ACCESS 如何实现如下分组逐行累加？

Question

表：
序号 类型 NUM1 NUM2
1 A 1 0
2 B 2 0
3 C 5 4
4 A 4 -2
5 B 0 1
6 C 2 1
实现如下查询：
序号 类型 NUM1 NUM2 累加
1 A 1 0 1
4 A 4 -2 3
2 B 2 0 2
5 B 0 1 3
3 C 5 4 9
6 C 2 1 12
请教来的
SELECT 序号,类型,num1,num2,
(select sum(num1+num2) from 表4 where 类型=t.类型 and 序号<=t.序号) as 累加 from 表4 t order by 类型,序号

Answer 1

给一个DB2的
SELECT t2.A, SUM(t1.A)
FROM (SELECT a, ROW_NUMBER() OVER(ORDER BY A) RK from tab) t1, (SELECT a, ROW_NUMBER() OVER(ORDER BY A) RK from tab) t2
WHERE t1.rk <= t2.rk
group by t2.a
ORDER BY T2.A