Getting the number of documents with the same field value

Imagine a situation where you have to return the number of documents with the same field value besides the search results. For example, you have an application that allows your user to search for companies in Europe and your client wants to have the number of companies in the cities where the companies that were found by the query are located. To do this, you can of course run several queries, but Solr provides a mechanism called faceting that can do this for you. This recipe will show you how to use it.

How to do it...

1. Let's start by assuming that we have the following fields present in the schema.xml file:

   <field name="id" type="string" indexed="true" stored="true" required="true" />
   <field name="name" type="text_general" indexed="true" stored="true" />
   <field name="city" type="string" indexed="true...