ES中文學習指南---入門篇

從最簡單的開始，了解索引(indexing)、搜索(search)以及聚合(aggregations)。

工具：Sense插件，head插件

讓我們建立一個員工目錄

假設我們剛好在Megacorp工作，這時人力資源部門出於某種目的需要讓我們創建一個員工目錄，這個目錄用於促進人文關懷和用於實時協同工作，所以它有以下不同的需求：

• 數據能夠包含多個值的標簽、數字和純文本。
• 檢索任何員工的所有信息。
• 支持結構化搜索，例如查找30歲以上的員工。
• 支持簡單的全文搜索和更復雜的短語(phrase)搜索
• 高亮搜索結果中的關鍵字
• 能夠利用圖表管理分析這些數據

1.直接上傳文檔到ES，能自動創建索引，可以在elasticsearch.yml設置里增加action.auto_create_index: false來取消自動創建索引的功能。

我們手動插入3條數據：

PUT /megacorp/employee/1
{
    "first_name" : "John",
    "last_name" :  "Smith",
    "age" :        25,
    "about" :      "I love to go rock climbing",
    "interests": [ "sports", "music" ]
}

PUT /megacorp/employee/2
{
    "first_name" :  "Jane",
    "last_name" :   "Smith",
    "age" :         32,
    "about" :       "I like to collect rock albums",
    "interests":  [ "music" ]
}

PUT /megacorp/employee/3
{
    "first_name" :  "Douglas",
    "last_name" :   "Fir",
    "age" :         35,
    "about":        "I like to build cabinets",
    "interests":  [ "forestry" ]
}

自動創建的索引結果為：

{

    "state": "open",
    "settings": {
        "index": {
            "creation_date": "1452563538027",
            "number_of_shards": "5",
            "number_of_replicas": "1",
            "uuid": "Vf1xw2nxRi20wsuByM5Yvw",
            "version": {
                "created": "2010199"
            }
        }
    },
    "mappings": {
        "employee": {
            "properties": {
                "about": {
                    "type": "string"
                },
                "last_name": {
                    "type": "string"
                },
                "interests": {
                    "type": "string"
                },
                "first_name": {
                    "type": "string"
                },
                "age": {
                    "type": "long"
                }
            }
        }
    },
    "aliases": [ ]

}

2. 進行簡單的搜索：

GET /megacorp/employee/_search?q=last_name:Smith

返回結果：

{
  "took": 3,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 2,
    "max_score": 0.30685282,
    "hits": [
      {
        "_index": "megacorp",
        "_type": "employee",
        "_id": "2",
        "_score": 0.30685282,
        "_source": {
          "first_name": "Jane",
          "last_name": "Smith",
          "age": 32,
          "about": "I like to collect rock albums",
          "interests": [
            "music"
          ]
        }
      },
      {
        "_index": "megacorp",
        "_type": "employee",
        "_id": "1",
        "_score": 0.30685282,
        "_source": {
          "first_name": "John",
          "last_name": "Smith",
          "age": 25,
          "about": "I love to go rock climbing",
          "interests": [
            "sports",
            "music"
          ]
        }
      }
    ]
  }
}

3.復雜一些的搜索

GET /megacorp/employee/_search
{
    "query" : {
        "match" : {
            "last_name" : "Smith"
        }
    }
}
//查找姓smith的人，確切值查詢。
GET /megacorp/employee/_search
{
    "query" : {
        "filtered" : {
            "filter" : {
                "range" : {
                    "age" : { "gt" : 30 } 
                }
            },
            "query" : {
                "match" : {
                    "last_name" : "smith" 
                }
            }
        }
    }
}
//查找年齡大於30並且姓smith的人。
           
GET /megacorp/employee/_search
{
    "query" : {
        "match" : {
            "about" : "rock climbing"
        }
    }
}
//全文檢索，對about字段里的clock climbing搜索結果進行相關性排序。
返回如下：

{
  "took": 5,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 2,
    "max_score": 0.16273327,
    "hits": [
      {
        "_index": "megacorp",
        "_type": "employee",
        "_id": "1",
        "_score": 0.16273327,
        "_source": {
          "first_name": "John",
          "last_name": "Smith",
          "age": 25,
          "about": "I love to go rock climbing",
          "interests": [
            "sports",
            "music"
          ]
        }
      },
      {
        "_index": "megacorp",
        "_type": "employee",
        "_id": "2",
        "_score": 0.016878016,
        "_source": {
          "first_name": "Jane",
          "last_name": "Smith",
          "age": 32,
          "about": "I like to collect rock albums",
          "interests": [
            "music"
          ]
        }
      }
    ]

//精確查找並將搜索結果高亮。↓
 GET /megacorp/employee/_search
{
    "query" : {
        "match_phrase" : {
            "about" : "rock climbing"
        }
    },
    "highlight": {
        "fields" : {
            "about" : {}
        }
    }
}
//聚合查詢↓ 數據量太大的時候會有性能的影響。
 GET /megacorp/employee/_search
{
  "aggs": {
    "all_interests": {
      "terms": { "field": "interests" }
    }
  }
}   
   
   
   GET /megacorp/employee/_search
{
  "query": {
    "match": {
      "last_name": "smith"
    }
  },
  "aggs": {
    "all_interests": {
      "terms": {
        "field": "interests"
      }
    }
  }
}
    GET /megacorp/employee/_search
{
    "aggs" : {
        "all_interests" : {
            "terms" : { "field" : "interests" },
            "aggs" : {
                "avg_age" : {
                    "avg" : { "field" : "age" }
                }
            }
        }
    }
}
  }
}