实战Elasticsearch6的join类型

程序员欣宸

发布于 2019-05-27 11:39:29

7890

发布于 2019-05-27 11:39:29

了一个类型为join的字段，如下所示，：

"mappings" : {
    "_doc" : {
      "_source" : {
        "enabled" : true
      },
      "properties" : {
        "relationship_type": {
          "type": "join",
          "relations" : {
            "group": "event"
          }
        },
        ...

这是es6新增的类型，一起来通过实战学习这个join；

环境信息

操作系统：Ubuntu 18.04.2 LTS
elasticsearch：6.7.1
kibana：6.7.1

官方说法

官方对join类型的说明如下：

我的理解：

join类型用于建立索引内文档的父子关系；
用父子文档的名字来表示关系；

接下来看看《Elasticsearch实战》的demo中是怎么使用这个字段的；

《Elasticsearch实战》的demo

demo中部分文档的创建脚本如下所示：

curl -s -XPOST "$ADDRESS/get-together/_doc/1" -H'Content-Type: application/json' -d'{
  "relationship_type": "group",
  "name": "Denver Clojure",
  "organizer": ["Daniel", "Lee"],
  "description": "Group of Clojure enthusiasts from Denver who want to hack on code together and learn more about Clojure",
  "created_on": "2012-06-15",
  "tags": ["clojure", "denver", "functional programming", "jvm", "java"],
  "members": ["Lee", "Daniel", "Mike"],
  "location_group": "Denver, Colorado, USA"
}'

curl -s -XPOST "$ADDRESS/get-together/_doc/100?routing=1" -H'Content-Type: application/json' -d'{
  "relationship_type": {
    "name": "event",
    "parent": "1"
  },
  "host": ["Lee", "Troy"],
  "title": "Liberator and Immutant",
  "description": "We will discuss two different frameworks in Clojure for doing different things. Liberator is a ring-compatible web framework based on Erlang Webmachine. Immutant is an all-in-one enterprise application based on JBoss.",
  "attendees": ["Lee", "Troy", "Daniel", "Tom"],
  "date": "2013-09-05T18:00",
  "location_event": {
    "name": "Stoneys Full Steam Tavern",
    "geolocation": "39.752337,-105.00083"
  },
  "reviews": 4
}'

如上所示，id为1的记录，其relationship_type字段的值为"group"，id为2的记录，relationship_type字段的值不是字符串，而是对象，parent为1表示父文档id为1，name为"event"表示父子关系是"group:event"类型；

注意：上述第二个文档的地址中携带了routing参数，以保持父子在同一个分片，这是在使用join类型是要格外注意的地方；

接下来，确保前面提到的populate.sh脚本已经执行，使得_doc索引及其文档数据在es环境中准备好，就可以实战了，实战环境是Kibana的Det Tools：

查找所有父类型为"group"的文档(结果是子文档)：

执行如下脚本：

GET get-together/_search
{
  "query": {
    "has_parent": {
      "parent_type": "group",
      "query": {
        "match_all": {}
      }
    }
  }
}

可以得到所有父类型为"group"的子文档：

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 15,
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "106",
        "_score" : 1.0,
        "_routing" : "3",
        "_source" : {
          "relationship_type" : {
            "name" : "event",
            "parent" : "3"
          },
          "host" : "Mik",
          "title" : "Social management and monitoring tools",
          "description" : "Shay Banon will be there to answer questions and we can talk about management tools.",
          "attendees" : [
            "Shay",
            "Mik",
            "John",
            "Chris"
          ],
          "date" : "2013-03-06T18:00",
          "location_event" : {
            "name" : "Quid Inc",
            "geolocation" : "37.798442,-122.399801"
          },
          "reviews" : 5
        }
      },
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "107",
        "_score" : 1.0,
        "_routing" : "3",
        "_source" : {
          "relationship_type" : {
            "name" : "event",
            "parent" : "3"
          },
          "host" : "Mik",
          "title" : "Logging and Elasticsearch",
          "description" : "Get a deep dive for what Elasticsearch is and how it can be used for logging with Logstash as well as Kibana!",
          "attendees" : [
            "Shay",
            "Rashid",
            "Erik",
            "Grant",
            "Mik"
          ],
          "date" : "2013-04-08T18:00",
          "location_event" : {
            "name" : "Salesforce headquarters",
            "geolocation" : "37.793592,-122.397033"
          },
          "reviews" : 3
        }
      },
     ...

