Question

我正在使用Java API查询ElasticSearch，并且获得了大量重复值。我只想从查询中获得唯一值（唯一值）。我们如何从查询生成器中获得不同的值。

请在下面找到我的Java代码，该代码给出重复的值。

dbClearResult()

Am使用带有RestHighLevelClient的弹性搜索6.2.3版本

Answer 1

方法1：您需要使用所谓的汇总API：

示例查询以获取不同的电子邮件客户端：

{
  "query" : {
    "match_all" : { }
  },
  "aggregations" : {
    "label_agg" : {
      "terms" : {
        "field" : "Email_client",
        "size" : 100
      }
    }
  }
}

Java代码示例=>

SearchRequestBuilder aggregationQuery = 
      client.prepareSearch("emails")
        .setQuery(QueryBuilders.matchAllQuery())
        .addAggregation(AggregationBuilders.terms("label_agg")
          .field("Email_client").size(100));

SearchResponse response = aggregationQuery.execute().get();
    Aggregation aggregation = response.getAggregations().get("label_agg");
    StringTerms st = (StringTerms) aggregation;
    return st.getBuckets().stream()
      .map(bucket -> bucket.getKeyAsString())
      .collect(toList());

方式2：使用聚合Api的基数：弹性查询示例：

{
  "size": 0,
  "aggs": {
    "distinct": {
      "cardinality": {
        "field": "Email_client",
        "size" : 100
      }
    }
  }

Java代码示例=>

AggregationBuilder agg11 = AggregationBuilders.cardinality("distinct").field("Email_client");
        SearchResponse response11 = client.prepareSearch("emails")// we can give multiple index names here
                .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
                .setQuery(query11)
                .addAggregation(agg11)
                .setExplain(true)
                .setSize(0)
                .get();

ElasticSearch Java API从查询构建器获取不同的值

1 个答案: