filter查询

query和filter的区别：query查询的时候，会先比较查询条件，然后计算分值，最后返回文档结果；而filter是先判断是否满足查询条件，如果不满足会缓存查询结果（记录该文档不满足结果），满足的话，就直接缓存结果，filter不会对结果进行评分，能够提高查询效率。
filter的使用方式比较多样，下面用几个例子演示一下。

单独使用

  1. {
  2.   "query": {
  3.     "bool": {
  4.       "filter": [
  5.         {
  6.           "term": {
  7.             "sex": {
  8.               "value": "男",
  9.               "boost": 1.0
  10.             }
  11.           }
  12.         }
  13.       ],
  14.       "adjust_pure_negative": true,
  15.       "boost": 1.0
  16.     }
  17.   }
  18. }

单独使用时，filter与must基本一样，不同的是filter不计算评分，效率更高。
Java构建查询语句：

  1. SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
  2. // 构建查询语句
  3. searchSourceBuilder.query(QueryBuilders.boolQuery()
  4.         .filter(QueryBuilders.termQuery("sex", "男"))
  5. );

和must、must_not同级，相当于子查询

  1. select * from (select * from persons where sect = '明教')) a where sex = '女';
  3. {
  4.  "query": {
  5.   "bool": {
  6.    "must": [
  7.     {
  8.      "term": {
  9.       "sect.keyword": {
  10.        "value": "明教",
  11.        "boost": 1.0
  12.       }
  13.      }
  14.     }
  15.    ],
  16.    "filter": [
  17.     {
  18.      "term": {
  19.       "sex": {
  20.        "value": "女",
  21.        "boost": 1.0
  22.       }
  23.      }
  24.     }
  25.    ],
  26.    "adjust_pure_negative": true,
  27.    "boost": 1.0
  28.   }
  29.  }
  30. }

es中java

  1. SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
  2. // 构建查询语句
  3. searchSourceBuilder.query(QueryBuilders.boolQuery()
  4.         .must(QueryBuilders.termQuery("sect.keyword", "明教"))
  5.         .filter(QueryBuilders.termQuery("sex", "女"))
  6. );

将must、must_not置于filter下

  1. {
  2.  "query": {
  3.   "bool": {
  4.    "filter": [
  5.     {
  6.      "bool": {
  7.       "must": [
  8.        {
  9.         "term": {
  10.          "sect.keyword": {
  11.           "value": "明教",
  12.           "boost": 1.0
  13.          }
  14.         }
  15.        },
  16.        {
  17.         "range": {
  18.          "age": {
  19.           "from": 20,
  20.           "to": 35,
  21.           "include_lower": true,
  22.           "include_upper": true,
  23.           "boost": 1.0
  24.          }
  25.         }
  26.        }
  27.       ],
  28.       "must_not": [
  29.        {
  30.         "term": {
  31.          "sex.keyword": {
  32.           "value": "女",
  33.           "boost": 1.0
  34.          }
  35.         }
  36.        }
  37.       ],
  38.       "adjust_pure_negative": true,
  39.       "boost": 1.0
  40.      }
  41.     }
  42.    ],
  43.    "adjust_pure_negative": true,
  44.    "boost": 1.0
  45.   }
  46.  }
  47. }

es中java

  1. SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
  2. // 构建查询语句
  3. searchSourceBuilder.query(QueryBuilders.boolQuery()
  4.         .filter(QueryBuilders.boolQuery()
  5.                 .must(QueryBuilders.termQuery("sect.keyword", "明教"))
  6.                 .must(QueryBuilders.rangeQuery("age").gte(20).lte(35))
  7.                 .mustNot(QueryBuilders.termQuery("sex.keyword", "女")))
  8. );