Es7.x 分组聚合查询

最新推荐文章于 2024-12-03 22:48:53 发布

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本文介绍如何使用Elasticsearch进行银行数据的聚合分析，通过DSL查询和Java代码实现，具体展示了根据州分组并计算各州平均工资的过程。

DSL查询如下：
在这里插入图片描述
Java代码如下：

public class BankTest extends BaseTests{

    @Autowired
    @Qualifier("elasticsearchTemplate")
    private ElasticsearchRestTemplate elasticsearchRestTemplate;

    @Qualifier("elasticsearchClient")
    @Autowired
    private RestHighLevelClient restHighLevelClient;


    @Test
    public void testAgg() throws IOException {
        SearchRequest searchRequest = new SearchRequest("bank");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        //根据state.keyword（州）分组，别名为state
        TermsAggregationBuilder state = AggregationBuilders.terms("state").field("state.keyword").size(200);
        //求平均工资
        AvgAggregationBuilder avgAggregationBuilder = AggregationBuilders.avg("balance").field("balance");
        //最终聚合结果是：根据州分组，然后求每个州的平均工资
        TermsAggregationBuilder termsAggregationBuilder = state.subAggregation(avgAggregationBuilder);
        searchSourceBuilder.aggregation(termsAggregationBuilder);
        System.out.println("********************************************");
        System.out.println(searchSourceBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
        //下面获得聚合查询
        Aggregations aggregations = search.getAggregations();
        for(Aggregation a:aggregations){
            Terms terms = (Terms) a;
            for(Terms.Bucket bucket:terms.getBuckets()){
                Avg balance = (Avg)bucket.getAggregations().asMap().get("balance");
                double value = balance.getValue();
                System.out.println(bucket.getKeyAsString()+"州的平均工资是"+value);
            }
        }
    }

}