# elasticsearch.demo **Repository Path**: dingnate/elasticsearch.demo ## Basic Information - **Project Name**: elasticsearch.demo - **Description**: ElasticSearch入门 - **Primary Language**: Java - **License**: Apache-2.0 - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2018-05-17 - **Last Updated**: 2020-12-19 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README 类型 表示的数据类型 String string Whole number byte , short , integer , long Floating point float , double Boolean boolean Date date # ElasticSearch入门 [ElasticSearch官网](https://www.elastic.co/cn/products/elasticsearch) [下载](https://www.elastic.co/downloads/elasticsearch) ## 创建文档 ### 指定id ```shell curl -H 'Content-Type: application/json' -XPUT localhost:9200/website/blog/123?pretty -d '{"title": "My first blog entry","text": "I am starting to get the hang of this...","date": "2014/01/01"}' ``` ```json { "_index": "website", "_type": "blog", "_id": "123", "_version": 1, "result": "created", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 0, "_primary_term": 1 } ``` ### 使用自动生成的ID ```shell curl -H 'Content-Type: application/json' -XPOST localhost:9200/website/blog?pretty -d '{"title": "My second blog entry","text": "I am using auto generatedId","date": "2014/01/03"}' ``` ```json { "_index" : "website", "_type" : "blog", "_id" : "QSP_XmMBCiEWwbhxyNxi", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 0, "_primary_term" : 1 } ``` ### 不存在则创建文档 只有在相同的 `_index` 、 `_type` 和 `_id` 不存在时才接受我们的索引请求 #### op_type参数 ```shell curl -H 'Content-Type: application/json' -XPUT 'localhost:9200/website/blog/123?op_type=create&pretty' -d '{"title": "My first blog entry","text": "I am starting to get the hang of this...","date": "2014/01/02"}' ``` ```json { "error": { "type": "version_conflict_engine_exception", "reason": "[blog][123]: version conflict, document already exists (current version [2])", "index_uuid": "5WSzbmd_Qs-irXSQpAoWbQ", "shard": "0", "index": "website" }, "status": 409 } ``` #### _create后缀 ```shell curl -H 'Content-Type: application/json' -XPUT 'localhost:9200/website/blog/123/_create?pretty' -d '{"title": "My first blog entry","text": "I am starting to get the hang of this...","date": "2014/01/02"}' ``` ``` 结果跟上面的一样 ``` ## 检索文档 ### 简易搜索 - 查询所有类型为tweet并在tweet字段中包含elasticsearch字符的文档： ```shell GET /_all/tweet/_search?q=tweet:elasticsearch ``` - 查找name字段中包含"john"和tweet字段包含"mary"的结果。实际的查询只需要： ```shell GET /_search?q=%2Bname%3Ajohn+%2Btweet%3Amary ``` *注："+"前缀表示语句匹配条件必须被满足,"-"前缀表示条件必须不被满足，上时url编码编码后字符串* - 包含"mary"字符的所有文档的简单搜索： ```shell GET /_search?q=mary ``` ### 检查文档是否存在 ```shell curl -I http://localhost:9200/website/blog/123 ``` ```http HTTP/1.1 200 OK content-type: application/json; charset=UTF-8 content-length: 192 ``` ### 通过id查询 ```shell curl http://localhost:9200/website/blog/123?pretty ``` ```json { "_index" : "website", "_type" : "blog", "_id" : "123", "_version" : 2, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "I am starting to get the hang of this...", "date" : "2014/01/02" } } ``` ### 通过 _search 查询 ```shell curl -H 'Content-Type:application/json' -XGET 'http://localhost:9200/website/blog/_search?pretty' -d '{"query":{"match":{"_id":"123"}}}' ``` ```json { "took" : 