elasticsearch筆記(8)聚合查詢

聚合查詢: 也就是類似mysql的count，max，avg等查詢，但要更為強大

聚合查詢語法

POST /index/type/_search
{
    "aggs":{ "名字":{ "agg_type":{ "屬性":"值" } } } }

一.  去重計數查詢:Cardinality

去掉重復的數據，然后算出總數，也就是Cardinality; 如查詢總共幾個省.

 

 

 java 中的重復計數查詢

//重復計數查詢
    @Test
    public void cardinalityQuery() throws IOException {
        //        1. 創建查詢對象
        String index = "sms-logs-index";
        String type = "sms-logs-type";
        SearchRequest searchRequest = new SearchRequest(index);//指定索引
        searchRequest.types(type);//指定類型
//    2. 封裝查詢條件
        String aggName = "agg";
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.aggregation(AggregationBuilders.cardinality(aggName).field("province"));
        searchRequest.source(searchSourceBuilder);

        //        3.執行查詢
        // client執行
        HttpHost httpHost = new HttpHost("192.168.43.30", 9200);
        RestClientBuilder restClientBuilder = RestClient.builder(httpHost);
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(restClientBuilder);
        SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);

//        4.獲取數據(source中的數據)
        Cardinality aggregation = search.getAggregations().get(aggName); //用Cardinality接收
        System.out.println(aggregation.getValue());
    }

 二. 范圍統計

根據某個屬性的范圍，統計文檔的個數，(from 包含, to不包含)

針對不同的類型指定不同的方法，

數值：range

時間：date_range

ip：ip_range

數值統計:

 

日期型范圍查詢(data_range):加一個format來規定格式

 

 

 ip范圍統計(ip_range)

 

 

 

java中用range查詢

    @Test
    public void rangeQuery() throws IOException {
        //        1. 創建查詢對象
        String index = "sms-logs-index";
        String type = "sms-logs-type";
        SearchRequest searchRequest = new SearchRequest(index);//指定索引
        searchRequest.types(type);//指定類型
//    2. 封裝查詢條件
        String aggName = "agg";
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.aggregation(AggregationBuilders.range(aggName).field("fee").addUnboundedTo(3)
12                 .addRange(3,4)
13                 .addUnboundedFrom(4));
        searchRequest.source(searchSourceBuilder);

        //        3.執行查詢
        // client執行
        HttpHost httpHost = new HttpHost("192.168.43.30", 9200);
        RestClientBuilder restClientBuilder = RestClient.builder(httpHost);
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(restClientBuilder);
        SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);

//        4.獲取數據(source中的數據)
        Range range = search.getAggregations().get(aggName);//用Range接收
25         List<? extends Range.Bucket> buckets = range.getBuckets();
        for(  Range.Bucket bucket : buckets ){
            System.out.println(bucket.getDocCount());

        }


    }

 3. 統計聚合查詢

可以查詢屬性(field)的最大值，最小值，平均值，平方和.......

 

 

  @Test
    public void extended_status_Query() throws IOException {
        //        1. 創建查詢對象
        String index = "sms-logs-index";
        String type = "sms-logs-type";
        SearchRequest searchRequest = new SearchRequest(index);//指定索引
        searchRequest.types(type);//指定類型
//    2. 封裝查詢條件
        String aggName = "agg";
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.aggregation(AggregationBuilders.extendedStats(aggName).field("fee"));
        searchRequest.source(searchSourceBuilder);

        //        3.執行查詢
        // client執行
        HttpHost httpHost = new HttpHost("192.168.43.30", 9200);
        RestClientBuilder restClientBuilder = RestClient.builder(httpHost);
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(restClientBuilder);
        SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);

//        4.獲取數據(source中的數據)
        ExtendedStats aggregation = search.getAggregations().get(aggName);//用Range接收
        System.out.println(aggregation.getMax());
        System.out.println(aggregation.getSum());
        System.out.println(aggregation.getAvg());
    }

 

https://www.elastic.co/guide/en/elasticsearch/reference/6.5/getting-started.html