Oracle sql命令按字符顺序排列

Question

美好的一天，也许有人可以帮助我，我想在oracle sql上获得n选择输出，但是当我按顺序排序时它是不正确的。

code_order
1.
2.
2.1
3.
4.2
10.1
10.0
21.
21.1
23.
31.

它需要按数字排序，所有值都在.

中有句号

任何想法??

Thanx，但我发现某些值可以包含非数字值，如C，B等。

1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 7C。 40. 50. 51. 6。
表格大纲：

code_order是varchar2

Answer 1

使用order by to_number(code_order)

Answer 2

    with
    val as
    (
      SELECT '1.' as c FROM dual
      union all
      SELECT '2.' as c FROM dual
      union all
      SELECT '3.' as c FROM dual
      union all
      SELECT '2.1' as c FROM dual
      union all
      SELECT '4.2' as c FROM dual
      union all
      SELECT '10.1' as c FROM dual
      union all
      SELECT '21.' as c FROM dual
      union all
      SELECT '10.0' as c FROM dual
      union all
      SELECT '21.1' as c FROM dual
      union all
      SELECT '23.' as c FROM dual
      union all
      SELECT '31.' as c FROM dual
    )
SELECT c FROM val
order by to_number(regexp_replace(c, '^(\d+)\..*$', '\1'))
    ;