If you're a user of the Solarium tool for querying Solr database already and have been wondering how to work with faceting, you should take a look at this new post from Jeroen van Dijk. He covers using Solarium to do multi-select faceting in a Solr query.

Solarium is a library I often use at Enrise for querying Solr. For one of the projects I work on, AutoTrack.nl a second hand car site, I was having issues on advanced faceting with Solr which I could easily solve using Solarium. [...] Faceting is a technique for guided navigation where search results are separated into categories, often including counts on those categories. The user can then select from those categories to restrict their search step by step.

He includes an example of what kind of results this sort of searching could return and how you can use the "facet.mincount" to restrict the results to an even finer set. There's a bit of code included showing how to use this filtering method with a combination of "addFilterQuery" and "createFacetField" calls before executing the select through Solarium.