使用ElasticSearch匹配多个文档

Question

I am relatively new to ElasticSearch. I am using it as a search platform for pdf documents. I break the PDFs into text-pages and enter each one as an elasticSearch record with it's corresponding page ID, parent info, etc.

What I'm finding difficult is matching a given query not only to a single document in ES, but making it match any document with the same parent ID. So if two terms are searched, if the terms existed on page 1 and 7 of the actual PDF document (2 separate entries into ES), I want to match this result.

Essentially my goal is to be able to search through the multiple pages of a single PDF, matching happening on any of the document-pages in the PDF, and to return a list of matching PDF documents for the search result, instead of matching "pages"

Answer 1

It's somewhat tricky. First of all, you will have to split your query into terms yourself. Having a list of terms (let's say foo, bar and baz, you can create a bool query against type representing PDFs (parent type) that would look like this:

{
    "bool" : {
        "must" : [{
            "has_child" : {
                "type": "page",
                "query": {
                    "match": {
                        "page_body": "foo"
                    }
                }
            }
        }, {
            "has_child" : {
                "type": "page",
                "query": {
                    "match": {
                        "page_body": "bar"
                    }
                }
            }
        }, {
            "has_child" : {
                "type": "page",
                "query": {
                    "match": {
                        "page_body": "baz"
                    }
                }
            }
        }]
   }
}

This query will find you all PDFs that contain at least one page with each term.