Query subdocuments in Elasticsearch

Question

As a simplified example, I have "book" documents stored in elastic search so that a request GET /myindex/book/1 returns something like

{
  "id": 1,
  "title": "Hamlet",
  "author": "William Shakespeare",
  "pages": [
    {"page_id": 1, "contents": "hello, world . . . this story is very well written"},
    {"page_id": 5, "contents": "goodbye, world . . . i am done writing this book"}
  ]
}

What I'd like to do is run some sort of query that will get me records with individual matching pages. That is something like GET /myindex/book/_mySpecialQuery?q=hello would have results [{"page_id": 1, "contents": "hello, world . . . this story is very well written", "_parent": 1}] and GET /myindex/book/_mySpecialQuery?q=world would have results [{"page_id": 1, "contents": "hello, world . . . this story is very well written", "_parent": 1}, {"page_id": 5, "contents": "goodbye, world . . . i am done writing this book", "_parent": 1}] where _parent is the book's ID.

I cannot easily denormalize the data since it is coming from Mongo (via mongo-connector).

(This seems like it should be simple but I haven't seen any good ways to do this -- please do comment with a link if I'm just looking at the wrong terminology etc.)

Mario Trucco · Accepted Answer · 2015-08-23 07:43:41Z

1

You try a match query with requesting fields; it should do the job:

{
    "query": {
        "match": {
              "pages.contents": "hello"
         }
    },
    "fields": [
        "pages.page_id",
        "pages.contents",
        "id"
    ]
}

Your result will be returned in the hits and is going to look like this:

[
    {
    "_index": <YOUR_INDEX_NAME>,
    "_type": <YOUR_TYPE_NAME>,
    "_id": 1,
    "_score": <SOME SCORE VALUE>,
    "fields": {
        "pages.page_id": [
            1
        ],
        "pages.contents": [
            "hello, world . . . this story is very well written"
        ],
        "id": [
              1
        ]
    }
    }
]

NOTE: I'm afraid the book's id is going to be still called id (in the fields, as part of the source), and _id (as id of the document), but not _parent (like you wished)

edited Aug 23, 2015 at 7:43

answered Aug 22, 2015 at 0:37

Mario Trucco

2,0213 gold badges34 silver badges45 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Query subdocuments in Elasticsearch

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related