用regexp_replace去注释

/*-/-*-/*-*-*/a/*哈哈**-*/b/*嘿嘿*/c

with t1 as
 (select '/*-/-*-/*-*-*/a/*哈哈**-*/b/*嘿嘿*/c' as v1 from dual)
select v1,
       regexp_replace(v1, '\/\*.*?\*\/', '') as v2
  from t1
  
 V1                                   V2
------------------------------------ ----
/*-/-*-/*-*-*/a/*哈哈**-*/b/*嘿嘿*/c  abc