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Elasticsearch 提供了JSON風格的特定領域語言，你可以用來執行自己的查詢

1.query索引中所有文件

curl 'localhost:9200/bank/_search?pretty' -d '
{
    "query":{"match_all":{}}
}

返回結果：
{
  "took" : 63,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1000,
    "max_score"
 
 : 1.0,
    "hits" : [ {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "25",
      "_score" : 1.0,
      "_source" : {
        "account_number" : 25,
        "balance" : 40540,
        "firstname" : "Virginia",
        "lastname" : "Ayala",
        "age" : 39,
        "gender" : "F",
        "address"
 
 : "171 Putnam Avenue",
        "employer" : "Filodyne",
        "email" : "[email protected]",
        "city" : "Nicholson",
        "state" : "PA"
      }
    }, {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "44",
      "_score" : 1.0,
      "_source" : {
        "account_number"
 
 : 44,
        "balance" : 34487,
        "firstname" : "Aurelia",
        "lastname" : "Harding",
        "age" : 37,
        "gender" : "M",
        "address" : "502 Baycliff Terrace",
        "employer" : "Orbalix",
        "email" : "[email protected]",
        "city" : "Yardville",
        "state" : "DE"
      }
    },
    ....
   } ]
  }
}


ruby程式碼：
require "elasticsearch"
$elastic =  Elasticsearch::Client.new hosts: [ 'localhost:9200' ], randomize_hosts: true
res = $elastic.search  index:'bank',body:{query:{match_all:{}}}
puts res

2.elasticsearch 預設返回文件的前十條資料，在查詢得時候可以指定想要返回的文件數量

curl -XPOST 'localhost:9200/bank/_search?pretty' -d '
{
  "query": { "match_all": {} },
  "size": 1
}'

只返回索引中第一條文件
{
  "took" : 3,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1000,
    "max_score" : 1.0,
    "hits" : [ {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "25",
      "_score" : 1.0,
      "_source" : {
        "account_number" : 25,
        "balance" : 40540,
        "firstname" : "Virginia",
        "lastname" : "Ayala",
        "age" : 39,
        "gender" : "F",
        "address" : "171 Putnam Avenue",
        "employer" : "Filodyne",
        "email" : "[email protected]",
        "city" : "Nicholson",
        "state" : "PA"
      }
    } ]
  }
}

ruby程式碼：
require "elasticsearch"
$elastic =  Elasticsearch::Client.new hosts: [ 'localhost:9200' ], randomize_hosts: true
res = $elastic.search  index:'bank',body:{query:{match_all:{}}，size:1}
puts res

3.返回索引中第11-20條文件（from： 開始位置 size：從開始位置返回的文件數）

curl -XPOST 'localhost:9200/bank/_search?pretty' -d '
{
  "query": { "match_all": {} },
  "from": 10,
  "size": 10
}'

返回結果
{
  "took" : 9,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1000,
    "max_score" : 1.0,
    "hits" : [ {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "227",
      "_score" : 1.0,
      "_source" : {
        "account_number" : 227,
        "balance" : 19780,
        "firstname" : "Coleman",
        "lastname" : "Berg",
        "age" : 22,
        "gender" : "M",
        "address" : "776 Little Street",
        "employer" : "Exoteric",
        "email" : "[email protected]",
        "city" : "Eagleville",
        "state" : "WV"
      }
    },
   .....（省略9條）
    } ]
  }
}

ruby程式碼：
require "elasticsearch"
$elastic =  Elasticsearch::Client.new hosts: [ 'localhost:9200' ], randomize_hosts: true
res = $elastic.search  index:'bank',body:{query:{match_all:{}},from:10,size:10}
puts res

4.按照年齡大小排序，返回年齡最大的Top3

curl -XPOST 'localhost:9200/bank/_search?pretty' -d '
{
  "query": { "match_all": {} },
  "sort": { "age": { "order": "desc" } },
  "size":3
}'
返回結果：
{
  "took" : 5,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1000,
    "max_score" : null,
    "hits" : [ {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "948",
      "_score" : null,
      "_source" : {
        "account_number" : 948,
        "balance" : 37074,
        "firstname" : "Sargent",
        "lastname" : "Powers",
        "age" : 40,
        "gender" : "M",
        "address" : "532 Fiske Place",
        "employer" : "Accuprint",
        "email" : "[email protected]",
        "city" : "Umapine",
        "state" : "AK"
      },
      "sort" : [ 40 ]
    }, {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "40",
      "_score" : null,
      "_source" : {
        "account_number" : 40,
        "balance" : 33882,
        "firstname" : "Pace",
        "lastname" : "Molina",
        "age" : 40,
        "gender" : "M",
        "address" : "263 Ovington Court",
        "employer" : "Cytrak",
        "email" : "[email protected]",
        "city" : "Silkworth",
        "state" : "OR"
      },
      "sort" : [ 40 ]
    }, {
      "_index" : "bank",
      "_type" : "account",
      "_id" : "468",
      "_score" : null,
      "_source" : {
        "account_number" : 468,
        "balance" : 18400,
        "firstname" : "Foreman",
        "lastname" : "Fowler",
        "age" : 40,
        "gender" : "M",
        "address" : "443 Jackson Court",
        "employer" : "Zillactic",
        "email" : "[email protected]",
        "city" : "Wakarusa",
        "state" : "WA"
      },
      "sort" : [ 40 ]
    } ]
  }
}

ruby程式碼：
require "elasticsearch"
$elastic =  Elasticsearch::Client.new hosts: [ 'localhost:9200' ], randomize_hosts: true
res = $elastic.search  index:'bank',body:{query:{match_all:{}},sort:{"age":{order:"desc"}}}
puts res