映射

# curl -XPUT node3:9200/books?pretty
{"acknowledged" : true
}# curl node3:9200/books/_mapping?pretty
{"books" : {"mappings" : { }}
}# curl -XPOST node3:9200/books/it/1?pretty -d '{
"id":1,
"publish_date":"2017-06-01",
"name":"master Elasticsearch"
}'
{"_index" : "books","_type" : "it","_id" : "1","_version" : 1,"_shards" : {"total" : 2,"successful" : 2,"failed" : 0},"created" : true
}# curl node3:9200/books/_mapping?pretty
{"books" : {"mappings" : {"it" : {"properties" : {"id" : {"type" : "long"},"name" : {"type" : "string"},"publish_date" : {"type" : "date","format" : "strict_date_optional_time||epoch_millis"}}}}}
}

如果将ES当作主要的数据存储使用，并希望出现未知字段时抛出异常来提醒你注意这一问题，那么开启动态Mapping并不适用。在Mapping中可以通过dynamic设置来控制是否自动新增字段，接受以下参数：

• true 默认值为true，自动添加字段
• false 忽略新的字段
• strict 严格模式，发现新的字段抛出异常

# curl -XDELETE node3:9200/books?pretty
{"acknowledged" : true
}# curl -XPOST node3:9200/books?pretty -d '{
"mappings": {
"it":{
"dynamic":"strict",
"properties": {
"title":{
"type":"string"
},
"publish_date":{
"type":"date"
}
}
}
}
}'# curl node3:9200/books/_mapping?pretty
{"books" : {"mappings" : {"it" : {"dynamic" : "strict","properties" : {"publish_date" : {"type" : "date","format" : "strict_date_optional_time||epoch_millis"},"title" : {"type" : "string"}}}}}
}# curl -XPOST node2:9200/books/it/1?pretty -d '{
"title":"master Elasticsearch",
"publish_date":"2017-06-01"
}'
{"_index" : "books","_type" : "it","_id" : "1","_version" : 3,"_shards" : {"total" : 2,"successful" : 2,"failed" : 0},"created" : true
}# curl -XPOST node2:9200/books/it/2?pretty -d '{
"title":"master Elasticsearch"
}'
{"_index" : "books","_type" : "it","_id" : "2","_version" : 1,"_shards" : {"total" : 2,"successful" : 2,"failed" : 0},"created" : true
}# curl -XPOST node2:9200/books/it/3?pretty -d '{"title":"master Elasticsearch","publish_date":"2017-06-01","author":"Tom"
}'
{"error" : {"root_cause" : [ {"type" : "strict_dynamic_mapping_exception","reason" : "mapping set to strict, dynamic introduction of [author] within [it] is not allowed"} ],"type" : "strict_dynamic_mapping_exception","reason" : "mapping set to strict, dynamic introduction of [author] within [it] is not allowed"},"status" : 400
}

当ES遇到一个新的字符串类型的字段的时候，它会检查这个字符串是否包含一个可识别的日期。如果看起来像日期，比如：2017-09-12，它会识别为一个date类型的字段，否则会将它作为string字符串添加。这样有一些问题。比如：

{"note":"2017-09-12"}

第一次识别为日期，但是如果下一条记录为：

{"note":"Logged out"}

就会导致一个异常。可以通过在根对象上将date_detection设置为false来关闭日期检测：

# curl -XPOST node2:9200/my_index?pretty
{"acknowledged" : true
}# curl node2:9200/my_index/_mapping?pretty
{"my_index" : {"mappings" : { }}
}# curl -XPOST node2:9200/my_index1?pretty -d'{
"mappings":{"my_type":{"date_detection":false
}}
}'
{"acknowledged" : true
}# curl node2:9200/my_index1/_mapping?pretty
{"my_index1" : {"mappings" : {"my_type" : {"date_detection" : false}}}
}

