100;
SELECT MAX(SUM(column1))
FROM table_name
GROUP BY column2;
SELECT column1,
(SELECT SUM(column2) FROM table_name WHERE column1 = t1.column1) AS total_sum
FROM table_name AS t1;
总的来说，在SQL中可以通过灵活组合和运用聚合函数，实现对数据的多维度分析和计算。
