Using a regexp query

In the previous recipes, we have explored different term queries (such as terms, prefix, and wildcard). Another powerful term query is the regexp (regular expression) query.

Getting ready

You will need an up-and-running Elasticsearch installation, as described in the Downloading and installing Elasticsearch recipe of Chapter 1, Getting Started.

To execute the commands, any HTTP client can be used, such as Curl (https://curl.haxx.se/), Postman (https://www.getpostman.com/), or similar. I suggest you use a Kibana console as it provides code completion and better character escaping for Elasticsearch.

To correctly execute the following commands, you will need an index populated with the ch04/populate_kibana.txt command, which is available in the online code.

How to do it...

To execute a regexp query, we will perform the following steps:

1. We can execute a regexp term query from the command line, as follows:

   POST /mybooks/_search...