(五)ElasticSearch7.X之聚合查询java代码（所有队伍指定字段的cardinality（去重之后总数））

NBA火箭队历年球员统计

最新推荐文章于 2024-11-16 14:41:13 发布

原创最新推荐文章于 2024-11-16 14:41:13 发布 · 1.6k 阅读

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本文通过Elasticsearch查询展示了NBA火箭队各年份的球员统计数据，使用了term查询限定队伍名称，并通过聚合查询统计了不同年份的球员数量，展示了如何解析并打印查询结果。

POST /nba/_search
{
"query": {
"term": {
"teamNameEn.keyword": {
"value": "Rockets"
}
}
},
"aggs": {
"counAget": {
"cardinality": {
"field": "playYear"
}
}
},
"size": 0
}

 @Test
    public void test04() throws IOException {
        SearchRequest searchRequest = new SearchRequest("nba");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        //限定了查询的队伍名称
//      searchSourceBuilder.query(QueryBuilders.termQuery("teamName.keyword","火箭")).size(100);
        TermsAggregationBuilder field = AggregationBuilders.terms("teamName").field("teamName.keyword").size(200);
        CardinalityAggregationBuilder cardinalityAggregationBuilder = AggregationBuilders.cardinality("playYear").field("playYear");
        TermsAggregationBuilder termsAggregationBuilder = field.subAggregation(cardinalityAggregationBuilder);
        searchSourceBuilder.aggregation(termsAggregationBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse search = client.search(searchRequest, RequestOptions.DEFAULT);
        Aggregations aggregations = search.getAggregations();
        //下面获得聚合查询
        for(Aggregation a:aggregations){
            Terms terms = (Terms) a;
            for(Terms.Bucket bucket:terms.getBuckets()){
                System.out.println("key is "+bucket.getKeyAsString());
                //这里是elasticsearch7的重大改动！！！！必须强转。
                Cardinality cardinality = (Cardinality) bucket.getAggregations().asMap().get("playYear");
                double value = cardinality.getValue();
                System.out.println("cardinality is "+value);
            }
        }
    }