java - How to get facet ranges in solr results?

Question

Assume that I have a field called price for the documents in Solr and I have that field faceted. I want to get the facets as ranges of values (eg: 0-100, 100-500, 500-1000, etc). How to do it?

I can specify the ranges beforehand, but I also want to know whether it is possible to calculate the ranges (say for 5 values) automatically based on the values in the documents?

Answer 1

To answer your first question, you can get facet ranges by using the the generic facet query support. Here's an example:

http://localhost:8983/solr/select?q=video&rows=0&facet=true&facet.query=price:[*+TO+500]&facet.query=price:[500+TO+*]

As for your second question (automatically suggesting facet ranges), that's not yet implemented. Some argue that this kind of querying would be best implemented on your application rather that letting Solr "guess" the best facet ranges.

Here are some discussions on the topic:

• (Archived) https://web.archive.org/web/20100416235126/http://old.nabble.com/Re:-faceted-browsing-p3753053.html
• (Archived) https://web.archive.org/web/20090430160232/http://www.nabble.com/Re:-Sorting-p6803791.html
• (Archived) https://web.archive.org/web/20090504020754/http://www.nabble.com/Dynamically-calculated-range-facet-td11314725.html