Elasticsearch: The Definitive Guide

Chapter 14. Multifield Search

Queries are seldom simple one-clause match queries. We frequently need to search for the same or different query strings in one or more fields, which means that we need to be able to combine multiple query clauses and their relevance scores in a way that makes sense.

Perhaps we’re looking for a book called War and Peace by an author called Leo Tolstoy. Perhaps we’re searching the Elasticsearch documentation for “minimum should match,” which might be in the title or the body of a page. Or perhaps we’re searching for users with first name John and last name Smith.

In this chapter, we present the available tools for constructing multiclause searches and how to figure out which solution you should apply to your particular use case.

Multiple Query Strings

The simplest multifield query to deal with is the one where we can map search terms to specific fields. If we know that War and Peace is the title, and Leo Tolstoy is the author, it is easy to write each of these conditions as a match clause and to combine them with a bool query:

GET /_search
{
  "query": {
    "bool": {
      "should": [
        { "match": { "title":  "War and Peace" }},
        { "match": { "author": "Leo Tolstoy"   }}
      ]
    }
  }
}

The bool query takes a more-matches-is-better approach, so the score from each match clause will be added together to provide the final _score for each document. Documents that match both clauses will score higher than documents that match just one clause.

Of course, you’re not restricted ...