静态映射

在创建索引时手工指定索引映射，类似于建表时在SQL中指定字段属性。

静态映射更详细、更精准。

# curl -XPOST node2:9200/my_index?pretty -d '{"mappings":{"user":{"_all":{"enabled":false},"properties":{"title":{"type":"string"},"name":{"type":"string"}, "age":{"type":"integer"}}},"blogpost":{"_all":{"enabled":false}, "properties":{"title":{"type":"string"},"body":{"type":"string"},"user_id":{"type":"string"},"created":{"type":"date","format":"strict_date_optional_time||epoch_millis"}}}}
}'
{"acknowledged" : true
}# curl node2:9200/my_index/_mapping?pretty
{"my_index" : {"mappings" : {"blogpost" : {"_all" : {"enabled" : false},"properties" : {"body" : {"type" : "string"},"created" : {"type" : "date","format" : "strict_date_optional_time||epoch_millis"},"title" : {"type" : "string"},"user_id" : {"type" : "string"}}},"user" : {"_all" : {"enabled" : false},"properties" : {"age" : {"type" : "integer"},"name" : {"type" : "string"},"title" : {"type" : "string"}}}}}
}

字段的类型

JSON格式的数据

自动推测的字段类型

null

不添加字段

true或false

boolean类型

浮点类型数字

float

数字

long

JSON对象

object类型

数组

由数组中第一个非空值决定

string

可能是date类型（开启日期检测）、double或long类型、text类型、keyword类型

ES字段类型包括核心类型、复合类型、地理类型和特殊类型。

一级分类

二级分类

具体类型

核心类型

字符串类型

string、text、keyword

数字类型

long、integer、short、byte、double、float、half_float、scaled_float

日期类型

date

布尔类型

boolean

二进制类型

binary

范围类型

range

复合类型

数组类型

array

对象类型

object

嵌套类型

nested

地理类型

地理坐标

geo_point

地理图形

geo_shape

特殊类型

IP类型

ip

范围类型

completion

令牌计数类型

token_count

附件类型

attachment

抽取类型

percolator

A.string 

ES 5.X之后字段类型不再支持，由text或keyword取代。

B.text

如果一个字段要被全文搜索，应该使用此类型。设置该类型后，字段内容会被分析，在生成倒排索引之前，字符串会被分词器分成一个一个词项。text类型字段不用于排序。

put my_index
{"mappings": {"my_type": {"properties": {"full_name": {"type": "text"}}}
}
}

C.keyword

适用于索引结构化的字段，如email地址、主机名、状态码和标签。通常用于过滤、排序、聚合。该类型的字段只能通过精确值搜索到，区别于text。

D.数字类型

类型

取值范围

类型

取值范围

long

-2^63到2^63-1

double

64位双精度IEEE 754浮点类型

integer

-2^31到2^31-1

float

32位单精度IEEE 754浮点类型

short

-32768到32767

half_float

16位单精度IEEE 754浮点类型

byte

-128到127

scaled_float

缩放类型的浮点数

处理浮点数时，优先考虑使用scaled_float类型。scaled_float通过缩放因子把浮点数变成long类型的。比如精确到分的价格，设置放大因子为100，存储的就是整数了。所有的API都会把价格当作浮点数，ES底层存储的是整数类型，因为压缩整数比压缩浮点数更加节省存储空间。

put my_index
{"mappings": {"my_type": {"properties": {"number_of_bytes": {"type": "integer"}"time_in_seconds": {"type": "float"}"price": {"type": "scaled_float","scaling_factor": 100
}
}
}
}
}

E.date

ES中日期可以是以下几种形式：

格式化日期的字符串，如2015-01-01或2015/01/01 12:10:30

毫秒值，从1970年1月1日00:00:00开始算起秒，从1970年

默认"strict_date_optional_time||epoch_millis"

put my_index
{"mappings": {"my_type": {"properties": {"date": {"type": "date"
}
}
}
}
}put my_index/my_type/1 {"date": "2015-01-01"}
put my_index/my_type/2 {"date": "2015-01-01T12:10:30Z"}
put my_index/my_type/3 {"date": 1420070400001}
上述三种时间都可以识别，ES内部存储的是毫秒计时的长整型数。

