ElasticSearch 自动补全实现

介绍

elasticsearch的suggester共有四类(term suggester, phrase suggester, completion suggester, context suggester), 其中completion suggester作为搜索框中的自动补齐功能，尤为常用。实现一个完整的completion suggester功能，需要三个步骤：创建映射，插入索引数据，搜索数据。
此外，本文此基础上用python实现ES自动补全。希望给大家一点启示吧！

说明

相关说明和参考只看官方文档即可：
https://www.elastic.co/guide/en/elasticsearch/reference/current/search-suggesters-completion.html#completion-suggester-mapping

关于创建映射时的参数说明：

查询补全时参数说明：

先创建索引、创建映射、插入数据

========================创建映射=========================
curl -XPUT localhost:9200/index
curl -XPUT localhost:9200/index/test/_mapping -d '{
  "test" : {
        "properties" : {
            "name" : { "type" : "string" },
            "name_suggest" : { "type" : "completion",
                          "analyzer" : "simple",
                          "search_analyzer" : "simple",
                          "payloads" : true
            },
        "tag_suggest" : { "type" : "completion",
                          "analyzer" : "simple",
                          "search_analyzer" : "simple",
                          "payloads" : true
            }
        }
    }
}'
========================插入索引数据=========================
curl -XPUT 'localhost:9200/index/test/1?refresh=true' -d '{
    "name" : "xdy",
    "name_suggest" : {
        "input": ["xdy", "hdu"]
    }
}'

curl -XPUT 'localhost:9200/index/test/2?refresh=true' -d '{
    "name" : "lz",
    "name_suggest" : {
        "input": ["lz", "hdu"],
        "output": "lz-hdu"
    }
}'

curl -XPUT 'localhost:9200/index/test/3?refresh=true' -d '{
    "name" : "xck",
    "name_suggest" : {
        "input": ["xck", "gbd"]
    }
}'

curl -XPUT 'localhost:9200/index/test/4?refresh=true' -d '{
    "name_suggest" : {
        "input": [ "hz", "bdata", "cas"]
    }
}'

curl -XPUT 'localhost:9200/index/test/5?refresh=true' -d '{
    "tag_suggest" : {
        "input": ["bfd", "bdata", "hadoop"]
    }
}'
========================创建查询=========================
curl -XPOST 'localhost:9200/index/_suggest?pretty' -d '{
    "index-suggest" : {
        "text" : "b",
        "completion" : {
            "field" : "name_suggest"
        }
    }
}'

Python 接口实现自动补全

from elasticsearch import Elasticsearch

def suggest(tag, query, suggest_size=10):
    # 设置条件
    es_suggest_options = set_suggest_optional(query, tag, suggest_size)
    # 发起检索。
    es_client = Elasticsearch(hosts=["127.0.0.1:9200"], timeout=5000)
    es_result = es_client.suggest(index='index',body=es_suggest_options)
    # 得到结果。
    final_results = get_suggest_list(es_result)
    return final_results

def get_suggest_list(es_result):
    result_items = es_result['suggest'][0]["options"]
    final_results = []
    for item in result_items:
        final_results.append(item['text'])
    return final_results

def set_suggest_optional(query, tag, suggest_size):
    # 检索选项
    es_suggest_options = {
        "suggest": {
            "text": query,
            "completion": {
                "field": tag,
                "size": suggest_size
            }
        }
    }
    return es_suggest_options

if __name__ == '__main__':
    final_results = suggest('name_suggest', 'b', 2)
    for item in final_results:
        print item
    print '========================================='
    final_results = suggest('tag_suggest', 'b', 2)
    for item in final_results:
        print item

输出：