在布尔查询中,弹性平均聚合(Elastic Averaging Aggregation)是一种用于计算布尔查询结果的聚合函数。它可以根据查询条件的匹配程度来为每个文档分配一个评分,并根据这些评分计算出最终的聚合结果。
以下是一个使用弹性平均聚合的代码示例(使用Elasticsearch的Java客户端):
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.Fuzziness;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.aggregations.metrics.avg.Avg;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import java.io.IOException;
public class ElasticAveragingAggregationExample {
public static void main(String[] args) throws IOException {
RestHighLevelClient client = new RestHighLevelClient();
// 构建布尔查询
BoolQueryBuilder queryBuilder = QueryBuilders.boolQuery()
.should(QueryBuilders.matchQuery("title", "keyword1").fuzziness(Fuzziness.AUTO))
.should(QueryBuilders.matchQuery("title", "keyword2").fuzziness(Fuzziness.AUTO));
// 构建弹性平均聚合
TermsAggregationBuilder aggregationBuilder = AggregationBuilders.terms("category")
.field("category.keyword")
.subAggregation(AggregationBuilders.avg("avg_score").field("score"));
// 构建搜索请求
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder()
.query(queryBuilder)
.aggregation(aggregationBuilder);
SearchRequest searchRequest = new SearchRequest("index_name")
.source(sourceBuilder);
// 执行搜索请求
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
// 解析聚合结果
Terms categoryTerms = searchResponse.getAggregations().get("category");
for (Terms.Bucket categoryBucket : categoryTerms.getBuckets()) {
String category = categoryBucket.getKeyAsString();
Avg avgScore = categoryBucket.getAggregations().get("avg_score");
double averageScore = avgScore.getValue();
System.out.println("Category: " + category + ", Average Score: " + averageScore);
}
// 关闭客户端连接
client.close();
}
}
在上述代码示例中,我们首先构建了一个布尔查询(BoolQueryBuilder),然后使用弹性平均聚合(TermsAggregationBuilder)根据文档的类别(category)进行聚合,并在每个类别的聚合结果中计算平均分数(avg_score)。
最后,我们执行搜索请求并解析聚合结果,输出每个类别的平均分数。
请注意,上述代码示例中的一些部分(如索引名称、字段名称)需要根据实际情况进行适当修改。此外,还需要根据实际情况设置Elasticsearch的连接配置(例如主机、端口、身份验证等)。
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