4, "timed_out" : false, "_shards" : { "total" : 5, "successful" : 5, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : 1, "max_score" : 1.0, "hits" : [ { "_index" : "website", "_type" : "blog", "_id" : "123", "_score" : 1.0, "_source" : { "title" : "My first blog entry", "text" : "I am starting to get the hang of this...", "date" : "2014/01/02" } } ] } } ``` ### \_source路径 只查询\_source部分 ```shell curl -H 'Content-Type:application/json' -XGET 'http://localhost:9200/website/blog/123/_source?pretty' ``` ```json { "title" : "My first blog entry", "text" : "I am starting to get the hang of this...", "date" : "2014/01/02" } ``` ### _source参数 检索文档的一部分 ```shell curl -H 'Content-Type:application/json' -XGET 'http://localhost:9200/website/blog/123/_source?_source=title,text&pretty=true' ``` ```json { "text" : "I am starting to get the hang of this...", "title" : "My first blog entry" } ``` ## 删除文档 ```shell curl -XDELETE http://localhost:9200/website/blog/123?pretty ``` ```json { "_index": "website", "_type": "blog", "_id": "123", "_version": 3, "result": "deleted", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 2, "_primary_term": 3 } ``` ## 更新文档 ```shell curl -H 'Content-Type: application/json' -XPUT localhost:9200/website/blog/123?pretty -d '{"title": "My first blog entry","text": "I am starting to get the hang of this...","date": "2014/01/02"}' ``` ```json { "_index" : "website", "_type" : "blog", "_id" : "123", "_version" : 2, "result" : "updated", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "_seq_no" : 1, "_primary_term" : 1 } ``` ## ### 乐观并发锁控制 创建doc ```shell curl -H 'Content-Type: application/json' -XPUT 'localhost:9200/website/blog/1/_create?pretty' -d '{"title": "My first blog entry", "text": "Just trying this out..."}' ``` ```shell curl 'localhost:9200/website/blog/1?pretty' ``` ```json { "_index" : "website", "_type" : "blog", "_id" : "1", "_version" : 1, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Just trying this out..." } } ``` - 指定version参数 ```shell curl -H 'Content-Type: application/json' -XPUT 'localhost:9200/website/blog/1?version=1&pretty' -d '{"title": "My first blog entry", "text": "Starting to get the hang of this..."}' ``` ```json { "_index": "website", "_type": "blog", "_id": "1", "_version": 2, "result": "updated", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 1, "_primary_term": 3 } ``` 继续用version=1去更新时会返回错误，因为当前的version=2 ```json { "error": { "type": "version_conflict_engine_exception", "reason": "[blog][1]: version conflict, current version [2] is different than the one provided [1]", "index_uuid": "5WSzbmd_Qs-irXSQpAoWbQ", "shard": "3", "index": "website" }, "status": 409 } ``` - version_type=external 不再检查_version 是否与请求中指定的一致，而是检查是否小于指定的版本。如果请求成功，外部版本号就会被存储。版 号必须是整数，大于零小于 9.2e+18 ——Java中的正的long ```shell curl -H 'Content-Type: application/json' -XPUT 'localhost:9200/website/blog/2?version=5&version_type=external&pretty' -d '{"title": "My first blog entry", "text": "Starting to get the hang of this..."