查找所有子类型为"event"的文档（结果是父文档）

执行如下脚本：

GET get-together/_search
{
  "query": {
    "has_child": {
      "type": "event",
      "query": {
        "match_all": {}
      }
    }
  }
}

可以得到所有子类型为"event"的文档：

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 5,
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "3",
        "_score" : 1.0,
        "_source" : {
          "relationship_type" : "group",
          "name" : "Elasticsearch San Francisco",
          "organizer" : "Mik",
          "description" : "Elasticsearch group for ES users of all knowledge levels",
          "created_on" : "2012-08-07",
          "tags" : [
            "elasticsearch",
            "big data",
            "lucene",
            "open source"
          ],
          "members" : [
            "Lee",
            "Igor"
          ],
          "location_group" : "San Francisco, California, USA"
        }
      },
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 1.0,
        "_source" : {
          "relationship_type" : "group",
          "name" : "Denver Clojure",
          "organizer" : [
            "Daniel",
            "Lee"
          ],
          "description" : "Group of Clojure enthusiasts from Denver who want to hack on code together and learn more about Clojure",
          "created_on" : "2012-06-15",
          "tags" : [
            "clojure",
            "denver",
            "functional programming",
            "jvm",
            "java"
          ],
          "members" : [
            "Lee",
            "Daniel",
            "Mike"
          ],
          "location_group" : "Denver, Colorado, USA"
        }
      },
     ...

查找parent的id等于1的子文档

执行如下脚本：

GET get-together/_search
{
  "query": {
    "parent_id": {
      "type": "event",
      "id": "1"
    }
  }
}

可以得到所有parent的id等于1的子文档：

{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 3,
    "max_score" : 1.3291359,
    "hits" : [
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "100",
        "_score" : 1.3291359,
        "_routing" : "1",
        "_source" : {
          "relationship_type" : {
            "name" : "event",
            "parent" : "1"
          },
          "host" : [
            "Lee",
            "Troy"
          ],
          "title" : "Liberator and Immutant",
          "description" : "We will discuss two different frameworks in Clojure for doing different things. Liberator is a ring-compatible web framework based on Erlang Webmachine. Immutant is an all-in-one enterprise application based on JBoss.",
          "attendees" : [
            "Lee",
            "Troy",
            "Daniel",
            "Tom"
          ],
          "date" : "2013-09-05T18:00",
          "location_event" : {
            "name" : "Stoneys Full Steam Tavern",
            "geolocation" : "39.752337,-105.00083"
          },
          "reviews" : 4
        }
      },
      ...

用script_fields简化返回内容

前面的查询，返回的内容是整个_source，如果不需要全部内容，可以用script_fields来简化；

查找所有父文档ID等1的的子文档，并且返回内容只有三个字段：父文档ID、子文档ID、子文档title字段：

GET get-together/_search
{
   "query": {
    "parent_id": {
      "type": "event",
      "id": "1"
    }
  },
  "script_fields":{
      "group_id":{
        "script":{
          "source":"doc['relationship_type#group']"
        }
      },"event_id":{
        "script":{
          "source":"doc['_id']"
        }
      },
      "title":{
        "script":"params['_source']['title']"
      }
    }
}

得到结果如下：

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : 3,
    "max_score" : 1.3291359,
    "hits" : [
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "100",
        "_score" : 1.3291359,
        "_routing" : "1",
        "fields" : {
          "event_id" : [
            "100"
          ],
          "title" : [
            "Liberator and Immutant"
          ],
          "group_id" : [
            "1"
          ]
        }
      },
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "101",
        "_score" : 1.3291359,
        "_routing" : "1",
        "fields" : {
          "event_id" : [
            "101"
          ],
          "title" : [
            "Sunday, Surly Sunday"
          ],
          "group_id" : [
            "1"
          ]
        }
      },
      {
        "_index" : "get-together",
        "_type" : "_doc",
        "_id" : "102",
        "_score" : 1.3291359,
        "_routing" : "1",
        "fields" : {
          "event_id" : [
            "102"
          ],
          "title" : [
            "10 Clojure coding techniques you should know, and project openbike"
          ],
          "group_id" : [
            "1"
          ]
        }
      }
    ]
  }
}

聚合

执行以下查询，会将所有父文档为group的子文档做桶聚合聚合：

GET get-together/_search
{
  "query": {
    "has_parent": {
      "parent_type": "group",
      "query": {
        "match_all": {}
      }
    }
  },
   "aggs":{
      "parents":{
        "terms":{
          "field":"relationship_type#group"
        }
      }
    }
}

得到的结果如下，按照父文档ID得到聚合结果：

"aggregations" : {
    "parents" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "1",
          "doc_count" : 3
        },
        {
          "key" : "2",
          "doc_count" : 3
        },
        {
          "key" : "3",
          "doc_count" : 3
        },
        {
          "key" : "4",
          "doc_count" : 3
        },
        {
          "key" : "5",
          "doc_count" : 3
        }
      ]
    }
  }
}

本文参与腾讯云自媒体分享计划，分享自作者个人站点/博客。

原始发表：2019年04月07日，如有侵权请联系 cloudcommunity@tencent.com 删除

Elasticsearch Service

本文分享自作者个人站点/博客前往查看

如有侵权，请联系 cloudcommunity@tencent.com 删除。

本文参与腾讯云自媒体分享计划，欢迎热爱写作的你一起参与！

Elasticsearch Service

登录后参与评论

0 条评论

热度