简单的sql语句，谁能给解决？来都即给分！

Question

如下表:XH                                                 KHCP
-------------------------------------------------- ----------------------------------------
a                                                  a1
a                                                  a2
b                                                  b1
b                                                  b2要的结果如下:XH                                                 result
-------------------------------------------------- ----------------------------------------
a                                                  a1 a2
b                                                  b1 b2大家懂我的意思吗？就是把a的全部加khcp全部连接起来，中间以空格隔开
求解

Answer 1

select xh,replace(wm_concat(khcp),',',' ')result from emp group by xh