Oracle regexp模式匹配但不是ab

Question

我从oracle文档中看到，我可以做一个| b，它将匹配字符'a'或字符'b'的所有实例。我想知道regexp中是否有可能有'a'而不是'b'，例如匹配'a'的所有实例，除非a后跟'b'。

所以这3个字符串

1. AAAA
2. ACAD
3. AAAB

我希望匹配1和2而不是3。

Answer 1

你可以尝试：

with x as (
  select 'AAAA' as str from dual
  union all
  select 'ACAD' as str from dual
  union all
  select 'AAAB' as str from dual
)
select * from x
where regexp_like(str, '[aA][^bB]')
and NOT regexp_like(str, '[aA][bB]')

输出：

AAAA
ACAD

注意：如果你不在乎A是否跟着其他一些非B字符，你可以这样做：

with x as (
  select 'AAAA' as str from dual
  union all
  select 'ACAD' as str from dual
  union all
  select 'AAAB' as str from dual
)
select * from x
where regexp_like(str, '[aA]')
and NOT regexp_like(str, '[aA][bB]')

匹配“AAAA”或“XYZA”