ES元字段

元字段分类

具体属性

作用

文档属性的元字段

_index

文档所属索引

_uid

包含_type和_id的符合字段

_type

文档的类型

_id

文档id

原文档的元字段

_source

文档的原始JSON字符串

_size

_source字段的大小

索引的元字段

_all

包含索引全部字段的超级字段

_field_names

文档中包含非空值的所有字段

路由的元字段

_parent

指定文档间的父子关系

_routing

将文档路由到特定分片的自定义路由值

自定义元字段

_meta

用于自定义元数据

_index

_index支持对索引名进行term查询、terms查询、聚合分析、使用脚本和排序。不支持prefix、wildcard、regexp和fuzzy查询。

# curl -XPUT node3:9200/index_1/my_type/1?pretty -d '{"text":"Document in index 1"
}'
{"_index" : "index_1","_type" : "my_type","_id" : "1","_version" : 1,"_shards" : {"total" : 2,"successful" : 1,"failed" : 0},"created" : true
}# curl -XPUT node3:9200/index_2/my_type/2?refresh=true -d '{
"text":"Document in index 2"
}'
{"_index":"index_2","_type":"my_type","_id":"2","_version":1,"_shards":{"total":2,"successful":2,"failed":0},"created":true}# curl node3:9200/index_1,index_2/_search?pretty -d '{"query":{"terms":{"_index":["index_1", "index_2"]}},"aggs":{"indices":{"terms":{"field":"_index","size":10}}},"sort":[{"_index":{"order":"asc"}}]
}'
{"took" : 105,"timed_out" : false,"_shards" : {"total" : 10,"successful" : 10,"failed" : 0},"hits" : {"total" : 2,"max_score" : null,"hits" : [ {"_index" : "index_1","_type" : "my_type","_id" : "1","_score" : null,"_source" : {"text" : "Document in index 1"},"sort" : [ "index_1" ]}, {"_index" : "index_2","_type" : "my_type","_id" : "2","_score" : null,"_source" : {"text" : "Document in index 2"},"sort" : [ "index_2" ]} ]},"aggregations" : {"indices" : {"doc_count_error_upper_bound" : 0,"sum_other_doc_count" : 0,"buckets" : [ {"key" : "index_1","doc_count" : 1}, {"key" : "index_2","doc_count" : 1} ]}}
}

_type

每条被索引的文档都有一个_type和_id字段，可以根据_type进行查询、聚合、脚本和排序。

# curl -XPUT node2:9200/my_index/type_1/1?pretty -d '{"text":"Document with type 1"
}'
{"_index" : "my_index","_type" : "type_1","_id" : "1","_version" : 1,"_shards" : {"total" : 2,"successful" : 2,"failed" : 0},"created" : true
}# curl -XPUT node2:9200/my_index/type_2/2?pretty -d '{
"text":"Document with type 2"
}'
{"_index" : "my_index","_type" : "type_2","_id" : "2","_version" : 1,"_shards" : {"total" : 2,"successful" : 2,"failed" : 0},"created" : true
}# curl node3:9200/my_index/_search?pretty -d '{"query":{"terms":{"_type":["type_1", "type_2"]}},"aggs":{"types":{"terms":{"field":"_type","size":"10"}}},"sort":[{"_type":{"order":"desc"}}]
}'
{"took" : 25,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"failed" : 0},"hits" : {"total" : 2,"max_score" : null,"hits" : [ {"_index" : "my_index","_type" : "type_2","_id" : "2","_score" : null,"_source" : {"text" : "Document with type 2"},"sort" : [ "type_2" ]}, {"_index" : "my_index","_type" : "type_1","_id" : "1","_score" : null,"_source" : {"text" : "Document with type 1"},"sort" : [ "type_1" ]} ]},"aggregations" : {"types" : {"doc_count_error_upper_bound" : 0,"sum_other_doc_count" : 0,"buckets" : [ {"key" : "type_1","doc_count" : 1}, {"key" : "type_2","doc_count" : 1} ]}}
}

_id

_id可以用于term查询、terms查询、match查询、query_string查询、simple_query_string查询，但是不能用于聚合、脚本和排序。

# curl node2:9200/my_index/_search?pretty -d '{
"query":{
"terms":{"_id":["1", "2"]}
}
}'
{"took" : 14,"timed_out" : false,"_shards" : {"total" : 5,"successful" : 5,"failed" : 0},"hits" : {"total" : 2,"max_score" : 0.35355338,"hits" : [ {"_index" : "my_index","_type" : "type_2","_id" : "2","_score" : 0.35355338,"_source" : {"text" : "Document with type 2"}}, {"_index" : "my_index","_type" : "type_1","_id" : "1","_score" : 0.35355338,"_source" : {"text" : "Document with type 1"}} ]}
}