ElasticSearch - SpringBoot整合ES之查询所有 match_all

官方文档地址：https://www.elastic.co/guide/en/elasticsearch/reference/index.html
权威指南：https://www.elastic.co/guide/cn/elasticsearch/guide/current/structured-search.html

1. 数据准备

官方测试数据下载地址：https://download.elastic.co/demos/kibana/gettingstarted/accounts.zip ，数据量很大，我们自己构造数据吧。

PUT /user/_doc/1
{"first_name" : "John","last_name" :  "Smith","age" :        25,"about" :      "I love to go rock climbing","interests": [ "sports"]
}PUT /user/_doc/2
{"first_name" : "zhangsan","last_name" :  "Smith","age" :        19,"about" :      "我是一个安静的人","interests": [ "read" ]
}PUT /user/_doc/3
{"first_name" : "lisi","last_name" :  "Alice","age" :        29,"about" :      "我喜欢规划自己的生活","interests": [ "sports", "read","music" ]
}

2. 全量查询 match_all

最简单的查询，它匹配所有文档，默认给它们一个_score 1.0。

GET /user/_search
{"query": {"match_all": {}}
}

为此对应的java实现如下：

@Slf4j
@Service
public class ElasticSearchImpl {private static final String KNOWLEDGE_INDEX = "knowledge";@Autowiredprivate RestHighLevelClient restHighLevelClient;public void searchUser() throws IOException {SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();MatchAllQueryBuilder matchAllQueryBuilder = QueryBuilders.matchAllQuery();searchSourceBuilder.query(matchAllQueryBuilder);SearchRequest searchRequest = new SearchRequest(new String[]{"user"},searchSourceBuilder);SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);System.out.println(searchResponse);}
}

{"took" : 21,"timed_out" : false,"_shards" : {"total" : 1,"successful" : 1,"skipped" : 0,"failed" : 0},"hits" : {"total" : {"value" : 3,"relation" : "eq"},"max_score" : 1.0,"hits" : [{"_index" : "user","_type" : "_doc","_id" : "1","_score" : 1.0,"_source" : {"first_name" : "John","last_name" : "Smith","age" : 25,"about" : "I love to go rock climbing","interests" : ["sports"]}},{"_index" : "user","_type" : "_doc","_id" : "2","_score" : 1.0,"_source" : {"first_name" : "zhangsan","last_name" : "Smith","age" : 19,"about" : "我是一个安静的人","interests" : ["read"]}},{"_index" : "user","_type" : "_doc","_id" : "3","_score" : 1.0,"_source" : {"first_name" : "lisi","last_name" : "Alice","age" : 29,"about" : "我喜欢规划自己的生活","interests" : ["sports","read","music"]}}]}
}

3. 使用 boost 参数更改 _score

默认情况下，Elasticsearch 按相关性分数对匹配的搜索结果进行排序，相关性分数衡量每个文档与查询的匹配程度。相关性分数是一个正浮点数，在 搜索_scoreAPI的元字段中返回。越高 ，文档越相关。

GET /user/_search
{"query": {"match_all": { "boost" : 1.2 }}
}

为此对应的java实现如下：

@Slf4j
@Service
public class ElasticSearchImpl {@Autowiredprivate RestHighLevelClient restHighLevelClient;public void searchUser() throws IOException {SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();MatchAllQueryBuilder matchAllQueryBuilder = QueryBuilders.matchAllQuery();matchAllQueryBuilder.boost(1.2f);searchSourceBuilder.query(matchAllQueryBuilder);SearchRequest searchRequest = new SearchRequest(new String[]{"user"},searchSourceBuilder);SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);System.out.println(searchResponse);}
}

查询结果：

{"took" : 2,"timed_out" : false,"_shards" : {"total" : 1,"successful" : 1,"skipped" : 0,"failed" : 0},"hits" : {"total" : {"value" : 3,"relation" : "eq"},"max_score" : 1.2,"hits" : [{"_index" : "user","_type" : "_doc","_id" : "1","_score" : 1.2,"_source" : {"first_name" : "John","last_name" : "Smith","age" : 25,"about" : "I love to go rock climbing","interests" : ["sports"]}},{"_index" : "user","_type" : "_doc","_id" : "2","_score" : 1.2,"_source" : {"first_name" : "zhangsan","last_name" : "Smith","age" : 19,"about" : "我是一个安静的人","interests" : ["read"]}},{"_index" : "user","_type" : "_doc","_id" : "3","_score" : 1.2,"_source" : {"first_name" : "lisi","last_name" : "Alice","age" : 29,"about" : "我喜欢规划自己的生活","interests" : ["sports","read","music"]}}]}
}