Book Image

ElasticSearch Cookbook

By : Alberto Paro
Book Image

ElasticSearch Cookbook

By: Alberto Paro

Overview of this book

Table of Contents (20 chapters)
ElasticSearch Cookbook Second Edition
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Using exists and missing filters


One of the main characteristics of ElasticSearch is its schema-less indexing capability. Records in ElasticSearch can have missing values. To manage them, two kinds of filters are supported:

  • Exists filter: This checks whether a field exists in a document

  • Missing filter: This checks whether a field is missing

Getting ready

You need a working ElasticSearch cluster and an index populated with the script chapter_05/populate_query.sh, available in the code bundle for this book.

How to do it...

In order to execute existing and missing filters, perform the following steps:

  1. To search all the test-type documents that have a field called parsedtext, this will be the query:

    curl -XPOST 'http://127.0.0.1:9200/test-index/test-type/_search?pretty=true' -d '{
      "query": {
        "filtered": {
          "filter": {
            "exists": {
              "field":"parsedtext"
            }
          },
          "query": {
            "match_all": {}
          }
        }
      }
    }'
    
  2. To search all the test-type documents...