关于java:分布式搜索引擎ElasticSearch之高级运用一

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1. 搜寻合乎匹配条件的信息：

创立数据：

PUT account/_doc/1
{"account": 10001, "balance": 10000, "name": "test1"} 

PUT account/_doc/2
{"account": 10002, "balance": 20000, "name": "test2"} 

PUT account/_doc/3
{"account": 10003, "balance": 30000, "name": "张三"} 

PUT account/_doc/4
{"account": 10004, "balance": 30000, "name": "王五"}

依据账号编号查找：

GET /account/_search 
{
  "query": { 
    "match": {"accountNo": "10001"}
  }
}

返回后果：

{
  ...
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : 1.0,
        "_source" : {
          "account" : 10002,
          "balance" : 20000,
          "name" : "test2"
        }
      }
    ]
  }
  ...
}

匹配胜利，返回所要查问的数据。

2. 反对分页查问：

GET /account/_search 
{
  "query": {"match_all": {}
  },
  "from": 0,
  "size": 2
}

可能返回 2 条数据。

"hits" : {
    "total" : {
      "value" : 3,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 1.0,
        "_source" : {
          "account" : 10001,
          "balance" : 10000,
          "name" : "test1"
        }
      },
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : 1.0,
        "_source" : {
          "account" : 10002,
          "balance" : 20000,
          "name" : "test2"
        }
      }
    ]
  }

3. 含糊查问：

数值类型不利于含糊匹配，这里通过字符类型进行测试：

GET /account/_search 
{
  "query": { 
    "match": {"name": "三四"}
  }
}

返回后果：

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.2876821,
    "hits" : [
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "4",
        "_score" : 0.2876821,
        "_source" : {
          "accountNo" : 10009,
          "balance" : 1000000,
          "name" : "张三"
        }
      }
    ]
  }
}

留神，这里默认会采纳单个汉字分词，所查问的关键字“三四”会拆成“三”和“四”进行含糊匹配。

4. filter 过滤查问 ：

GET /account/_search 
{
  "query": { 
    "bool": {
      "filter": [
        {
          "term": {"name": "张三"}
        }
      ]
    }
  }
}

term 是精准查问，代表齐全匹配，不须要查问评分计算。

返回后果：

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

能够看到没有匹配到任何后果，因为 term 是拿整个词“张三”进行匹配，而 ES 默认是做单字分词，将“张三”划分为了“张”和“三”，所以匹配不到后果。

should 查问：只有其中一个为 true 则成立。

GET /movies/_search
{
  "query":{
   "bool": {
     "must": [{"match": {"title": "good hearts sea"}},
       {"match": {"overview": "good hearts sea"}}
     ]
   }
  }
}

must 查问：必须所有条件都成立。

GET /movies/_search
{

  "query":{
   "bool": {
     "must": [{"match": {"title": "good hearts sea"}},
       {"match": {"overview": "good hearts sea"}}
     ]
   }
  }
}

must_not 查问：必须所有条件都不成立。

GET /movies/_search
{

  "query":{
   "bool": {
     "must_not": [{"match": {"title": "good hearts sea"}},
       {"match": {"overview": "good hearts sea"}}
     ]
   }
  }
}

依据用户的资金 balance 来做分组统计：

GET /account/_search 
{
  "query": { 
    "bool": {
      "filter": [
        {
          "range": {
            "account": {"gte": 10001}
          }
        }
      ]
    }
  },
  "sort": [
    {
      "balance": {"order": "desc"}
    }
  ],
  "aggs":{
    "group_by_balance": {
      "terms": {"field": "balance"}
    }
  }
}

找出账户编号大于等于 10001 的数据，依据 balance 做倒序排列，采纳 aggs 依据 balance 做分组汇总统计：

"aggregations" : {
    "group_by_balance" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : 30000,
          "doc_count" : 2
        },
        {
          "key" : 10000,
          "doc_count" : 1
        },
        {
          "key" : 20000,
          "doc_count" : 1
        }
      ]
    }
  }

能够看到，最初会输入分组统计的汇总信息。