Question

ORACLE 10g，如何将不同ID号的数据按ID顺序合并成一行

数据举例：
表A：
code ID context
01 1 hh
01 2 dd
01 3 c,c
02 1 ww
02 2 e,e
02 3 tt
查询出的结果应为：
code ID context
01 1 hhddc,c
02 1 wwe,ett
既按code分组，再按ID顺序将context合并为一行，在ORACLE 10g环境，我试了wm_concat函数，select wm_concat(context) from A group by code;发现不能按ID顺序合并，请高手指教！

Answer 1

加上order by 试试

select wm_concat(context) from A group by code
order by code,id;

或者

select wm_concat(context) from A group by code
order by id;

追问

这两条SQL均在 order by 之后报：不是group by 表达式

追答

select code,substr(max(sys_connect_by_path(context,',')),2) context from (select a.*,row_number()over(partition by code order by id) rn from a) group by code
start with rn=1
connect by rn-1=prior rn and code=prior code
order by code;