SQL，它在给定的起点和终点之间生成字母序列

3 回答

• 6

  select chr(ascii('C') + level - 1) 
  from dual
  connect by ascii('C') + level - 1 <= ascii('G');
  

  像这样使用 connect by （没有 start with 和只取决于级别的结束条件）是未记录的（并且不受支持），因此它可能会中断任何时间（尽管我不知道任何不适用的版本） .

  从11.2开始，您还可以使用递归公用表表达式：

  with letters (letter, inc) as (
     select 'C', 1 as inc
     from dual
     union all
     select chr(ascii('C') + p.inc), p.inc + 1
     from letters p
     where p.inc < 5
  )
  select letter
  from letters;
  

  回复于 2023-09-27T07:52:24+00:00
• 0

  这样的事情起作用了

  WITH X AS
  (SELECT 'C' as St, 'G' as En FROM dual)
  SELECT CHR(ASCII(X.St)+ROWNUM-1)
  FROM X
  CONNECT BY ROWNUM<=(ASCII(X.En)-ASCII(X.St)+1)
  

  回复于 2023-09-27T07:52:24+00:00
• 0

  修改了@a_horse_with_no_name，如下所示

  WITH X(lettr) AS 
  (SELECT 'C' lettr FROM DUAL
   UNION ALL
   SELECT CHR(ASCII(X.lettr)+1) letter
   FROM X 
   WHERE ASCII(X.lettr)<ASCII('G'))
   SELECT * FROM X
  

  回复于 2023-09-27T07:52:24+00:00