Question

给出以下2个字符串 -

select * from abc;
select * from abc where;

我希望正则表达式匹配任何东西 -

在from之后;。
介于from和where之间。

以下2个正则表达式适用于上述2个案例 -

(re-find #"(?<=from |FROM ).*(?= where| WHERE)" "select * from abc where")   => abc
(re-find #"(?<=from |FROM ).*(?=;)" "Select * from abc;")                    => abc

如何将上述2个正则表达式组合用于上述两个字符串？

我尝试了以下但是这不起作用 -

(re-find #"(?<=from |FROM ).*(?= where| WHERE)|(?=;) " "select * from abc;") => nil

编辑 -

如何使正则表达式适用于以下字符串 -

select * from abc \n where;
select * from abc   \n \n;

语句始终使用;终止。

但是之前可能会有空格或换行符。

Answer 1

只需在前瞻中包含<select id="productextra[@count@]"> <option value="[@option_id@]">Yes</option> <option value="[@option_id@]">No</option> </select>。

DEMO

Answer 2

您可以按如下方式修改正则表达式。 (?i)修饰符用于不区分大小写的匹配：

user> (re-find #"(?i)(?<=from ).*?(?= where|;)" "SELECT * FROM abc WHERE")
"abc"
user> (re-find #"(?i)(?<=from ).*?(?= where|;)" "Select * from abc;")
"abc"

更新：您可以加入s修饰符，以强制.跨越换行符。

(re-find #"(?si)(?<=from ).*?(?= where|;)" "select * from abc \n where;")

Answer 3

如果您想捕获多行语句，请使用此选项。参见演示。

https://regex101.com/r/fM9lY3/26

Answer 4

>>> s
'select * from abc;'
>>> s2
'select * from abc where;'
>>> s3
'select * from abc WHERE;'
>>> s4
'select * from abc \n where;'
>>> s5
'select * from abc   \n \n;'
>>> s6
'select * from efg   \n \n;'
>>> s7
'select * from efg  where \n \n;'
>>> for i in s, s2, s3, s4, s5, s6, s7:
...     re.search(r'from (\S+)(?:\s+)?(?=;|where)', i, flags=re.I).groups()
...
('abc',)
('abc',)
('abc',)
('abc',)
('abc',)
('efg',)
('efg',)
>>>

在正则表达式

4 个答案: