elasticsearch的mapping

PUT /website/article/1

{

  "post_date": "2017-01-01",

  "title": "my first article",

  "content": "this is my first article in this website",

  "author_id": 11400

}

 

执行上面的语句，es会创建type对应的mapping，mapping中包含了每个field对应的数据类型。

 

GET /website/_mapping/article

 

响应：

{

  "website": {

    "mappings": {

      "article": {

        "properties": {

          "author_id": {

            "type": "long"

          },

          "content": {

            "type": "text",

            "fields": {

              "keyword": {

                "type": "keyword",

                "ignore_above": 256

              }

            }

          },

          "post_date": {

            "type": "date"

          },

          "title": {

            "type": "text",

            "fields": {

              "keyword": {

                "type": "keyword",

                "ignore_above": 256

              }

            }

          }

        }

      }

    }

  }

}

 

 

1、exact value

 

2017-01-01，exact value，搜索的时候，必须输入2017-01-01，才能搜索出来

如果你输入一个01，是搜索不出来的

 

2、full text  全文检索

（1）缩写 vs. 全程：cn vs. china

（2）格式转化：like liked likes

（3）大小写：Tom vs tom

（4）同义词：like vs love

 

china，搜索cn，也可以将china搜索出来

likes，搜索like，也可以将likes搜索出来

Tom，搜索tom，也可以将Tom搜索出来

like，搜索love，同义词，也可以将like搜索出来

 

就不是说单纯的只是匹配完整的一个值，而是可以对值进行拆分词语后（分词）进行匹配，也可以通过缩写、时态、大小写、同义词等进行匹配。

 

 

3、数据类型

 

1、核心的数据类型

 

string

byte，short，integer，long

float，double

boolean

date

 

2、dynamic mapping

 

true or false --> boolean

123 --> long

123.45 --> double

2017-01-01 --> date

"hello world" --> string/text

 

3、查看mapping

 

GET /index/_mapping/type

 

4、如何建立索引

1、如何建立索引

 

analyzed

not_analyzed

no

 

2、修改mapping

 

只能创建index时手动建立mapping，或者新增field mapping，但是不能update field mapping

 

PUT /website

{

  "mappings": {

    "article": {

      "properties": {

        "author_id": {

          "type": "long"

        },

        "title": {

          "type": "text",

          "analyzer": "english"

        },

        "content": {

          "type": "text"

        },

        "post_date": {

          "type": "date"

        },

        "publisher_id": {

          "type": "text",

          "index": "not_analyzed"   //not_analyzed

        }

      }

    }

  }

}

 

不能update field mapping

 

PUT /website

{

  "mappings": {

    "article": {

      "properties": {

        "author_id": {

          "type": "text"

        }

      }

    }

  }

}

 

{

  "error": {

    "root_cause": [

      {

        "type": "index_already_exists_exception",

        "reason": "index [website/co1dgJ-uTYGBEEOOL8GsQQ] already exists",

        "index_uuid": "co1dgJ-uTYGBEEOOL8GsQQ",

        "index": "website"

      }

    ],

    "type": "index_already_exists_exception",

    "reason": "index [website/co1dgJ-uTYGBEEOOL8GsQQ] already exists",

    "index_uuid": "co1dgJ-uTYGBEEOOL8GsQQ",

    "index": "website"

  },

  "status": 400

}

 

 

 

//建立一个新的field并指定mapping

PUT /website/_mapping/article

{

  "properties" : {

    "new_field" : {

      "type" :    "string",

      "index":    "not_analyzed"

    }

  }

}

 

3、测试mapping

 

GET /website/_analyze

{

  "field": "content",

  "text": "my-dogs"

}

 

GET website/_analyze

{

  "field": "new_field",

  "text": "my dogs"

}

 

//下面报错是因为new_field不允许分词

{

  "error": {

    "root_cause": [

      {

        "type": "remote_transport_exception",

        "reason": "[4onsTYV][127.0.0.1:9300][indices:admin/analyze[s]]"

      }

    ],

    "type": "illegal_argument_exception",

    "reason": "Can't process field [new_field], Analysis requests are only supported on tokenized fields"

  },

  "status": 400

}