java : get distinct values from an elasticsearch index

Question

Currently I'm using this code which I had written to get the values from a field :

QueryBuilder qb = QueryBuilders.matchPhrasePrefixQuery("tagName", "june");
            SearchResponse response = esclient.prepareSearch(index).setTypes(type)
                    .setQuery(qb)
                    .execute().actionGet();

            SearchHit[] hits = response.getHits().getHits();
            System.out.println(hits.length);

            for (SearchHit hit : hits) {
                Map map = hit.getSource();
                System.out.println((String) map.get("tagName"));
                strings.add((String) map.get("tagName"));
            }

But is there an alternative to get distinct values from an index? Or can the above can be modified?

Please look in this question. if you are able to help stackoverflow.com/questions/59570496/… — Siva
– Siva, Commented Jan 2, 2020 at 22:05

user9350114 · Accepted Answer · 2018-02-12 15:34:30Z

You Can Use terms aggregation

This requires the field to be not analyzed.

    public static List<String> getDistinctAgg(TransportClient client, String indexName, String fieldName, int requiredSize) {
    List<String> values = new LinkedList<>();

    try {


        TermsAggregationBuilder aggregationBuilder = new TermsAggregationBuilder(fieldName + "_Agg", ValueType.STRING);
        aggregationBuilder.field(fieldName);
        aggregationBuilder.bucketCountThresholds(new TermsAggregator.BucketCountThresholds(1, 1, requiredSize, 5));

        QueryBuilder query = QueryBuilders.matchAllQuery();


        SearchResponse response = client.prepareSearch(indexName)
                .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
                .setQuery(query).addAggregation(aggregationBuilder).setSize(0).get();
        if (response == null) return null;

        StringTerms terms = ((StringTerms) response.getAggregations().get(fieldName + "_Agg"));

        if (terms != null) {

            List<Terms.Bucket> buckets = terms.getBuckets();
            if (buckets != null && buckets.size() > 0) {


                for (Terms.Bucket bucket : buckets) {
                    values.add(bucket.getKeyAsString());
                }
            }
            return values;
        }

    } catch (Exception e) {
        return null;
    }
    return null;
}

Collectives™ on Stack Overflow

java : get distinct values from an elasticsearch index

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related