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

}