}' ``` ```json { "_index": "website", "_type": "blog", "_id": "2", "_version": 5, "result": "created", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 1, "_primary_term": 3 } ``` ### 文档局部更新 ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/blog/1/_update?pretty' -d '{ "doc":{"tags":["testing"],"views":0}}' ``` ```json { "_index": "website", "_type": "blog", "_id": "1", "_version": 3, "result": "updated", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 2, "_primary_term": 3 } ``` ### 使用脚本局部更新 （groovy） 脚本能够使用updateAPI改变_source字段的内容，它在脚本内部以ctx._source表示。例如，我们可以使用脚本增加博客的views数量： ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/blog/1/_update?pretty' -d '{"script":"ctx._source.views+=1"}' ``` 查看更新后的结果： ```shell curl localhost:9200/website/blog/1?pretty ``` ```json { "_index" : "website", "_type" : "blog", "_id" : "1", "_version" : 4, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Starting to get the hang of this...", "views" : 1, "tags" : [ "testing" ] } } ``` 以使用脚本增加一个新标签到tags数组中，使用脚本参数： ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/blog/1/_update?pretty' -d '{"script":{"inline":"ctx._source.tags.add(params.new_tag)","params":{"new_tag":"search"}}}' ``` 查看更新后的结果： ```shell curl 'localhost:9200/website/blog/1?pretty' ``` ```json { "_index" : "website", "_type" : "blog", "_id" : "1", "_version" : 5, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Starting to get the hang of this...", "views" : 1, "tags" : [ "testing", "search" ] } } ``` #### ctx.op 通过设置ctx.op为delete我们可以根据内容删除文档 *注：5.6.4、6.2.4版本测试不支持下面的操作* ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/blog/1/_update?pretty' -d '{"script":{"inline":"ctx.op=ctx._source.views==params.count?'delete':'none'","params":{"count":1}}}' ``` ### 更新可能不存在的文档 #### upsert 在这种情况下，我们可以使用upsert参数定义文档来使其不存在时被创建。 ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/pageviews/1/_update?pretty' -d ' {"script":"ctx._source.views+=1","upsert":{"views":1}}' ``` 查看更新后的结果： ```shell curl 'localhost:9200/website/pageviews/1?pretty' ``` ```json { "_index" : "website", "_type" : "pageviews", "_id" : "1", "_version" : 1, "found" : true, "_source" : { "views" : 1 } } ``` ### 更新和冲突 #### retry_on_conflict 默认值为0 对于多用户的局部更新，文档被修改了并不要紧。例如，两个进程都要增加页面浏览量，增加的顺序我们并不关心——如果冲突发生，我们唯一要做的仅仅是重新尝试更新既可。 这些可以通过retry_on_conflict参数设置重试次数来自动完成，这样update操作将会在发生错误前重试，下面的例子中retry_on_conflict=5 ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/pageviews/1/_update?retry_on_conflict=5&pretty' -d ' {"script":"ctx._source.views+=1","upsert":{"views":0}}' ``` 查看更新后的结果： ```shell curl localhost:9200/website/pageviews/1?pretty ``` ```json { "_index" : "website", "_type" : "pageviews", "_id" : "1", "_version" : 5, "found" : true, "_source" : { "views" : 2 } } ``` - 接受一个version参数 许你使用乐观并发控制(optimistic concurrency control)来指定你要更细文档的版本。 ## mget批量检索 参数是一个docs数组，数组的每个节点定义一个文档的`_index`、`_type`、`_id`元数据。如果你只想检索一个或几个确定的字段，也可以定义一个_source参数: ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/_mget?pretty' -d '{"docs":[{"_index":"website","_type":"blog","_id":2},{"_index":"website","_type":"pageviews","_id":1,"_source":"views"}]}' ``` 响应体也包含一个docs数组，每个文档还包含一个响应，它们按照请求定义的顺序排列。每个这样的响应与单独使用get request响应体相同： ```json { "docs" : [ { "_index" : "website", "_type" : "blog", "_id" : "2", "_version" : 5, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Starting to get the hang of this..." } }, { "_index" : "website", "_type" : "pageviews", "_id" : "1", "_version" : 1, "found" : true, "_source" : { "views" : 0 } } ] } ``` 如果你想检索的文档在同一个`_index`中（甚至在同一个`_type`中），你就可以在URL中定义 一个默认的/`_index`或者/`_index`/`_type`。 ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/blog/_mget?pretty' -d '{"docs":[{"_id":2},{"_type":"pageviews","_id":1}]}' ``` ```json { "docs" : [ { "_index" : "website", "_type" : "blog", "_id" : "2", "_version" : 5, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Starting to get the hang of this..." } }, { "_index" : "website", "_type" : "pageviews", "_id" : "1", "_version" : 1, "found" : true, "_source" : { "views" : 0 } } ] } ``` 如果所有文档具有相同`_index`和`_type`，你可以通过简单的ids数组来代替完整 的docs数组： ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/website/blog/_mget?pretty' -d '{"ids":["2","1"]}' ``` ```json { "docs" : [ { "_index" : "website", "_type" : "blog", "_id" : "2", "_version" : 5, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Starting to get the hang of this..." } }, { "_index" : "website", "_type" : "blog", "_id" : "1", "_version" : 2, "found" : true, "_source" : { "title" : "My first blog entry", "text" : "Starting to get the hang of this..." } } ] } ``` ## bulk批量更新 ### bulk API允许我们使用单一请求来实现多个 文档的create、index、update或delete。这对索引类似于日志活动这样的数据流非常有 用，它们可以以成百上千的数据为一个批次按序进行索引 bulk请求体如下，它有一点不同寻常： { action: { metadata }}\n { request body }\n { action: { metadata }}\n { request body }\n ... 注意： - 每行必须以"\n"符号结尾，包括最后一行。这些都是作为每行有效的分离而做的标记。 - 每一行的数据不能包含未被转义的换行符，它们会干扰分析——这意味着JSON不能被美化打印。 行为(action)必须是以下几种： | 行为 | 解释 | | ---- | ---- | |create | 当文档不存在时创建之。详见《创建文档》| |index | 创建新文档或替换已有文档。见《索引文档》和《更新文档》| |update | 局部更新文档。见《局部更新》| |delete | 删除一个文档。见《删除文档》| *注：delete操作不需要请求体(requestbody)，create、index、update操作需要请求体。* #### delete ```shell {"delete":{"_index":"website","_type":"blog","_id":"123"}} ``` #### create ```json {"create":{"_index":"website","_type":"blog","_id":"123"}} {"title":"Myfirstblogpost"} ``` #### index ```json {"index":{"_index":"website","_type":"blog"}} {"title":"Mysecondblogpost"} ``` #### update ```json {"update":{"_index":"website","_type":"blog","_id":"123","_retry_on_conflict":"5"}} {"doc":{"title":"Myupdatedblogpost"}} ``` #### 批量更新 *注:在shell中输入时，每行尾使用enter键代替\n* ```shell curl -H 'Content-Type: application/json' -XPOST 'localhost:9200/_bulk?pretty' -d ' {"delete":{"_index":"website","_type":"blog","_id":"123"}}\n {"create":{"_index":"website","_type":"blog","_id":"123"}}\n {"title":"Myfirstblogpost"}\n {"index":{"_index":"website","_type":"blog"}}\n {"title":"Mysecondblogpost"}\n {"update":{"_index":"website","_type":"blog","_id":"123","_retry_on_conflict":"5"}}\n {"doc":{"title":"Myupdatedblogpost"}}\n' ``` ```json { "took" : 291, "errors" : false, "items" : [ { "delete" : { "found" : false, "_index" : "website", "_type" : "blog", "_id" : "123", "_version" : 1, "result" : "not_found", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "status" : 404 } }, { "create" : { "_index" : "website", "_type" : "blog", "_id" : "123", "_version" : 2, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "created" : true, "status" : 201 } }, { "index" : { "_index" : "website", "_type" : "blog", "_id" : "AWNsti9ewhD4-ecniVQP", "_version" : 1, "result" : "created", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "created" : true, "status" : 201 } }, { "update" : { "_index" : "website", "_type" : "blog", "_id" : "123", "_version" : 3, "result" : "updated", "_shards" : { "total" : 2, "successful" : 1, "failed" : 0 }, "status" : 200 } } ] } ``` ## 聚合 ### aggs 有一个功能叫做聚合(aggregations)，它允许你在数据上生成复杂的分析统计。