Elasticsearch自动补全/联想搜索

原文地址：

搜索引擎的自动补全，本文基于搜索历史进行补全，适用于拥有大量数据的搜索引擎。在ElasticSearch中可以使用Completion Suggester实现。

---

首先创建基于ik插件的自动补全mapping：

curl -XPOST  -d'
{
  "suggest": {
    "properties": {
      "tag": {
        "type": "string",
        "analyzer": "ik",
        "search_analyzer": "ik"
      },
      "tag_suggest": {
        "type": "completion",
        "analyzer": "ik",
        "search_analyzer": "ik",
        "payloads": false
      }
    }
  }
}'

插入测试数据：

curl -XPUT "" -d'{
    "tag":["梭织","蕾丝","汗布","针织","毛呢"],
    "tag_suggest":{
        "input":["梭织","蕾丝","汗布","针织","毛呢"]
    }
}'

curl -XPUT "" -d'{
    "tag":["绒布","牛仔布","罗纹","网眼","平板布"],
    "tag_suggest":{
        "input":["绒布","牛仔布","罗纹","网眼","平板布"]
    }
}'
curl -XPUT "" -d'{
    "tag":["蕾丝布","蕾丝网"],
    "tag_suggest":{
        "input":["蕾丝布","蕾丝网"]
    }
}'

最后通过_suggest对Completion Suggester数据进行搜索:

curl -XPOST "" -d'
{
    "suggest-suggest": {
    "text": "蕾丝",
    "completion": {
      "field": "tag_suggest",
      "size": 10 //返回结果数量
      }
    }
}'

其中suggest-suggest中第一个suggest代表当前索引文档的type，^_^，比较懒，不想改type名了。

如果结果返回：

{
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "suggest_suggest": [
    {
      "text": "蕾丝",
      "offset": 0,
      "length": 2,
      "options": [
        {
          "text": "蕾丝",
          "score": 1
        },
        {
          "text": "蕾丝布",
          "score": 1
        },
        {
          "text": "蕾丝网",
          "score": 1
        }
      ]
    }
  ]
}

恭喜你，自动补全功能即已实现。