How do I create a Solr query that returns results even if one field in my query has no matches?

Question

Suppose I want to create a recommendation system to suggest people you should connect with based off of certain attributes that I know about you and attributes I have about other people that are stored in a Solr index. Is it possible to query the index with a list of attributes (along with boosts for each attribute) and have Solr return scored results even if some of my fields return no matches? The way that I understand that Solr works is that if one of your fields doesn't contain a match in any documents found in your index, you get zero results for the entire query (even if other fields in the query matched) - is that right? What I would hope is that I could query the index and get a list of results back in order of a score given based on how many (and which) fields matched to something, even if some fields have no matches, for example:

Say that there are 2 people documents stored in the index as follows (figuratively):

Person 1:
     Industry: Manufacturing
     City: Oakland

Person 2:
     Industry: Manufacturing 
     City: San Jose

And say that I perform a pseudo-Solr query that basically says "Search for everyone whose industry is equal to manufacturing and whose city is equal to Oakland". What I would like is to receive both results back in the result set, even though one of the "Persons" does not reside in Oakland. I just want that person to come back as a result with a lower score than Person1. Is this possible? What might a solr query look like to handle this? Assume that I have many more than 2 attributes for each person (so saying that I can use "And" and "Or" in my solr query isn't really feasible.. or is it?) Thanks in advance for your helpful input! (PS I'm using Solr 3.6)

Answer 1

You mention using the AND operator, which is likely your problem.

The default behavior of Lucene, and Solr, query syntax is exactly what you are asking for. A query like:

industry:manufacturing city:oakland

Will match either, with scoring preference on those that match both. See the lucene query syntax documentation

Answer 2

You can use the bq parameter (boost query) does not affect matching, but affects the scores only.

http://localhost:8983/solr/persons/select?q=industry:manufacturing&bq=City:Oakland^2

play with the boosting factor at the end to get the correct balance between matching score, and boosting score.