两字段相同时.第三字段数据合并起来,该如何实现?
条件是:字段f1,f2相同时,把字f3的内容合并.sql语句该如何实现?   
 示例如下: 
 f1	f2	f3 
 0001	A	AA 
 0002	B	AC 
 0001	A   	AB 
 0003	C	BD 
 0001	A	BD   
 需要得出结果: 
 f1	f2	f3 
 001	A	AA/AB/BD 
 002	B	AC 
 003	C	BD
------解决方案--------------------select t.f1, 
 	   t.f2, 
 (select max(sys_connect_by_path(f3, '/ ')) result from  
                (select f1||f2 temp,f3,rn,lead(rn) over(partition by f1||f2 order by rn) rn1  
                from (select f1, f2, f3, row_number() over(order by f1, f2 desc) rn  
 			   		 	from t_test ) 
                ) 
         start with temp = t.temp and rn1 is null connect by rn1 = prior rn 
        ) value 
 from (select distinct f1, f2, f1||f2 as temp from t_test) t 
 --------------------------- 
 调试过,可以用的