java - ElasticSearch 日期直方图聚合 填充缺失数据

Question

我正在尝试使用 ElasticSearch spring 数据进行一些聚合

这是我的查询

final FilteredQueryBuilder filteredQuery = QueryBuilders.filteredQuery(QueryBuilders.matchAllQuery(),
      FilterBuilders.andFilter(FilterBuilders.termFilter("gender", "F"),
      FilterBuilders.termFilter("place", "Arizona"),
      FilterBuilders.rangeFilter("dob").from(from).to(to)));

final MetricsAggregationBuilder<?> aggregateArtifactcount = AggregationBuilders.sum("delivery")
            .field("birth");

    final AggregationBuilder<?> dailyDateHistogarm =
       AggregationBuilders.dateHistogram(AggregationConstants.DAILY).field("dob")
        .interval(DateHistogram.Interval.DAY).subAggregation(aggregateArtifactcount);

    final SearchQuery query = new NativeSearchQueryBuilder().withIndices(index).withTypes(type)
        .withQuery(filteredQuery).addAggregation(dailyDateHistogarm).build();

    return elasticsearchTemplate.query(query, new DailyDeliveryAggregation());

这也是我的聚合

        public class DailyDeliveryAggregation implements ResultsExtractor<List<DailyDeliverySum>> {

@SuppressWarnings("unchecked")
@Override
public List<DailyDeliverySum> extract(final SearchResponse response) {
    final List<DailyDeliverySum> dailyDeliverySum = new ArrayList<DailyDeliverySum>();
    final Aggregations aggregations = response.getAggregations();
    final DateHistogram daily = aggregations.get(AggregationConstants.DAILY);
    final List<DateHistogram.Bucket> buckets = (List<DateHistogram.Bucket>) daily.getBuckets();
    for (final DateHistogram.Bucket bucket : buckets) {
        final Sum sum = (Sum) bucket.getAggregations().getAsMap().get("delivery");
        final int deliverySum = (int) sum.getValue();
        final int delivery = (int) bucket.getDocCount();
        final String dateString = bucket.getKeyAsText().string();
        dailyDeliverySum.add(new DailyDeliverySum(deliverySum, delivery, dateString));
    }
    return dailyDeliverySum;
}
}

它给了我正确的数据，但它并不能满足我的所有需求假设如果我查询 10 天的时间范围，如果给定时间范围内没有某个日期的数据，那么它会错过日期直方图存储桶中的该日期，但我想将 0 设置为聚合和文档计数的默认值(如果有)无可用数据

有什么办法可以做到吗？

Answer 1

是的，您可以使用"minimum document count" feature date_histogram 聚合的值并将其设置为 0。这样，您还将获得不包含任何数据的存储桶:

final AggregationBuilder<?> dailyDateHistogarm =
   AggregationBuilders.dateHistogram(AggregationConstants.DAILY)
        .field("dob")        
        .minDocCount(0)                          <--- add this line
        .interval(DateHistogram.Interval.DAY)
        .subAggregation(aggregateArtifactcount);