[elasticsearch笔记] Joining Queries - nested/join

文章目录

    • note
    • demo
      • nested
      • join/has_parent/has_child
        • init data
        • join
        • has_parent
        • has_child

note

  • 干货 | Elasticsearch Nested类型深入详解
  • elasticsearch(lucene)使用的库没有内部对象的概念,因此内部对象被扁平化为一个简单的字段名称和值列表。
  • 为了解决这个问题,需要用到 nested,nested对象会被作为隐式对象处理。其内容不会被扁平化处理。
  • 关联 doc 必须保存于同一个分片,所以在构建 index的时候,需要添加 routing=parent_id 参数

demo

nested

DELETE /netest_index
PUT /netest_index
{
  "mappings": {
    "properties": {
      "title":{
        "type":"text"
      },
      "comments": {
        "type": "nested",
        "properties": {
          "name":{
            "type":"text"
          },
          "count":{
            "type":"integer"
          }
        }
      }
    }
  }
}

POST /netest_index/_doc/1
{
  "title":"es",
  "comments":[ 
    {
      "name": "zhengcj",
      "count": 6
    },
    {
      "name":"dongyc",
      "count":1
    }
  ]
}

POST /netest_index/_doc/2
{
  "title":"java",
  "comments": [
    {
      "name": "zhengcj",
      "count": 6
    },
    {
      "name":"ljr",
      "count":2
    }
  ]
}

GET /netest_index/_search
{
  "query": {
    "nested": {
      "path": "comments",
      "query": {
        "bool": {
          "must": [
            {
              "match": {
                "comments.name": "zhengcj"
              }
            },
            {
              "range": {
                "comments.count": {
                  "gte": 6
                }
              }
            }
          ]
        }
      },
      "score_mode": "avg"
    }
  }
}

POST netest_index/_update/1
{
  "script": {
    "lang": "painless",
    "source": "ctx._source.comments.removeIf(it->it.name=='dongyc')"
  }
}

POST /netest_index/_update/1
{
  "script":{
    "source": "for(e in ctx._source.comments){if(e.name=='zhengcj'){e.count+=1;}}"
  }
}

GET /netest_index/_search
{
  "size": 0,
  "aggs":{
    "nested_aggs":{
      "nested":{
        "path":"comments"
      },
      "aggs":{
        "min_count":{
          "min":{
            "field":"comments.count"
          }
        }
      }
    }
  }
}

join/has_parent/has_child

init data

DELETE stack_overflow
PUT stack_overflow
{
  "mappings": {
    "properties": {
      "join": {
        "type": "join",
        "relations": {
          "question": "answer"
        }
      },
      "key":{
        "type": "keyword"
      },
      "view_count":{
        "type":"integer"
      }
    }
  }
}

PUT stack_overflow/_doc/1
{
  "join": {
    "name": "question"
  },
  "body": "

I have Windows 2003 server and i bought a new Windows 2008 server...", "title": "Whats the best way to file transfer my site from server to a newer one?", "tags": [ "windows-server-2003", "windows-server-2008", "file-transfer" ], "key":"2003-2008", "view_count":10 } PUT stack_overflow/_doc/2 { "join": { "name": "question" }, "body": "ELK body", "title": "ELK", "tags": [ "es", "kibana", "logstash" ], "key":"ELK", "view_count":2 } # 必须包含 routing=n,关联 doc 必须保存于同一个分片 PUT stack_overflow/_doc/11?routing=1 { "join": { "name": "answer", "parent": "1" }, "owner": { "location": "Norfolk, United Kingdom", "display_name": "Sam", "id": 48 }, "body": "

Unfortunately you're pretty much limited to FTP...", "creation_date": "2009-05-04T13:45:37.030", "key":"FTP", "view_count":3 } PUT stack_overflow/_doc/12?routing=1&refresh { "join": { "name": "answer", "parent": "1" }, "owner": { "location": "Norfolk, United Kingdom", "display_name": "Troll", "id": 49 }, "body": "

Use Linux...", "creation_date": "2009-05-05T13:45:37.030", "key":"Linux", "view_count":4 } PUT stack_overflow/_doc/21?routing=2 { "join": { "name": "answer", "parent": "2" }, "owner": { "location": "Norfolk, United Kingdom", "display_name": "Sam", "id": 48 }, "body": "this is answer to es in body", "creation_date": "2009-05-04T13:45:37.030", "key":"es", "view_count":5 }

join

查询一个人回答过问题的标签,即这个人关注的问题

POST stack_overflow/_search?size=0
{
  "aggs": {
    "top-names": {
      "terms": {
        "field": "owner.display_name.keyword",
        "size": 10
      },
      "aggs": {
        "to-questions": {
          "parent": {
            "type": "answer"
          },
          "aggs": {
            "top-tags": {
              "terms": {
                "field": "tags.keyword",
                "size": 10
              }
            }
          }
        }
      }
    }
  }
}

has_parent

根据 parent是否满足条件,返回child

GET /stack_overflow/_search
{
  "query": {
    "has_parent": {
      "parent_type": "question",
      "query": {
        "term": {
          "key": {
            "value": "ELK"
          }
        }
      }
    }
  }
}

GET /stack_overflow/_search
{
  "query": {
    "has_parent": {
      "parent_type": "question",
      "score":true,
      "query": {
        "function_score": {
          "script_score": {
            "script": "_score * doc['view_count'].value+1"
          }
        }
      }
    }
  }
}

has_child

根据 child是否满足条件,返回parent

GET /stack_overflow/_search
{
  "query": {
    "has_child": {
      "type": "answer",
      "query": {
        "match_all": {}
      },
      "max_children": 5,
      "min_children": 2,
      "score_mode": "min"
    }
  }
}

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