它很像SQL 中的GROUP BY但是功能更强大。举个例子，让我们找到所有职员中最大的共同点（兴趣爱好）是什么： ``` GET /megacorp/employee/_search { "aggs": { "all_interests": { "terms": {"field": "interests"} } } } ``` 如果我们想知道所有姓"Smith"的人最大的共同点（兴趣爱好），我们只需要增加合适的语句既可： ``` GET /megacorp/employee/_search { "query": { "match": {"last_name": "smith"} }, "aggs": { "all_interests": { "terms": {"field": "interests"} } } } ``` all_interests聚合已经变成只包含和查询语句相匹配的文档了： ``` ... "all_interests": { "buckets": [ { "key": "music", "doc_count": 2 }, { "key": "sports", "doc_count": 1 } ] } } ``` ## 分页 ### from和size参数 size:结果数，默认 10 from:跳过开始的结果数，默认 0 如果你想每页显示5个结果，页码从1到3，那请求如下： ```shell GET /_search?size=5 GET /_search?size=5&from=5 GET /_search?size=5&from=10 ``` ## 分析器 指定分析器解析 ```shell GET /_analyze?analyzer=standard&text=Text to analyze ``` ## 映射 ### 查看映射 ```shell GET /index/_mapping/type ``` ```json { "website" : { "mappings" : { "blog" : { "properties" : { "date" : { "type" : "date", "format" : "yyyy/MM/dd HH:mm:ss||yyyy/MM/dd||epoch_millis" }, "text" : { "type" : "text", "fields" : { "keyword" : { "type" : "keyword", "ignore_above" : 256 } } } } } } } } ``` ### 字段映射 ```json { "tag": { "type": "string", "index": "not_analyzed", "analyzer": "english" } } ``` #### type Elasticsearch支持以下简单字段类型： | 类型 | 表示的数据类型 | | ----------------- | -------------------- | | String | string | | Whole number | short, integer, long | | Floating point | float ,double | | Boolean | boolean | | Date | date | #### index 参数控制字符串以何种方式被索引。它包含以下三个值当中的一个： |值|解释| |--|--| |analyzed|首先分析这个字符串，然后索引。换言之，以全文形式索引此字段。| |not_analyzed|索引这个字段，使之可以被搜索，但是索引内容和指定值一样。不分析此字段。| |no|索引这个字段。这个字段不能为搜索到| #### analyzer 对于 analyzed类型的字符串字段，使用 analyzer参数来指定哪一种分析器将在搜索和索引 的时候使用。默认的，Elasticsearch使用 `standard`分析器，但是你可以通过指定一个内建的 分析器来更改它 例如 `whitespace`、 `simple`或 `english`。 ### 更新映射 你可以向已有映射中增加字段，但你不能修改它。 #### 创建映射 ```shell curl -H 'Content-Type: application/json' -XPUT 'localhost:9200/gb?pretty' -d '{"mappings":{"tweet":{"properties":{"tweet":{"type":"string","analyzer":"english"},"date":{"type":"date"},"name":{"type":"string"},"user_id":{"type":"long"}}}}}' ``` ## 结构化查询(Query DSL) ### match_all 下方两行代码是等价的 ```shell curl 'localhost:9200/_search?pretty' -d '{"query":{"match_all":{}}}' ``` ```shell curl 'localhost:9200/_search?pretty' -d '{}' ``` ### match 查询title字段中包含“my” ``` curl 'localhost:9200/_search?pretty' -d '{"query":{"match":{"title":"my"}}}' ``` ### multi_match multi_match 查询允许你做match查询的基础上同时搜索多个字段： ```json { "multi_match": { "query": "full text search", "fields": ["title", "body"] } } ``` ### bool 查询子句就像是搭积木一样，可以合并简单的子句为一个复杂的查询语句。 - 叶子子句(leaf clauses)(比如 match子句)用以在将查询字符串与一个字段(或多字段)进行比较 - 复合子句(compound)用以合并其他的子句。 