让elasticsearch查询结果里输出_version字段

elasticsearch每条记录都会有一个_version字段，在文档被改变时加一。

插入文档

curl 'http://你的elasticsearch地址/web/blog/1' -d '{"title": "test", "content": "test test test"}'

响应结果为

{
    "_index": "web", 
    "_type": "blog", 
    "_id": "1", 
    "_version": 1, 
    "created": true
}

检索文档

curl 'http://你的elasticsearch地址/web/blog/1'

响应结果为

{
  "_index" : "web",
  "_type" : "blog",
  "_id" : "1",
  "_version" : 1,
  "found" : true,
  "_source":{"title": "test", "content": "test test test"}
}

但是query查询默认是不会带_version字段的。

检索文档

curl 'http://你的elasticsearch地址/web/blog/_search?q=title:test'

响应结果为

{
  "took" : 27,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1,
    "max_score" : 0.30685282,
    "hits" : [ {
      "_index" : "web",
      "_type" : "blog",
      "_id" : "1",
      "_score" : 0.30685282,
      "_source":{"title": "test", "content": "test test test"}
    } ]
  }
}

可以通过指定version字段为true，来实现查询结果里也带上_version字段。

检索文档

curl 'http://你的elasticsearch地址/web/blog/_search?q=title:test&version=truey'

响应结果为

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1,
    "max_score" : 0.30685282,
    "hits" : [ {
      "_index" : "web",
      "_type" : "blog",
      "_id" : "1",
      "_version" : 1,
      "_score" : 0.30685282,
      "_source":{"title": "test", "content": "test test test"}
    } ]
  }
}

使用Query DSL语法也是同样的。

curl 'http://你的elasticsearch地址/web/blog/_search' -d '{"query":{"term":{"title":"test"}}, "version":true}'