test:

c1   c2

1    a

1     b

2     c

select
            to_char(wmsys.wm_concat(c2))                                   ,
            to_char(replace(wmsys.wm_concat(c2),‘,‘,‘/‘))

     from
            test   

  group by
             c1

show case:

1     a,b   a/b

2      c       c

同样的功能函数：

 select listagg(c2,‘,‘) within group(order by c1)        from test      ;  

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