如何在弹性搜索的前缀匹配 [英] How to match on prefix in Elasticsearch

问题描述

让我们说，在我的弹性搜索索引中，我有一个名为dots的字段，它将包含一串标点符号分隔的单词（例如first.second.third）。

let's say that in my elasticsearch index I have a field called "dots" which will contain a string of punctuation separated words (e.g. "first.second.third").

我需要搜索例如first.second，然后获取所有条目，其点字段包含一个正好为first.second的字符串，或以first.second开头。

I need to search for e.g. "first.second" and then get all entries whose "dots" field contains a string being exactly "first.second" or starting with "first.second.".

我有一个问题，了解文本查询的工作原理，至少我无法创建一个查询作业。

I have a problem understanding how the text querying works, at least I have not been able to create a query which does the job.

推荐答案

p> Elasticsearch有路径层次令牌化器，这是正是为这种用例创建的。以下是如何为您的索引设置示例：

Elasticsearch has Path Hierarchy Tokenizer that was created exactly for such use case. Here is an example of how to set it for your index:

# Create a new index with custom path_hierarchy analyzer 
# See http://www.elasticsearch.org/guide/reference/index-modules/analysis/pathhierarchy-tokenizer.html
curl -XPUT "localhost:9200/prefix-test" -d '{
    "settings": {
        "analysis": {
            "analyzer": {
                "prefix-test-analyzer": {
                    "type": "custom",
                    "tokenizer": "prefix-test-tokenizer"
                }
            },
            "tokenizer": {
                "prefix-test-tokenizer": {
                    "type": "path_hierarchy",
                    "delimiter": "."
                }
            }
        }
    },
    "mappings": {
        "doc": {
            "properties": {
                "dots": {
                    "type": "string",
                    "analyzer": "prefix-test-analyzer",
                    //"index_analyzer": "prefix-test-analyzer", //deprecated
                    "search_analyzer": "keyword"
                }
            }
        }
    }
}'
echo
# Put some test data
curl -XPUT "localhost:9200/prefix-test/doc/1" -d '{"dots": "first.second.third"}'
curl -XPUT "localhost:9200/prefix-test/doc/2" -d '{"dots": "first.second.foo-bar"}'
curl -XPUT "localhost:9200/prefix-test/doc/3" -d '{"dots": "first.baz.something"}'
curl -XPOST "localhost:9200/prefix-test/_refresh"
echo
# Test searches. 
curl -XPOST "localhost:9200/prefix-test/doc/_search?pretty=true" -d '{
    "query": {
        "term": {
            "dots": "first"
        }
    }
}'
echo
curl -XPOST "localhost:9200/prefix-test/doc/_search?pretty=true" -d '{
    "query": {
        "term": {
            "dots": "first.second"
        }
    }
}'
echo
curl -XPOST "localhost:9200/prefix-test/doc/_search?pretty=true" -d '{
    "query": {
        "term": {
            "dots": "first.second.foo-bar"
        }
    }
}'
echo
curl -XPOST "localhost:9200/prefix-test/doc/_search?pretty=true&q=dots:first.second"
echo

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