我想用REGEXP_INSTR()
在 oracle 数据库中检查小写/大写字符。我知道[:upper:]
and [:lower:]
POSIX 字符类,但我选择了a-z
这给了我非常奇怪的结果,我不明白。有人可以解释一下吗?
SELECT REGEXP_INSTR('abc','[A-Z]',1,1,0,'c') FROM DUAL
-- Got 2, expected 0
SELECT REGEXP_INSTR('zyx','[A-Z]',1,1,0,'c') FROM DUAL
-- Got 1, expected 0
SELECT REGEXP_INSTR('ABC','[a-z]',1,1,0,'c') FROM DUAL
-- Got 1, expected 0
SELECT REGEXP_INSTR('ZYX','[a-z]',1,1,0,'c') FROM DUAL
-- Got 2, expected 0
SELECT REGEXP_INSTR('a3','[A-F0-9]',1,1,0,'c') FROM DUAL
-- Got 2, expected 2
SELECT REGEXP_INSTR('b3','[A-F0-9]',1,1,0,'c') FROM DUAL
-- Got 1, expected 2
SELECT REGEXP_INSTR('b3','[A-F0-9]') FROM DUAL
-- Got 1, expected 1 or 2
SELECT REGEXP_INSTR('a3','[A-F0-9]') FROM DUAL
-- Got 2, expected same as above