如何在Elasticsearch中进行部分匹配? [英] How do I do a partial match in Elasticsearch?

问题描述

我有一个类似于 http://drive.google.com 的链接，并且我想匹配"google"不在链接中.

I have a link like http://drive.google.com and I want to match "google" out of the link.

我有:

query: {
    bool : {
        must: {
            match: { text: 'google'} 
        }
    }
}

但这仅在整个文本为"google"时才匹配(不区分大小写，因此也匹配Google或GooGlE等).如何匹配另一个字符串中的"google"?

But this only matches if the whole text is 'google' (case insensitive, so it also matches Google or GooGlE etc). How do I match for the 'google' inside of another string?

推荐答案

重点是您正在使用的ElasticSearch正则表达式

The point is that the ElasticSearch regex you are using requires a full string match:

Lucene的模式始终是固定的.提供的模式必须匹配整个字符串.

因此，要匹配任何字符(除了换行符)，可以使用.*模式:

Thus, to match any character (but a newline), you can use .* pattern:

match: { text: '.*google.*'}
                ^^      ^^

对于字符串可以包含换行符的情况，还有另一种变体:match: { text: '(.|\n)*google(.|\n)*'}.在ElasticSearch中，此可怕的(.|\n)*是必需的，因为此正则表达式风格不允许任何[\s\S]解决方法，也不允许任何DOTALL/Singleline标志. "Lucene正则表达式引擎不兼容Perl，但支持较小范围的运算符."

One more variation is for cases when your string can have newlines: match: { text: '(.|\n)*google(.|\n)*'}. This awful (.|\n)* is a must in ElasticSearch because this regex flavor does not allow any [\s\S] workarounds, nor any DOTALL/Singleline flags. "The Lucene regular expression engine is not Perl-compatible but supports a smaller range of operators."

但是，如果您不打算匹配任何复杂的模式并且不需要单词边界检查，那么仅使用通配符搜索就可以更好地执行正则表达式搜索子字符串:

However, if you do not plan to match any complicated patterns and need no word boundary checking, regex search for a mere substring is better performed with a mere wildcard search:

{
    "query": {
        "wildcard": {
            "text": {
                "value": "*google*",
                "boost": 1.0,
                "rewrite": "constant_score"
            }
        }
    }
} 

请参见 通配符搜索 以获取更多详细信息.

See Wildcard search for more details.

注意:通配符模式还需要匹配整个输入字符串，因此

NOTE: The wildcard pattern also needs to match the whole input string, thus

• google*查找所有以开头 google
的字符串
• *google*查找所有包含 google
的字符串
• *google查找所有以结尾 google
的字符串

• google* finds all strings starting with google
• *google* finds all strings containing google
• *google finds all strings ending with google

此外，请记住通配符模式中仅有的一对特殊字符:

Also, bear in mind the only pair of special characters in wildcard patterns:

?, which matches any single character
*, which can match zero or more characters, including an empty one

这篇关于如何在Elasticsearch中进行部分匹配?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！