问题描述
我在使用正则表达式从 MySQL 表中选择一些结果时遇到问题.
I'm having trouble using a regular expression to select some results from my MySQL table.
我正在使用这个查询
SELECT text
FROM `articles`
WHERE content REGEXP '.*<img.*?src=\"http://www'
ORDER BY date DESC
它说
#1139 - Got error 'repetition-operator operand invalid' from regexp
我用 Notepad++ 测试了正则表达式，它有效，为什么 MySQL 给我这个错误，我该如何解决?
I tested the regex with Notepad++ and it works, why MySQL is giving me this error and how can i fix it?
推荐答案
根据MySQL 手册
MySQL 使用 Henry Spencer 的正则表达式实现，旨在符合 POSIX 1003.2
MySQL uses Henry Spencer's implementation of regular expressions, which is aimed at conformance with POSIX 1003.2
POSIX 正则表达式不支持使用问号 ? 作为星号的非贪婪(懒惰)修饰符以及 PCRE(Perl 兼容正则表达式)等量词.这意味着你不能使用 +? 和 *?
POSIX regexes don't support using the question mark ? as a non-greedy (lazy) modifier to the star and plus quantifiers like PCRE (Perl Compatible Regular Expressions). This means you can't use +? and *?
看起来你只需要使用贪婪的版本，它应该仍然有效.为了避免<img style="/*some style*/" src="a.png"><script src="www.example.com/js/abc.js">，可以使用否定字符类:
It looks like you'll just have to use the greedy version, which should still work. To avoid the matching of things like <img style="/*some style*/" src="a.png"> <script src="www.example.com/js/abc.js">, you can use a negated character class:
']*src="http://www'
注意:" 不必转义，开头的 .* 是隐含的.
Note: The " doesn't have to escaped and the .* at the beginning is implied.
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