实现AAAA到ZZZZ

[碧水幽幽泉]

现在有这样一个需求，
实现一种编码，实现AAAA-ZZZZ的序列变化！
如：AAAA
AAAB
....
AAAZ
AABA
AABB
....
AABZ
....
ZZZZ

请问，用SQL或PL/SQL该怎么实现？

[tangren]

WITH ch AS
 (SELECT chr(LEVEL - 1 + ascii('A')) c FROM dual CONNECT BY LEVEL <= 26)
SELECT a.c || b.c || c.c || d.c FROM ch a, ch b, ch c, ch d;

[小灰狼W]

select chr(trunc((rownum - 1) / 26 / 26 / 26) + 65) ||
       chr(mod(trunc((rownum - 1) / 26 / 26), 26) + 65) ||
       chr(mod(trunc((rownum - 1) / 26), 26) + 65) ||
       chr(mod(rownum - 1, 26) + 65)
  from dual
connect by rownum < 26 * 26 * 26 * 26;

[Adebayor]

[Quote=引用 2 楼 wildwave 的回复:]

SQL code
select chr(trunc((rownum - 1) / 26 / 26 / 26) + 65) ||
chr(mod(trunc((rownum - 1) / 26 / 26), 26) + 65) ||
chr(mod(trunc((rownum - 1) / 26), 26) + 65) ||
chr(mod(rownum……
[/Quote]
狂顶
不过有点小问题 connect by 改成小于等于就完美了

[Adebayor]

[Quote=引用 1 楼 tangren 的回复:]

SQL code
WITH ch AS
(SELECT chr(LEVEL - 1 + ascii('A')) c FROM dual CONNECT BY LEVEL <= 26)
SELECT a.c || b.c || c.c || d.c FROM ch a, ch b, ch c, ch d;
[/Quote]
这个方法也挺牛的

[碧水幽幽泉]

感谢wildwave和tangren
问题已经解决了！
就此结帖！