ES中文学习指南---入门篇

从最简单的开始，了解索引(indexing)、搜索(search)以及聚合(aggregations)。

工具：Sense插件，head插件

让我们建立一个员工目录

假设我们刚好在Megacorp工作，这时人力资源部门出于某种目的需要让我们创建一个员工目录，这个目录用于促进人文关怀和用于实时协同工作，所以它有以下不同的需求：

• 数据能够包含多个值的标签、数字和纯文本。
• 检索任何员工的所有信息。
• 支持结构化搜索，例如查找30岁以上的员工。
• 支持简单的全文搜索和更复杂的短语(phrase)搜索
• 高亮搜索结果中的关键字
• 能够利用图表管理分析这些数据

1.直接上传文档到ES，能自动创建索引，可以在elasticsearch.yml设置里增加action.auto_create_index: false来取消自动创建索引的功能。

我们手动插入3条数据：

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" ]
}

自动创建的索引结果为：

{

    "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. 进行简单的搜索：

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

返回结果：

{
  "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.复杂一些的搜索

GET /megacorp/employee/_search
{
    "query" : {
        "match" : {
            "last_name" : "Smith"
        }
    }
}
//查找姓smith的人，确切值查询。
GET /megacorp/employee/_search
{
    "query" : {
        "filtered" : {
            "filter" : {
                "range" : {
                    "age" : { "gt" : 30 } 
                }
            },
            "query" : {
                "match" : {
                    "last_name" : "smith" 
                }
            }
        }
    }
}
//查找年龄大于30并且姓smith的人。
           
GET /megacorp/employee/_search
{
    "query" : {
        "match" : {
            "about" : "rock climbing"
        }
    }
}
//全文检索，对about字段里的clock climbing搜索结果进行相关性排序。
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"
          ]
        }
      }
    ]

//精确查找并将搜索结果高亮。↓
 GET /megacorp/employee/_search
{
    "query" : {
        "match_phrase" : {
            "about" : "rock climbing"
        }
    },
    "highlight": {
        "fields" : {
            "about" : {}
        }
    }
}
//聚合查询↓ 数据量太大的时候会有性能的影响。
 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" }
                }
            }
        }
    }
}
  }
}