elasticsearch學習

一、es特性

二、使用命令

1. 查看集羣健康狀況

   curl 127.0.0.1:9200/_cat/health?v

2. 列出所有node節點

   curl 127.0.0.1:9200/_cat/nodes?v

3. 查看索引信息

   curl 127.0.0.1:9200/_cat/indices?v

4. 創建索引

   curl -X PUT 127.0.0.1:9200/customer?pretty

5. 添加文檔

   curl -X PUT "localhost:9200/customer/_doc/1?pretty&pretty" -H 'Content-Type: application/json' -d'
   

   {

     "name": "John Doe"

   }

6. 檢索索引的文檔

   curl -X GET "localhost:9200/customer/_doc/1?pretty&pretty"

7. 刪除索引

   curl -X DELETE "localhost:9200/customer?pretty"

8. 更新文檔

   curl -X PUT "localhost:9200/customer/_doc/1?pretty&pretty" -H 'Content-Type: application/json' -d'

   {

   "name": "John Doe"

   }'

9. 索引一個新文檔

   curl -X PUT "localhost:9200/customer/_doc/2?pretty&pretty" -H 'Content-Type: application/json' -d'

   {

     "name": "Jane Doe"

   }'

   
   

10. 索引一個沒有顯式id的文檔

    
    

11. curl -X POST "localhost:9200/customer/_doc?pretty&pretty" -H 'Content-Type: application/json' -d'

    {

      "name": "Jane Doe"

    }'

12. 更新文檔

    curl -X POST "localhost:9200/customer/_update/1?pretty&pretty" -H 'Content-Type: application/json' -d'
    

    {

      "doc": { "name": "Jane Doe" }

    }'

13. 更新文檔並添加字段

    curl -X POST "localhost:9200/customer/_update/1?pretty&pretty" -H 'Content-Type: application/json' -d'
    

    {

      "doc": { "name": "Jane Doe", "age": 20 }

    }'

14. 使用腳本執行更新年齡到25歲

    curl -X POST "localhost:9200/customer/_update/1?pretty&pretty" -H 'Content-Type: application/json' -d'
    

    {

     "script" : "ctx._source.age += 5"

    }'

15. 查看文檔

    curl -X GET "localhost:9200/customer/_doc/2?pretty"

16. 刪除文檔

    curl -X DELETE "localhost:9200/customer/_doc/2?pretty&pretty"

17. 批量創建文檔

    curl -X POST "localhost:9200/customer/_bulk?pretty&pretty" -H 'Content-Type: application/json' -d'
    

    {"index":{"_id":"1"}}

    {"name": "John Doe" }

    {"index":{"_id":"2"}}

    {"name": "Jane Doe" }'

18. 更新第一個文檔並刪除第二個文檔

    curl -X POST "localhost:9200/customer/_bulk?pretty&pretty" -H 'Content-Type: application/json' -d'
    

    {"update":{"_id":"1"}}

    {"doc": { "name": "John Doe becomes Jane Doe" } }

    {"delete":{"_id":"2"}}'

19. 搜索文檔 "*"參數匹配索引中的所有文檔, account_number按照文檔的這個字段升序排列

    curl -X GET "localhost:9200/bank/_search?q=*&sort=account_number:asc&pretty&pretty"

    注意命中的準確性由請求參數track_total_hits控制，當設置爲true時，請求將精確地跟蹤總命中(“relationship”:“eq”)。默認值爲10,000，這意味着總命中數可以精確地跟蹤到10,000個文檔。通過顯式地將track_total_hits設置爲true，可以強制進行準確的計數。有關詳細信息，請參閱請求主體文檔

20. 同一效果一樣,用json風格查詢請求體

    curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

    {

      "query": { "match_all": {} },

      "sort": [

        { "account_number": "asc" }

      ]

    }'

三、DSL查詢語言

1.

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match_all": {} }

}

'

2.

