Elasticsearch Start searching

Once you have ingested some data into an Elasticsearch index, you can search it by sending requests to the _search endpoint. To access the full suite of search capabilities, you use the Elasticsearch Query DSL to specify the search criteria in the request body. You specify the name of the index you want to search in the request URI.

For example, the following request retrieves all documents in the bank index sorted by account number:

复制代码
GET /bank/_search
{
  "query": { "match_all": {} },
  "sort": [
    { "account_number": "asc" }
  ]
}

By default, the hits section of the response includes the first 10 documents that match the search criteria:

复制代码
{
  "took" : 63,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
        "value": 1000,
        "relation": "eq"
    },
    "max_score" : null,
    "hits" : [ {
      "_index" : "bank",
      "_type" : "_doc",
      "_id" : "0",
      "sort": [0],
      "_score" : null,
      "_source" : {"account_number":0,"balance":16623,"firstname":"Bradshaw","lastname":"Mckenzie","age":29,"gender":"F","address":"244 Columbus Place","employer":"Euron","email":"bradshawmckenzie@euron.com","city":"Hobucken","state":"CO"}
    }, {
      "_index" : "bank",
      "_type" : "_doc",
      "_id" : "1",
      "sort": [1],
      "_score" : null,
      "_source" : {"account_number":1,"balance":39225,"firstname":"Amber","lastname":"Duke","age":32,"gender":"M","address":"880 Holmes Lane","employer":"Pyrami","email":"amberduke@pyrami.com","city":"Brogan","state":"IL"}
    }, ...
    ]
  }
}

The response also provides the following information about the search request:

  • took -- how long it took Elasticsearch to run the query, in milliseconds
  • timed_out -- whether or not the search request timed out
  • _shards -- how many shards were searched and a breakdown of how many shards succeeded, failed, or were skipped.
  • max_score -- the score of the most relevant document found
  • hits.total.value - how many matching documents were found
  • hits.sort - the document's sort position (when not sorting by relevance score)
  • hits._score - the document's relevance score (not applicable when using match_all)

Each search request is self-contained: Elasticsearch does not maintain any state information across requests. To page through the search hits, specify the from and size parameters in your request.

For example, the following request gets hits 10 through 19:

复制代码
GET /bank/_search
{
  "query": { "match_all": {} },
  "sort": [
    { "account_number": "asc" }
  ],
  "from": 10,
  "size": 10
}

Now that you've seen how to submit a basic search request, you can start to construct queries that are a bit more interesting than match_all.

To search for specific terms within a field, you can use a match query. For example, the following request searches the address field to find customers whose addresses contain mill or lane:

复制代码
GET /bank/_search
{
  "query": { "match": { "address": "mill lane" } }
}

To perform a phrase search rather than matching individual terms, you use match_phrase instead of match. For example, the following request only matches addresses that contain the phrase mill lane:

复制代码
GET /bank/_search
{
  "query": { "match_phrase": { "address": "mill lane" } }
}

To construct more complex queries, you can use a bool query to combine multiple query criteria. You can designate criteria as required (must match), desirable (should match), or undesirable (must not match).

For example, the following request searches the bank index for accounts that belong to customers who are 40 years old, but excludes anyone who lives in Idaho (ID):

复制代码
GET /bank/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "age": "40" } }
      ],
      "must_not": [
        { "match": { "state": "ID" } }
      ]
    }
  }
}

Each must, should, and must_not element in a Boolean query is referred to as a query clause. How well a document meets the criteria in each must or should clause contributes to the document's relevance score. The higher the score, the better the document matches your search criteria. By default, Elasticsearch returns documents ranked by these relevance scores.

The criteria in a must_not clause is treated as a filter. It affects whether or not the document is included in the results, but does not contribute to how documents are scored. You can also explicitly specify arbitrary filters to include or exclude documents based on structured data.

For example, the following request uses a range filter to limit the results to accounts with a balance between 20,000 and 30,000 (inclusive).

复制代码
GET /bank/_search
{
  "query": {
    "bool": {
      "must": { "match_all": {} },
      "filter": {
        "range": {
          "balance": {
            "gte": 20000,
            "lte": 30000
          }
        }
      }
    }
  }
}
相关推荐
鸭鸭鸭进京赶烤1 小时前
大学专业科普 | 云计算、大数据
大数据·云计算
ldj20202 小时前
Jenkins 部署脚本
jenkins
你想考研啊2 小时前
三、jenkins使用tomcat部署项目
运维·tomcat·jenkins
G皮T5 小时前
【Elasticsearch】自定义评分检索
大数据·elasticsearch·搜索引擎·查询·检索·自定义评分·_score
你想考研啊5 小时前
四、jenkins自动构建和设置邮箱
运维·jenkins
Code blocks5 小时前
使用Jenkins完成springboot项目快速更新
java·运维·spring boot·后端·jenkins
搞笑的秀儿8 小时前
信息新技术
大数据·人工智能·物联网·云计算·区块链
SelectDB8 小时前
SelectDB 在 AWS Graviton ARM 架构下相比 x86 实现 36% 性价比提升
大数据·架构·aws
二二孚日9 小时前
自用华为ICT云赛道Big Data第五章知识点-Flume海量日志聚合
大数据·华为
会又不会9 小时前
Jenkins-Email Extension 插件插件
运维·jenkins