为什么这个正则表达式不起作用!?!?!?
create table SAMPLE (STR char(3));
insert into SAMPLE values ('aaa');
insert into SAMPLE values ('bbb');
insert into SAMPLE values ('ccc');
select
STR
, xmlquery('fn:matches($STR,"a")') as A
, xmlquery('fn:matches($STR,"b")') as B
, xmlquery('fn:matches($STR,"a|b")') as A_OR_B
from SAMPLE;
结果:
STR; A; B; A_OR_B
'aaa'; true; false; false
'bbb'; false; true; false
'ccc'; false; false; false
A_OR_B
始终为false,即使A
或B
为真。
PS:我正在使用DB2 10
答案 0 :(得分:1)
通过多次调用RegExp并将它们与or
运算符组合,我找到了一个狡猾的工作。
select
xmlquery('fn:matches($COL_NAME,"a")') as A
, xmlquery('fn:matches($COL_NAME,"b")') as B
, xmlquery('fn:matches($COL_NAME,"a|b")') as A_OR_B_Error
, xmlquery('fn:matches($COL_NAME,"a") or fn:matches($COL_NAME,"b")') as A_OR_B
from MYTABLE
答案 1 :(得分:1)
可能是字符编码。例如。如果|
实际上不是|
,但看起来相同或类似,请说¦
。在这种情况下,正则表达式尝试按字面匹配a¦b
而不是a
或b
。