group by语句加序号的问题

[tjm1]

表有a, b, c三个字段，数据如下：

A B C
---------------
A A 1
A B 2
B A 3
B A 4

要求对a, b字段分组，对c求和，实现如下效果：

序号 A B C
-------------------
1 A A 1
2 A B 2
1 B A 7

上面的序号(流水号)怎么实现，用一句sql?

[hongqi162]

select rownum ,t.* from
(select a,b,sum(c) c from t2 group by a,b) t

[tjm1]

我试了，不是我想要的结果：
1 a a 1
2 a b 2
3 b a 7

[dragon188]

SELECT row_number() OVER(PARTITION BY A ORDER BY A) XL,T.* FROM (
SELECT A,B,SUM(C) C FROM (
SELECT 'A' A,'A' B,1 C FROM DUAL
UNION
SELECT 'A' A,'B' B,2 C FROM DUAL
UNION
SELECT 'B' A,'A' B,3 C FROM DUAL
UNION
SELECT 'B' A,'A' B,4 C FROM DUAL)
GROUP BY A,B
)T

[bjt_]

select rank() over (partition by t.a order by t.b),a,b,sum(c) c
from t2 group by a,b