How to group results in elasticsearch?

Question

I am storing Book Titles in elasticsearch and they all belong to many shops. Like this:

{
    \"books\": [
        {
            \"id\": 1,
            \"tit         


        

Answer 1

On the similar lines with SQL'S GROUP BY Elasticsearch provides aggregation

With aggregation queries, Elasticsearch responsds with Buckets.

One bucket corresponds to one category (group).