ElasticSearch 学习笔记 - 5. 文档

摘要：程序编程面向对象程序设计更新文档更新数据文档在中是不可变的，不能修改。更新字段是一个开源的分布式版本控制软件添加新字段查询更新删除文档

（1）一般格式

PUT blog/segmentfault/1
{
  "id":1,
  "title":"Elasticsearch简介",
  "author":"kyle",
  "content":"Elasticsearch是一个基于Lucene的搜索引擎"
}

（2）未指定文档ID

POST blog/segmentfault
{
  "id":3,
  "title":"Java编程",
  "author":"kyle",
  "content":"Java面向对象程序设计"
}

（3）添加多个type
6.x之后不允许添加多个type

POST blog/csdn
{
  "id":3,
  "title":"Java编程",
  "author":"chengyuqiang",
  "content":"Java面向对象程序设计"
}

{
  "error": {
    "root_cause": [
      {
        "type": "illegal_argument_exception",
        "reason": "Rejecting mapping update to [blog] as the final mapping would have more than 1 type: [csdn, segmentfault]"
      }
    ],
    "type": "illegal_argument_exception",
    "reason": "Rejecting mapping update to [blog] as the final mapping would have more than 1 type: [csdn, segmentfault]"
  },
  "status": 400
}

GET /blog/segmentfault/1

{
  "_index": "blog",
  "_type": "segmentfault",
  "_id": "1",
  "_version": 1,
  "found": true,
  "_source": {
    "id": 1,
    "title": "Elasticsearch简介",
    "author": "kyle",
    "content": "Elasticsearch是一个基于Lucene的搜索引擎"
  }
}

（1）、检索全部

GET /blog/_search

(2)、term查询
term查询用于查找指定字段中包含指定分词的文件，只有当查询分词和文档中的分词精确匹配时才被检索到。

GET /blog/_search
{
  "query": {
    "term": {
      "content": {
        "value": "程"
      }
    }
  }
}

{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.2876821,
    "hits": [
      {
        "_index": "blog",
        "_type": "segmentfault",
        "_id": "V0JLZmYBnUSb-hp-GzV6",
        "_score": 0.2876821,
        "_source": {
          "id": 3,
          "title": "Java编程",
          "author": "kyle",
          "content": "Java面向对象程序设计"
        }
      }
    ]
  }
}

当查询”程序”时，title字段中找不到这样的分词，默认汉字被分为单字词。

GET /blog/_search
{
  "query": {
    "term": {
      "content": {
        "value": "程序"
      }
    }
  }
}

{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 0,
    "max_score": null,
    "hits": []
  }
}

（3）terms查询

GET /blog/_search
{
  "query": {
    "terms": {
      "title": [
        "java",
        "git"
      ]
    }
  }
}
注意，经过分词后英文单词变成了小写，比如”Java”词项变成了”java”


{
  "took": 4,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 2,
    "max_score": 1,
    "hits": [
      {
        "_index": "blog",
        "_type": "segmentfault",
        "_id": "V0JLZmYBnUSb-hp-GzV6",
        "_score": 1,
        "_source": {
          "id": 3,
          "title": "Java编程",
          "author": "kyle",
          "content": "Java面向对象程序设计"
        }
      },
      {
        "_index": "blog",
        "_type": "segmentfault",
        "_id": "2",
        "_score": 1,
        "_source": {
          "id": 2,
          "title": "Git简介",
          "author": "lalala",
          "content": "Git是一个版本控制软件"
        }
      }
    ]
  }
}

（4）match查询
与term精确查询不同，对于match查询，只要被查询字段中存在任何一个词项被匹配，就会搜索到该文档。

GET /blog/_search
{
  "query": {
    "match": {
      "content": "程序"
    }
  }
}

{
  "took": 18,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.5753642,
    "hits": [
      {
        "_index": "blog",
        "_type": "segmentfault",
        "_id": "V0JLZmYBnUSb-hp-GzV6",
        "_score": 0.5753642,
        "_source": {
          "id": 3,
          "title": "Java编程",
          "author": "kyle",
          "content": "Java面向对象程序设计"
        }
      }
    ]
  }
}

（1）更新数据
文档在Elasticsearch中是不可变的，不能修改。如果我们需要修改文档，Elasticsearch实际上重建新文档替换掉旧文档。

POST /blog/segmentfault/2
{
  "id":2,
  "title":"Git简介",
  "author":"hahaha",
  "content":"Git是一个分布式版本控制软件"
}

{
  "_index": "blog",
  "_type": "segmentfault",
  "_id": "2",
  "_version": 2,
  "result": "updated",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "_seq_no": 1,
  "_primary_term": 1
}

NOTE:

版本加1。

"result": "updated"，因为同索引同类型下已经存在同ID的文档。

在ES内部，_version为1的文件已经被标记“删除”，并添加了一个完整的新文档。旧文档不会立即消失，但是不能再访问它。

（2）更新字段

POST /blog/segmentfault/2/_update
{
  "script": {
    "source": "ctx._source.content="GIT是一个开源的分布式版本控制软件""  
  }
}

{
  "_index": "blog",
  "_type": "segmentfault",
  "_id": "2",
  "_version": 3,
  "result": "updated",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "_seq_no": 2,
  "_primary_term": 1
}

（3）添加新字段

POST /blog/segmentfault/2/_update
{
  "script": "ctx._source.posttime="2018-10-09""
}

{
  "_index": "blog",
  "_type": "segmentfault",
  "_id": "2",
  "_version": 4,
  "result": "updated",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "_seq_no": 3,
  "_primary_term": 1
}

（4）查询更新

POST blog/_update_by_query
{
  "script": {
    "source": "ctx._source.category=params.category",
    "lang":"painless",
    "params":{"category":"git"}
  },
  "query":{
    "term": {"title":"git"}
  }
}

DELETE /blog/segmentfault/2

{
  "_index": "blog",
  "_type": "segmentfault",
  "_id": "2",
  "_version": 7,
  "result": "deleted",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "_seq_no": 6,
  "_primary_term": 1
}