如何从elasticsearch中的父ID获取子列表

Question

I'm using elasticsearch with java. I'm having parent as A and child B. parent A has more than one child. I want to generate list of child using parent A's id. any leads or tutorial will be helpful.

Thx in adv.

Answer 1

This is the relevant documentation.

And you can use something similar to:

GET /library/chapter/_search
{
  "size": 5, 
  "query": {
    "has_parent": {
      "type": "book",
      "query": {
        "term": {
          "_id": {
            "value": "book1"
          }
        }
      },
      "inner_hits" : {}
    }
  }
}

book is the parent and chapter is the children. Note one important bit: the URL refers to the children type GET /library/chapter .

Answer 2

The Elasticsearch based query would be something like this

{
    "query": {
        "has_parent": {
            "parent_type": "A",
            "query": {
                "term": {
                    "_id": {
                        "value": "ID"
                    }
                }
            }
        }
    }
}

Here is the java based implementation.

NativeSearchQuery query = new NativeSearchQueryBuilder()
                .withQuery(JoinQueryBuilders.hasParentQuery("A", QueryBuilders.termQuery("_id", "ID"), true))
                .build();
System.out.println(elasticsearchRestTemplate.search(query, Infections.class).getTotalHits());

I am printing hits you can do whatever you want.

I hope this will fulfill your requirement.