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match_all": {} },

  "size": 1

}

'

size: 返回文檔數

3.返回第10到第19個文檔

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match_all": {} },

  "from": 10,

  "size": 10

}

'

from:從哪個索引文檔開始,默認爲0

4. 降序排列並返回前10個文檔

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match_all": {} },

  "sort": { "balance": { "order": "desc" } }

}

'

5.默認返回搜索文檔的所有字段，可以指定返回字段

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match_all": {} },

  "_source": ["account_number", "balance"]

}

'

只返回["account_number", "balance"]字段

6.match匹配查詢

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match": { "account_number": 20 } }

}

'

只返回account_number是20的文檔

7.匹配address包含"mill"的文檔,不區分大小寫

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match": { "address": "mill" } }

}

'

8.返回address 包含"mill" 或者"lane"的文檔

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match": { "address": "mill lane" } }

}

'

9.match的變體,返回address包含"mill lane"字段的文檔

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": { "match_phrase": { "address": "mill lane" } }

}

'

10.bool查詢返回匹配到{ "match": { "address": "mill" } },和{ "match": { "address": "lane" } }的文檔,must指定必須同時滿足

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": {

    "bool": {

      "must": [

        { "match": { "address": "mill" } },

        { "match": { "address": "lane" } }

      ]

    }

  }

}

'

11.bool或查詢滿足{ "match": { "address": "mill" } },或{ "match": { "address": "lane" } }的文檔，should指定滿足其中一個條件即可

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": {

    "bool": {

      "should": [

        { "match": { "address": "mill" } },

        { "match": { "address": "lane" } }

      ]

    }

  }

}'

12,bool反向查詢 查詢既不滿足{ "match": { "address": "mill" } },也不滿足{ "match": { "address": "lane" } }的文檔，must_not跟mast相反　

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": {

    "bool": {

      "must_not": [

        { "match": { "address": "mill" } },

        { "match": { "address": "lane" } }

      ]

    }

  }

}

'

13.bool聯合查詢,must,must_not同時使用

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": {

    "bool": {

      "must": [

        { "match": { "age": "40" } }

      ],

      "must_not": [

        { "match": { "state": "ID" } }

      ]

    }

  }

}

'

_score字段值越大，查詢的文檔越相關

四、filter過濾

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "query": {

    "bool": {

      "must": { "match_all": {} },

      "filter": {

        "range": {

          "balance": {

            "gte": 20000,

            "lte": 30000

          }

        }

      }

    }

  }

}

五、聚合查詢

1.按狀態對所有賬戶分組，然後返回按count降序排列的前10個(默認)狀態(也是默認)

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "size": 0,

  "aggs": {

    "group_by_state": {

      "terms": {

        "field": "state.keyword"

      }

    }

  }

}

'

相當於sql語句：

SELECT state, COUNT(*) FROM bank GROUP BY state ORDER BY COUNT(*) DESC LIMIT 10;

注意：將size=0設置爲不顯示搜索結果，因爲我們只想看到響應中的聚合結果,group_by_state以state字段聚合

2.聚合求平均值

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "size": 0,

  "aggs": {

    "group_by_state": {

      "terms": {

        "field": "state.keyword"

      },

      "aggs": {

        "average_balance": {

          "avg": {

            "field": "balance"

          }

        }

      }

    }

  }

}

'

本示例按狀態計算平均帳戶餘額(同樣只針對按count降序排列的前10個狀態)

3.平均值降序聚合

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "size": 0,

  "aggs": {

    "group_by_state": {

      "terms": {

        "field": "state.keyword",

        "order": {

          "average_balance": "desc"

        }

      },

      "aggs": {

        "average_balance": {

          "avg": {

            "field": "balance"

          }

        }

      }

    }

  }

}

'

4.多個聚合一起使用

curl -X GET "localhost:9200/bank/_search?pretty" -H 'Content-Type: application/json' -d'

{

  "size": 0,

  "aggs": {

    "group_by_age": {

      "range": {

        "field": "age",

        "ranges": [

          {

            "from": 20,

            "to": 30

          },

          {

            "from": 30,

            "to": 40

          },

          {

            "from": 40,

            "to": 50

          }

        ]

      },

      "aggs": {

        "group_by_gender": {

          "terms": {

            "field": "gender.keyword"

          },

          "aggs": {

            "average_balance": {

              "avg": {

                "field": "balance"

              }

            }

          }

        }

      }

    }

  }

}

'

這個例子展示了我們如何按照年齡等級(20-29歲，30-39歲，40-49歲)分組，然後按性別分組，最後得到每個年齡等級，每個性別的平均賬戶餘額