例如，bool子句允许你合并其他的合法子 句，must，must_not或者should，如果可能的话： ```json { "bool": { "must": {"match": {"tweet": "elasticsearch"} }, "must_not": {"match": {"name": "mary"} }, "should": {"match": {"tweet": "fulltext"} } } } ``` ## 过滤 ### term term主要用于精确匹配哪些值，比如数字，日期，布尔值或 not_analyzed的字符串(未经分析的文本数据类型)： ```json {"term":{"age":26}} {"term":{"date":"2014-09-01"}} {"term":{"public":true}} {"term":{"tag":"full_text"}} ``` ### terms terms跟term有点类似，但terms允许指定多个匹配条件。如果某个字段指定了多个 值，那么文档需要一起去做匹配： ```json { "terms": { "tag": ["search", "full_text", "nosql"] } } ``` ### range range过滤允许我们按照指定范围查找一批数据： ```json { "range": { "age": { "gte": 20, "lt": 30 } } } ``` 范围操作符包含： | 名称 | 解释 | | ---- | -------- | | gt | 大于 | | gte | 大于等于 | | lt | 小于 | | lte | 小于等于 | ### exists|missing exists和missing过滤可以用于查找文档中是否包含指定字段或没有某个字段，类似于SQL语句中的 IS_NULL条件 ```json { "exists": {"field": "title"} } ``` ### bool bool过滤可以用来合并多个过滤条件查询结果的布尔逻辑，它包含一下操作符： | 操作符 | 解释 | | -------- | ----------------------------------- | | must | 多个查询条件的完全匹配,相当于and。 | | must_not | 多个查询条件的相反匹配，相当于not。 | | should | 至少有一个查询条件匹配,相当于 or。 | 这些参数可以分别继承一个过滤条件或者一个过滤条件的数组： ```json { "bool": { "must": { "term": {"folder": "inbox"} }, "must_not": { "term": {"tag": "spam"} }, "should": [ {"term": {"starred": true } }, {"term": {"unread": true } } ] } } ``` ## 带过滤的查询语句 searchAPI中只能包含query语句，所以我们需要用filtered来同时包含"query"和 "filter"子句,在外层再加入query的上下文关系 ```json { "query":{ "filtered": { "query": {"match": {"email": "businessopportunity"}}, "filter": {"term": {"folder": "inbox"} } } } } ``` ## rollover Elasticsearch 从 5.0 开始，为日志场景的用户提供了一个很不错的接口，叫 rollover。其作用是：当某个别名指向的实际索引过大的时候，自动将别名指向下一个实际索引。 创建一个开始滚动的起始索引： ```shell curl -XPUT 'http://localhost:9200/logstash-2016.11.25-1' -d '{ "aliases":{ "logstash":{} } }' ``` 然后就可以尝试发起 rollover 请求了： ```shell curl -XPOST 'http://localhost:9200/logstash/_rollover' -d '{ "conditions":{ "max_age":"1d", "max_docs":10000000, "max_size":"500gb", } }' ``` 上面的定义意思就是：当索引超过 1 天，或者索引内的数据量超过一千万条的时候，自动创建并指向下一个索引。 ## 索引（index） ### 查看所有索引 ```shell curl -XGET 'localhost:9200/_cat/indices?h=i&s=i:desc' ``` 健康指标只显示index名：h=i 按索引名倒排序：s=i:desc 删除索引 ```shell curl -XGET 'localhost:9200/index_name' ``` ## 排序 ### 相关性排序 #### _score 为了使结果可以按照相关性进行排序，我们需要一个相关性的值。在`ElasticSearch`的查询结果中，相关性分值会用`_score`字段来给出一个浮点型的数值，所以默认情况下，结果集以 `_score`进行倒序排列。 ### 字段值排序 #### sort ##### 单级排序 ```shell curl -XGET 'localhost:9200/_search' -d '{"query":{"filtered":{"filter":{"term":{"user_id":1}}}},"sort":{"date":{"order":"desc"}}}' ``` `_score`和`max_score`字段都为null。计算`_score`是比较消耗性能的,而且通常主要用作排序--我们不是用相关性进行排序的时候，就不需要统计其相关性。如果你想强 制计算其相关性，可以设置`track_scores`为`true`。 *注：字段值默认以顺序排列，而`_score`默认以倒序排列。* ##### 多级排序 ```shell curl -XGET 'localhost:9200/_search' -d '{"query":{"filtered":{"filter":{"term":{"user_id":1}}}},"sort":[{"date":{"order":"desc"}},{"location":{"order":"desc"}}]}' ``` ##### 字符串参数排序 ```shell GET /_search?sort=date:desc&sort=_score&q=search ``` ##### 为多值字段排序 ###### 数字和日期 你可以从多个值中取出一个来进行排序，你可以使用min,max,avg或sum这些模式。比说你可以在dates字段中用最早的日期来进行排序： ```json {"sort": { "dates": { "order": "asc", "mode": "min" } } } ``` ###### 字符串 修改多值字段的mapping，新增的tweet.raw子字段索引方式是not_analyzed。 ```json {"tweet": { "type": "string", "analyzer": "english", "fields": { "raw": { "type": "string", "index": "not_analyzed" } } }} ``` 现在，在给数据重建索引后，我们既可以使用tweet字段进行全文本搜索，也可以用tweet.raw字段进行排序： ```json ``` > 警告：对analyzed字段进行强制排序会消耗大量内存。详情请查阅《字段类型简介》相关内容。